1. An image processing apparatus for performing processing on image data which is formed of a predetermined number of pixel data obtained by an image-capturing device including a predetermined number of pixels and having a time integrating function, said image processing apparatus comprising: area specifying means (103) for specifying a non-mixed area formed of a foreground area consisting of foreground object components which form a foreground object of the image data and a background area consisting of background object components which form a background object of the image data, or a mixed area in which the foreground object components and the background object components area mixed; and processing execution means (1503) for simultaneously performing, based on a result obtained by specifying the area by said area specifying means (103), processing for separating the foreground object components and the background object components from the pixel data of the mixed area, and processing for eliminating motion blur from the separated foreground object components.

2. An image processing apparatus as claimed in claim 1, further comprising equal-portion detection means (1501) for detecting an equal portion consisting of adjacent pixel data of the foreground area whose values are substantially equal to each other, wherein said processing execution means (1503) simultaneously performs at least the processing for separating the foreground object components and the background object components from the pixel data of the mixed area and the processing for eliminating motion blur from the separated foreground object 2 3 JAN 2009 components based on the detected equal portion and the result obtained by specifying the area by said area specifying means (103).

3. An image processing apparatus as claimed in claim 2, further comprising unit -of-processing determining means (1502) for determining a unit of processing consisting of a plurality of the foreground object components and the background object components based on a position of the equal portion, wherein said processing execution means (1503) simultaneously performs, for each unit of processing, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components.

4. An image processing apparatus as claimed in claim 3, wherein said unit-of-processing determining means (1502) determines the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion.

5. An image processing apparatus as claimed in to claim 2, wherein said equal-portion detection means (1501) detects the equal portion by comparing a difference of the pixel data with a threshold.

6. An image processing apparatus as claimed in claim 2, wherein said equal-portion detection means (1501) detects the equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to-the number of pixels corresponding to an amount of movement of the foreground object. 2 3 JAN 2009

7. An image processing apparatus as claimed in claim 1, wherein said processing execution means (1503) simultaneously performs the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components by applying a calculation corresponding to a motion vector.

8. An image processing apparatus as claimed in claim 1, wherein said processing execution means (1503) comprises: model acquiring means (1521) for acquiring a model corresponding to the unit of processing and a motion vector; equation generating (1522) means for generating, based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in the unit of processing; and calculation means (1523) for calculating the foreground object components and the background object components contained in the unit of processing based on the generated equation.

9. An image processing method for performing processing on image data which is formed of a predetermined number of pixel data obtained by an image-capturing device including a predetermined number of pixels and having a time integrating function, said image processing method comprising: an area specifying step of specifying a non-mixed area formed of a foreground area consisting of foreground object components which form a foreground object of the image data and a background area consisting of background object components which form a background object of the 2 3 JAN 2009 image data, or a mixed area in which the foreground object components and the background object components area mixed; and a processing execution step of simultaneously performing, based on a result obtained by specifying the area by the processing of said area specifying step, processing for separating the foreground object components and the background object components from the pixel data of the mixed area, and processing for eliminating motion blur from the separated foreground object components.

10. An image processing method as claimed in claim 9, further comprising an equal-portion detection step of detecting an equal portion consisting of adjacent pixel data of the foreground area whose values are substantially equal to each other, wherein, in the processing of said processing execution step, at least the processing for separating the foreground object components and the background object components from the pixel data of the mixed area and the processing for eliminating motion blur from the separated foreground object components are simultaneously performed based on the detected equal portion and the result obtained by specifying the area by said area specifying step.

11. An image processing method as claimed in claim 10, further comprising a unit-of-processing determining step of determining a unit of processing consisting of a plurality of the foreground object components and the background object components based on a position of the equal portion, wherein, in the processing of said processing execution step, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components are simultaneously performed for each unit of processing. 13 JAN 2009

12. An image processing method as claimed in claim 11, wherein, in the processing of said unit-of-processing determining step, the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion is determined.

13. An image processing method as claimed in claim 10, wherein in the processing of said equal-portion detection step, the equal portion is detected by comparing a difference of the pixel data with a threshold.

14. An image processing method as claimed in claim 10, wherein, in the processing of said equal-portion detection step, the equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of the foreground object is detected.

15. An image processing method as claimed in claim 9, wherein, in the processing of said processing execution step, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components are simultaneously performed by applying a calculation corresponding to a motion vector.

16. An image processing method as claimed in claim 9, wherein the processing of said processing execution step comprises; a model acquiring step of acquiring a model corresponding to the unit of processing and a motion vector; an equation generating step of generating, based on the acquired model, an equation corresponding to a relationship between the pixel 2 3 JAN 2009

FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See Section 10; rule 13]
"IMAGE PROCESSING APPARATUS AND METHOD THEREOF"
SONY CORPORATION, a Japanese company, of 7-35 Kitashinagawa 6-chome, Shinagawa-ku, Tokyo, 141-0001, Japan,
The following specification particularly describes the invention and the manner in which it is to be performed:



obtain sharp images.
Disclosure of Invention
The present invention has been made in view of the above-described background. Accordingly, it is an object of the present invention to make it possible to eliminate motion blur contained in a blurred image.
A first image processing apparatus of the present invention includes: area specifying means for specifying a non-mixed area formed of a foreground area consisting of foreground object components which form a foreground object of image data and a background area consisting of background object components which form a background object of the image data, or a mixed area in which the foreground object components and the background object components area mixed; and processing execution means for simultaneously performing, based on a result obtained by specifying the area by the area specifying means, processing for separating the foreground object components and the background object components from pixel data of the mixed area, and processing for eliminating motion blur from the separated foreground object components.
The image processing apparatus may further include equal-portion detection means for detecting an equal portion consisting of adjacent pixel data of the foreground area

whose values are substantially equal to each other. The processing execution means may simultaneously perform at least the processing for separating the foreground object components and the background object components from the pixel data of the mixed area and the processing for eliminating motion blur from the separated foreground object components based on the detected equal portion and the result obtained by specifying the area by the area specifying means.
The image processing apparatus may further include unit-of-processing determining means for determining a unit of processing consisting of a plurality of the foreground object components and the background object components based on a position of the equal portion. The processing execution means may simultaneously perform, for each unit of processing, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components.
The unit-of-processing determining means may determine the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal, portion.
The equal-portion detection means may detect the equal


portion by comparing a difference of the pixel data with a threshold.
The equal-portion detection means may detect the equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to the amount of movement of the foreground object.
The processing execution means may simultaneously perform the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components by applying a calculation corresponding to a motion vector.
The processing execution means may include: model acquiring means for acquiring a model corresponding to the unit of processing and a motion vector; equation generating means for generating, based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in the unit of processing; and calculation means for calculating the foreground object components and the background object components contained in the unit of processing based on the generated equation.
A first image processing method of the present


invention includes: an area specifying step of specifying a non-mixed area formed of a foreground area consisting of foreground object components which form a foreground object of image data and a background area consisting of background object components which form a background object of the image data, or a mixed area in which the foreground object components and the background object components area mixed; and a processing execution step of simultaneously performing, based on a result obtained by specifying the area by the processing of the area specifying step, processing for separating the foreground object components and the background object components from the pixel data of the mixed area, and processing for eliminating motion blur from the separated foreground object components.
The image processing method may further include an equal-portion detection step of detecting an equal portion consisting of adjacent pixel data of the foreground area whose values are substantially equal to each other. In the processing of the processing execution step, at least the processing for separating the foreground object components and the background object components from the pixel data of the mixed area and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed based on the detected equal portion and the result obtained by specifying the area by the area


specifying step.
The image processing method may further include a unit-of-processing determining step of determining a unit of processing consisting of a plurality of the foreground object components and the background object components based on a position of the equal portion. In the processing of the processing execution step, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed for each unit of processing.
In the processing of the unit-of-processing determining step, the unit of processing corresponding to the pixel data
belonging to the mixed area or the foreground area which is located on one straight line and which is other than the
pixel data of the equal- portion may be determined.
In the processing of the equal-portion detection step,
the equal portion may be detected by comparing a difference
of the pixel data with a threshold.
In the processing of the equal-portion detection step,
the equal portion consisting of the adjacent pixel data
having the number of pixels greater than or equal to the
number of pixels corresponding to an amount of movement of
the foreground object may be detected..
In the processing of the processing execution step, the


processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed by applying a calculation corresponding to a motion vector.
The processing of the processing execution step may include: a model acquiring step of acquiring a model corresponding to the unit of processing and a motion vector; an equation generating step of generating, based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in the unit of processing; and a calculation step of calculating the foreground object components and the background object components contained in the unit of processing based on the generated equation.
A program of a first storage medium of the present invention includes: an area specifying step of specifying a non-mixed area formed of a foreground area consisting of foreground object components which form a foreground object of image data and a background area consisting of background object components which form a background object of the image data, or a mixed area in which the foreground object components and the background object components area mixed; and a processing execution step of simultaneously performing,


based on a result obtained by specifying the area by the processing of the area specifying step, processing for separating the foreground object components and the background object components from the pixel data of the mixed area, and processing for eliminating motion blur from the separated foreground object components.
The program of the storage medium may further include an equal-portion detection step of detecting an equal portion consisting of adjacent pixel data of the foreground area whose values are substantially equal to each other. In the processing of the processing execution step, at least the processing for separating the foreground object components and the background object components from the pixel data of the mixed area and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed based on the detected equal portion and the result obtained by specifying the area by the area specifying step.
The program of the storage medium may further include a unit-of-processing determining step of determining a unit of processing consisting of a plurality of the foreground object components and the background object components based on a position of the equal portion. In the processing of the processing execution step, the processing for separating the foreground object components and the background object


components and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed for each .unit of processing.
In the processing of the unit-of-processing determining step, the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion may be determined.
In the processing of the equal-portion detection step, the equal portion may be detected by comparing a difference of the pixel data with a threshold.
In the processing of the equal-portion detection step, the equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of the foreground object may be detected.
In the processing of the processing execution step, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed by applying a calculation corresponding to a motion vector.
The processing of the processing execution step may include: a model acquiring step of acquiring a model corresponding to the unit of processing and a motion vector;


an equation generating step of generating, based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in the unit of processing; and a calculation step of calculating the foreground object components and the background object components contained in the unit of processing based on the generated equation.
A first program of the present invention allows a computer to execute: an area specifying step of specifying a non-mixed area formed of a foreground area consisting of foreground object components which form a foreground object of image data and a background area consisting of background object components which form a background object of the image data, or a mixed area in which the foreground object components and the background object components area mixed; and a processing execution step of simultaneously performing, based on a result obtained by specifying the area by the processing of the area specifying step, processing for separating the foreground object components and the background object components from the pixel data of the mixed area, and processing for eliminating motion blur from the separated foreground object components.
The program may further include an equal-portion detection step of detecting an equal portion consisting of


adjacent pixel data of the foreground area whose values are substantially equal to each other. In the processing of the processing execution step, at least the processing for separating the foreground object components and the background object components from the pixel data of the mixed area and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed based on the detected equal portion and the result.obtained by specifying the area by the processing of the area specifying step.
The program may further include a unit-of-processing determining step of determining a unit of processing consisting of a plurality of the foreground object components and the background object components based on a position of the equal portion. In the processing of the processing execution step, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed for each unit of processing.
In the processing of the unit-of-processing determining step, the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion may be determined.


In the processing of the equal-portion detection step, the equal portion may be detected by comparing a difference . of the pixel data with a threshold.
In the processing of the equal-portion detection step, the equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal,to the number of pixels corresponding to an amount of movement of the foreground object may be detected.
In the processing of the processing execution step, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed by applying a calculation corresponding to a motion vector.
The processing of the processing execution step may include: a model acquiring step of acquiring a model corresponding to the unit of processing and a motion vector; an equation generating step of generating, based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in the unit of processing; and a calculation step of calculating the foreground object components and the background object components contained in the unit of processing based on the generated equation.


A second image processing apparatus of the present invention includes: input means for inputting image data having an object area consisting of object components which form an object; and motion-blur eliminating means for eliminating motion blur occurring in the object area by assuming that values of part of the pixel data in,the object area of the image data input by the input means are substantially equal.
The input means may input the image data having a foreground area consisting of foreground object components which form the object, a background area consisting of background object components which form a background object, and a mixed area in which the foreground object components and the background object components are mixed. The motion-blur eliminating means may eliminate motion blur occurring in the foreground area by assuming that values of part of the pixel data in the foreground area of the image data input by the input means are substantially equal.
The image processing apparatus may further include equal-portion detection means for detecting an equal portion in which the values of the pixel data in the foreground area of the image data are substantially equal. The motion-blur eliminating means may eliminate motion blur occurring in the foreground area based on the equal portion detected by the equal-portion detection means.
-14

The image processing apparatus may further include unit-of-processing determining means for determining a unit of processing consisting of a plurality of the foreground object components based on a position of the equal portion. The motion-blur eliminating means may eliminate motion blur of the foreground area for each unit of processing.
The unit-of-processing determining means may determine the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion.
The image processing apparatus may further include area specifying means for specifying the foreground area, the background area, or the mixed area.
The equal-portion detection means may detect the equal portion by comparing a difference of the pixel data with a threshold.
The equal-portion detection means may detect the equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of the foreground object.
The motion-blur eliminating means may eliminate motion blur occurring in the foreground area by applying a calculation corresponding to a motion vector.


The motion-blur eliminating means may include: model acquiring means for acquiring a model corresponding to the unit of processing and a motion vector; equation generating means for generating, based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components contained in the unit of processing; and calculation means for calculating the foreground object components contained in the unit of processing based on the generated equation.
The motion-blur eliminating means may simultaneously perform processing for separating, the pixel data of the mixed area into the foreground object components and the background object components and processing for eliminating motion blur from the separated foreground object components based on area information indicating a non-mixed area consisting of the foreground area and the background area or the mixed area and based on the equal portion.
The image processing apparatus may further include unit-of-processing determining means for determining a unit of processing consisting of a plurality of the foreground object components and the background object components based on a position of the equal portion. The processing execution means may simultaneously perform, for each unit of processing the processing for separating the foreground


object components and the background object components and the processing for eliminating motion blur from the separated foreground object components.
The unit-of-processing determining means may determine the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion.
The image processing apparatus may further include area specifying means for specifying the foreground area, the background area, or the mixed area.
The equal-portion detection means may detect the equal portion by comparing a difference of the pixel data with a threshold.
The equal-portion detection means may detect the equal portion consisting of adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of the foreground object.
The unit-or-processing determining means may simultaneously perform the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components by applying a calculation corresponding to a motion vector.


The unit-of-processing determining means may include: model acquiring means for acquiring a model corresponding to the unit of processing and a motion vector; equation generating means for generating, based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in the unit of processing; and calculation means for calculating the foreground object components and the background object components contained in the unit of processing based on the generated equation.
A second image processing method of the present invention includes: an input step of inputting image data having an object area consisting of object components which form an object; and a motion-blur eliminating step of eliminating motion blur occurring in an object area by assuming that values of part of the pixel data in the object area of the image data input by the processing of the input step are substantially equal.
In the processing of the input step, the image data having a foreground area consisting of foreground object components which form the object, a background area consisting of background object components which form a background object, and a mixed area in which the foreground object components and the background object components are


mixed may be input. In the processing of. the motion-blur eliminating step, motion blur occurring in the foreground area may be eliminated by assuming that values of part of the pixel data in the foreground area of the image data input by the processing of the input step are substantially equal.
The image processing method may further include an equal-portion detection step of detecting an equal portion in which the values of the pixel data in the foreground area of the image data are substantially equal. In the processing of the motion-blur eliminating step, motion blur occurring in the foreground area may be eliminated based on the equal portion detected by the processing of the equal-portion detection step.
The image processing method may further include a unit-of-processing determining step of determining a unit of processing consisting of a plurality of the foreground object components based on a position of the equal portion. In the processing of the motion-blur eliminating step, motion blur of the foreground area may be eliminated for each unit of processing.
In the processing of the unit-of-processing determining step, the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the


pixel data of the equal portion may be determined.
The image processing method may further include an area specifying step of specifying the foreground area, the background area, or the mixed area.
In the processing of the equal-portion detection step, the equal portion may be detected by comparing a difference of the pixel data with a threshold.
In the processing of the equal-portion detection step, the equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of
into the foreground object components and the background 5 object components and processing for eliminating motion blur from the separated foreground object components may be simultaneously performed based on area information indicating a non-mixed area consisting of the foreground area and the background area or the mixed area and based on i the equal portion.
The image processing method may further include a unit-of-processing determining step of determining a unit of processing consisting of a plurality of the foreground object components and the background object components based on a position of the equal portion. In the processing of the processing execution step, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed for each unit of processing.
In the processing of the unit-of-processing determining step, the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion may be determined.
I


The image processing method may further include an area specifying step of specifying the foreground area, the background area, or the mixed area.
In the processing of the equal-portion detection step, the equal portion may be detected by comparing a difference of the pixel data with a threshold.
In the processing of the equal-portion detection step, the equal portion consisting of adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of the foreground object may be detected.
In the processing of the unit-or-processing determining step, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components may be simultaneously performed by applying a calculation corresponding to a motion vector.
The processing of the unit-of-processing determining step may include: a model acquiring step of acquiring a model corresponding to the unit of processing and a motion vector; an equation generating step of generating, based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in the unit of

22-

corresponding to the foreground is a rigid body moving with constant velocity, and that it is moving such that it is displayed four pixels to the right in the subsequent frame. Accordingly, the amount of movement v is 4.
For example, the foreground component of the leftmost pixel of frame #n-l in Fig. 17 corresponding to the first portion of the shutter time/v from when the shutter has opened is F13/v, and the foreground component of the second pixel from the left in Fig. 17 corresponding to the second portion of the shutter time/v from when the shutter has opened is also F13/v. The foreground component of the third pixel from the left in Fig. 17 corresponding to the third


portion of the shutter time/v from when the shutter has opened and the foreground component of the fourth pixel from the left in Fig. 17 corresponding to the fourth portion of the shutter time/v from when the shutter has opened are F13/v.
The foreground component of the second pixel.from the left of frame #n-l in Fig. 17 corresponding to the first portion of the shutter time/v from when the shutter has opened is F14/v. The foreground component of the third pixel from the left in Fig. 17 corresponding to the second portion of the shutter time/v from when the shutter has opened is also F14/v. The foreground component of the third pixel from the left in Fig. 17 corresponding to the first portion of the shutter time/v from when the shutter has opened is F15/v.
Since the object corresponding to the background is stationary, the background components of the leftmost pixel of frame #n-l in Fig. 17 corresponding to the second through fourth portions of the shutter time/v from when the shutter has opened are B25/v. The background components of the second pixel from the left of frame #n-l in Fig*. 17 corresponding to the third and fourth portions of the shutter time/v from when the shutter has opened are B2 6/v. The background component of the third pixel from the left of frame #n-l in Fig. 17 corresponding to the fourth portion of


the shutter time/v from when the shutter has opened is B27/v.
In frame #n-l in Fig. 17, the leftmost pixel through the third pixel belong to the mixed area, which is an uncovered background area.
The fourth through twelfth pixels from the left of frame #n-l in Fig. 17 belong to the foreground area. The foreground component of the frame is any one of F13/v through F24/v.
The leftmost pixel through the fourth pixel from the left of frame #n in Fig. 17 belong to the background area, and the pixel values thereof are B25 through B28, respectively.
It can be assumed that the object corresponding to the foreground is a rigid body moving with constant velocity, and that it is moving such that it is displayed four pixels to the right in the subsequent frame. Accordingly, the foreground component of the fifth pixel from the left of frame #n in Fig. 17 corresponding to the first portion of the shutter time/v from when the shutter has opened is F13/v, and the foreground component of the sixth pixel from the left in Fig. 17 corresponding to the second portion of the shutter time/v from when the shutter has opened is also F13/v. The foreground component of the seventh pixel from the left in Fig. 17 corresponding to the third portion of the shutter time/v from when the shutter has opened and the


foreground component of the eighth pixel from the left in Fig. 17 corresponding to the fourth portion of the shutter time/v from when the shutter has opened are F13/v.
The foreground component of the sixth pixel from the left of frame #n in Fig. 17 corresponding to the first portion of the shutter time/v from when the shutter has opened is F14/v. The foreground component of the seventh pixel from the left in Fig. 17 corresponding to the second portion of the shutter time/v from when the shutter has opened is also F14/v. The foreground component of the eighth pixel from the left in Fig. 17 corresponding to the first portion of the shutter time/v from when the shutter has opened is F15/v.
Since the object corresponding to the background is stationary, the background components of the fifth pixel from the left of frame #n in Fig. 17 corresponding to the second through fourth portions of the shutter time/v from when the shutter has opened are B29/v. The background components of the sixth pixel from the left of frame #n in Fig. 17 corresponding to the third and fourth portions of the shutter time/v from when the shutter has opened are B30/v. The background component of the seventh pixel from the left of frame #n in Fig. 17 corresponding to the fourth portion of the shutter tlme/v from when the shutter has opened.is B31/v.


In frame #n in Fig. 17, the fifth pixel through the seventh pixel from the left belong to the mixed area, which is an uncovered background area.
The eighth through twelfth pixels from the left of frame #n in Fig. 17 belong to the foreground area. The value in the foreground area of frame #n corresponding to the period of the shutter time/v is any one of F13/v through F20/v.
The leftmost pixel through the eighth pixel from the left of frame #n+l in Fig. 17 belong to the background area, and the pixel values thereof are B25 through B32, respectively.
It can be assumed that the object corresponding to the foreground is a rigid body moving with constant velocity, and that it is moving such that it is displayed four pixels to the right in the subsequent frame. Accordingly, the foreground component of the ninth pixel from the left of frame #n+l in Fig. 17 corresponding to the first portion of the shutter time/v from when the shutter has opened is F13/v, and the foreground component of the tenth pixel from the left in Fig. 17 corresponding to the second portion of the shutter time/v from when the shutter has opened is also F13/v. The foreground component of the eleventh pixel from the left in Fig. 17 corresponding to the third portion of the shutter time/v from when the shutter has opened and the


foreground component of the twelfth pixel from the left in Fig. 17 corresponding to the fourth portion of the shutter time/v from when the shutter has opened are F13/v.
The foreground component of the tenth pixel from the left of frame #n+l in Fig. 17 corresponding to the first portion of the shutter time/v from when the shutter has opened is F14/v. The foreground component of the eleventh pixel from the left in Fig. 17 corresponding to the second portion of the shutter time/v from when the shutter has opened is also F14/v. The foreground component of the twelfth pixel from the left in Fig. 17 corresponding to the first portion of the shutter time/v from when the shutter has opened is F15/v.
Since the object corresponding to the background is stationary, the background components of the ninth pixel from the left of frame #n+l in Fig. 17 corresponding to the second through fourth portions of the shutter time/v from when the shutter has opened are B33/v. The background components of the tenth pixel from the left of frame #n+l in Fig. 17 corresponding to the third and fourth portions of the shutter time/v from when the shutter has opened are B34/v. The background component of the eleventh pixel from the left of frame #n+l in Fig. 17 corresponding to the fourth portion of the shutter time/v from when the shutter has opened is B35/v.


In frame #n+l in Fig. 17, the ninth through eleventh pixels from the left in Fig. 17 belong to the mixed area, which is an uncovered background area.
The twelfth pixel from the left of frame #n+l in Fig. 17 belongs to the foreground area. The foreground component in the shutter time/v in the foreground area of frame #n+l is any one of F13 through F16, respectively.
Fig. 18 illustrates a model of an image obtained by extracting the foreground components from the pixel values shown in Fig. 17.
Referring back to Fig. 2, the area specifying unit 103 specifies flags indicating to which of a foreground area, a background area, a covered background area, or an uncovered background area the individual pixels of the input image belong by using the pixel values of a plurality of frames, and supplies the flags to the mixture-ratio calculator 104 and the motion-blur adjusting unit 106 as the area information.
The mixture-ratio calculator 104 calculates the mixture ratio a for each pixel contained in the mixed area based on the pixel values of a plurality of frames and the area information, and supplies the calculated mixture ratio a to the foreground/background separator 105.
The foreground/background separator 105 extracts the foreground component image consisting of only the foreground


components based on the pixel values of a plurality of frames, the area information, and the mixture ratio a, and supplies the foreground component image to the motion-blur adjusting unit 106.
The motion-blur adjusting unit 106 adjusts the amount of motion blur contained in the foreground component image based on the foreground component image supplied from the foreground/background separator 105, the motion vector supplied from the motion detector 102, and the area information supplied from the area specifying unit 103, and then outputs the foreground component image in which motion blur is adjusted.
The processing for adjusting the amount of motion blur performed by the signal processing apparatus is described below with reference to the flowchart of Fig. 19. In step Sll, the area specifying unit 103 executes area specifying processing, based on an input image, for generating area information indicating to which of a foreground area, a background area, a covered background area, or an uncovered background area each pixel of the input image belongs. Details of the area specifying processing are given below. The area specifying unit 103 supplies the generated area information to the mixture-ratio calculator 104.
In step Sll, the area specifying unit 103 may generate, based on the input image, area information indicating to

which of the foreground area, the background area, or the mixed area (regardless of whether each pixel belongs to a covered background area or an uncovered background area) each pixel of the input image belongs. In this case, the foreground/background separator 105 and the motion-blur adjusting unit 106 determine based on the direction of the motion vector whether the mixed area is a covered background area or an uncovered background area. For example, if the input image is disposed in the order of the foreground area, the mixed area, and the background area in the direction of the motion vector, it is determined that the mixed area is a covered background area. If the input image is disposed in the order of the background area, the mixed area, and the foreground area in the direction of the motion vector, it is determined that the mixed area is an uncovered background area.
In step S12, the mixture-ratio calculator 104 calculates the mixture ratio a for each pixel contained in the mixed area based on the input image and the area information. Details of the mixture ratio calculating processing are given below. The mixture-ratio calculator 104 supplies the calculated mixture ratio a to the foreground/background separator 105.
In step S13, the foreground/background separator 105 extracts the foreground components from the input image


based on the area information and the mixture ratio a, and supplies the foreground components to the motion-blur adjusting unit 106 as the foreground component image.
In step S14, the motion-blur adjusting unit 106 generates, based on the motion vector and the area information, the unit of processing that indicates the positions of consecutive pixels disposed in the moving direction and belonging to any of the uncovered background area, the foreground area, and the covered background area, and adjusts the amount of motion blur contained in the foreground components corresponding to the unit of processing. Details of the processing for adjusting the amount of motion blur are given below.
In step S15, the signal processing apparatus determines whether the processing is finished for the whole screen. If it is determined that the processing is not finished for the whole screen, the' process proceeds to step S14, and the processing for adjusting the amount of motion blur for the foreground components corresponding to the unit of processing is repeated.
If it is determined in step S15 that the processing is finished for the whole screen, the processing is completed.
In this manner, the signal processing apparatus is capable of adjusting the amount of motion blur contained in the foreground by separating the foreground and the


background. That is, the signal processing apparatus is capable of adjusting the amount of motion blur contained in sampled data indicating the pixel values of the foreground pixels.
The configuration of each of the area specifying unit 103, the mixture-ratio calculator 104, the foreground/background separator 105, and the motion-blur adjusting unit 106 is described below.
Fig. 20 is a block diagram illustrating an example of the configuration of the area specifying unit 103. The area specifying unit 103 shown in Fig. 20 does not use a motion vector. A frame memory 201 stores an input image in units of frames. When the image to be processed is frame #n, the frame memory 201 stores frame #n-2, which is the frame two frames before frame #n, frame #n-l, which is the frame one frame before frame #n, frame #n, frame #n+l, which is the frame one frame after frame #n, frame #n+2, which is the frame two frames.after frame #n.
A stationary/moving determining portion 202-1 reads the pixel value of the pixel of frame #n+2 located at the same position as a designated pixel of frame #n in which the area to which the pixel belongs is determined, and reads the pixel value of the pixel of frame #n+l located at the same position of the designated pixel of frame #n from the frame memory 201, and calculates the absolute value of the
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difference between the read pixel values. The stationary/moving determining portion 202-1 determines whether the absolute value of the difference between the pixel value of frame #n+2 and the pixel value of frame #n+l is greater than a preset threshold Th. If it is determined that the difference is greater than the threshold,Th, a stationary/moving determination indicating "moving" is supplied to an area determining portion 203-1. If it is determined that the absolute value of the difference between the pixel value of the pixel of frame #n+2 and the pixel value of the pixel of frame #n+l is smaller than or equal to the threshold Th, the stationary/moving determining portion 202-1 supplies a stationary/moving determination indicating "stationary" to the area determining portion 203-1.
A stationary/moving determining portion 202-2 reads the pixel value of a designated pixel of frame #n in which the area to which the pixel belongs is determined, and reads the pixel value of the pixel of frame #n+l located at the same position as the designated pixel of frame #n from the frame memory 201, and calculates the absolute value of the difference between the pixel values. The stationary/moving determining portion 202-2 determines whether the absolute value of the difference between the pixel value of frame #n+l and the pixel value of frame #n is greater than a preset threshold Th. If it is determined that the absolute


value of the difference between the pixel values is greater than the threshold Th, a stationary/moving determination indicating "moving" is supplied to the area determining portion 203-1 and an area determining portion 203-2. If it is determined that the absolute value of the difference between the pixel value of the pixel of frame #n+l and the pixel value of the pixel of frame #n is smaller than or equal to the threshold Th, the stationary/moving determining portion 202-2 supplies a stationary/moving determination indicating "stationary" to the area determining portion 203-1 and the area determining portion 203-2.
A stationary/moving determining portion 202-3 reads the pixel value of a designated pixel of frame #n in which the area to which the pixel belongs is determined, and reads the pixel value of the pixel of frame #n-l located at the same position as the designated pixel of frame #n from the frame memory 201, and calculates the absolute value of the difference between the pixel values. The stationary/moving determining portion 202-3 determines whether the absolute value of the difference between the pixel value of frame #n and the pixel value of frame #n-l is greater than a preset threshold Th. If it is determined that the absolute value of the difference between the pixel values is greater than the threshold Th, a stationary/moving determination indicating "moving" is supplied to the area determining
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portion 203-2 and an area determining portion 203-3. If it is determined that the absolute value of the difference between the pixel value of the pixel of frame #n and the pixel value of the pixel of frame #n-l is smaller than or equal to the threshold Th, the stationary/moving determining portion 202-3 supplies a stationary/moving determination indicating-"stationary" to the area determining portion 203-2 and the area determining portion 203-3.
A stationary/moving determining portion 202-4 reads the pixel value of the pixel of frame #n-l located at the same position as a designated pixel of frame #n in which the area to which the pixel belongs is determined, and reads the pixel value of the pixel of frame #n-2 located at the same position as the designated pixel of frame #n from the frame memory 201, and calculates the absolute value of the difference between the pixel values. The stationary/moving determining portion 202-4 determines whether-the absolute value of the difference between the pixel value of frame #n-1 and the pixel value of frame #n-2 is greater than a preset threshold Th. If it is determined that the absolute value of the difference between the pixel values is greater than the threshold Th, a stationary/moving determination indicating "moving" is supplied to the area determining portion 203-3. If it is determined that the absolute value of the difference between the pixel value of the pixel of
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frame #n-l and the pixel value of the pixel of frame #n-2 is smaller than or equal to the threshold Th, the stationary/moving determining portion 202-4 supplies a stationary/moving determination indicating "stationary" to the area determining portion 203-3.
When the stationary/moving determination supplied from the stationary/moving determining portion 202-1 indicates "stationary" and when the stationary/moving determination supplied from the stationary/moving determining portion 202-2 indicates "moving", the area determining portion 203-1 determines that the designated pixel of frame #n belongs to an uncovered background area, and sets "1", which indicates that the designated pixel belongs to an uncovered background area, in an uncovered-background-area determining flag associated with the designated pixel.
When the stationary/moving determination supplied from the stationary/moving determining portion 202-1 indicates "moving" or when the stationary/moving determination supplied from the stationary/moving determining portion 202-2 indicates "stationary", the area specifying unit 203-1 determines that the designated pixel of frame #n does not belong to'an uncovered background area, and sets "0", which indicates that the designated pixel does not belong to an uncovered background area, in the uncovered-background-area determining flag associated with the designated pixel.
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The area determining portion 203-1 supplies the uncovered-background-area determining flag in which "1" or "0" is set as discussed above to a determining-flag-storing frame memory 204.
When the stationary/moving determination supplied from the stationary/moving determining portion 202-2 indicates "stationary" and when the stationary/moving determination supplied from the stationary/moving determining portion 202-3 indicate "stationary", the area determining portion 203-2 determines that the designated pixel of frame #n belongs to the stationary area, and sets "1", which indicates that the pixel belongs to the stationary area, in a stationary-area determining flag associated with the designated pixel.
When the stationary/moving determination supplied from the stationary/moving determining portion 202-2 indicates "moving" or when the stationary/moving determination supplied from the stationary/moving determining portion 202-3 indicate "moving", the area determining portion 203-2 determines that the designated pixel of frame #n does not belong to the stationary area, and sets "0", which indicates that the pixel does not belong to the stationary area, in the stationary-area determining flag associated with the designated pixel.
The area determining portion 203-2 supplies the stationary-area determining flag in which "1" or "0" is set

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as discussed above to the determining-flag-storing frame memory 204.
When the stationary/moving determination supplied from the stationary/moving determining portion 202-2 indicates "moving" and when the stationary/moving determination supplied from the stationary/moving determining portion 202-3 indicate "moving", the area determining portion 203-2 determines that the designated pixel of frame #n belongs to the moving area, and sets "1", which indicates that the designated pixel belongs to the moving area, in a moving-area determining flag associated with the designated pixel.
When the stationary/moving determination supplied from the stationary/moving determining portion 202-2 indicates "stationary" or when the stationary/moving determination supplied from the stationary/moving determining portion 2 02-3 indicate "stationary", the area determining portion 203-2 determines that the designated pixel of frame #n does not belong to the moving area, and sets "0", which indicates that the pixel does not belong to the moving area, in the moving-area determining flag associated with the designated pixel.
The area determining portion 203-2 supplies the moving-area determining flag in which "1" or "0" is set as discussed above to the determining-flag-storing frame memory °04.
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When the stationary/moving determination supplied from the stationary/moving determining portion 202-3 indicates "moving" and when the stationary/moving determination supplied from the stationary/moving determining portion 202-4 indicate "stationary", the area determining portion 203-3 determines that the designated pixel of frame #n belongs to a covered background area, and sets "1", which indicates that the designated pixel belongs to the covered background area, in a covered-background-area determining flag associated with the designated pixel.
When the stationary/moving determination supplied from the stationary/moving determining portion 202-3 indicates "stationary" or when the stationary/moving determination supplied from the stationary/moving determining portion 202-4 indicate "moving", the area determining portion 203-3 determines that the designated pixel of frame #n does not belong to a covered background area, and sets "0", which indicates that the designated pixel does not belong to a covered background area, in the covered-background-area determining flag associated with the designated pixel.
The area determining portion 203-3 supplies the covered-background-area determining flag in which "1" or "0" is set as discussed above to the determining-flag-storing frame memory 204.
The determining-flag-storing frame memory 204 thus


stores the uncovered-background-area determining flag supplied from the area determining portion 203-1, the stationary-area determining flag supplied from the area determining portion 203-2, the moving-area determining flag supplied from the area determining portion 203-2, and the covered-background-area determining flag supplied, from the area determining portion 203-3.
The determining-flag-storing frame memory 204 supplies the uncovered-background-area determining flag, the stationary-area determining flag, the moving-area determining flag, and the covered-background-area determining flag stored therein to a synthesizer 205. The synthesizer 205 generates area information indicating to which of the uncovered background area, the stationary area, the moving area, or the covered background area each pixel belongs based on the uncovered-background-area determining flag, the stationary-area determining flag, the moving-area determining flag, and the covered-background-area determining flag supplied from the determining-flag-storing frame memory 204, and supplies the area information to a determining-flag-storing frame memory 206.
The determining-flag-storing frame memory 206 stores the area information supplied from the synthesizer 205, and also outputs the area information stored therein.
An example of the processing performed by the area


specifying unit 103 is described below with reference to Figs. 21 through 25.
When the object corresponding to the foreground is moving, the position of the image corresponding to the object on the screen changes in every frame. As shown in Fig. 21, the image corresponding to the object lopated at the position indicated by Yn(x, y) in frame #n is positioned at Yn+1(x, y) in frame #n+l, which is subsequent to frame #n.
A model obtained by expanding in the time direction the pixel values of the pixels aligned side-by-side in the moving direction of the image corresponding to the foreground object is shown in Fig. 24. For example, if the moving direction of the image corresponding to the foreground object is horizontal with respect to the screen, the model shown in Fig. 22 is a model obtained by expanding in the time direction the pixel values of the.pixels disposed on a line side-by-side.
In Fig. 22, the line in frame #n is equal to the line in frame #n+l.
The foreground components corresponding to the object contained in the second pixel to the thirteenth pixel from the left' in frame #n are contained in the sixth pixel through the seventeenth pixel from the left in frame #n+l.
In frame #n, the pixels belonging to the covered background area are the eleventh through thirteenth pixels


from the left, and the pixels belonging to the uncovered background area are the second through fourth pixels from the left. In frame #n+l, the pixels belonging to the covered background area are the fifteenth through seventeenth pixels from the left, and the pixels belonging to the uncovered background area are the sixth through eighth pixels from the left.
In the example shown in Fig. 22, since the foreground components contained in frame #n are moved by four pixels in frame #n+l, the amount of movement v is 4. The number of virtual divided portions is 4 in accordance with the amount of movement v.
A description is now given of a change in pixel values of the pixels belonging to the mixed area in the frames before and after a designated frame.
In Fig. 23, the pixels belonging to a covered background area in frame #n in which the background is stationary and the amount of movement v in the foreground is 4 are the fifteenth through seventeenth pixels from the left, Since the amount of movement v is 4, the fifteenth through seventeenth frames from the left in the previous frame #n-l contain only background components and belong to the background area. The fifteenth through seventeenth pixels from the left in frame #n-2, which is one before frame #n-l, contain only background components and belong to the


background area.
Since the object corresponding to the background is stationary, the pixel value of the fifteenth pixel from the left in frame #n-l does not change from the pixel value of the fifteenth pixel from the left in frame #n-2. Similarly, the pixel value of the sixteenth pixel from the left in frame #n-l does not change from the pixel value of the sixteenth pixel from the left in frame #n-2, and the pixel value of the seventeenth pixel from the left in frame #n-l does not change from the pixel value of the seventeenth pixel from the left in frame #n-2.
That is, the pixels in frame #n-l and frame #n-2 corresponding to the pixels belonging to the covered background area in frame #n consist of only background components,'and the pixel values thereof do not change. Accordingly, the absolute value of the difference between the pixel values is almost 0. Thus, the stationary/moving determination made for the pixels in frame #n-l and frame #n-2 corresponding to the pixels belonging to the mixed area in frame #n by the stationary/moving determining portion 202-4 is "stationary".
Since the pixels belonging to the covered background area in frame #n contain foreground components, the pixel values, thereof are different from those of frame #n-l consisting of only background components. Accordingly, the


stationary/moving determination made for the pixels belonging to the mixed area in frame #n and the corresponding pixels in frame #n-l by.the stationary/moving determining portion 202-3 is "moving".
When the stationary/moving determination result indicating "moving" is supplied from the stationary/moving determining portion 202-3, and when the stationary/moving determination result indicating "stationary" is supplied from the stationary/moving determining portion 202-4, as discussed above, the area determining portion 203-3 determines that the corresponding pixels belong to a covered background area.
In Fig. 24, in frame #n in which the background is stationary and the amount of movement v in the foreground is 4, the pixels contained in an uncovered background area are the second through fourth pixels from the left. Since the amount of movement v is 4, the second through fourth pixels from the left in the subsequent frame #n+l contain only background components and belong to the background area. In frame #n+2, which is subsequent to frame #n+l, the second through fourth pixels from the left contain only background components and belong to the background area.
Since the object corresponding to the background is stationary, the pixel value of the second pixel from the left in frame #n+2 does not change from the pixel value of


the second pixel from the left in frame #n+l. Similarly, the pixel value of the third pixel from the left in frame #n+2 does not change from the pixel value of the third pixel from the left in frame #n+l, and the pixel value of the fourth pixel from the left in frame #n+2 does not change from the pixel value of the fourth pixel from the,left in frame #n+l.
That is, the pixels in frame #n+l and frame #n+2 corresponding to the pixels belonging to the uncovered background area in frame #n consist of only background components, and the pixel values thereof do not change. Accordingly, the absolute value of the difference between the pixel values is almost 0. Thus, the stationary/moving determination made for the pixels in frame #n+l and frame #n+2 corresponding to the pixels belonging to the mixed area in frame #n by the stationary/moving determining portion 202-1 is "stationary".
Since the pixels belonging to the uncovered background area in frame #n contain foreground components, the pixel values thereof are different from those of frame #n+l consisting of only background components. Accordingly, the stationary/moving determination made for the pixels belonging to the mixed area in frame #n and the corresponding pixels in frame #n+l by the stationary/moving determining portion 202-2 is "moving".


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When the stationary/moving determination result indicating "moving" is supplied from the stationary/moving determining portion 202-2, and when the stationary/moving determination result indicating "stationary" is supplied from the stationary/moving determining portion 202-1, as discussed above, the area determining portion 203-1 determines that the corresponding pixels belong to an uncovered background area.
Fig. 25 illustrates determination conditions in frame #n made by the area specifying unit 103. When the determination result for the pixel in frame #n-2 located at the same image position as a designated pixel in frame #n to be processed and for the pixel in frame #n-l located at the same position as the designated pixel in frame #n is stationary, and when the determination result for the designated pixel in frame #n and the pixel in frame #n-l located at the same image position as the designated pixel in frame #n is moving, the area specifying unit 103 determines that the pixel in frame #n+l belongs to a covered background area.
When the determination result for the pixel in frame #n and the pixel in frame #n-l located at the same image position as the designated pixel in frame #n is stationary, and when the determination result for the pixel in frame #n and the pixel in frame #n+l located at the same image


position as the designated pixel in frame #n is stationary, the area specifying unit 103 determines that the designated pixel in frame #n belongs to the stationary area.
When the determination result for the pixel in frame #n and the pixel in frame #n-l located at the same image position as the designated pixel in frame #n is mpving, and when the determination result for the pixel in frame #n and the pixel in frame #n+l located at the same image position as the designated pixel in frame #n is moving, the area specifying unit 103 determines that the designated pixel in frame #n belongs to the moving area.
When the determination result for the pixel in frame #n and the pixel in frame #n+l located at the same image position as the designated pixel in frame #n is moving, and when the determination result for the pixel in frame #n+l located at the same image position as the designated pixel in frame #n and the pixel in frame #n+2 located at the same image position as the designated pixel in frame #n is stationary, the area specifying unit 103 determines that the designated pixel in frame #n belongs to an uncovered background area.
Figs. 26A through 26D illustrate examples of the area determination results obtained by the area specifying unit 103. In Fig. 2 6A, the pixels which are determined to belong to a covered background area are indicated in white. In Fig.


2 6B, the pixels which are determined to belong to an uncovered background area are indicated in white.
In Fig. 26C, the pixels which are determined to belong to a moving area are indicated in white. In Fig. 26D, the pixels which are determined to belong to a stationary area are indicated in white.
Fig. 27 illustrates the area information indicating the mixed area, in the form of an image, selected from the area information output from the determining-flag-storing frame memory 206. In Fig. 27, the pixels which are determined to belong to the covered background area or the uncovered background area, i.e., the pixels which are determined to belong to the mixed area, are indicated in white. The area information indicating the mixed area output from the determining-flag-storing frame memory 206 designates the mixed area and the portions having a texture surrounded by the portions without a texture in the foreground area.
The area specifying processing performed by the area specifying unit 103 is described below with reference to the flowchart of Fig. 28. In step S201, the frame memory 201 obtains an image of frame #n-2 through frame #n+2 including frame #n.
In step S202, the stationary/moving determining portion 202-3 determines whether the determination result for the pixel in frame #n-l and the pixel in frame #n located at the


same position is stationary. If it is determined that the determination result is stationary, the process proceeds to step S203 in which the stationary/moving determining portion 202-2 determines whether the determination result for the pixel in frame #n and the pixel in frame #n+l located at the same position is stationary.
If it is determined in step S203 that the determination result for the pixel in frame #n and the pixel in frame #n+l located at the same position is stationary, the process proceeds to step S204. In step S204, the area determining portion 203-2 sets "1", which indicates that the pixel to be processed belongs to the stationary area, in the stationary-area determining flag associated with the pixel to be processed. The area determining portion 203-2 "supplies the stationary-area determining flag to the determining-flag-storing frame memory 204, and the process proceeds to step S205.
If it is determined in step S202 that the determination result for the pixel in frame #n-l and the pixel in frame #n located at the same position is moving, or if it is determined in step S203 that the determination result for the pixel in frame #n and the pixel in frame #n+l located at the same position is moving, the pixel to be processed does not belong to a stationary area. Accordingly, the processing of step S204 is skipped, and the process proceeds


to step S205.
In step S205, the stationary/moving determining portion 202-3 determines whether the determination result for the pixel in frame #n-l and the pixel in frame #n located at the same position is moving. If it is determined that the determination result is moving, the process proceeds to step S206 in which the stationary/moving determining portion 202-2 determines whether the determination result for the pixel in frame #n and the pixel in frame #n+l located at the same position is moving.
If it is determined in step S206 that the determination result for the pixel in frame #n and the pixel in frame #n+l located at the same position is moving, the process proceeds to step S207. In step S207, the area determining portion 203-2 sets "1", which indicates that the pixel to be processed belongs to a moving area, in the moving-area determining flag associated with the pixel to be processed. The area determining area 203-2 supplies the moving-area determining flag to the determining-flag-storing frame memory 204, and the process proceeds to step S208.
If it is determined in step S205 that the determination result for the pixel in frame #n-l and the pixel in frame #n located at the same position is stationary, or if it is determined in step S206 that the determination result for the pixel in frame #n and the pixel in frame #n+l located at


the same position is stationary, the pixel in frame #n does not belong to a moving area. Accordingly, the processing of step S207 is skipped, and the process proceeds to step S208. In step S208, the stationary/moving determining portion 202-4 determines whether the determination result for the pixel in frame #n-2 and the pixel in frame #n-l located at the same position is stationary. If it is determined that the determination result is stationary, the process proceeds to step S209 in' which the stationary/moving determining portion 202-3 determines whether the determination result for the pixel in frame #n-l and the pixel in frame #n located at the same position is moving.
If it is determined in step S209 that the determination result for the pixel in frame #n-l and the pixel in frame #n located at the same position is moving, the process proceeds to step S210. In step S210, the area determining portion 203-3 sets "1", which indicates that the pixel to be processed belongs to a covered background area, in the covered-background-area determining flag associated with the pixel to be processed. The area determining portion 203-3 supplies the covered-background-area determining flag to the determining-flag-storing frame memory 204, and the process proceeds to step S211. The area determining portion 203-3 supplies the covered-backgxound-area determining flag to the determining-flag-storing frame memory 204, and the process


proceeds to step S211.
If it is determined in step S208 that the determination result for the pixel in frame #n-2 and the pixel in frame #n-l located at the same position is moving, or if it is determined in step S209 that the pixel in frame #n-l and the pixel in frame #n located at the same position is stationary, the pixel in frame #n does not belong to a covered background area. Accordingly, the processing of step S210 is skipped, and the process proceeds to step S211.
In step S211, the stationary/moving determining portion 202-2 determines whether the determination result for the pixel in frame #n and the pixel in frame #n+l located at the same position is moving. If it is determined in step S211 that the determination result is moving, the process proceeds to step S212 in which the stationary/moving determining portion 202-1 determines whether the determination result for the pixel in frame #n+l and the pixel in frame #n+2 located at the same position is stationary.
If it is determined in step S212 that the determination result for the pixel in frame #n+l and the pixel in frame #n+2 located at the same position is stationary, the process proceeds to step S213. In step S213, the area determining portion 203-1 sets "1", which indicates that the. pixel to be processed belongs to an uncovered background area, in the


uncovered-background-area determining flag associated with the pixel to be processed. The area determining portion 203-1 supplies the uncovered-background-flag determining flag to the determining-flag-storing frame memory 204, and the process proceeds to step S214.
If it is determined in step S211 that the determination result for the pixel in frame #n and the pixel in frame #n+l located at the same position is stationary, or if it is determined in step S212 that the determination result for the pixel in frame #n+l and the pixel in frame #n+2 is moving, the pixel in frame #n does not belong to an uncovered background area. Accordingly, the processing of step S213 is skipped, and the process proceeds to step S214.
In step S214, the area specifying unit 103 determines whether the areas of all the pixels in frame #n are specified. If it is determined that the areas of all the pixels in frame #n are not yet specified, the process returns to step S202, and the area specifying processing is repeated for the remaining pixels.
If it is determined in step S214 that the areas of all the pixels in frame #n are specified, the process proceeds to step S215. In step S215, the synthesizer 215 generates area information indicating the mixed area based on the uncovered-background-area determining flag and the covered-background-area determining flag stored in the determining-


flag-storing frame memory 204, and also generates area information indicating to which of the uncovered background area, the stationary area, the moving area, or the covered background area each pixel belongs, and sets the generated area information in the determining-flag-storing frame memory 206. The processing is then completed. (
As discussed above, the area specifying unit 103 is capable of generating area information indicating to which of the moving area, the stationary area, the uncovered background area, or the covered background area each of the pixels contained in a frame belongs.
The area specifying unit 103 may apply logical OR to the area information corresponding to the uncovered background area and the area information corresponding to the covered background area so as to generate area information corresponding to the mixed area, and then may generate area information consisting of flags indicating to which of the moving area, the stationary area, or the mixed area the individual pixels contained in the frame belong.
When the object corresponding to the foreground has a texture, the area specifying unit 103 is able to specify the moving area more precisely.
The area specifying unit 103 is able to output the area information indicating the moving area as the area information indicating the foreground area, and outputs the


area information indicating the stationary area as the area information indicating the background area.
The embodiment has been described, assuming that the object corresponding to the background is stationary. However, the above-described area specifying processing can be applied even if the image corresponding to the, background area contains motion. For example, if the image corresponding to the background area is uniformly moving, the area specifying unit 103 shifts the overall image in accordance with this motion, and performs processing in a manner similar to the case in which the object corresponding to the background is stationary. If the image corresponding to the background area contains locally different motions, the area specifying unit 103 selects the pixels corresponding to the motions, and executes the above-described processing.
Fig. 29 is a block diagram illustrating an example of the configuration of the area specifying unit 103. The area specifying unit 103 shown in Fig. 29 does not use a motion vector. A background image generator 301 generates a background image corresponding to an input image, and supplies the generated background image to a binary-object-image extracting portion 302. The background image generator 301 extracts, for example, an image object corresponding to a background object contained in the input


image, and generates the background image.
An example of a model obtained by expanding in the time direction the pixel values of pixels aligned side-by-side in the moving direction of an image corresponding to a foreground object is shown in Fig. 30. For example, if the moving direction of the image corresponding to the foreground object is horizontal with respect to the screen, the model shown in Fig. 30 is a model obtained by expanding the pixel values of pixels disposed side-by-side on a single line in the time domain.
In Fig. 30, the line in frame #n is the same as the line in frame #n-l and the line in frame #n+l.
In frame #n, the foreground components corresponding to the object contained in the sixth through seventeenth pixels from the left are contained in the second through thirteenth pixels from the left in frame #n-l and are also contained in the tenth through twenty-first pixel from the left in frame #n+l.
In frame #n-l, the pixels belonging to the covered background area are the eleventh through thirteenth pixels from the left, and the pixels belonging to the uncovered background area are the second through fourth pixels from the left. In frame #n, the pixels belonging to the covered background area are the fifteenth through seventeenth pixels from the left, and the pixels belonging to the uncovered


background area are the sixth through eighth; pixels from the left. In frame #n+l, the pixels belonging to the covered background area are the nineteenth through twenty-first pixels from the left, and the pixels belonging to the uncovered background area are the tenth through twelfth pixels from the left.
In frame #n-l, the pixels belonging to the background area are the first pixel from the left, and the fourteenth through twenty-first pixels from the left. In frame #n, the pixels belonging to the background area are the first through fifth pixels from the left, and the eighteenth through twenty-first pixels from the left. In frame #n+l, the pixels belonging to the background area are the first through ninth pixels from the left.
An example of the background image corresponding to the example shown in Fig. 30 generated by the background image generator 301 is shown in Fig. 31. The background image consists of the pixels corresponding to the background object, and does not contain image components corresponding to the foreground object.
The binary-object-image extracting portion 302 generates a binary object image based on the correlation between the background image and the input image, and supplies the generated binary object image to a time change detector 303.

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Fig. 32 is a block diagram illustrating the configuration of the binary-object-image extracting portion 302. A correlation-"7al\ie calculator 321 calculates the correlation between the background image supplied from the background image generator 301 and the input image so as to generate a correlation value, and supplies the generated correlation value to a threshold-value processor 322.
The correlation-value calculator 321 applies equation (4) to, for example, 3x3-background image blocks having X4 at the center, as shown in Fig. 33A, and to, for example, 3x3-background image blocks having Y4 at the center which corresponds to the background image blocks, as shown in Fig. 33B, thereby calculating a correlation value corresponding to Y4.
Correlation value - (4)

The correlation-value calculator 321 supplies the correlation value calculated for each pixel as discussed above to the threshold-value processor 322.


Alternatively, the correlation-value calculator 321 may apply equation (7) to, for example, 3x3-background image blocks having X4 at the center, as shown in Fig. 34A, and to, for example, 3x3-background image blocks having Y4 at the center which corresponds to the background image blocks, as shown in Fig. 34B, thereby calculating the sum of,absolute values of differences corresponding to
Sum of absolute values of differences = (7)
The correlation-value calculator 321 supplies the sum of the absolute values of the differences calculated as described above to the threshold-value processor 322 as the correlation value.
The threshold-value processor 322 compares the pixel value of the correlation image with a threshold thO. If the correlation value is smaller than or equal to the threshold thO, 1 is set in the pixel value of the binary object image. If the correlation value is greater than the threshold thO, 0 is set in the pixel value of the binary object image. The threshold-value processor 322 then outputs the binary object image whose pixel value is set to 0 or 1. The threshold-value processor 322 may store the threshold thO therein in advance, or may use the threshold thO input from an external source.
Fig. 35 illustrates the binary object image


corresponding to the model of the input image shown in Fig. 30. In the binary object image, 0 is set in the pixel values of the pixels having a higher correlation with the background image.
Fig. 36 is a block diagram illustrating the configuration of the time change detector 303. When determining the area of a pixel in frame #n, a frame memory 341 stores a binary object image of frame #n-l, frame #n, and frame #n+l supplied from the binary-object-image extracting portion 302.
An area determining portion 342 determines the area of each pixel of frame #n based on the binary object image of frame #n-l, frame #n, and frame #n+l so as to generate area information, and outputs the generated area information.
Fig. 37 illustrates the determinations made by the area determining portion 342. When the designated pixel of the binary object image in frame #n is 0, the area determining portion 342 determines that the designated pixel in frame #n belongs to the background area.
When the designated pixel of the binary object image in frame #n is 1, and when the corresponding pixel of the binary object image in frame #n-l is 1, and when the corresponding pixel of the binary object image in frame #n+l is 1, the area determining portion 342 determines that the designated pixel in frame #n belongs to the foreground area.
123

When the designated pixel of the binary object image in frame #n is 1, and when the corresponding pixel of the binary object image in frame #n-l is 0, the area determining portion 342 determines that the designated pixel in frame #n belongs to a covered background area.
When the designated pixel of the binary object image in frame #n is 1, and when the corresponding pixel of the binary object image in frame #n+l is 0, the area determining portion 342 determines that the designated pixel in frame #n belongs to an uncovered background area.
Fig. 38 illustrates an example of the determinations made by the time change detector 303 on the binary object image corresponding to the model of the input image shown in Fig. 30.. The time change detector 303 determines that the first through fifth pixels from the left in frame #n belong to the background area since the corresponding pixels of the binary object image in frame #n are 0.
The time change detector 303 determines that the sixth through ninth pixels from the left belong to the uncovered background area since the pixels of the binary object image in frame #n are 1, and the corresponding pixels in frame #n+l are 0.
The time change detector 303 determines that the tenth through thirteenth pixels from the left belong to the foreground area since the pixels of the binary object image


in frame #n are 1, the corresponding pixels in frame #n-l are 1, and the corresponding pixels in frame #n+l are 1.
The time change detector 303 determines that the fourteenth through seventeenth pixels from the left belong to the covered background area since the pixels of the binary object image in frame #n are 1, and the corresponding pixels in frame #n-l are 0.
The time change detector 303 determines that the eighteenth through twenty-first pixels from the left belong to the background area since the corresponding pixels of the binary object image in frame #n are 0.
The area specifying processing performed by1the area specifying unit 103 is described below with reference to the flowchart of Fig. 39. In step S301, the background image generator 301 of the area specifying unit 103 extracts, for example, an image object corresponding to a background object contained in an input image based on the input image so as to generate a background image, and supplies the generated background image to the binary-object-image extracting portion 302.
In step S302, the binary-object-image extracting portion 302 calculates a correlation value between the input image and the background image supplied from the background image generator 301 according to, for example., calculation discussed with reference to Fig. 33. In step S303, the


binary-object-image extracting portion 302 computes a binary object image from the correlation value and the threshold thO by, for example, comparing the correlation value with the threshold thO.
In step S304, the time change detector 303 executes the area determining processing, and the processing is completed.
Details of the area determining processing in step S304 are described below with reference to the flowchart of Fig. 40. In step S321, the area determining portion 342 of the time change detector 303 determines whether the designated pixel in frame #n stored in the frame memory 341 is 0. If it is determined that the designated pixel in frame #n is 0, the process proceeds to step S322. In step S322, it is
-a
determined that.the designated pixel in frame #n belongs to the background area, and the processing is completed.
If it is determined in step S321 that the designated pixel in frame #n is 1, the process proceeds to step S323. In step S323, the-area determining portion 342 of the time change detector 303 determines whether the designated pixel in frame #n stored in the frame memory 341 is 1, and whether the corresponding pixel in frame #n-l is 0. If it is determined that the designated pixel in frame #n is 1 and the corresponding pixel in frame #n-l is 0, the process proceeds to step S324. In step S324, it is determined that the designated pixel in frame #n belongs to the covered


background area, and the processing is completed.
If it is determined in step S323 that the designated pixel in frame #n is 0, or that the corresponding pixel in frame #n-l is 1, the process proceeds to step S325. In step S325, the area determining portion 342 of the time change detector 303 determines whether the designated pixel in frame #n stored in the frame memory 341 is 1, and whether the corresponding pixel in frame #n+l is 0. If it is determined that the designated pixel in frame #n is 1 and the corresponding pixel in frame #n+l is 0, the process proceeds to step S326. In step S32 6, it is determined that the designated pixel in frame #n belongs to the uncovered background area, and the processing is completed.
If it is determined in step S325 that the designated pixel in frame #n is 0, or that the corresponding pixel in frame #n+l is 1, the process proceeds to step S327. In step S327, the area determining portion 342 of the time change detector 303 determines that the designated pixel in frame #n belongs to the foreground area, and the processing is completed.
As discussed above, the area specifying unit 103 is able to specify,- based on the correlation value between the input image and the corresponding background image, to which of -the foreground area, the background area, the covered background area, or the uncovered background area each pixel


of the input image belongs, and generates area information corresponding to the specified result.
Fig. 41 is a block diagram illustrating another configuration of the area specifying unit 103. The area specifying unit 103 shown in Fig. 41 uses a motion vector and positional information thereof supplied from the motion detector 102. The same elements as those shown in Fig. 29 are designated with like reference numerals, and an explanation thereof is thus omitted.
A robust-processing portion 361 generates a robust binary object image based on binary object images of N frames supplied from the binary-object-image extracting portion 302, and outputs the robust binary object image to the time change detector 303.
Fig. 42 is a block diagram illustrating the configuration of the robust-processing portion 361. A motion compensator 381 compensates for the motion of the binary object images of N frames based on the motion vector and the positional information thereof supplied from the motion detector 102, and outputs a motion-compensated binary object image to a switch 382.
The motion compensation performed by the motion compensator 381 is discussed below with reference to examples shown in Figs. 43 and 44. It is now assumed, for example, that the area in frame #n is to be processed. When


binary object images of frame #n-l, frame #n, and frame #n+l shown in Fig. 43 are input, the motion compensator 381 compensates for the motion of the binary object image of frame #n-l and the binary object image of frame #n+l, as indicated by the example shown in Fig. 44, based on the motion vector supplied from the motion detector 1P2, and supplies the motion-compensated binary object images to the switch 382.
The switch 382 outputs the motion-compensated binary object image of the first frame to a frame memory 383-1, and outputs the motion-compensated binary object image of the second frame to a frame memory 383-2. Similarly, the switch 382 outputs the motion-compensated binary object images of the third through (N-l)-th frame to frame memories 383-3 through 383-(N-1), and outputs the motion-compensated binary object image of the N-th frame to a frame memory 383-N.
The frame memory 383-1 stores the motion-compensated binary object image of the first frame, and outputs the stored binary object image to a weighting portion 384-1. The frame memory 383-2 stores the motion-compensated binary object image of the second frame, and outputs the stored binary object image to a weighting portion 384-2.
Similarly, the frame memories 383-3 through 383-(N-1) stores the motion-compensated binary object images of the third through (N-l)-th frames, and outputs the stored binary


object images to weighting portions 384-3.through 384-(N-l). The frame memory 383-N stores the motion-compensated binary object image of the N-th frame, and outputs the stored binary object image to a weighting portion 384-N.
The weighting portion 384-1 multiplies the pixel value of the motion-compensated binary object image of the first frame supplied from the frame memory 383-1 by a predetermined weight wl, and supplies a weighted binary object image to an accumulator 385.. The weighting portion 384-2 multiplies the pixel value of the motion-compensated binary object image of the second frame supplied from the frame memory 383-2 by a predetermined weight w2, and supplies the weighted binary object image to the accumulator 385.
Likewise, the weighting portions 384-3 through 384-(N-1) multiply the pixel values of the motion-compensated binary object images of the third through (N-l)-th frames supplied from the frame memories 383-3 through 383-(N-l) by predetermined weights w3 through w(N-l), and supplies the weighted binary object images to the accumulator 385. The weighting portion 384-N multiplies the pixel value of the motion-compensated binary object image of the N-th frame supplied from the frame memory 383-N by a predetermined weight wN, and supplies the weighted binary.object image to the accumulator 385.


The accumulator 385 accumulates the pixel values of the motion-compensated binary object images multiplied by the weights wl through wN of the first through N-th frames, and compares the accumulated pixel value with the predetermined threshold thO, thereby generating the binary object image.
As discussed above, the robust-processing portion 3 61 generates a robust binary object image.from N binary object images, and.supplies it to the time change detector 303. Accordingly, the area specifying unit 103 configured as shown in Fig. 41 is able to specify the area more precisely than that shown in Fig. 29 even if noise is contained in the input image.
The area specifying processing performed by the area specifying unit 103 configured as shown in Fig. 41 is described below with reference to the flowchart of Fig. 45. The processings of step S341 through step S343 are similar to those of step S301 through step S303 discussed with reference to the flowchart of Fig. 39, and an explanation thereof is thus omitted.
In step S344, the robust-processing portion 361 performs the robust processing.
In step S345, the time change detector 303 performs the area determining processing, and the processing is completed. Details of the processing of step S345 are similar to the processing discussed with reference to the flowchart of Fig.


40, and an explanation thereof is thus omitted.
Details of the robust processing corresponding to the processing of step S344 in Fig. 45 are given below with reference to the flowchart of Fig. 46. In step S361, the motion compensator 381 performs the motion compensation of an input binary object image based on the motion vector and the positional information thereof supplied from the motion detector 102. In step S362, one of the frame memories 383-1 through 383-N stores the corresponding motion-compensated binary object image supplied via the switch 382.
In step S363, the robust-processing portion 361 determines whether N binary object images are stored. If it is determined that N binary object images are not stored, the process returns to step S361, and the processing for compensating for the motion of the binary object image and the processing for storing the binary object image are repeated.
If it is determined in step S363 that N binary object images are stored, the process proceeds to step S364 in which weighting is performed. In step S364, the weighting portions 384-1 through 384-N multiply the corresponding N binary object images by the weights wl through wN.
In step S365, the accumulator 385 accumulates the N weighted binary object images.
In step S366, the accumulator 385 generates a binary

|

object image from the accumulated images by, for example, comparing the accumulated value with a predetermined threshold thl, and the processing is completed.
As discussed above, the area specifying unit 103 configured as shown in Fig. 41 is able to generate area information based on the robust binary object image.
As is seen from the foregoing description, the area specifying unit 103 is able to generate area information indicating to which of the moving area, the stationary area, the uncovered background area, or the covered background area each pixel contained in a frame belongs.
Fig. 47 is a block diagram illustrating an example of the configuration of the mixture-ratio calculator 104. An estimated-mixture-ratio processor 401 calculates an estimated mixture ratio for each pixel by calculating a model of a covered background area based on the input image, and supplies the calculated estimated mixture ratio to a mixture-ratio determining portion 403.
An estimated-mixture-ratio processor 402 calculates an estimated mixture ratio for each pixel by calculating a model of an uncovered background area based on the input image, and supplies the calculated estimated mixture ratio to the mixture-ratio determining portion 403.
Since it can be assumed that the object corresponding, to the foreground is moving with constant velocity within


the shutter time, the mixture ratio a of the pixels belonging to a mixed area exhibits the following characteristics. That is, the mixture ratio a linearly changes according to the positional change in the pixels. If the positional change in the pixels is one-dimensional, a change in the mixture ratio a can be represented linearly. If the positional change in the pixels is two-dimensional, a change in the mixture ratio a can be represented on a plane.
Since the period of one frame is short, it can be assumed that the object corresponding to the foreground is a rigid body moving with constant velocity.
The gradient of the mixture ratio a is inversely proportional to the amount of movement v within the shutter time of the foreground.
An example of the ideal mixture ratio a is shown in Fig. 48. The gradient 1 of the ideal mixture ratio a in the mixed area can be represented by the reciprocal of the amount of movement v.
As shown in Fig. 48, the ideal mixture ratio a has the value of 1 in the background area, the value of 0 in the foreground area, and the value of greater than 0 and smaller than 1 in the mixed area.
In the example shown in Fig. 49, the pixel value C06 of the seventh pixel from the left in frame #n can be indicated by equation (8) by using the pixel value P06 of the seventh


pixel from the left in frame #n-l.
C06 = B06 / v + B06 / v + F01 / v + F02 / v
= P06 / v + P06 / v + F01 / v + F02 / v (8)
2
= 2 / v • P06 + 2 Fi / v
i=l
In equation (8), the pixel value C06 is indicated by a pixel value M of the pixel in the mixed area, while the pixel value P06 is indicated by a pixel value B of the pixel in the background, area. That is, the pixel value M of the pixel in the mixed area and the pixel value B of the pixel in the background area can be represented by equations (9) and (10), respectively.
M = C06 (9)
B = P06 * (10)
In equation (8), 2/v corresponds to the mixture ratio a. Since the amount of movement v is 4, the mixture ratio a of. the seventh pixel from the left in frame #n is 0.5.
As discussed above, the pixel value C in the designated frame #n is considered as the pixel value in the mixed area, while the pixel value P of frame #n-l prior to frame #n is considered as the pixel value in the background area. Accordingly, equation (3) indicating the mixture ratio a can be represented by equation (11):
C = a • P+f (11)
where f in equation (11) indicates the sum of the .foreground


components contained in the designated pixel. The variables contained in equation (11) are two factors, i.e., the mixture ratio a and the sum f of the foreground components.
Similarly, a model obtained by expanding in the time direction the pixel values in which the amount of, movement is 4 and the number of virtual divided portions is 4 in an uncovered background area is shown in Fig. 50.
As in the.representation of the covered background area, in the uncovered background area, the pixel value C of the designated frame #n is considered as the pixel value in the mixed area, while the pixel value N of frame #n+l subsequent to frame #n is considered as the background area. Accordingly, equation (3) indicating the mixture ratio a can be represented by equation (12).
C = a • N+f (12)
The embodiment has been described, assuming that the background object is stationary. However, equations (8) through (12) can be applied to the case in which the background object is moving by using the pixel value of a pixel located corresponding to the amount of movement v of the background. It is now assumed, for example, in Fig. 49 that the amount of movement v of the object corresponding to the background is 2, and the number of virtual divided portions is 2. In this case, when the object corresponding


to the background is moving to the right in Fig. 49, the pixel value B of the pixel in the background area in equation (10) is represented by a pixel value P04.
Since equations (11) and (12) each contain two variables, the mixture ratio a cannot be determined without modifying the equations. Generally, an image has,a strong spatial correlation, and accordingly, pixels located in close proximity with each other have almost the same pixel values.
Since the foreground components have a spatially strong correlation, the equation is modified so that the sum f of the foreground components can be deduced from the previous or subsequent frame, thereby determining the mixture ratio a.
The pixel value Mc of the seventh pixel from the left in frame #n in Fig. 51 can be expressed by equation (13).
(13)
The first term 2/v of the right side in equation (13) corresponds to the mixture ratio a. The second term of the right side in equation (13) can be expressed by equation (14) by utilizing the pixel value in the subsequent frame #n+l.
(14)
j
It is now assumed that equation (15) holds true by


In equations (19) and (20), since C, N, and P are known pixel values, the variable contained in equations (19) and (20) is only the mixture ratio a. The relationship among C, N, and P in equations (19) and (20) is shown in Fig. 52. C is the pixel value of the designated pixel in frame #n for which the mixture ratio a is calculated. N is the pixel value of the pixel in frame #n+l located at the position spatially corresponding to the designated pixel. P is the pixel value of the pixel in frame #n-l located at the position spatially corresponding to the designated pixel.
Accordingly, since one variable is contained in each of equations (19) and (20), the mixture ratio a is calculated by utilizing the pixels in the three frames. The condition for solving the correct mixture ratio a by solving equations (19) and (20) is as follows. In the image object having the same foreground components in the mixed area, i.e., in the image object of the foreground which is captured when the foreground object is stationary, the pixel values of the consecutive pixels positioned at the boundary of the image object corresponding to the moving direction of the foreground object, the number of pixels being two times the amount of movement v, must be uniform.
As discussed above, the mixture ratio a of the pixels belonging to the covered background area is calculated by equation (21), and the mixture ratio a of the pixels


belonging to the uncovered background area is calculated by equation (22).
α - (C-N)/(P-N) (21)
α = (C-P)/(N-P) (22)
Fig. 53 is a block diagram illustrating the configuration of the estimated-mixture-ratio processor 401. A frame memory 421.stores an input image in the units of frames, and supplies the frame subsequent to the frame which is input as the input image to a frame memory 422 and a mixture-ratio calculator 423.
A frame memory 422 stores an input image in the units of frames, and supplies the frame subsequent to the frame supplied from the frame memory 421 to the mixture-ratio
■a
calculator 423.
Accordingly, when frame #n+l is input into the mixture-ratio calculator 423 as the input image, the frame memory 421 supplies frame #n to the mixture-ratio calculator 423, and the frame memory 422 supplies frame #n-l to the mixture-ratio calculator 423.
The mixture-ratio calculator 423 calculates the estimated mixture ratio of the designated pixel by solving equation (21) based on the pixel value C of the designated pixel in frame #n, the pixel value N of the pixel in frame #n+l located at the position corresponding to the position of the designated pixel, and the pixel value P of the pixel


#n-l located at the position corresponding to the position of the designated pixel, and outputs the calculated estimated mixture ratio. For example, when the background is stationary, the mixture-ratio calculator 423 calculates the estimated mixture ratio of the designated pixel based on the pixel value C of the designated pixel in frame #n, the pixel value N of the pixel in frame #n+l located at the same position as the designated pixel, and the pixel value P of the pixel in frame #n-l located at the same position as the designated pixel, and outputs the calculated estimated mixture ratio.
In this manner, the estimated-mixture-ratio calculator 401 calculates the estimated mixture ratio based on the input image, and supplies it to the mixture-ratio determining portion 403,
The estimated-mixture-ratio calculator 401 calculates the estimated mixture ratio of the designated pixel by solving equation (21). The operation of the estimated-mixture-ratio calculator 402 is similar to that of the estimated-mixture-ratio calculator 401, except that the estimated-mixture-ratio calculator 402 calculates a different estimated mixture ratio of the designated pixel by solving equation (22) . Thus, an explanation of the estimated-mixture-ratio calculator 402 is omitted.
Fig. 54 illustrates an example of the estimated mixture


ratio calculated by the estimated-mixture-ratio processor 401. The estimated mixture ratio shown in Fig. 54 is the result represented by one line when the amount of movement v of the foreground object moving with constant velocity is 11.
It is seen, as shown in Fig. 48, that the estimated mixture ratio changes almost linearly in the mixed area.
Referring back to Fig. 47, the mixture-ratio determining portion 403 sets the mixture ratio a based on the area information supplied from the area specifying unit 103 and indicating to which of the foreground area, the background area, the covered background area, or the uncovered background area the pixel for which the mixture ratio a is to be calculated belongs. The mixture-ratio determining portion 403 sets the mixture ratio a to 0 when the corresponding pixel belongs to the foreground area, and sets the mixture ratio a to 1 when the corresponding pixel belongs to the background area. When the corresponding pixel belongs to the covered background area, the mixture-ratio determining portion 403 sets the mixture ratio a to the estimated mixture ratio supplied from the estimated-mixture-ratio processor 401. When the corresponding pixel belongs to the uncovered background area, the mixture-ratio determining portion 403 sets the mixture ratio a to the estimated mixture ratio supplied from the estimated-mixture-ratio processor 402. The mixture-ratio determining portion


403 outputs the mixture ratio a which has been set based on the area information.
Fig. 55 is a block diagram illustrating another configuration of the mixture-ratio calculator 104. A selector 441 supplies a pixel belonging to the covered background area and the corresponding pixels in the previous and subsequent frames to an estimated-mixture-ratio processor 442 based on the area information supplied from the area specifying unit 103. The selector 441 supplies a pixel belonging to the uncovered background area and the corresponding pixels in the previous and subsequent frames to an estimated-mixture-ratio processor 443 based on the area information supplied from the area specifying unit 103.
The estimated-mixture-ratio processor 442 calculates the estimated mixture ratio of the designated pixel belonging to the covered background area by the calculation expressed in equation (21) based on the pixel values input from the selector 441, and supplies the calculated estimated mixture ratio to a selector 444.
The estimated-mixture-ratio processor 443 calculates the estimated mixture ratio of the designated pixel belonging to the uncovered background area by the calculation expressed in equation (22) based on the pixel values input from the selector 441, and supplies the calculated estimated mixture ratio to the selector 444.


Based on the area information supplied from the area specifying unit 103, the selector 444 selects the estimated mixture ratio 0 and sets it as the mixture ratio a when the designated pixel belongs to the foreground area, and selects the estimated mixture ratio 1 and sets it as the mixture ratio a when the designated pixel belongs to the background area. When the designated pixel belongs to the covered background area, the selector 444 selects the estimated mixture ratio supplied from the estimated-mixture-ratio processor 442 and sets it as the mixture ratio a. When the designated pixel belongs to the uncovered background area, the selector 444 selects the estimated mixture ratio supplied from the estimated-mixture-ratio processor 443 and sets it as the mixture ratio a. The selector 444 then outputs the mixture ratio a which has been selected and set based on the area information.
As discussed above, the mixture-ratio calculator 104 configured as shown in Fig. 55 is able to calculate the mixture ratio a for each pixel contained in the image, and outputs the calculated mixture ratio a.
The calculation processing for the mixture ratio a performed by the mixture-ratio calculator 104 configured as shown in Fig. 47 is discussed below with reference to the flowchart of Fig. 56. In step S401, the mixture-ratio calculator 104 obtains area information supplied from the


area specifying unit 103. In step S402, the estimated-mixture-ratio processor 401 executes the processing for estimating the mixture ratio by using a model corresponding to a covered background area, and supplies the estimated mixture ratio to the mixture-ratio determining portion 403. Details of the processing for estimating the mixture ratio are discussed below with reference to the flowchart of Fig. 57.
In step S403, the estimated-mixture-ratio processor 402 executes the processing for estimating the mixture ratio by using a model corresponding to an uncovered background area, and supplies the estimated mixture ratio to the mixture-ratio determining portion 403.
In step S404, the mixture-ratio calculator 104 determines whether the mixture ratios have been estimated for the whole frame. If it is determined that the mixture ratios have not yet been estimated for the whole frame, the process returns to step S402, and the processing for estimating the mixture ratio for the subsequent pixel is executed.
If it is determined in step S404 that the mixture ratios have been estimated for the whole frame, the process proceeds to step S405. In step S405, the mixture-ratio determining portion 403 sets the mixture ratio based on the area information supplied from the area specifying unit 10;3


and indicating to which of the foreground area, the background area, the covered background area, or the uncovered background area the pixel for which the mixture' ratio a is to be calculated belongs. The mixture-ratio determining portion 403 sets the mixture ratio a to 0 when the corresponding pixel belongs to the foreground,area, and sets the mixture ratio a to 1 when the corresponding pixel belongs to the background area. When the corresponding pixel belongs to the covered background area, the mixture-ratio determining portion 403 sets the estimated mixture ratio supplied from the estimated-mixture-ratio processor 401 as the mixture ratio a. When the corresponding pixel belongs to the uncovered background area, the mixture-ratio determining portion 403 sets the estimated mixture ratio supplied from the estimated-mixture-ratio processor 402 as the mixture ratio a. The processing is then completed.
As discussed above, the mixture-ratio calculator 104 is able to calculate the mixture ratio a, which indicates a feature quantity corresponding to each pixel, based on the area information supplied from the area specifying unit 103, and-the input image.
The processing for calculating the mixture ratio a performed by the mixture-ratio calculator 104 configured as shown in Fig. 55 is similar to that discussed with reference to the flowchart of Fig. 56, and an explanation thereof is


thus omitted.
A description is now given of, with reference to the flowchart of Fig. 57, the mixture-ratio estimating processing by using a model corresponding to the covered background area in step S402 of Fig. 56.
In step S421, the mixture-ratio calculator 423 obtains the pixel value C of the designated pixel in frame #n from the frame memory 421.
In step S422, the mixture-ratio calculator 423 obtains from the frame memory 422 the pixel value P of the pixel in frame #n-l corresponding to the designated pixel contained in the. input image.
In step S423, the mixture-ratio calculator 423 obtains the pixel value N of the pixel in frame #n+l corresponding to the designated pixel contained in the input image.
In step S424, the mixture-ratio calculator 423 calculates the estimated mixture ratio based on the pixel value C of the designated pixel in frame #n, the pixel value P of the pixel in frame #n-l, and the pixel value N of the pixel in frame #n+l.
In step S425, the mixture-ratio calculator 423 determines whether the processing for calculating the estimated mixture ratio is finished for the whole frame. If it is determined that the processing for calculating the estimated mixture ratio is not finished for the whole frame,


the process returns to step S421, the processing for calculating the estimated mixture ratio for the subsequent pixel is repeated.
If it is determined in step S425 thajt the processing for calculating the estimated mixture ratio for the whole frame is finished, the processing is completed. ,
As discussed above, the estimated-mixture-ratio processor 401 is able to calculate the estimated mixture ratio based on the input image.
The mixture-ratio estimating processing performed by using a model corresponding to the uncovered background area in step S403 of Fig. 56 is similar to the processing indicated by the flowchart of Fig. 57 performed by using a model corresponding to the uncovered background area, and an explanation thereof is thus omitted.
The estimated-mixture-ratio processor 442 and the estimated-mixture-ratio processor 443 shown in Fig. 55 calculate the estimated mixture ratios by performing processing similar to that of the flowchart of Fig. 57, and an explanation thereof is thus omitted.
The embodiment has been described, assuming that the object corresponding to the background is stationary. However, the above-described processing for determining the mixture ratio a can be applied even if the image corresponding to the background area contains motion. For


example, if the image corresponding to the background area is uniformly moving, the estimated-mixture-ratio processor 401 shifts the overall image in accordance with the motion of the background, and performs processing in a manner similar to the case in which the object corresponding to the background is stationary. If the image corresponding to the background area contains locally different motions, the estimated-mixture-ratio processor 401 selects the pixels corresponding to the motions as. the corresponding pixels belonging to the mixed area, and executes the above-described processing.
The estimated-mixture ratio calculator 104 may execute only the mixture-ratio estimating processing for all the pixels by using a model corresponding to the covered background area so as to output the calculated estimated mixture ratio as the mixture ratio a. In this case, the mixture ratio a indicates the ratio of the background components for the background components of the pixels belonging to the covered background area, and indicates the ratio of the foreground components for the pixels belonging to the uncovered background area. For the pixels belonging to the uncovered background area, the absolute value of the difference between the mixture ratio a and 1 is calculated, and the calculated absolute value is set as the mixture ratio a. Then, the signal processing apparatus is able to

(H1

determine the mixture ratio a indicating the ratio of the background components for the pixels belonging to the uncovered background area.
Similarly, the mixture-ratio calculator 104 may execute only the mixture-ratio estimating processing for all the pixels by using a model corresponding to the uncovered background area so as to output the calculated estimated mixture ratio as the mixture ratio a.
Another processing performed by the mixture-ratio calculator 104 is discussed below.
The mixture ratio a linearly changes in accordance with a change in the position of the pixels because the object corresponding to the foreground is moving with .constant . velocity. By utilizing this characteristic, an equation in which the mixture ratio a and the sum f of the foreground components are approximated in the spatial direction can hold true. By utilizing a plurality of sets of the pixel values of the pixels belonging to the mixed area and the pixel values of the pixels belonging to the background area, the equations in which the mixture ratio a and the sum f of the foreground components are approximated are solved, thereby calculating the .mixture ratio a.
When a change in the mixture ratio a is approximated as a straight line, the mixture ratio a can be expressed by equation (23).
15 0

α = il + p (23)
In equation (23), i indicates the spatial index when the position of the designated pixel is set to 0, 1 designates the gradient of the straight line of the mixture ratio a, and p designates the intercept of the straight line of the mixture ratio a and also indicates the mixture ratio a of the designated pixel. In equation (23), the index i is known, and the gradient 1 and the intercept p are unknown.
The relationship among the index i, the gradient 1, and the intercept p is shown in Fig. 58.
By approximating the mixture ratio a as equation (23), a plurality of different mixture ratios a for a plurality of pixels can be expressed by two variables. In the example shown in Fig. 58, the five mixture ratios for five pixels are expressed by the two variables, i.e., the gradient 1 and the intercept p.
When the mixture ratio a is approximated in the plane shown in Fig. 59, equation (23) is expanded into the plane by considering the movement v corresponding to the two directions, i.e., the horizontal direction and the vertical direction of the image, and the mixture ratio a can be expressed by equation (24).
α = jm + kq + p (24)
In equation (24), j is the index in the horizontal direction and k is the index in the vertical direction when the
151

position of the designated pixel is 0. In equation (24), m designates the horizontal gradient of the mixture ratio a in the plane, and q indicates the vertical gradient of the mixture ratio a. in the plane. In equation (24), p indicates the intercept of the mixture ratio a in the plane.
For example, in frame #n shown in Fig. 49, equations (25) through (27) can hold true for C05 through C07, respectively.
C05 = α05-B05/v+f05 (25)
C06 = α06-B06/v+f06 (26)
C07 = α07-B07/v+f07 (27)
Assuming that the foreground components positioned in close proximity with each other are equal to each other, i.e., that F01 through F03 are equal, equation'(28) holds true by -replacing F01 through F03 by fc.
f (x) = (l-α(x)) -Fc (28)
In equation (28), x indicates the position in the spatial direction.
When a(x) is replaced by equation (24), equation (28) can be expressed by equation (29). f (x) = (l-(jm+kq+p) ) -Fc
= j • (-m-Fc)+k- (-q-Fc) + ( (1-p) -Fc)
= js+kt+u (29)
In equation (29),. (-m-Fc), (-q-Fc), and (1-p)-"Fc are replaced, as expressed by equations (30) through (32),
152

respectively.
s = -m-Fc (30)
t = -q-Fc (31)
u = (1-p)-Fc (32)
In equation (29), j is the index in the horizontal
direction and k is the index in the vertical direction when
the position of the designated pixel is 0.
As discussed above, since it can be assumed that the
object corresponding to the foreground is moving with
constant velocity within the shutter time, and that the
foreground components positioned in close proximity with
each other are uniform, the sum of the foreground components
can be approximated by equation (29).
When the mixture ratio a is approximated by a straight
line, the sum of the foreground components can be expressed
by equation (33).
f(x) = is + u (33)
By replacing the mixture ratio a and the sum of the
foreground components in equation (13) by using equations
(24) and (29), the pixel value M can be expressed by
equation (34) .
M = (jm+kq+p)'B+js+kt+u
= jB-m+kB-q+B-p+j-s+k-t+u (34)
In equation (34), unknown variables are six factors, such as the horizontal gradient m of the mixture ratio a in
I53

the plane, the vertical gradient q of the mixture ratio a in the plane, and the intercepts of the mixture ratio a in the plane, p, s, t, and u.
The pixel value M and the pixel value B are set in equation (34) in accordance with the pixels close to the designated pixel, and then, a plurality of equations in which the pixel value M and the pixel value B are set are solved by the method of least squares, thereby calculating the mixture ratio a.
It is now assumed, for example, that the horizontal index j of the designated pixel is set to 0, and the vertical index k of the designated pixel is set to 0. In this case, when the pixel value M or the pixel value B is set in the normal equation expressed by equation (34) for 3x3 pixels located in the proximity with the designated pixel, equations (35) through (43) are obtained. M_lf_! = (-1) 'B.li_1-m+[-l) •B_1/_1-q+B_1/_1-p+(-l) -s+(-l) • t+u
(35) M,,,-! = (0) •B0/.1-m+(-l) •B0/_1-q+B0,_i-p+(0) -s+(-l) -t+u (36) M+i,-i = ( + D -B+1/_x-m+(-l) •B+1/_1«q+B+1/_1-p+( + l) -s+(-l) -t+u
(37)
M_1#0 = (-1) -B_1/O-m+(0) -B_1/0-q+B_1/0-p+(-l) -s+(0) -t+u (38)
M0#0 = (0) ■B0,0-m+(0) -B0/0'q+B0/0-p+(0) -s+(0) -t+u (39)
M+i,o =■ ( + D •B+lf0-m+(0) •B+1/0*q+B+1,0-P+( + l) -s+(0) -t+u (40) M_1/+1 = (-1) •B_1(+1-m+(+l) •B_1/+1-q+B_lf+1-p+(-l) -s+(+l) -t+u
154

(41)

. (43) Since the horizontal index j of the designated pixel is 0, and the vertical index k of the designated pixel is 0, the mixture ratio a of the designated pixel is equal to the value when j is 0 and k is 0 in equation (24), i.e., the mixture ratio a is equal to the intercept p in equation (24).
Accordingly, based on the nine equations, i.e., equations (35) through (43), the horizontal gradient m, the vertical gradient q, and the intercepts p, s, t, and u are calculated by the method of least squares, and the intercept p is output as the mixture ratio a.
A specific process for calculating the mixture ratio a by applying the method of least squares is as follows.
When the index i and the index k are expressed by a
single index x, the relationship among the index i, the
index k, and the index x can be expressed by equation (44).
x = (j + 1) -3+(k+l) (44)
It is now assumed that the horizontal gradient m, the vertical gradient q, and the intercepts p, s, t, and u are expressed by variables wO, wl, w2, w3, w4, and w5, respectively, and jB, kB, B, j, k and 1 are expressed by aO, al, a2, a3, a4, and a5, respectively. In consideration of


For example, the sweep-out method (Gauss-Jordan elimination) is applied to the normal equations consisting of six equations obtained by substituting one of the integers from 0 to 5 into v in equation (49), thereby obtaining wy. As stated above, wO is the horizontal gradient m, wl is the vertical gradient q, w2 is %he intercept p, w3 is s, w4 is t, and w5 is u.
As discussed above, by applying the method of least squares to the equations in which the pixel value M and the pixel value B are set, the horizontal gradient m, the vertical gradient q, and the intercepts p, s, t, and u can be determined.
Since the intercept p is positioned at the point when
■a
the indexes i and k are 0, i.e., the mixture ratio a at the central position, it is output.
A description has been given with reference to equations (35) through (43), by assuming that the pixel value of the pixel contained in the mixed area is M, and the pixel value of the pixel contained in the background area is B. In this case, it is necessary to set normal equations for each of the cases where the designated pixel is contained in the covered background area, or the designated pixel is contained in the uncovered background area.
For example, if.the mixture ratio a of the pixel contained in the covered background area in frame #n shown
157

in Fig. 49 is determined, C04 through C08 of the pixels in frame #n and the pixel values P04 through P08 of the pixels in frame #n-l are set in the normal equations.
If the mixture ratio a of the pixels contained in the uncovered background area in frame #n shown in Fig. 50 is determined, C28 through C32 of the pixels in frame #n and the pixel values N28 through N32 of the pixels in frame #n+l are set in the normal equations.
Moreover, if, for example, the mixture ratio a of the pixel contained in the covered background area shown in Fig. 60 is calculated, the following equations (50) through (58) are set. The pixel value of the pixel for which the mixture ratio a is calculated is Mc5.
Mel = (-1) -Bcl-m+(-l)-Bcl-q+Bcl-p+f-l) -s+(-l) -t+u (50) Mc2 = (0) •Bc2-m+(-l) -Bc2-.q+Bc2'p+(0) -s+(-l) «t+u (51) Mc3 = (+1)■Bc3-m+(-l)-Bc3•q+Bc3-p+(+1)-s+(-l)-t+u (52) Mc4 = (-1) •Bc4-m+(0) -Bc4•q+Bc4-p+(-1) •s+ (0) -t+u (53) Mc5 - (0)-Bc5-m+(0)-Bc5-q+Bc5-p+(0)-s+(0)-t+u (54) Mc6 = (+1)'Bc6-m+(0)-Bc6-q+Bc6-p+(+1)-s+(0)-t+u (55) Mc7 = (-1)-Bc7'm+(+l)-Bc7-q+Bc7-p+(-l)-s+(+l)-t+u (56) Mc8 = (0) -Bc8-m+( + 1) -Bc8•q+Bc8-p+(0) -s+( + l) -t+u (57) Mc9 = (+1)-Bc9-m+(+1)\Bc9-q+Bc9-p+(+1)•s+(+1)-t+u (58)
When the mixture ratio a of the pixel contained in the covered background area in frame #n is calculated,, the pixel values Bel through Bc9 of the pixels of the background area


in frame #n-l in equations (50) through (58), respectively, corresponding to the pixels in frame #n are used.
.If, for example, the mixture ratio a of the pixel contained in the uncovered background area shown in Fig. 60 is calculated, the following equations (59) through (67) are set. The pixel value of the pixel for which the mixture ratio a is calculated is Mu5.
Mul = (-1) •Bul-nH-(-l) •Bul-q+Bul-p+(-l) -s+(-l) -t+u (59) Mu2 = (0) -Bu2-m+(-1)-Bu2-q+Bu2-p+(0) -s+(-1) -t+u (60) Mu3 = (+1)-Bu3-m+(-l)-Bu3-q+Bu3-p+(+1)-s+(-l)-t+u (61) Mu4 = (-1)-Bu4-m+(0) •B.u4-q+Bu4-p+(-l) -s+(0)-t+u (62) Mu5 = (0)-Bu5-m+(0)-Bu5-q+Bu5-p+(0)•s+(0)-t+u (63) Mu6 = (+1)-Bu6-m+(0)-Bu6-q+Bu6-p+(+l)-s+(0)-t+u (64) Mu7 = (-1)-Bu7-m+(+l)-Bu7-q+Bu7-p+(-l)-s+(+l)-t+U (65) Mu8 = (0)-Bu8-m+(+l)-Bu8•q+Bu8-p+(0)-s+( + l)-t+u (66) Mu9 = (+1)-Bu9-m+(+l)-Bu9-q+Bu9-p+(+l)-s+(+l)-t+u (67)
When the mixture ratio a of the pixel contained in the uncovered background area in frame #n is calculated, the pixel values Bui through Bu9 of the pixels of the background area in frame #n+l in equations (59) through (67), respectively, corresponding to the pixels in frame #n are used.
Fig. 61 is a block diagram illustrating the configuration of the estimated-mixture-ratio processor 401. An image input into the estimated-mixture-ratio processor
159

401 is supplied to a delay portion 501 and an adder 502.
A delay circuit 221 delays the input image for one frame, and.supplies the image to the adder 502. When frame #n is supplied as the input image to the adder 502, the delay circuit 221 supplies frame #n-l to the adder 502.
The adder 502 sets the pixel value of the pixel adjacent to the pixel for which the mixture ratio a is calculated, and the pixel value of frame #n-l in the normal equation. For example, the adder 502 sets the pixel values Mel through Mc9 and the pixel values Bel through Bc9 in the normal equations based on equations (50) through (58), respectively. The adder 502 supplies the normal equations in which the pixel values are set to a calculator 503.
The calculator 503 determines the estimated mixture ratio by solving the normal equations supplied from the adder 502 by, for example, a sweep-out method, and outputs the determined estimated mixture ratio.
In this manner, the estimated-mixture-ratio processor 401 is able to calculate the estimated mixture ratio based on the input image, and supplies it to the mixture-ratio determining portion 403.
The estimated-mixture-ratio processor 402 is configured similar to the estimated-mixture-ratio processor 401, and an explanation thereof is thus omitted-
Fig. 62 illustrates an example of the estimated mixture


ratio calculated by the estimated-mixture-ratio processor 401. The estimated mixture ratio shown in Fig. 62 is the result represented by one line and obtained by performing the calculation by generating equations in units of 7x7-pixel blocks when the movement v of the foreground corresponding to the object moving with constant yelocity is 11.
The estimated mixture ratio changes almost linearly in the mixed area, as shown in Fig. 48.
The mixture-ratio determining portion 403 sets the mixture ratio based on the area information supplied from the area specifying unit 101 and indicating to which of the foreground area, the background area, the covered background area, or the uncovered background area the pixel for Which the mixture ratio a is to be calculated belongs. The mixture-ratio determining portion 403 sets the mixture ratio to 0 when the corresponding pixel belongs to the foreground area, and sets the mixture ratio to 1 when the corresponding pixel belongs to the background area. When the corresponding pixel belongs to the covered background area, the mixture-ratio determining portion 403 sets the mixture ratio to the estimated mixture ratio supplied from-the estimated-mixture-ratio processor 401. When the corresponding pixel belongs to the uncovered background area, the mixture-ratio determining portion 403 sets the mixture


ratio to the estimated mixture ratio supplied from the estimated-mixture-ratio processor 402. The mixture-ratio determining portion 403 outputs the mixture ratio which has been set based on the area information.
The calculation processing for the mixture ratio performed by the mixture-ratio calculator 102 when the estimated-mixture-ratio processor 401 is configured as shown in Fig. 61 is discussed below with reference to the flowchart of Fig. 63. In step S501, the mixture-ratio calculator 102 obtains area information supplied from the area specifying unit 101. In step S502, the estimated-mixture-ratio processor 401 executes the processing for estimating the mixture ratio by using a model corresponding to a covered background area, and supplies the 'estimated mixture ratio to the mixture-ratio determining portion 403. Details of the processing for estimating the mixture ratio are discussed below with reference to the flowchart of Fig. 64.
In step S503, the estimated-mixture-ratio processor 402 executes the processing for estimating the mixture ratio by using a model corresponding to an uncovered background area, and supplies the estimated mixture ratio to the mixture-ratio determining portion 403.
In step S504, the mixture-ratio calculator 102 determines whether the mixture ratios have been estimated


for the whole frame. If it is determined that the mixture ratios have not yet been estimated for the whole frame, the process returns to step S502, and the processing for estimating the mixture ratio for the subsequent pixel is executed.
If it is determined in step S504 that the mixture ratios have been estimated for the whole frame, the process proceeds to step S505. In step S505, the mixture-ratio determining portion 403 sets the mixture ratio, based on the area information supplied from the area specifying unit 101 and indicating to which of the foreground area, the background area, the covered background area, or the uncovered background area the pixel for which the mixture ratio is to be calculated belongs. The mixture-ratio determining portion 403 sets the mixture ratio to .0 when the corresponding pixel belongs to the foreground area, and sets the mixture ratio to 1 when the corresponding pixel belongs to the background area. When the corresponding pixel belongs to the covered background area, the mixture-ratio determining portion 403 sets the estimated mixture ratio supplied from the estimated-mixture-ratio processor 401 as the mixture ratio. When the corresponding pixel belongs to the uncovered background area, the mixture-ratio determining portion 403 sets the estimated mixture ratio supplied from the estimated-mixture-ratio processor 402 as the mixture


ratio. The processing is then completed.
As discussed above/ the mixture-ratio calculator 102 is
able to calculate the mixture ratio a, which indicates a
feature quantity corresponding to each pixel, based on the
area information supplied from the area specifying unit 101,
and the input image. ,
By using the mixture ratio a, it is possible to separate the foreground components and the background components contained in the pixel value while maintaining the information of the motion blur contained in the image corresponding to the moving object.
If the image is synthesized based on the mixture ratio a, it is possible to create an image containing motion blur that matches the speed of the moving object which faithfully reflects the real world.
A description is now given of, with reference to the flowchart of Fig. 64, the mixture-ratio estimating processing by using a model corresponding to the covered background area in step S502 of Fig. 63.
In step S521, the adder 502 sets the pixel value contained in the input image and the pixel value contained in the image supplied from the delay circuit 221 in a normal equation corresponding to a model of the covered background area.
In step S522, the estimated-mixture-ratio processor 401


determines whether the setting of the target pixels is finished. If it is determined that the setting of the target pixels is not finished, the process returns to step S521, and the processing for setting the pixel values in the normal equation is repeated.
If it is determined in step S522 that the setting for the target pixels is finished, the process proceeds to step S523. In step S523, a calculator 173 calculates the estimated mixture ratio based on the normal equations in which the pixels values are set, and outputs the calculated mixture ratio.
As discussed above, the estimated-mixture-ratio processor 401 is able to calculate the estimated mixture ratio based on the input image.
The mixture-ratio estimating processing by using a model corresponding to the uncovered background area in step S153 of Fig. 63 is similar to the processing indicated by the flowchart of Fig. 64 by using the normal equations corresponding to a model of the uncovered background area, and an explanation thereof is thus omitted.
The embodiment has been described, assuming that the object corresponding to the background is stationary. However, the above-described mixture-ratio calculation processing can be applied even if the image corresponding to the background area contains motion. For example, if the


image corresponding to the background area is uniformly moving, the estimated-mixture-ratio processor 401 shifts the overall image in accordance with this motion, and performs processing in a manner similar to the case in which the object corresponding to the background is stationary. If the image corresponding to the background area contains locally different motions, the estimated-mixture-ratio processor 401 selects the pixels corresponding to the motions as the pixels belonging to the mixed area, and executes the above-described processing.
The foreground/background separator 105 is discussed below. Fig. 65 is a block diagram illustrating an example of the configuration of the foreground/background separator 105. The input image supplied to the foreground/background separator 105 is supplied to a separating portion 601, a switch 602, and a switch 604. The area information supplied from the area specifying unit 103 and indicating the information of the covered background area and the uncovered background area is supplied to the separating portion 601. The area information indicating the foreground area is supplied to the switch 602. The area information indicating the background area supplied to the switch 604.
The mixture ratio a supplied from the mixture-ratio calculator 104 is supplied to the separating portion 601.
The separating portion 601 separates the foreground

components from the input image based on the area information indicating the covered background area, the area information indicating the uncovered background area, and the mixture ratio cc, and supplies the separated foreground components to a synthesizer 603. The separating portion 601 also separates the background components from the,input image, and supplies the separated background components to a synthesizer 605.
The switch 602 is closed when a pixel corresponding to the foreground is input based on the area information indicating the foreground area, and supplies only the pixels corresponding to the foreground contained in the input image to the synthesizer 603.
The switch 604 is closed when a pixel corresponding to the background is input based on the area information indicating the background area, and supplies only the pixels corresponding to the background contained in the input image to the synthesizer 605.
The synthesizer 603 synthesizes a foreground component image based on the foreground components supplied from the separating portion 601 and the pixels corresponding to the foreground supplied from the switch 602, and outputs the synthesized foreground component image. Since the foreground area and the mixed area do not overlap, the synthesizer 603 applies, for example, logical OR to the

foreground components and the foreground pixels, thereby synthesizing the foreground component image.
In the initializing processing executed at the start of the synthesizing processing for the foreground component image, the synthesizer 603 stores an image whose pixel values are all 0 in a built-in frame memory. Then/ in the synthesizing processing for the foreground component image, the synthesizer 603 stores the foreground component image (overwrites the previous image by the foreground component image). Accordingly, 0 is stored in the pixels corresponding to the background area in the foreground component image output from the synthesizer 603.
The synthesizer 605 synthesizes a background component image based on the background components supplied from the separating portion 601 and the pixels corresponding to the background supplied from the switch 604, and outputs the synthesized background component image. Since the background area and the mixed area do not overlap, the synthesizer 605 applies, for example, logical OR to the background components and the background pixels, thereby synthesizing the background component image.
In the initializing processing executed at the start of the synthesizing processing for the background component image, the synthesizer 605 stores an image whose pixel values are all 0 in a built-in frame memory. Then, in the


synthesizing processing for the background component image, the synthesizer 605 stores the background component image (overwrites the previous image by the background component image). Accordingly, 0 is stored in the pixels corresponding to the foreground area in the background component image output from the synthesizer 605. ,
Figs. 66A and 66B illustrate the input image input into the foreground/background separator 105 and the foreground component image and the background component image output from the foreground/background separator 105.
Fig. 66A is a schematic diagram of an image to be displayed, and Fig. 66B is a model in which pixels for one line corresponding to the image shown in Fig. 66A and containing pixels belonging to the foreground area, pixels belonging to the background area, and pixels belonging to the mixed area are expanded in the time direction.
As shown in Figs. 66A and 66B, the background component image output from the foreground/background separator 105 consists of the pixels belonging to the background area and the background components contained in the pixels of the mixed area.
As shown in Figs. 66A and 66B, the foreground component image output from the foreground/background separator 105 consists of the pixel belonging to the foreground area and the foreground components contained in the pixels of the


mixed area.
The pixel values of the pixels in the mixed area are separated into the background components and the foreground components by the foreground/background separator 105. The separated background components form the background component image together with the pixels belonging to the background area. The separated foreground components form the foreground component image together with the pixels belonging to the foreground area.
As discussed above, in the foreground component image, the pixel values of the pixels corresponding to the background area are set to 0, and significant pixel values are set in the pixels corresponding to the foreground area and the pixels corresponding to the mixed area. Similarly, in the background component image, the pixel values of the pixels corresponding to the foreground area are set to 0, and significant pixel values are set in the pixels corresponding to the background area and the pixels corresponding to the mixed area.
A description is given below of the processing executed by the separating portion 601 for separating the foreground components and the background components from the pixels belonging to the mixed area.
Fig. 67 illustrates a model of an image indicating foreground components and background components in two


frames including a foreground object moving from the left to the right in Fig. 67. in the model of the image.shown in Fig. 67, the amount of movement v is 4, and the number of virtual divided portions is 4.
In frame #n, the leftmost pixel and the fourteenth through eighteenth pixels from the left consist of only the background components &nd belong to the background area. In frame #n, the second through fourth pixels from the left contain the background components and the foreground components, and belong to the uncovered background area. In frame #n, the eleventh through thirteenth pixels from the left contain background components and foreground components, and belong to the coveted background area. In frame #n, the fifth through tenth pixels from the left consis't of only the foreground components, and belong to the foreground area.
In frame #n+l, the first through fifth pixels from the left and the eighteenth pixel from the left consist of only the background componerits, and belong to the background area. In frame #n+l, the sixth through eighth pixels from the left contain background components and foreground components, and belong to the uncovered background area. In frame #n+l, the fifteenth through seventeenth pixels from the left contain background components and foreground components, and belong to the covered background area. In frame #n+l, the ninth through fourteenth pixels from the left consist of only the


foreground components, and belong to the foreground area.
Fig. 68 illustrates the processing for separating the foreground components from the pixels belonging to the covered background area. In Fig. 68, al through al8 indicate mixture ratios of the individual pixels of frame #n. In Fig. 68, the fifteenth through seventeenth pixels from the left belong to the covered background area.
The pixel value C15 of the fifteenth pixel from the
left in frame #n can be expressed by equation (68):
C15 = Bl5/v+F09/v+F08/v+F07/v
= corresponding to another flat portion are removed from the pixels belonging to the foreground area.
In this manner, the pixels belonging to the foreground area and sandwiched by flat portions, from which the foreground components corresponding to the flat portions are i removed, are supplied from the unit-of-processing determining/classifying unit 1601 to the motion-blur eliminating unit 1602 together with the corresponding unit of processing.
The model-forming portion 1621 of the motion-blur eliminating unit 1602 forms, based on the unit of processing, a model for generating equations corresponding to the relationship between the pixels belonging to the foreground area and sandwiched by the flat portions, from which the foreground components corresponding to the flat portions are removed, and the remaining foreground components.
The model-forming portion 1621 supplies the generated model to the equation generator 1622.
The equation generator 1622 generates, based on the model supplied from the model-forming portion 1621, equations corresponding to the relationship between the


pixels belonging to the foreground area and sandwiched by the flat portions, from which the foreground components corresponding to the flat portions are removed, and the remaining foreground components.
For example, the relationships between the foreground components FlOl/v through F105/v and the pixel values are indicated by equations (139) through (147).

C101' = FlOl/v (139)
C102' = F101/v+F102/v (140)
CI 03' = F101/v+F102/v+F103/v (141)
C104* = F101/v+F102/v+F103/v+F104/v (142)
C105' = F101/v+F102/v+F103/v+F104/v+F105/v (143)
C106' = F102/v+F103/v+F104/v+F105/v (144)
C107' = F103/v+F104/v+F105/v "(145)
C108' = F104/v+F105/v (146)
C109' = F105/v (147)
The relationships between the foreground components FlOl/v through F105/v and the pixel values are indicated by equations (148) through (156).
C1151 = F115/V (148)
C116* - F115/v+F116/v (149)
C117' = F115/v+F116/v+F117/v (150)
C118' = F115/v+F116/v+F117/v+F118/v (151) C119' = F115/v+F116/v+F117/v+F118/v+F119/v (152) C120' = F116/v+F117/v+F118/v+F119/v (153)
236

(154) (155) (156)
C121' = F117/v+F118/v+F119/v C122" = F118/v+F119/v C123' = F119/V
The equation generator 1622 solves equations (139) through (147) and equations (148) through (156) in which the pixel values are set according to the method of least squares so as to obtain normal equations, for example, equations (157) and (158).


The equation generator 1622 generates equations based on the model supplied from the model-forming portion 1621, and supplies the generated equations to an adder 1623
237

together with the foreground component image.
The adder 1623 adds the equation supplied from the equation generator 1622 to the normal equations obtained by the method of least squares. The adder.1623 supplies the resulting normal equations to a calculator 1624.
The calculator 1624 calculates the foreground components contained in the foreground component image other than the foreground components contained in the pixels belonging to the flat portions by applying a solution, such as the Cholesky decomposition to the normal equations in which the pixel values are set. The calculator 1624 generates the foreground component image without motion blur based on the calculated foreground components, and outputs the foreground component image without motion blur.
For example, when the foreground components FlOl/v through F105/v and the foreground components F115/v through F119/v are determined, the calculator 1624 multiplies the foreground components FlOl/v through F105/v and the foreground components F115/v through F119/v by the amount of movement v, as shown in Fig. 109, thereby calculating the pixel values F101 through F105 and the pixel values F115 through F119, respectively.
The calculator 1624 generates a foreground component image without motion blur consisting of, for example, the pixel values F101 through F105 and the pixel values F115


through F119.
The processing for eliminating motion blur performed by the signal processing apparatus having the configuration shown in Fig. 94 is described below with reference to the flowchart of Fig. 110.
The processing of step S1101 through step S1103 is similar to that of stepsiOOl through step S1003 in Fig. 103, and an explanation thereof is thus omitted.
In step S1104, the unit-of-processing determining/classifying unit 1601 classifies the pixels of an input image based on the motion vector and the positional information thereof supplied from the motion detector 102, the area information supplied from the area specifying unit 103, and the foreground-flat-portion positional information supplied from the flat-portion extracting unit 1501, and supplies the classified pixels to one of the separating/blur-eliminating unit 1503, the motion-blur eliminating unit 1602, the foreground-component-image reproducing unit 1603, and the background-component-image reproducing unit 1604.
In step S1105, the separating/blur-eliminating unit 1503 performs simultaneous processing for separating the foreground and the background and for eliminating motion blur on the pixels belonging to the mixed area from which the foreground components corresponding to the flat portions


of the foreground area are removed, and the pixels belonging to the foreground area selected, among the pixels consecutively arranged in the moving direction from the pixel belonging to the uncovered background area to the pixel belonging to the covered background area. Details of the processing of step S1105 is similar to those of the processing of step S1004 of Fig. 103, and an explanation thereof is thus omitted.
In step S1106, the separating/blur-eliminating unit 1503 calculates the pixel values of the foreground component image without motion blur and the pixel values of the background component image based on the calculated foreground components and the background components. The separating/blur-eliminating unit 1503 supplies the foreground component image without motion blur to the foreground-component-image reproducing unit 1603, and also supplies the background component image to the background-component -image reproducing unit 1604.
In step S1107, the signal processing apparatus determines whether the processing for the mixed area and the foreground area has been finished. If it is determined that ;he processing for the mixed area and the foreground area las not been finished, the process returns to step S1105, md the processing for separating the foreground and the background and for eliminating motion blur is repeated.


If it is determined in step S1107 that the processing for the mixed area and the foreground area has been finished, the process proceeds to step S1108. In step S1108, the motion-blur eliminating unit 1602 performs processing for eliminating motion blur for the pixels belonging to the foreground area without the foreground components corresponding to flat portions and sandwiched by the flat portion selected among the pixels consecutively arranged in the moving direction. Details of the motion-blur eliminating processing are described below with reference to the flowchart of Fig. 111.
In step S1109, the motion-blur eliminating unit 1602 calculates the pixel values of the foreground component image without motion blur based on the calculated foreground components. The motion-blur eliminating unit 1602 supplies the foreground component image without motion blur to the foreground-component-image reproducing unit 1603.
In step S1110, the signal processing apparatus determines whether the processing for the foreground area has been finished. If it is determined that the processing of the foreground area has not been finished, the process returns to step S1108, and the motion-blur eliminating processing is repeated.
If it is determined in step S1110 that the processing has been finished for the foreground area, the process


proceeds to step Sllll.
It should be noted that the processing of step S1108 through SlllO is simultaneously executed with the processing of step SI105 through SI107.
In step Sllll, the foreground-component-image reproducing unit 1603 reproduces the overall foreground component image without motion blur based on the flat-portion image supplied from the unit-of-processing determining/classifying unit 1601, the foreground component image without motion blur supplied from the separating/blur-eliminating unit 1503, and the foreground component image without motion blur supplied from the motion-blur eliminating unit 1602. The background-component-image reproducing unit 1604 reproduces the overall background component image based on the background area image supplied from the unit-of-processing determining/classifying unit 1601 and the background component image separated from the separating/blur-eliminating unit 1503. The processing is then completed.
As described above, the information processing apparatus having the configuration shown in Fig. 105 is able to eliminate motion blur from the foreground object.
The processing for eliminating motion blur of the foreground component image, which corresponds to the unit of processing, performed by the motion-blur eliminating unit


1602 in step S1108 of Fig. 110 is described below with reference to the flowchart of Fig. 111.
In step S1121, the model-forming portion 1621 of the motion-blur eliminating unit 1602 forms a model corresponding to the amount of movement v and the unit of processing. In step S1122, the equation generator 1622 generates equations based on the generated model.
In step S1123, the adder 1623 sets the pixel values of the foreground component image from which the foreground components corresponding to the flat portions are removed in the generated equations. In step S1124, the adder 1123 determines whether the pixel values of all the pixels corresponding to the unit of processing have been set. If it is determined that the pixel values have not been set in all the equations, the process returns to step S1123, and the processing for setting the pixel values in the equations is repeated.
If it is determined in step S1124 that all the pixel values have been set in all the equations, the process proceeds to step S1125. In step S1125, the calculator 1624 calculates the pixel values of the foreground without motion blur based on the equations in which the pixel values are set supplied from the adder 1623.
As discussed above, the motion-blur eliminating unit 1602 is able to eliminate motion blur from the foreground


component image containing motion blur based on the amount of movement v and the unit of processing.
The invention has been discussed above by setting the mixture ratio a to the ratio of the background components contained in the pixel values. However, the mixture ratio a may be set to the ratio of the foreground components contained in the pixel values.
The invention has been discussed above by setting the moving direction of the foreground object to the direction from the left to the right. However, the moving direction is not restricted to the above-described direction.
A non-mixed area formed of a foreground area consisting of foreground object components which form a foreground object of image data and a background area consisting of background object components which form a background object of the image data, or a mixed area in which the foreground object components and the background object components area mixed is specified. Based on a result obtained by specifying the area, processing for separating the foreground object components and the background object components from the pixel data of the mixed area, and processing for eliminating motion blur from the separated foreground object components are simultaneously performed. In this case, motion blur contained in a blurred image can be eliminated.


An equal portion consisting of adjacent pixel data of the foreground area whose values are substantially equal to each other is detected. At least the processing for separating the foreground object components and the background object components from the pixel data of the mixed area and the processing for eliminating motion blur from the separated foreground object components can be simultaneously performed based on the detected equal portion and the result obtained by specifying the area.
A unit of processing consisting of a plurality of the foreground object components and the background object components is determined based on a position of the equal portion. The processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components can be simultaneously performed for each unit of processing.
The unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion can be determined.
The equal portion can be detected by comparing a difference of the pixel data with a threshold.
The equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to the


number of pixels corresponding to an amount of movement of the foreground object can be detected.
The processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components can be simultaneously performed by applying a calculation corresponding to a motion vector.
A model corresponding to the unit of processing and a motion vector is acquired. Based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in the unit of processing is generated. The foreground object components and the background object components contained in the unit of processing can be calculated based on the generated equation.
Image data having an object area consisting of object components which form an object is input. Motion blur occurring in an object area is eliminated by assuming that values of part of the pixel data in the object area of the image data input are substantially equal. In this case, motion blur contained in a blurred image can be eliminated.
The image data having a foreground area consisting of foreground object components which form the object, a background area consisting of background object components


which form a background object, and a mixed area in which the foreground object components and the background object components are mixed is input. Motion blur occurring in the foreground area can be eliminated by assuming that values of part of the pixel data in the foreground area of the input image data are substantially equal.
An equal portion in which the values of the pixel data in the foreground area of the image data are substantially equal is detected. Motion blur occurring in the foreground area can be eliminated based on the detected equal portion.
A unit of processing consisting of a plurality of the foreground object components is determined based on a position of the equal portion. Motion blur of the foreground area can be eliminated for each unit of processing.
The unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion can be determined.
The foreground area, the background area, or the mixed area can be specified.
The equal portion can be detected by comparing a difference of the pixel data with a threshold.
The equal portion consisting of the adjacent pixel data haying the number of pixels greater than or equal to the


number of pixels corresponding to an amount of movement of the foreground object can be detected.
Motion blur occurring in the foreground area can be eliminated by applying a calculation corresponding to a motion vector.
A model corresponding to the unit of processing and a motion vector is acquired. Based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components contained in the unit of processing is generated. The foreground object components contained in the unit of processing can be calculated based on the generated equation.
Processing for.separating the pixel data of the mixed area into the foreground object components and the background object components and processing for eliminating motion blur from the separated foreground object components can be simultaneously performed based on area information indicating a non-mixed area consisting of the foreground area and the background area or the mixed area and based on the equal portion.
A unit of processing consisting of a plurality of the foreground object components and the background object components is determined based on a position of the equal portion. The processing for separating the foreground object components and the background object components and


the processing for eliminating motion blur from the separated foreground object components can be simultaneously performed for each unit of processing.
The unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the' pixel data of the equal portion can be determined.
The foreground area, the background area, or the mixed area can be specified.
The equal portion can be detected by comparing a difference of the pixel data with a threshold.
The equal portion consisting of adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of the foreground object can be detected.
The processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components can be simultaneously performed by applying a calculation corresponding to a motion vector.
A model corresponding to the unit of processing and a motion vector is acquired. Based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in


the unit of processing is generated. The foreground object components and the background object components contained in the unit of processing can be calculated based on the generated equation.
A subject image captured by an image-capturing device including a predetermined number of pixels and having a time integrating function is output as image data formed of a predetermined number of pixel data. A non-mixed area formed of a foreground area consisting of foreground object components which form a foreground object of the image data and a background area consisting of background object components which form a background object of the image data, or a mixed area in which the foreground object components and the background object components area mixed is specified. Based on a result obtained by specifying the area, processing for separating the foreground object components and the background object components from the pixel data of the mixed area, and processing for eliminating motion blur from the separated foreground object components can be simultaneously performed. In this case, an image without motion blur can be captured.
An equal portion consisting of adjacent pixel data of the foreground area whose values are substantially equal to each other is detected. At least' the processing for separating the foreground object components and the


background object components from the pixel data of the mixed area and the processing for eliminating motion blur from the separated foreground object components can be simultaneously performed based on the detected equal portion and the result obtained by specifying the area.
A unit of processing consisting of a plurality of the foreground object components and the background object components is determined based on a position of the equal portion. For each unit of processing, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components can be simultaneously performed.
The unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion can be determined.
The equal portion can be detected by comparing a difference of the pixel data with a threshold.
The equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of the foreground object can be detected.
The processing for separating the foreground object components and the background object components and the


processing for eliminating motion blur from the separated foreground object components can be simultaneously performed by applying a calculation corresponding to a motion vector.
A model corresponding to the unit of processing and a
i ■ I motion vector is acquired. Based on the acquired model, an
equation corresponding to a relationship between the pixel
data of the unit of processing and the foreground object
components and the background object components contained in
the unit of processing is generated. The foreground object
components and the background object components contained in
the unit of processing can be calculated based on the
generated equation.
A subject image captured by an image-capturing device including a predetermined number of pixels and having a time integrating function is output as image data formed of a predetermined number of pixel data and having an object area consisting of object components which form an object. Motion blur occurring in the object area is eliminated by assuming that values of part of the pixel data in the object area of the image data are substantially equal. In this case, an image without motion blur can be captured.
The image data having a foreground area consisting of foreground object components which form the object, a background area consisting of background object components which form a background object, and a mixed area in which


the foreground object components and the background object components are mixed is input. Motion blur occurring in the foreground area can be eliminated by assuming that values of part of the pixel data in the foreground area of the input image data are substantially equal.
An equal portion in which the values of the pixel data in the foreground area of the image data are substantially equal is detected. Motion blur occurring in the foreground area can be eliminated based on the detected equal portion.
A unit of processing consisting of a plurality of the foreground object components is determined based on a position of the equal portion. Motion blur of the foreground area can be eliminated for each unit of processing.
The unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion can be determined.
The foreground area, the background area, or the mixed area can be specified.
The equal portion can be detected by comparing a difference of the pixel data with a threshold.
The equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of

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the foreground object can be detected.
Motion blur occurring in the foreground area can be eliminated by applying a calculation corresponding to a. motion vector.
A model corresponding to the unit of processing and a motion vector is acquired. Based on the acquired,model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components contained in the unit of processing is generated. The foreground object components contained in the unit of processing can be calculated based on the generated equation.
Processing for separating the pixel data of the mixed area into the foreground object components and the background object components and processing for eliminating motion blur from the separated foreground object components can be simultaneously performed based on area information indicating a non-mixed area consisting of the foreground area and the background area or the mixed area and based on the equal portion.
A unit of processing consisting of a plurality of the foreground object components and the background object components is determined based on a position of the equal portion. For each'unit of processing, the processing for separating the foreground object components and the background object components and the processing for

J?)

eliminating motion blur from the separated foreground object components can be simultaneously performed.
The unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion can be determined.
The foreground area, the background area, or the mixed area can be specified.
The equal portion can be detected by comparing a difference of the pixel data with a threshold.
The equal portion consisting of adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of the foreground object can be detected.
The processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components can be simultaneously performed by applying a calculation corresponding to a motion vector.
A model corresponding to the unit of processing and a motion vector is acquired. Based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in the unit of processing is generated. The foreground object


components and the background object components contained in the unit of processing can be calculated based on the generated equation.
In the above description, a real-space image having a three-dimensional space and time axis information is projected onto a time space having a two-dimensional space and time axis information by using a video camera. However, the present invention is not restricted to this example, and can be applied to the following case. When a greater amount of first information in one-dimensional space is projected onto a smaller amount of second information in a two-dimensional space, distortion generated by the projection can be corrected, significant information can be extracted, or a more natural image can be synthesized.
The sensor is not restricted to a CCD, and may be another type of sensor, such as a solid-state imaging device, for example, a CMOS (Complementary Mental-Oxide Semiconductor) image sensor, a BBD (Bucket Brigade Device), a CID (Charge Injection Device), or a CPD (Charge Priming Device). Also, the sensor does not have to be a sensor in which detection devices are arranged in a matrix, and may be a sensor in which detection devices are arranged "in one line.
A recording medium in which a program for performing the signal processing of the present invention is recorded may be formed of a package medium in which the program is

$S6

recorded, which is distributed for providing the program to a user separately from the computer, as shown in Fig. 1, such as the magnetic disk 51 (including a flexible disk), the optical disc 52 (CD-ROM (Compact Disc-Read Only Memory) and a DVD (Digital Versatile Disc)), the magneto-optical disk 53 (including MD (Mini-Disk)), or the semiconductor memory 54. The recording medium may also be formed of the ROM 22 or a hard disk contained in the storage unit 28 in which the program is recorded, such recording medium being provided to the user while being prestored in the computer.
The steps forming the program recorded in a recording medium may be executed chronologically according to the orders described in the specification. However, they do not
■x
have to be executed in a time-series manner, and they may be executed concurrently or individually.
Industrial Applicability
According to the first invention, it is possible to eliminate motion blur contained in a blurred image.
According to the second invention, it is possible to eliminate motion blur contained in a blurred image.
According to the third invention, it is possible to capture an image from which motion blur is eliminated.
According to the fourth invention, it is possible to capture an image from which motion blur is eliminated.


WE CLAIM:
1. An image processing apparatus for performing processing on image
data which is formed of a predetermined number of pixel data obtained
by an image-capturing device including a predetermined number of
pixels and having a time integrating function, said image processing
apparatus comprising:
area specifying means (103) for specifying a non-mixed area formed of a foreground area consisting of foreground object components which form a foreground object of the image data and a background area consisting of background object components which form a background object of the image data, or a mixed area in which the foreground object components and the background object components area mixed; and
processing execution means (1503) for simultaneously performing, based on a result obtained by specifying the area by said area specifying means (103), processing for separating the foreground object components and the background object components from the pixel data of the mixed area, and processing for eliminating motion blur from the separated foreground object components.
2. An image processing apparatus as claimed in claim 1, further
comprising equal-portion detection means (1501) for detecting an equal
portion consisting of adjacent pixel data of the foreground area whose
values are substantially equal to each other, wherein said processing
execution means (1503) simultaneously performs at least the processing
for
separating the foreground object components and the background object components from the pixel data of the mixed area and the processing for eliminating motion blur from the separated foreground object

2 3 JAN 2009

components based on the detected equal portion and the result obtained by specifying the area by said area specifying means (103).
3. An image processing apparatus as claimed in claim 2, further comprising unit -of-processing determining means (1502) for determining a unit of processing consisting of a plurality of the foreground object components and the background object components based on a position of the equal portion, wherein said processing execution means (1503) simultaneously performs, for each unit of processing, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components.
4. An image processing apparatus as claimed in claim 3, wherein said unit-of-processing determining means (1502) determines the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion.
5. An image processing apparatus as claimed in to claim 2, wherein said equal-portion detection means (1501) detects the equal portion by comparing a difference of the pixel data with a threshold.
6. An image processing apparatus as claimed in claim 2, wherein said equal-portion detection means (1501) detects the equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to-the number of pixels corresponding to an amount of movement of the foreground object.


2 3 JAN 2009

7. An image processing apparatus as claimed in claim 1, wherein said processing execution means (1503) simultaneously performs the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components by applying a calculation corresponding to a motion vector.
8. An image processing apparatus as claimed in claim 1, wherein said processing execution means (1503) comprises:
model acquiring means (1521) for acquiring a model corresponding to the unit of processing and a motion vector;
equation generating (1522) means for generating, based on the acquired model, an equation corresponding to a relationship between the pixel data of the unit of processing and the foreground object components and the background object components contained in the unit of processing; and
calculation means (1523) for calculating the foreground object components and the background object components contained in the unit of processing based on the generated equation.
9. An image processing method for performing processing on image
data which is formed of a predetermined number of pixel data obtained
by an image-capturing device including a predetermined number of
pixels and having a time integrating function, said image processing
method comprising:
an area specifying step of specifying a non-mixed area formed of a foreground area consisting of foreground object components which form a foreground object of the image data and a background area consisting of background object components which form a background object of the
2 3 JAN 2009


image data, or a mixed area in which the foreground object components and the background object components area mixed; and
a processing execution step of simultaneously performing, based on a result obtained by specifying the area by the processing of said area specifying step, processing for separating the foreground object components and the background object components from the pixel data of the mixed area, and processing for eliminating motion blur from the separated foreground object components.
10. An image processing method as claimed in claim 9, further comprising an equal-portion detection step of detecting an equal portion consisting of adjacent pixel data of the foreground area whose values are substantially equal to each other, wherein, in the processing of said processing execution step, at least the processing for separating the foreground object components and the background object components from the pixel data of the mixed area and the processing for eliminating motion blur from the separated foreground object components are simultaneously performed based on the detected equal portion and the result obtained by specifying the area by said area specifying step.
11. An image processing method as claimed in claim 10, further comprising a unit-of-processing determining step of determining a unit of processing consisting of a plurality of the foreground object components and the background object components based on a position of the equal portion, wherein, in the processing of said processing execution step, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components are simultaneously performed for each unit of processing.


13 JAN 2009

12. An image processing method as claimed in claim 11, wherein, in the processing of said unit-of-processing determining step, the unit of processing corresponding to the pixel data belonging to the mixed area or the foreground area which is located on one straight line and which is other than the pixel data of the equal portion is determined.
13. An image processing method as claimed in claim 10, wherein in the processing of said equal-portion detection step, the equal portion is detected by comparing a difference of the pixel data with a threshold.
14. An image processing method as claimed in claim 10, wherein, in the processing of said equal-portion detection step, the equal portion consisting of the adjacent pixel data having the number of pixels greater than or equal to the number of pixels corresponding to an amount of movement of the foreground object is detected.
15. An image processing method as claimed in claim 9, wherein, in the processing of said processing execution step, the processing for separating the foreground object components and the background object components and the processing for eliminating motion blur from the separated foreground object components are simultaneously performed by applying a calculation corresponding to a motion vector.
16. An image processing method as claimed in claim 9, wherein the processing of said processing execution step comprises;
a model acquiring step of acquiring a model corresponding to the unit of processing and a motion vector;
an equation generating step of generating, based on the acquired model, an equation corresponding to a relationship between the pixel


2 3 JAN 2009