Description
High Speed Image and Thermal Signature Acquisition using Low
Frame Rate Cameras
The embodiments herein generally relate to imaging systems
and methods, and more particularly to, image acquisition
using low resolution cameras.
High speed image acquisition is essential for diverse
applications, for instance, diagnostic applications,
inspection applications etc. Conventionally, high speed
cameras are used for high speed image acquisition. The high
speed image acquisition systems employs short exposure times
to minimize the image motion blur.
In conventional image acquisition systems, the image data
produced by the system are processed at various frame rates.
Generally, high speed cameras acquire image frames rapidly
and then perform read out for each frame captured. However,
frame capture rates are limited by read out times. Further,
the high speed cameras are prohibitively expensive, require
peripheral devices and also necessitate cooling at intervals.
The object of the invention is to reduce the cost of a high
speed image acquisition system and to enhance the quality of
images obtained during high speed capture.
These problems are solved by a method according to claim 1
and system according to claim 10.
In view of the foregoing, an embodiment herein provides an
improved high-frame rate image acquisition method and system.
The image acquisition is performed using a digital micro
mirror device placed between the imaging device, e.g. a
camera, and the scene. The method comprises controlling a

micro mirror device comprising a plurality of mirrors to
selectively toggle on and off the mirrors according to a
mirror pattern, reflecting light incident on the mirrors
which are toggled on to an imaging device, the imaging device
storing image frames at a given frame rate based on light
detected by an array of sensors and changing the mirror
pattern at a rate higher than frame rate of the imaging
device. The mirror patterns are selected in such a way that
the plurality of mirrors reflects light only to a subset of
the sensors at a given time. Thus embedding a high speed
micro mirror device enables the use of low cost imaging
devices to capture high speed images frames. Additionally,
this allows flexible image data rates and also shortening the
exposure time minimizes the motion blur between successive
image frames.
According to another embodiment herein, the mirror patterns
are changed to enable different subsets of the sensors to
acquire the image data at different instance of time. Each
time instant is a small interval in order to ensure
continuous and meaningful capture of high speed images. The
time separated image data thus obtained represents image
patterns indicating spatial displacement of the high speed
moving object.
According to another embodiment herein, the mirrors are
turned on in such a way that the sensors receive light only
one time during one cycle of the mirror pattern. This
prevents overlapping of image data in any pixel of the image
frame and helps in acquiring a clear picture of the object
without motion blur. The pattern of the sensors receiving
light at a given time is equally spaced on the array of
sensors. This allows the spatial distribution of light at the
sensor. The spatial light modulation and high speed of DMD
can then be leveraged to obtain high speed temporal
information of the image.

According to another embodiment herein, the image data is
captured during one cycle of the mirror pattern and the cycle
of the mirror patterns are repeated at finite intervals. This
helps in continuously acquiring image frames to detect the
displacement of the object at different instances. The image
data captured during a cycle of the mirror pattern are
retained on pixels corresponding to subsets of the sensors.
Further, different subsets of one of the image frames can be
correlated with each other to detect different positions of
an object at different times. This enables motion tracking of
fast moving objects.
According to another embodiment herein, the image frame is
composed of successive image patterns from each subset of the
array of sensors. This enables to increase the frame rate by
capturing a larger number of image patterns at different time
instances. Each image pattern shows the object at a different
instance of time.
Another embodiment disclosed herein provides a system for
acquiring high speed images with high resolution. The system
comprises of a micro mirror device comprising a plurality of
mirrors to selectively toggle on and off the mirrors
according to a mirror pattern, a reflecting means to reflect
light incident on the mirrors which are toggled on, an
imaging device storing image frames at a given frame rate
based on light detected by an array of sensors, and a means
for changing the mirror pattern at a rate higher than frame
rate of the imaging device. The system thus enables to detect
the rate of the image data and processes the image data at
higher frame rate to obtain high speed high quality images.

According to another embodiment., the system further comprises
of a program executable on a controller for the micro mirror
device performing at least one of determining the pattern of
the mirrors to reflect light to the imaging device and
changing pattern of the mirrors at a rate higher than frame
rate of the imaging device. This increases the system
throughput by transmitting image data only from within the
region of interest to the imaging device.
According to yet another embodiment, the imaging device
includes a Charge Coupled Device (CCD) configured to receive
reflected light and operative to output image data. This
increases the sensitivity of the imaging device to acquire
images at low lighting conditions. The imaging device
correlates different subsets of one of the image frames with
each other to detect different positions of an object at
different times. Further, the imaging device captures image
at different subsets of the image frame during a cycle of the
mirror pattern, where cycle of the mirror patterns are
repeated at finite intervals. The imaging device equally
space pattern of the sensors receiving light at a given time
on the array of sensors. This helps in spatial distribution
of light at a sensor in a preferred manner. Moreover, the
imaging device composes the image frame from successive image
patterns from each subset of the array of sensors, where the
image patterns captured during cycle of the mirror patterns
are retained on pixels of subsets of the sensor. The system
is thus capable of integrating high speed sub images and
displays the multiple image patterns as a single seamless and
continuous image in large formats and at high quality.

According to yet another embodiment, the image frame includes
subsets of pixels corresponding to subsets of the sensor
detecting light at a given time. An image frame can be
fractioned to a plurality of sub images each corresponding to
a different subset of sensors which have been exposed to
light at different times. This permits to obtain successive
image data at different time instances and thus restrains
image pattern from distortions or misalignments induced due
to motion of objects.
The present invention is further described hereinafter with
reference to illustrated embodiments shown in the
accompanying drawings, in which:
FIG 1 illustrates a perspective view of optical arrangement
of an image acquisition system in accordance with an
embodiment herein,
FIG 2 illustrates a schematic view of a micro mirror device
with a mirror pattern in accordance with an embodiment
herein,
FIG 3A-3D illustrates different mirror patterns of the micro
mirror device, in accordance with an embodiment
herein,
FIG 4 illustrates a pattern of an array of sensors at the
imaging device, in accordance with an embodiment
herein,
FIG 5A-5c illustrates an exemplary depiction of an image
frame, in accordance with an embodiment herein,

FIG 6A-6D illustrates another exemplary depiction of an image
acquisition process, in accordance with an embodiment
herein, and
FIG 7 illustrates a flow chart depicting the method of high
speed image acquisition, in accordance with an
embodiment herein.
Various embodiments are described with reference to the
drawings, wherein like reference numerals are used to refer
to like elements throughout. In the following description,
for purpose of explanation, numerous specific details are set
forth in order to provide a thorough understanding of one or
more embodiments. It may be evident that such embodiments may
be practiced without these specific details.
FIG 1 illustrates an image acquisition system 10 in
accordance with an embodiment herein. The arrangement
comprises of a micro mirror device 14 placed between the
imaging device 20 and an external scene, of which the image
is to be captured. The imaging acquisition system 10 can be
digital cameras, scanners, digital video cameras, or the
like. The light rays 11 from the scene are incident on a lens
12. The lens 12 then directs the light towards the micro
mirror device 14, where the micro mirror device 14 can be for
instance, a digital micro mirror device (DMD) chip. The micro
mirror device 14 comprises of a plurality of mirrors 16 which
can be toggled on and off in a brief period of time. Any
desired mirror pattern 24 can be loaded onto the micro mirror
device 14, where some of the mirrors 16 are turned on and
some others turned off. The mirrors patterns 24 (as shown in
FIG.3) can be depicted by using a controller 18 associated
with the micro mirror device 14.
The light ray 11 which impinges on the mirrors 16 which are
turned on reflects incident light onto an array of sensors 21

(refer FIG.4) of the imaging device 20. The pixels
corresponding to the sensors 2 L receiving light receives the
reflected light and register an intensity rise. In other
areas of the image frame 26 of FIG. 5, the light ray 11
impinging on the mirrors 16 which are turned off is reflected
onto a sink 22. An image pattern is then stored on the
sensors 21 at a given frame rate based on light detected by
an array of sensors 21. The image pattern follows the pattern
of the mirrors 16 which are turned on, reflecting light to
the sensors 21.
In an embodiment as illustrated in FIG. 1, the mirror
patterns 24 loaded on the micro mirror device 14 controls the
spatial distribution of light at the sensors 21. The mirror
patterns 24 are changed at intervals at a rate higher than
frame rate of the imaging device 20. The mirror patterns 24
are changed at different time instances in such a way that
the pixels corresponding to subsets of sensors 21 receive
light only once at one time instant. This prevents
overlapping of image data at the sensors 21 and hence quality
of image can be maintained high. Further, the cycle of mirror
patterns 24 are repeated at finite intervals to eliminate
motion blur and to obtain continuous and meaningful capture
of high speed images.
The image acquisition system 10 leverages the high speed of
the micro mirror device 14 and the spatial distribution of
the reflected light at the sensors 21 to obtain temporal
image data. The frame rate of the image frame 2 6 can be
increased by reducing the rate of change of mirror patters.
This helps in quick capturing of image data at different time
instance and hence providing high speed temporal information
about an image.
FIG 2 illustrates perspective view of a micro mirror device
14 with a mirror pattern 24 in accordance with an embodiment

herein. The micro mirror device 14 includes a plurality of
mirrors 16 which can be toggled on and off in a brief period
of time, for instance at intervals of 20 microseconds. The
mirrors 16 are toggled on and off according to a mirror
pattern 24 loaded on to the micro mirror device 14, where
some mirrors 16 are turned on end some mirrors 16 are turned
off. The mirror patterns 24 are depicted by using a
controller 18 with the micro mirror device 14. The micro
mirror device 14 is programmed to change the mirror patterns
24 at finite time intervals using the controller 18. The
mirror patterns 24 can be toggled on the micro mirror device
14 at a rate of 50,000 frames per second. The mirror patterns
24 are selected in such a way that the mirrors 16 reflect
light only to a subset of the sensors 21 at a given time. The
cycles of mirror patterns 24 are repeated at finite
intervals. This enables to acquire time separated image data
and reduces the image blur due to overlapping.
FIG 3A-3D illustrates different mirror patterns 24 of the
micro mirror device 14, in accordance with an embodiment
herein. In the.example of FIG. 3, mirror patterns 24 for a
kernel size of 4 are exemplified. The kernel size determines
how from many different time instances the image can be
captured in one image frame 26. At the first time instant tO,
the mirrors 16 are turned on in a pattern as depicted in FIG.
3A. The pixels corresponding to sensors 21 receiving light
are high lightened at the time instant tO in a pattern same
as that of the mirror pattern 24. At second time instant tl,
a mirror pattern 24 as depicted in FIG. 3A is loaded on the
micro mirror device 14. Subsequently, mirror patterns 24 in
FIGS 3C and 3D are loaded at different time instances t2 and
t3 and hence complete the acquisition for the kernel size of
4.
The mirror patterns 24 are selected in such a way that the
plurality of mirrors 16 reflects light only to a subset of

the sensors 21 at a given time. There is finite time gap
between each mirror pattern 24 displayed in FIGS. 3A, 3B, 3C
and 3D. This allows different pixels at the image sensor 21
to acquire light at different times, thereby preventing
overlapping of image data. Thus. the spatial resolution is
converted to temporal resolution at the sensors 21. A kernel
size of 4 provides images of resolution l/4th of the original
image in 4 quick successions. Further, more image frames 26
at different instances of time can be quickly captured by
using kernel size higher than 4 and thereby providing high
speed temporal information about the image.
The cycle of mirror pattern 24 are repeated at finite
intervals. This permits to acquire images frames 26
continuously. Here, the time gap between two mirror patterns
24 should be held lesser than the time difference between two
image patterns to attain higher frame rate.
FIG. 4 illustrates an array of sensors 21 at the imaging
device 20, in accordance with an embodiment herein. The
sensors 21 are arranged on said imaging device 20
corresponding to the number and position with respect to the
arrangement of mirrors 16 on the micro mirror device 14. The
number of sensors 21 could however be greater or lesser than
the number of mirrors 16.The pattern of said sensors 21
receiving light at a given time may be equally or diversely
spaced on the array of sensors 21. The imaging device 20
composes the image frame 26 from successive image patterns
from each subset of the array of sensors 21. The sensors 21
store the image patterns captured during a cycle of the
mirror patterns 24 on pixels of subsets of the array of
sensors 21.
FIG 5A-5C illustrates an exemplary depiction of an image
frame 26, in accordance with an embodiment herein. The

embodiment herein describes sub-images corresponding to an
image frame 26 for a cycle of mirror pattern 24. The image
data is captured at finite time intervals during a cycle of
mirror pattern 24. The subsets of pixels corresponding to
subsets of sensors 21 receiving light at a given time tl is
shown in FIG. 5A. The second image pattern indicates subsets
of pixels corresponding to subsets of sensors 21 receiving
light at a time t2 is illustrated in FIG. 5B. From the
figure, it is evident that the mirrors 16 are toggled on and
off in a manner that the pixels corresponding to the sensors
21 receiving light exhibits intensity rise only once.
Further, the pattern of sensors 21 receiving light at one
instance is evenly spaced on an array of sensors 21. Thus
only a fraction of the sensors 21 receive light according to
the mirror pattern. The mirror patterns 24 are changed at a
rate that time difference between the different mirror
patterns 24 should be less than time difference between two
image frames 26. The image frame 26 as shown in FIG. 5C for a
cycle of 2 mirror pattern 24 is composed of successive image
patterns from each subset of said array of sensors 21 as
shown in FIGS 5A-5B. The image patterns captured during a
cycle of the mirror pattern 24 are retained on pixels of
subsets of the sensor 21 and further combined to get high
quality image as in FIG. 5C.
FIG 6A-6D illustrates another exemplary depiction of an image
acquisition process, in accordance with an embodiment herein.
The example shown in FIG. 6 herein, illustrates image
acquisition process for tracking the motion of turbine shafts
28 to perform transient speed analysis of a turbine. Turbine
shafts 28 rotate at high speed and measurement of turbine
shaft speed at transient stage is critical as various
stability parameters depend on transient performance. The
imaging device 20 is coupled with a micro mirror device 14
between the lens 10 and the sensor 21 such that light from
the lens 10 incidents on the micro mirror device 14. For

instance, if a sensor 21 of 1 million pixel and a micro
mirror resolution of 1 million pixel is considered, one
mirror 16 on the micro mirror device 14 may impinge light 11
on a pixel corresponding to the sensor 21.
The micro mirror device 14 is divided into 4 quadrants which
are turned on at different instances of time. The mirror
patterns 24 are customized to help receive similar light on
all the quadrants. Figure 6A-6D shows the mirror pattern 24
on the left and the image data captured by the corresponding
quadrant at the imaging device 20 on the right. At the first
time instant, tO, the first quadrant 32 of the micro mirror
device 14 is turned on and the same quadrant of sensors 21 of
imaging device 20 receives image data corresponding to the
mirror pattern 24. The second quadrant 34 is then turned on
at tl, a small time instant apert, the first quadrant 32 is
turned off and the image data is captured in second quadrant
34 in a pattern as shown in FIg. 6B. Since the sensor 21 is
exposed for the whole duration of time, the previously
captured image data is retained on the pixels of the
corresponding quadrant. Subsequently, image data
corresponding to position of the turbine blade 30 at time
instances t2 and t3 are captured in the quadrants of the
imaging device 20 in quick succession. The successive image
frames 26 are then extracted from the sensors 21 quadrant by
quadrant. The image frames 26 are then analyzed using
different mathematical models to obtain the transient speed
of the turbine shaft 28. The micro mirror device 14 can be
divided into a larger number of segments to get more image
frames 26 at lower resolution.
The splitting of mirrors 16 into quadrants prevents the
overlapping of image data corresponding to the mirror pattern
24 at the sensors. This in turn improves the quality of the
image. Moreover, the image data is captured at finite time

intervals, which helps in analyzing the displacement of the
shaft 28 at various time instances.
FIG 7 illustrates a flow chart depicting the method 70,
describing high speed image acquisition, in accordance with
an embodiment herein. A high speed micro mirror device 14 is
placed between the imaging device 20 and the scene of which
the image data is to be captured in step 61. A mirror pattern
24 is loaded on to the micro mirror device 14 according to
step 72. The mirror patterns 24 are set in a manner where
some mirrors 16 are turned on while some other mirrors 16 are
turned off. Any mirror pattern 24 can be depicted by
programming the micro mirror device 14 by using a controller
18 associated with the device. When light rays 11 from the
external scene are incident on the lens 12, it reflects the
light incident to the micro mirror device 14 in step 73. In
step 74, the mirrors 16 which are turned on according to the
pattern reflect the impinging light to the array of sensors
21 at the imaging device 20. The sensor 21 receives the light
and the pixels corresponding to subset of sensor 21 receiving
light register an intensity rise. The subsets of sensors 21
store the image data in a pattern defined by the mirror
pattern 24 of the micro mirror device 14 in step 75. The
image frames 26 are stored at a given frame rate based on
light detected by an array of sensors 21. The mirror patterns
24 are then changed at finite time intervals at a rate higher
than frame rate of the imaging device 20 in step 76. The
mirror patterns 24 are selected in such a way that the
plurality of mirrors 16 reflects light only to a subset of
the sensors 21 at a given time.
The difference in mirror pattern 24 enables different subsets
of sensors 21 to capture image data at different times, as in
step 77. The imaging device 20 captures image frames at
repeating cycle of mirror patterns. Image frames 26 can be
fractioned to a plurality of sub images each corresponding to

a different subset of sensors 21 which have been exposed to
light at different times. Finally, the image frames 26 are
correlated with each other to detect different positions of
an object at different times.
As per the preferred embodiment., to capture 1024 frames
rapidly of resolution of 1024 {32 x 32) pixels, the mirrors
16 on locations (1,1) ... (33,1) .. (65,1) .... (993,1)
(1,33)... (33, 33)...(65, 33).... (993,33)
(1,993)...(33,993)...(65, 993).... (993, 993)are turned at time
instant tO.
At t1 a small interval apart (-20 microseconds), the mirrors
at the locations (2,1) ... (34, 1: ... (66,1) .... (994,1)
(2,33)...(34,33)...(66,33).... (994,33)
(2,993)...(34,993)...(66, 993).... (994, 993)are turned on.
In this fashion, every 20 microseconds apart, a new set of
mirrors 16 are turned on. Therefore, a new set of pixels
receive light at different time instances. Each instant is
very small interval of time apart in order to ensure
continuous, meaningful capture of the high speed rotation of
the turbine shaft 28.
Such a system can acquire 1024 images within 100
milliseconds, each sized 32x32. The turbine shaft 28
positions can then be deduced from the image data and the
transient behavior of speed can be analyzed.
The techniques described herein increases the image quality
by splitting the resolution of images and providing the image
data in rapid successions. Further, the point spread nature
of point source of light per pixel remains the same since
inter pixel smearing is of a considerably low intensity than
the signal intensity. Moreover, when the optics is used to
magnify, a single mirror acts as a light source to a sub-set
of pixels. The Point Spread Function (PSF) integrates over
the sub-set and smearing does not integrate outside the

subset, which leads to increased Signal to Noise ratio (SNR)
thereby improving the image quality.
The techniques described herein enables to capture larger
number of image frames 26 at different time instances.
Further, the image acquisition can be time profiled;
adaptively images can be obtained at different time instances
predetermined at real-time. Moreover, adaptive spatial and
temporal resolution is possible with the system 10 thus
rendering way for newer imaging paradigms to leverage this
advantage.
In view of the foregoing, owing to the advantages described,
the image acquisition system 10 disclosed herein has
extensive applications in machine vision. It can be used in
precise tracking and prediction systems which are needed for
accurate ejection of defective objects. The systems 10 are
used with high speed sorting systems which require velocity,
acceleration and higher spatio-temporal derivatives of
position to understand and efficiently route parcels to a
conveyor. Moreover, the system 10 is employed to determine
kinematic and dynamic performance metrics of moving objects
to provide vital indication of manufacturing defects that may
not be visible. Furthermore, online inspection of moving
parts of a machine is feasible with the low cost image
acquisition system. High speed monitoring of rapidly moving
objects, such as cascaded drives, turbine shaft 28 and blade
30 speed inspection can be accomplished with the low cost
monitoring system 10. For instance, a drive running at
6000rpm needs at least $10000 high speed camera for
continuous and precise measurement of speed whereas the
described system costs less than $3000. Moreover, thermal
profiles of any object can be inspected as a function of time
with the aid of an infrared or thermal camera, which aid to
thermal studies that affect manufacture and performance of
many consumables and devices.

While this invention has been described in detail with
reference to certain preferred embodiments, it should be
appreciated that the present invention is not limited to
those precise embodiments. Rather, in view of the present
disclosure which describes the current best mode for
practicing the invention, many modifications and variations
would present themselves, to those of skill in the art
without departing from the scope and spirit of this
invention. The scope of the invention is, therefore,
indicated by the following claims rather than by the
foregoing description. All changes, modifications, and
variations coming within the meaning and range of equivalency
of the claims are to be considered within their scope.

We claim:
1. A method of acquiring images, said method comprising steps
of:
- controlling a micro mirror device (14) comprising a
plurality of mirrors (16) to selectively toggle on and off
said mirrors (16) according to a mirror pattern (24);
- reflecting light incident on said mirrors (16) which are
toggled on to an imaging device (20);
.- said imaging device (20) storing image frames (26) at a
given frame rate based on light detected by an array of
sensors (21); and
- changing said mirror pattern (24) at a rate higher than the
frame rate of said imaging device (20),
- wherein said mirror patterns (24) are selected in such a
way that said plurality of mirrors (16) reflect light only to
a subset of said sensors (21) at a given time.
2. The method as claimed in claim 1, wherein said image frame
(26) comprises of subsets of pixels corresponding to subsets
of said sensor (21) detecting light at a given time.
3. The method as claimed in claim 1, wherein changing said
mirror patterns (24) enable different subsets of said sensors
(21) to acquire said image data at different times.
4. The method as claimed in claim 1, wherein one of said
image frames (26) can be fractioned to a plurality of sub
images each corresponding to a different subset of sensors
(21) which have been exposed to light at different times.
5. The method as claimed in claim 1, wherein different
subsets of one of said image frames (26) can be correlated

with each other to detect different positions of an object
(28) at different times.
6. The method as claimed in claim 1, wherein said image data
is captured during a cycle of said mirror pattern (24), where
cycle of said mirror patterns (24) are repeated at finite
intervals.
7. The method as claimed in claim 1, wherein said mirrors
(16) are turned on in such a way that pixels at each of said
sensor (21) receive light only one time during one cycle of
said mirror pattern (24).
8. The method as claimed in claim 1, wherein pattern of said
sensors (21) receiving light at a given time are equally
spaced on said array of sensors (21).
9. The method as claimed in claim 1, wherein said image frame
(26) is composed of successive image patterns from each
subset of said array of sensors (21), where said image
patterns captured during a cycle of said mirror patterns (24)
are retained on pixels of subsets of said sensor (24).
10. A system (10) for acquiring images, said system
comprising:
- a micro mirror device (14) comprising a plurality of
mirrors 16 to selectively toggle on and off said mirrors (16)
according to a mirror pattern (24);
- a reflecting means to reflect light incident on said
mirrors (16) which are toggled on;

- an imaging device (20) storing image frames (26) at a given
frame rate based on light detected by an array of sensors
(21); and
- a means for changing said mirror pattern (24) at a rate
higher than frame rate of said imaging device (20),
- wherein said mirror patterns (24) are selected in such a
way that said plurality of mirrors (16) reflect light only to
a subset of said sensors (21) at a given time.
11. The system as claimed in claim 10, further comprising a
program executable on a controller (18) for said micro mirror
device (14) to perform at least one of:
- determining pattern of said mirrors (16) to reflect light
to said imaging device (20); and
- changing pattern of said mirrors (16) at a rate higher than
frame rate of said imaging device (20).

12. The system as claimed in claim 10, wherein said imaging
device (20) comprises of a Charge Coupled Device configured
to receive reflected light and operative to output image
data.
13. The system as claimed in claim 10, wherein said image
frame (26) comprises of subsets of pixels corresponding to
subsets of said sensor (21) detecting light at a given time.
14. The system as claimed in claim 10, wherein said micro
mirror device (14) is programmed to change said mirror
patterns (24) to allow different subsets of said sensors (21)
to acquire said image data at different times.

15. The system as claimed in claim 10, wherein one of said
image frames (26) can be fractioned to a plurality of sub
images each corresponding to a different subset of sensors
(21) which have been exposed to light at different times.
16. The system as claimed in claim 10, wherein said imaging
device (20) correlates different subsets of one of said image
frames (26) with each other to detect different positions of
an object at different times.
17. The system as claimed in claim 10, wherein said imaging
device (20) captures image at different subsets of said image
frame (26) during a cycle of said mirror pattern (24), where
cycle of said mirror patterns (24) are repeated at finite
intervals.
20. The system as claimed in claim 10, wherein said micro
mirror device (14) toggle on said mirrors (16) in such a way
that pixels at each of said sensor (21) receive light only
one time during one cycle of said mirror pattern (24).
19. The system as claimed in claim 10, wherein said imaging
device (20) equally space pattern of said sensors (21)
receiving light at a given tine on said array of sensors
(21) .
20. The system as claimed in claim 10, wherein said imaging
device (20) composes said image frame (26) from successive
image patterns from each subset of said array of sensors
(21), where said image patterns captured during cycle of said
mirror patterns (24) are retained on pixels of subsets of
said sensors (21).

A method and system for acquiring images using low cost imaging devices (20) is disclosed. The image acquisition is performed using a digital micro mirror device (14) placed between the imaging device (20) and the scene. The method
comprises controlling a micro mirror device (14) to selectively toggle on and off the mirrors (16) according to a mirror pattern (24), reflecting light incident on the mirrors (16) which are toggled on to an imaging device (20), the imaging device (20) storing image frames (26) at a given frame rate based on light detected by an array of sensors (21) and changing the mirror pattern (24) at a rate higher
than frame rate of the imaging device (20).