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DESCRIPTION IMAGE PROCESSING APPARATUS AND METHOD
TECHNICAL FIELb' [0001]'
The present disclosure relates to an image processing device and method, and more particularly relates to an image processing device and method capable of suppressing image deterioration.
10
BACKGROUND ART [0002]
In recent years, dovices have come into widely use in which an image is subjected to compression encoding by
15 employing a coding system by handling image information as digital, and at this time compressing the image by orthogonal transform, such as discrete cosine transform or the like, and motion compensation, taking advantage of redundancy which is a feature of the image information,
20 in order to perform highly efficient transmission and
storage of information. Examples of this coding system include a Moving Picture Experts Group (MPEG) and so forth. [0003]
25 In particular, MPEG2 {ISO/IEC 13818-2) is defined as a general-purpose imago coding system, and is a standard that covers both interlaced scanning images and progressive scanning images as well as standard-resolution images and high-definition images. For
30 example, the MPEG2 is currently widely used in a wido range of applications ITor professional use and for

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consumer use. With use of the MPEG2 compression method, in the case of a standard-resolution interlaced scanning image having, for example, 720 x '5 80 pixels, an amount of encode (bit rate} of 4 to 8 Mbps is allocated. In 5 addition, with use of the iy!PEG-2 compression method, in the case of a high-resolution-interlaced scanning image having, for example, 1920 x 1088 pixels, an amount of encode (bit rate) of 18 to 22 Mbps is allocated. Owing to this, it is possible to realize a high compression
10 rate and favorable image quality. [0004]
The MPEG2 has been mainly used for high image quality encoding suitable for broadcasting, but has not been compatible with coding systems of an amount of
15 encode (bit rate) lower than that of MPEGl, in other
words, a higher compression rate. With the widespread use of mobile terminals, i t is expected that the demand for such a coding system will increase in the future, and in response to this, standardization of a MPEG4 coding
20 system has been performed. With regard to an image
coding system, the specification thereof was approved as an international standard as ISO/IF,C 14496-2 in December 1998. [0005]
25 Further, in recent years, standard!zat.Ion of a standard called H.26L {ITU-T (International
Telecommunication Union Telecommunication Standardization Sector) Q6/16 VCEG (Video Coding Expert Group)) has progressed, the object of which was initially imago
30 encoding for videoconferencing usage. With H, 2 6IP, it has been known that though greater computatJ.on amount is

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requested for encoding and decoding thereof as compared to a conventional coding system such as MPEG2 or MPEG4, higher encoding efficiency is realized. Also, currently, as part of activity of MPEG4, standardization including a 5 function that is not supported by H.25L with this H.26L taken as base to realize higher encoding efficiency has been performed as Joint Model of Enhanced-Compression Video Coding. [0006]
10 As a standardization schedule, an international
standard called H.264 and MPEG-4 Part 10 (Advanced Video Coding, hereinafter referred to as AVC) was established in March 2003. [0007]
15 Furthermore, as an extension of the H.264/AVC, standardization of FRExt {Fidelity Range Extension), including encoding tools necessary for business use, such as RGB, 4:2:2, or 4:4:4, as well as 8 X 8 DCT and quantization matrices defined in MPEG-2, was completed in
20 February 2005, Accordingly, a coding system capable of favorably expressing even film noise included in movies, using II. 264/AVC, has been established, which is used for a wide range of. applications such as Blu-Ray Discs (registered trademark).
25 [0008]
However, there have recently been growing needs for encoding at a higher compression rate, for example, needs for compressing an image having about 4000 x 2000 pixels, which is four times that of a high-vision image, or for
30 distributing high-vision images in an environment with a limited transmission capacity, such as the Internet.

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Therefore, in a Video Coding Expert Group (VCEG) under
ITU~T, which is described above, studies for improving
encoding efficiency have been continuously performed. [0009] ' ' 5 Therefore, for the purpose of further improving an
encoding efficiency compared with the AVC,
standardization of a coding system called High Efficiency
Video Coding (HEVC) is currently being conducted by Joint
Collaboration Team-Video Coding (JCTVC), which is a joint 10 standardization team of ITU-T and ISO/IEC {see, for
example, Non-Patent Document 1).
[0010]
However, in the HEVC standard disclosed in iSJon-
Patent Document 1, a technique called "Intra Transform 15 Skipping" is employed (see, for example, Non-Patent
Document 2),
[0011]
That is, first, a flag relating whether Transform
Skip (referred also to as an "orthogonal transform skip") 20 is applicable in the sequence, is transmitted to a
Sequence Parameter Set (SPS).
[0012]
When the value is 1, it is possible to apply the
Transformskip to 4 x 4 luminance and chrominance 25 orthogonal transform blocks.
[0013]
A flag relating on/off of the Transformskip is
transmitted to each block.
[0014] 30 With respect to the block to whJ.ch the
TransformSkip is applied, there is no change in entropy

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encoding, quantization, loop filter processing or the like.
CITATION LIST 5 NON-PATENT DOCUMENT [0015]
Non-Patent Document 1: Benjamin Bross, Woo-Jin Han, Jens-Rainer Ohm, Gary J. Sullivan, Thomas Wiegand, "Working Draft 4 of High-Efficiency Video Coding", JCTVC-10 F803_d2, Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16- WP3 and ISO/IEC JTC1/SC29/WG11 6th Meeting: Torino, IT, 14-22 July, 2011 .
Non-Patent Document 2: Culling Lan, Jizheng Xu, Gary J. Sullivan, Feng Wu, "Intra transform skipping", 15 JCTVC-I0408, Joint Collaborative Team on Video Coding
(JCT-VC) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 119th Meeting: Geneva, CH, 27 April - 7 May 2012
SUMMARY OF THE INVENTION 20 PROBLEMS TO BE SOLVED BY THE INVENTION
[0016]
However, a coefficient of a block to which a
TransformSkip is applied is a value relating to a spatial
domain, a coefficient of a block to whj.ch the 25 TransformSkip is not applied is a value relating to a
frequency domain, and thus both characteristics are
different from each other.
[0017]
For this reason, when an encoding process is 30 performed on both o.[y the block to which the TransformSkip
is applied and the b],ock to which the TransformSkip is

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not applied without taking the difference in these characteristics into consideration, there is a concern that encoding efficiency is deteriorated, [0018] " ' 5 The present disclosure is developed in
consideration of such a situation and can suppress the reduction of image quality due to encoding/decoding processes.
10 SOLUTIONS TO PROBLEMS [0019]
According to an aspect of the present disclosure, there is provided an image processing device including: a decoding unit that decodes coded data and generates a
15 quantized coefficient; and an inverse quantization unit that uses a weighting coefficient applied to an orthogonal transform skip block, in which orthogonal transform processing is skipped, to inversely quantize the quantized coefficient of the orthogonal transform
20 skip block generated by the decoding unit. [0020]
The inverse quantizatJ.on unit may use the one weighting coefficient. [0021]
25 The inverse quantization unit may inversely quantize a quantized coefficient of an orthogonal transform skip block having a block size of 4x4, using the weighting coefficient. [0022]
30 The image processing device may further include a receiving unit that rece.i.ves skip enable information

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transmitted as a picture parameter set and indicating whether or not to enable the skip oJT the orthogonal transform processing. [0023] ' ' 5 The receiving unit may further receive the transmitted weighting coefficient, and the inverse quantization unit may inversely quantize the quantized coefficient of the orthogonal transform skip block, using the weighting coefficient received by the receiving unit.
10 [0024]
The inverse' quantization unit may inversely quantize a quantized coefficient of a non-orthogonal transform skip block in which the orthogonal transform processing is performed, using a quantization matrix
15 different from a weighting coefficient matrix obtained by performing matrix processing on the weighting coefficient, [0025]
The image processing device may further include a transmission unit that extracts a desired channel signal
20 by receiving broadcasting signals and obtains coded data by decoding the extracted signal, and the decoding uni t may decode the coded data obtained from the broadcasting signals by the transmission unit. [0026]
25 The image processing device may further include a demultiplexer that demultiplexes and separates the transmitted coded data into video coded data and audio coded data, and the decoding unit may decode the video coded data separated from the audio coded data by the
30 demu.ltiplexer. [0027]

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The image processing device may further include a reproduction unit that reproduces video data obtained by performing decoding processing by the decoding unit and inverse quantization processing by the inverse 5 quantization unit on the coded data. [0028]
The image processing device may further include an audio codec unit that performs encoding and decoding on audio data.
10 [0029]
The image processing device may further include a reproduction unit that reads out coded data recorded on a storage medium, and the decoding unit may decode the coded data read out from the storage medium by the
15 reproduction unit. [0030]
According to another aspect of the present disclosure, there is provided an image processing method including: decoding coded data and generating a quantized
20 coefficient; and inversely quantizing the generated
quantized coefficient of the orthogonal transform :";kip block using a weighting coefficient applied to an orthogonal transform skip block in which orthogonal transform processing is skipped.
25 [0031]
In the another aspect of the present disclosure, coded data is decoded, a quantized coefficient is generated, and a weighting coefficient applied to an orthogonal transform skip block, in which orthogonal
30 transform processing is skipped, are used to inversely quantize the generated quantized coefficient of the

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orthogonal transform skip block. [0032]
Further, the image processing device described above may be an independent device or may be an internal 5 block constituting one image decoding device.
EFFECTS OF THE INVENTION [0033]
According to the present, disclosure, it is possible 10 to decode an image. In particularly, it is possible to suppress the reduction of image quality due to decoding.
BRIEF DESCRIPTION OF DRAWINGS [0034] 15 Fig. 1 is a block diagram illustrating an example oJ: a main configuration of an image encoding device.
Fig. 2 is a diagram for describing an example of a configuration of a coding unit.
Fig. 3 is a diagram illustrating an example of a 20 quantization matrix transmission.
Fig. 4 is a diagram illustrating an example oiy a sequence parameter set.
Fig. 5 is a diagram illustrating an example of the sequence parameter set which follows Fig. 4. 25 E'ig. 6 is a diagram illustrating an example of a picture parameter set.
Fig. 7 is a diagram illustrating an example of the picture parameter set which follows Fig. 6.
Fig. 8 is a diagram for describing an example of a 30 cond.ition of quantization.
Fig. 9 is a diagram illustrating an example of a

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sequence parameter set.
Fig, 10 is a diagram illustrating an example of the sequence parameter set which follows Fig. 9.
Fig. 11 is a diagram illustrating an example of a 5 picture parameter set,
Fig. 12 is a diagram illustrating an example of the picture parameter set which follows Fig, 11.
Fig. 13 is a block diagram illustrating an example of a main configuration of an .orthogonal transform skip 10 or the like.
Fig, 14 is .a flowchart for describing an example of a flow of an encoding process.
Fig, 15 is a flowchart for describing an example of a flow of orthogonal transform skip control processing, 15 Fig, 15 is a flowchart for describing an example of a flow of orthogonal transform processing.
Fig. 17 is a flowchart for describ.i.ng an example of a flow of quantization processing.
Fig. 18 is a flowchart for describing an example of 20 a flow of deblocking filter processing.
Fig. 19 is a block diagram illustrating an example of a main configuration of an image decoding device,
Fig. 20 is a block diagram illustrating an example of a main configuration of an inverse orthogonal 25 transform skip unit or the like.
Fig, 21 is a flowchart for describing an example of a flow of a decoding process.
Fig, 22 is a flowchart for describing an example of a flow of inverse quanti/alion processing. 30 Fig,23isa flowchart for describing an example oT a n.ow of inverse orthogona]. transform process! ng,

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Fig. 24 is a diagram illustrating another example of a sequence parameter set.
Fig. 25 is a diagram illustrating an example of a picture parameter set. 5 Fig. 2 6 is a flowchart for describing an example of a flow of skip enable information generation processing.
Fig. 27 is a flowchart for describing an example of a flow of skip enable information reception processing.
Fig. 28 is a diagram illustrating an example of a 10 multiple viewpoint image coding system.
Fig. 29 is a diagram illustrating an example of a main configuration of a multiple viewpoint image encoding device to which the present technology is applied.
Fig. 30 is a diagram illustrating an example of a 15 main configuration of a multiple viewpoint image decoding device to which the present technology is applied.
Fig. 31 is a diagram illustrating an example of a hierarchical image coding system.
Fig. 32 is a diagram illustrating an example of a 20 main configuration of a hierarchical image encoding device to which the present technology is applied.
Fig. 33 a diagram illustrating an example of a main configuration of a hierarchical image decoding device to which the present technology is applied. 25 Fig. 34 is a block diagram illustrating an example of a main configuration of a computer,
Fig. 35 is a block dJ.agram illustrating an example a schematic configuration of a television apparatus.
Fig. 36 is a block diagram illustrating an example 30 of a schematic configuration of a mobi].e phone,
FLg. 37 is a block diagram illustrat i.ng an example

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of a schematic configuration of a recording and reproducing device,
Fig. 38 is a block diagram illustrating an example of a schematic configuration of an imaging device. 5 Fig. 39 is a block diagram illustrating an example of scalable encoding utilization.
Fig, 40 is a block diagram illustrating another example of the scalable encoding utilization.
Fig. 41 is a block diagram illustrating further 10 another example of the scalable encoding utilization.
Fig. 42 is a block diagram illustrating an example of a schematic configuration of a video set,
Fig. 43 is a block diagram illustrating an example of a schematic configuration of a video processor, 15 Fig. 44 is a block diagram illustrating another example of a schematic configuration of the video processor,
MODE FOR CARRYING ODT THE INVENTION 20 [0035]
Hereinafter, modes for carrying out the present
disclosure (hereinafter, referred to as embodiments) will
be described. Further, the description is given in the
following order. 25 1, First embodiment {Image encoding device)
2. Second embodiment (Image decoding device)
3. Third embodiment {Transmission control of skip enable information)

4. Fourth embodiment (Multiple viewpoint image 30 encoding/Multiple viewpoint image decoding device)
5. Fifth embodiment (Hierarchical imtige

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encoding/Hierarchical image decoding device)
6. Sixth embodiment (Computer)
7. Seventh embodiment (Application example)
8. Eightti embodiment (Application example of 5 scalable encoding)
9. Ninth embodiment (Set/Unit/Module/Processor)
[0035]
<1. First embodiment> [Image encoding device] 10 Fig. 1 is a block diagram illustrating an example of a main configuration of an image encoding device. [0037]
An image encoding device 100 illustrated in Fig. 1 encodes image data using prediction processing of, for 15 example, high efficiency video coding (HEVC) or a system that is compliant therewith. [0038]
As illustrated in Fig. 1, the image encoding device 100 includes an A/D converter 101, a screen rearrangement 20 buffer 102, a computation unit 103, an orthogonal
transform unit 104, a quantization unit 105, a lossless encoding unit 106, an accumulation buffer 107, an inverse quantization unit 108, and an inverse orthogonal transform unit 109. In addition, the image encoding 25 device 100 includes a computation unit 110, a deblocl^ing filter 111, a frame memory 112, a selecti,on unit 113, an intra prediction unit 114, a motion
prediction/compensation unit 115, a predicted image selection unit 116, and a rate control unJt 117. 30 [0039]
The image encoding device 100 further J.ncludes an

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orthogonal transform skip unit 121. [0040]
The A/D converter 101 performs A/D .conversion on input image data, supplies the image data {digital data) 5 obtained by the conversion to the screen rearrangement buffer 102, and stores the ima'ge data therein, The screen rearrangement buffer 102 rearranges the frame images stored in display order into order of frames for encoding according to a group of picture (GOP) structure
10 and supplies the image, in which order of the frames has been rearranged, to the computation unit 103. In addition, the screen rearrangement buffer 102 supplies the image, in which the order of the frames has been rearranged, to the intra prediction unit 114 and the
15 motion prediction/compensation unit 115. [0041]
The computation unit 103 subtracts a predicted image supplied from the intra prediction unit 114 or the motion prediction/compensation unit 115 through the
20 predicted image selection unit 116 from the image read from the screen rearrangement buffer 102 and outputs difference information to the orthogonal transform unit 104. For example, in a case of the image to which intra encoding is performed, the computation unit 103 subtracts,
25 from the image read from the screen rearrangement buffer 102, the predicted image supplied from the intra prediction unit 114, Further, in a case of the image to which inter encoding is performed, for example, the computation unit 103 subtracts, from the image read from
30 the screen rearrangement buffer 102, the predicted image
supplied from the motion predict;! on/compensation unit 115.

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[0042]
The orthogonal transform unit 104 performs an orthogonal transform such as a discrete cosine transform and a Karhunen-Loeve transform on the difference 5 information supplied from the computation unit 103 and supplies a transform coefficient thereof to the quantization unit 105. [0043]
The quantization unit 105 quantizes the transform
10 coefficient supplied from the orthogonal transform unit 104. The quantization unit 105 sets a quantization parameter based on information on a target value of an encode amount supplied from the rate control unit 117 and performs quantization thereof. The quantization unit 105
15 supplies the quantized transform coefficient to the lossless encoding unit 106. [0044]
The lossless encoding unit 106 encodes the transform coefficient, which is quantized by the
20 quantization unit 105, using any coding system. Since coefficient data is quantized under control of the rate control unit 117, the encode amount thereof is the target value set by the rate control unit 117 (or approximates the target value),
25 [0045]
In addition, the lossless encoding unit 106 acquires information indicating a mode of intra prediction and the like from the intra prediction unit 114 and acquires information indicating a mode of inter
30 prediction or difference motion vector information from the motion prediction/compensatJ.on unit lib.

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[0046]
The lossless encoding unit 106 encodes these
"Various information pieces according to a codj.ng system,
' ' '. to contain .(multiplex) the various information pieces as
5 part of header information of coded data [referred also
to as a coded stream). The lossless encoding unit 106
.supplies the coded data obtained by the encoding to the
accumulation buffer 107 and accumulates the coded data
therein.
10 [0047]
For example, the coding system of the lossless encoding unit 106 includes variable-length encoding or computation encoding. For example, the variable-length encoding includes Context-Adaptive Variable Length Coding
15 (CAVLC) and the liice defined by the H.264/AVC system.
For example, the computation encoding includes Context-Adaptive Binary Arithmetic Coding [CABAC) and the like. [0048]
The accumulation buffer 107 temporarily holds the
20 coded data supplied from the lossless encoding unit 106. The accumulation buffer 107 outputs the held coded data to, for example, a recording device (receding medium) or a transmission path not illustrated in the latter part at predetermined timing. That is, the accumulation buffer
2b 107 is also a transmission unit for transmitting the coded data, [0049]
The quantized transform coefficient by the quantization unit 105 is also supplied to the inverse
30 quantization unit 108. The inverse quantization unit 108 inversely quantizes the quantized transform coefficient

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by a method corresponding to the quantization by the quantization unit 105. The inverse quantization unit 108 supplies the obtained transform coefficient to the inverse orthogonal transform unit 109, 5 [0050]
The inverse orthogonal transform unit 109 performs inverse orthogonal transform on the transform coefficient supplied from the inverse quantization unit 108 by a method corresponding to orthogonal transform processing
10 by the orthogonal transform unit 104. An output obtained by the inverse orthogonal transform processing (restored difference information) is supplied to ■ the computation unit 110. [0051]
15 The computation unit 110 adds an predicted image
supplied from the intra prediction unit 114 or the motion prediction/compensation unit 115 through the predicted image selection unit 116 to the restored difference information which is a result of the inverse orthogonal
20 transform processing supplied from the inverse orthogonal transform unit 109, thereby obtaining a loca.lly derioded image (decoded image), The decoded imago is supplied to the deblocking filter 111 or the frame memory 112. [0062]
2 5 The debloc]<:ing filter 111 appropriately performs deblocking filter processing on the decoded imago supplied from the computation unit 110. For example, the deblocking filter 111 performs the deblocking filter processing on the decoded image to remove block
30 distortion of the decoded image. [0053]

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The deblocking filter 111 supplies a result of the filter processing (decoded image after filter processing) to the frame memory 112. Further, as described above, the decoded image output from the computation unit 110 5 can be supplied to the frame memory 112 without passing through the deblocking filter 111. That is, it is possible to omit the filter processing by the deblocking filter 111. [0054]
10 The frame memory 112 stores the decoded image to be supplied and supplies the stored decoded image as a reference image to the selection unit 113 at predetermined timing. [0055]
15 The selection unit 113 selects a supply destination of the reference image supplied from the frame memory 112 For example, in the case of the inter prediction, the selection unit 113 supplies the reference image supp].ied from the frame memory 112 to the motion
20 prediction/compensation unit 115. [0056]
The intra prediction unit 114 performs an intra prediction (in-screen prediction} to generate the predicted image using a pixel value within a current
25 picture which is the reference image supplied from the frame memory 112 through the selection unit 113, The intra prediction unit 114 performs the intra prediction in a plurality of intra prediction modes prepared :i.n advance,
30 [0057]
The intra prediction unit 114 generates the

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predicted image in all of the intra prediction modes to be candidates and evaluates a cost function value of each predicted image using the input image supplied from the screen rearrangement buffer 102 to select an optimal mode, 5 Upon selecting the optimal intra prediction mode, the intra prediction unit 114 supplies the generated predicted image to the predicted image selection unit 116 in the optimal mode. [0058]
10 In addition, as described above, the intra prediction unit 114 appropriately supplies intra prediction mode information indicating■an adopted intra prediction mode to the lossless encoding unit 106 to encode the supplied intra prediction mode information.
15 [0059]
The motion prediction/compensation unit 115 performs motion prediction (inter prediction) using the input image supplied from the screen rearrangement buffer 102 and the reference image supplied from the frame
20 memory 112 through the selection unit 113. The motion prediction/coi!ipensation unit 115 performs motion compensation processing according to a detected motion vector and generates the predicted image (inter predicted image information). The motion prediction/compensation
25 unit 115 performs such an inter prediction in the
plura].ity of inter prediction modes prepared in advance. [0060]
The motion prediction/compensation unit 115 generates the predicted image in all of the inter
30 prediction modes to be candidates. The motion
prediction/compensation unit 115 evaluates the cost

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function value of each predicted image using the input image supplied from the screen rearrangement buffer 102
and the information of the generated difference motion
' t * vector to select an optimal mode. Upon selecting the
5 optimal inter prediction mode, the motion
prediction/compensation unit 115 supplies the generated
predicted image in the optimal mode to the predicted
image selection unit 116.
[0061]
10 The motion prsdiction/compensation unit 115
supplies the information indicating an adopted inter prediction mode, information reguired for performing the processing in the inter prediction mode at the time of decoding the coded data and the like to the lossless
15 encoding unit 106 and encodes the supplied information. Cor example, the required information may include information of the generated difference motion vector, a flag J.ndicating the index of a prediction motion vector as prediction motion vector information, and the like.
20 [0062]
The predicted image selection unit 116 selects a supply source of the predicted image to be supplied to the computation unit 103 or the computation unit 110. For example, in the case of intra encoding, the predicted
25 image selection unit 116 selects intra prediction unit 114 as the supply source of the predicted image and supplies the predicted image to be supplied Irom the intra prediction unit 114 to the computation unit 103 or the computatj.on unit 110. In addition, Tor example, in
30 the case of inter encoding, the predicted image selection unit 116 selects the motion prediction/compensation unit

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115 as the supply source of the predicted image and supplies the predicted image to be supplied from the
motion prediction/compensation unit 115 to the
' t * computation, unit 103 or the computation unit 110.
5 [0063]
Based on an encode amouht of the coded data
accumulated in the accumulation buffer 107, the rate
control unit 117 controls a rate of quantization
operation of the quantization unit 105 such that overflow
10 or underflow does not occur. [0064]
The orthogonal transform skip unit 121 controls execution of the orthogonal transform processing in the orthogonal transform unit 104. In addition, according to
15 the control, the orthogonal transform skip unit 121
controls quantization processing by the quantization unit 105, inverse quantization processing by the inverse quantization unit 108, inverse orthogonal transform processing by the inverse orthogonal transform unit 109,
20 and deblocking filter processing by the deblocking filter 111. Further, the orthogonal transform skip unit !121 supplies information necessary on a skip of tho orthogonal transform processing and information on the quantization or the deblocking filter to the lossless
25 encoding unit 106 and transmits the supplied information to a decoding side from the accumulation buffer 107. [0065]
[Coding unit]
In an AVC system, a hierarchi.cal structure
30 including a macroblock and a sub macroblock is specified. However, a macroblock of 16 pixels x 16 pixels is not

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most suitable for a large Image frame, such as an ultra high definition (UHD; 4000 pixels x 2000 pixels), that will be the subject of a next-generation coding system. [0066]
5 Thus, for example, a coding unit (CU) is specified in an HEVC system as illustrated in Fig. 2,
[0057]
The CU is also called a coding tree block (CTB), and is a partial region of an image in a picture unit,
10 which serves the similar role as the' macroblock in the AVC system. The latter has a fixed size of 16 x 16 pixels, whereas the size of the former is not fixed and is thus specified in image compression information in each sequence.
15 [0068]
For example, the maximum size (Largest Coding Unit (LCU)) and the minimum size (Smallest Coding Unit (SCO)) of the CU are specified in a sequence parameter sot (Sequence Parameter Set (SPS)) included in the coded data
20 to be output. [0069]
Each LCU can be further divided into a smaller CU by sotting split flag = 1 within the range not falling below the size of the SCU, In an example illustrated in
25 Fig. 2, the LCU is 128 x 128 pixels in size while the
max:!.mum hj.erarchical depth becomes 5 . The CU having the
size of 2H x 2N pixels is divided into CUs havJ.ng the size of N X N pixels that is one level lower in the hierarchy when the value of split flag is '^1",
30 [0070]

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Further, the CU is divided into a prediction unit (PU) that is a region (a partial region of an image in a picture unit) to be a processing unit for the intra prediction or the inter prediction and is also into a 5 transform unit (TU) that is a region {a partial region of an image in a picture unit) to be a processing unit for the orthogonal transform. Currently, the HEVC system can perform 16 x 16 and 32 x 32 orthogonal transforms in addition to block and the non-orthogonal transform skip block.
5 [0117]'
Thus, a detection whether the orthogonal transform
skip block and the non-orthogonal transform skip block
come in contact with each other across the block boundary
is performed, and the strength' adjustment of the
10 deblocking filter is performed on the boundary between the orthogonal transform skip block and the non-orthogonal transform skip block in the.following manner to make deblocking filtering easily performed, [0118]
15 For example, when the deblocking filter processing is applied to the boundary between the orthogonal transform skip block and the non-orthogonal transform skip block, a value of boundary strength (bs) acting as block-boundary strength is set to be "tl". By increasing
20 the bs value in this manner, the control is made so as to apply stronger filtering. That is, a stronger deb.locking filter can be applied to the boundary between the orthogonal transform skip block and the non-orthogonal transform skip block. Further, instead of setting the bs
25 value to +1, the bs value may be fixed to a large value of, for example, 2 and l:.hG like. [0119]
In addition, for example, adjustment of the filter strength is performed from parameters such as the bs
30 value, a, and \i, but a strong filter may be applied Lo
the boundary between the orthogonal transform skip block

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and the non-orthogonal transform skip block regardless of the control result of such a filter strength. Thus, it is possible to apply more directly a strong deblocking filter to the 'boundary between the orthogonal transform 5 skip block and the non-orthogonal transform skip block. [0120]
Further, for example, the boundary between the orthogonal transform skip block and the non-orthogonal transform skip block may be set as a smaller offset
10 compared to the p and tc. Thus, it is possible to easily apply the deblocking filter to the boundary between the orthogonal transform skip block and the non-orthogonal transform skip block. [0121]
15 By applying the strength adjustment of the
deblocking filter as described above, it is possible to more easily apply the deblocking filter to the boundary between the orthogonal transform skip block and the non-orthogonal transform skip block and to improve the
20 efficiency of image compression information to be output. [0122]
L'urther, plural- methods of applying the deblocking filter are considered as described above, and it may be used in combination with the plural methods. Naturally,
25 methods other than those described above may be included in such methods. [0123]
[Example of configuration of orthogonal transform sk.lp or the ].ikel
30 Fig. 13 J s a block dJ.agram illustrating an example of a main conf i.gurat i.on of the orthogonal transform skip

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unit 121 and the like. [0124J
As illustrated in Fig, 12, the orthogonal transform skip unit 121 IS configured to include a skip encoding 5 unit 131 and a skip determination unit 132. [0125]
The skip encoding unit 131 acquires the orthogonal transform coefficient and the pre-orthogonal transform differential value of the current block from the
10 orthogonal transform unit 104 when the current block is 4 X 4 block. The skip encoding unit 131 performs the encoding process in the case where the^ orthogonal transform skip is not applied, using the supplied orthogonal transform coefficient, and generates a cost
15 function value thereof. In addition, the skip encoding unit 131 performs the encoding process in the case where the orthogonal transform skip is applied, using the supplied pre-orthogonal transform differential value and generates a cost function value thereof. The skip
20 encoding unit 131 supplies the cost function values to the skip determination unit 132. [0126]
Further, when the current block is larger than the
4x4 block, the skJ.p encoding unit 131 omits such 25 processing. In this case, the skip determination unit
132 supplies a control signal which issues an instruction for performing the orthogonal transform, to the orthogonal transform unit 104 , The orthogonal transform unit 104 performs the orthogonal transform of the current 30 block based on the controJ., [0127]

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The skip determination unit 132 acquires the skip enable information (transform_skip_enabled flag} indicating whether or not to enable the skip of the orthogonal transform processing, from the lossless 5 encoding unit 106. This skip enable information
(transform_skip_enabled_flag) is set in advance by, for example, a user or the like and is stored in the lossless encoding unit 10 6. The skip determination unit 132 supplies a control signal for instructing whether or not
10 to enable the orthogonal transform skip corresponding to the skip enable information {transform skip enabled flag) to the orthogonal transform unit 104, [0128]
For example, when the skip enable information
15 {transform_skip_enabled_flag) indicates that the
orthogonal transform skip (for example, the value is 1) is enabled, the skip determination unit 132 supplies the control signal for enabling the orthogonal transform skip to the orthogonal transform unit 104. In addition, when
20 the skip enable information (transform_skip_enabled_flag) indicates that the orthogonal transform skip (for oxample, the value is 0) is disabled, the skip determination unit 132 supplies the control signal for prohibiting the orthogona], transform skip to the orthogonal transform
25 unit 104. [0129]
In addition, the skip determination unit 132 determines ^in optimal mode based on the cost function values supplied from the skip encoding unit 131. That is,
30 it is determined whether or not to app.ly the orthogonal
transform skip (TransformSkip) to the current block. The

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skip determination unit 132 supplies the determined result (information indicating the determined optimal mode) as the control signal to the orthogonal transform unit 104, the quantization unit 105, the deblocking 5 filter 111, the inverse quantization unit 108, and the inverse orthogonal transform unit 109. [0130]
In addition, the skip determination unit 132 generates skip identification information
10 (TransformSkipFlag) for identifying the determined result (whether the orthogonal transform skip is applied to the current block) and supplies and transmits the skip identification information to the lossless encoding unit 106.
15 [0131]
With respect to the pre-orthogonal transform differential value acquired from the computation unit 103, the orthogonal transform unit 104 generates the orthogonal transform coefficient and the pre-orthogonal
20 transform differential value of the current block which are not disabled by the control signal supplied from the skip encoding unit 131 in all modes, The orthogonal transform unit 104 supplies the generated the orthogonal transform coefficient and the pre-orthogonal transform
25 differential value of the current block to the skip encoding unit 131. Further, when the orthogonal transform skip is disabled by the control signal, the orthogonal, transform unit 104 supplies only the orthogonal transform coefficient of the current block to
30 the skip encoding unit 131, [0132]

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As described above, when a mode is determined in the orthogonal transform skip unit 121, the orthogonal transform unit 104 acquires the control signal supplied from the skip determination unit 132 and performs 5 processing of the designated mode according to the
■
control, That is, the orthogonal transform unit 104 executes or skips the orthogonal transform processing. In case of executing, the orthogonal transform unit supplies the orthogonal transform coefficient to the
10 quantization unit 105 and in the case of skipping, the pre-orthogonal transform differential value to the quantization unit 105. [0133]
In this manner, the orthogonal transform unit 104
15 can appropriately perform the orthogonal transform as necessary to suppress the reduction of the encoding efficiency, and thus it is possible to suppress the deterioration of the image quality due to encoding/decoding.
20 [0134]
Further, the orthogonal transform unit 104 holds the orthogonal transform coefficient and the pre-orthogonal transform differential value of the current block in all modes to be supplied to the skip encoding
25 unit 131 and, from among the coefficients and values, may select an orthogonal transform coefficient and a pre-orthogonal transform differential value in a mode according to the control signal supplied from the skip determination unit 132 to supply it the quantization unit
30 105. Thus, it is possible to omit the processing and reduce a load.

41
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[0135]
As illustrated in Fig. 13, the quantization unit 105 is configured to include a quantization matrix setting unit 141, a weighting coefficient generation unit 5 142, and a quantization processing unit 143. [0135]
The quantization matrix setting unit 141 supplies the quantization matrix, which is set by the user or the like, to. the weighting coefficient generation unit 142.
10 [0137]
The weighting coefficient generation unit 142 acquires the control signal supplied from the skip determination unit 132. The weighting coefficient generation unit 142 supplies the quantization matrix or
15 the weighting coefficient to the quantization processing unit 143 based on the control of the control signal. [0138]
For example, when the orthogonal transform skip is not applied, the weighting coefficient generation unit
20 142 supplies the quantization matrix, which is supplied
from the quantization matrix setting unit 141 in tho mode designated by the control signal, to the quantization processing unit 143, [0139]
25 In addition, for example, when the orthogonal transform skip is applied, the weighting coefficient generation unit 142 generates the weighting coefficient and supplies the generated weighting coefficient to the quantization proceasing unit 143, As described above, a
30 method of generating the weighting coefficient is
arbi i:rary. For example, a DC component extracted from

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the quantization matrix supplied from the quantization matrix setting unit 141 may be set as the weighting coefficient, apart from the quantization matrix supplied from the guantization matrix setting unit 141, another 5 weighting coefficient may be set, and the weighting
coefficient may be calculated'from the DC component of the quantizatJ.on matrix of the peripheral block, [0140]
The quantization processing unit 143 quantizes the
10 orthogonal transform coefficient or the pre-orthogonal
transform differential value supplied from the orthogonal transform unit 104 using the quantization matrix or the weighting coefficient supplied from the weighting coefficient generation unit 142 and the quantization
15 parameter or the like supplied from the rate control unit 117. [0141]
That is, the quantization processing unit 143 quantizes the orthogonal transform coefficient of the
20 current block using the quantization matrix, the
quantization parameter or the like when the orthogonal transform coefficient is supplied from the orthogonal transform unit 104. In addition, the quantization processing unit 143 quantizes the pre-orthogonal
25 transform differential value of tho current block using the weighti.ng coefClcient, the quantization parameter or tho like when the pre-orthogonal transform differential value is supplied from the orthogonal transform unit 104. [0142]
30 The quantization processing unit 143 supplies the quantized coefficienL to the lossless encoding unit 106

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and the inverse quantization unit 108. In addition, the quantization processing unit 143 supplies and transmits a parameter regarding the quantization of, for example, the weighting coefficient or the like to the lossless 5 encoding unit 106, when necessary. [0143]
Thus, the quantization processing unit 143 can appropriately perform the quantization so as to suppress the deterioration of the image■quality. Accordingly, the
10 image encoding device 100 can suppress the deterioration of the image quality due to the encoding/decoding. In other words, the image encoding device 100 can improve the encoding efficiency. [0144]
15 t'urther, the quantization processing unit 143 may supply the quantization matrix or the weighting coefficient applied to the quantization processing together with, for example, the quantized coefficient to the inverse quantization unit 108,
20 [0145]
Further, since a processing unit similar to Lhe inverse quantization unit 108 and the inverse orthogonal transform unit 109 is also formed in an image decoding device to be described below, the description thereof is
25 a.lso applied to the inverse quantisation unit 108 and the inverse orthogonal, transform unit 109, and thus the detailed description of the inverse quantization unit 108 and the .inverse orthogonal transform unit 109 will be not presented.
30 [01-16]
as illustrated in E'ig. 13, the deblocking filter

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111 is configured to include a boundary determination unit 151, a strength adjustment unit 152, and a filtering unit 153. [0147] 5 The boundary determination unit 151 acquires the control signal supplied from the skip determination unit 132, with respect to the current block. Further, the boundary determination unit 151 acquires skip identification information {TransformSkipFlag) for
10 identifying whether the orthogonal transform skip is applied to the peripheral block of the current block (TransformSkipFlag), The boundary determination unit 151 determines whether a current block boundary is the boundary between the orthogonal transform skip block and
15 the non-orthogonal transform skip block, based on such
information, and supplies a control signal indicating the determined result to the strength adjustment unit 152, [0148]
The strength adjustment unit 152 generates various
20 parameters such as Bs value, a, p, and tc and determines strength of the deblocking fj.lter based on these values and the control signal supplied from the boundary determination unit 151. That is, the strength adjustment unit 152 determines the strength of the deblocking filter
25 based on values ol". various parameters such as the
generated Bs value, a, p, and tc when the current block boundary is not the boundary between the orthogonal transform skip block and the non-orthogonal transform skip block. In addition, when the currant block boundary
30 is the boundary between the orthogonal transform skip block and the non-orthogonal transform skip block, the

45
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strength adjustment unit 152 further makes filter strength strong based on the control signal in any manner as described above, for example. [0149] 5 In this manner, the strength adjustment unit 152
■
notifies the filtering unit 153 of the set filter
strength.
[0150]
The filtering unit 153 performs the deblocking
10 filter processing on a pre-deblocking filter pixel value of the block boundary supplied from the computation unit 110 with the filter strength supplied from the strength adjustment unit 152. The filtering unit 153 supplies a post-deblocking filter pixel value to the frame memory
15 112 to store it therein. This information is used intra or inter prediction processing. [0151]
Thus, the deblocking filter 111 can perform the filter processing on the boundary between the orthogonal
20 transform skip block and the non-orthogonal transform skip block such that the stronger deblocking filtei; is applied. Accordingly, the deterioration of the image quality is further suppressed. That is, the image encoding device 100 can suppress the deterioration of the
25 image quality due to the encoding/decoding. In other words, the image encoding device 100 can improve the encoding efficiency. [0152]
[Flow of encoding process]

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Next, a flow of individual processing operations to be executed by the image encoding device 100 as described above will be described. First, an example of a flow of an encoding process will be described with reference to a 5 flowchart of Fig. 14.
[0153]
In step Si01, the lossless encoding unit 106 generates the skip enable information
{transform_skip_enabled_flag) indicating whether or not 10 to enable the skip of the orthogonal' transform procGssing, based on the user's instruction or the like, for example. For example, the skip enable information
(transform__skip_enabled_f lag) is transmitted to the SPS . [0154] 15 In step S102, the A/D converter 101 performs A/D conversion on an input image. In step S103, the screen rearrangement buffer 102 stores the image obtained by the A/D conversion and rearranges respective pictures from a display order to an encoding order. In step SI04, the 20 intra prediction unit 114 performs intra prediction processing in the intra prediction mode. [0155]
In step S105, the motion prediction/compensation unit 115 performs inter motion prediction processing, in 25 which the motion prediction or the motion compensation is performed J.n the inter prediction mode.
[0156]
In step S10 6, the predicted image selection unit 116 determines an optimal mode based on each of the cost 30 functj.on values output from the intra prediction unit 114

47
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and the motion prediction/compensation unit 115. That is, the predicted image selection unit 116 selects either one
of a predicted image generated by the intra prediction
' t ' unit 114 and a predicted image generated by the motion
5 prediction/compensation unit 115,
[0157]
In step S107, the computation unit 103 computes a difference between the rearranged image obtained by the processing in step SI03 and the predicted image selocted 10 by the processing in step S106. The'difference data is reduced in the data amount as compared to original image data. Accordingly, the data amount can be compressed as compared to a case in which images are directly encoded.
[0158] 15 In step S108, the orthogonal transform skip unit
121 performs orthogonal transform skip control processing. [0159]
In step S109, the orthogonal transform unit 104 performs orthogonal transform processing on the 20 difference information generated by the processing in
step S107 according to Lho processing result in step S108, [0160]
In step SllO, the quantization unit 105 quantizes the orthogonal transform coefficient or the pre-25 orthogonal transform differential value obtained by the
processing in step S109, using tho quantization parameter supplied from the rate control unit 117, according to the processing result in step SI 08.
[0161]

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The difference information quantized by the processing in step SllO is locally decoded as follows, That is, in step Sill, the inverse quantization unit 108 performs inverse quantization on the quantized 5 coefficient {also referred to as a quantization
coefficient) generated by the processing in step Sill with characteristics corresponding to those of the quantization unit 105, according to the processing result in step .3108. In step S112, the inverse orthogonal 10 transform unit 109 performs inverse orthogonal transform on the orthogonal' transform coefficient or the pre-orthogonal transform differential value obtained by the processing in step Sill according to the processing result in step S108.
15 . [0162]
Since the description of each processing operation in step Sill and step S112 corresponds to that of a similar processing operatj.on to be executed in the decoding process, the detailed description thereof will
20 be not presented. [0163]
In step S113, the computation unit' 110 adds the predicted image to the locally decoded difference information to generate a locally decoded image (an image 25 corresponding to that input to the computation unit 103).
[0164]
In step S114, the deblocking filter 111 appropriately performs the deblocking filter processing on the local].y decoded .image obtained by the processing 3 0 in step S113, according to the processing result in step

SP348382WO00
S108. [0165]
In step S115, the frame memory 112 "stores the decoded image subjected to the deblocking filter 5 processing by the processing in step S114. Further, images that are not subjected to the filtering by the deblocking filter 111 are also supplied from the computation unit 110 and stored in the frame memory 112.
[0166]
10 In step S116, the lossless encoding unit 106
encodes the quantized coefficient by the processing in step SllO, That is, lossless encoding such as variable-length encoding or computation encoding is performed on data corresponding to the difference image.
15 [0167]
In addition, at this time, the lossless encoding unit 106 encodes information on a prediction mode of the predicted image selected by the processing in step S106 and adds the encoded information to the coded data
20 obtained by encoding the difference image. That is, the lossless encoding unit 106 also encodes information such as optimal intra prediction mode information supplied from the intra prediction unit 114 or information according to the optimal inter prediction mode supplied
25 from the motion prediction/compensation unit 115 and adds the encoded information to the coded data.
[0168]
Further, the lossless encoding unit 106 appropriately further encodes information on the

50
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orthogonal transform or the quanLization and the encoded
information to the coded data.
[0169]
i '
In step S117, the accumulation buffer 107 5 accumulates the coded data obtained by the processing in step Sll6. The coded data accumulated in the accumulation buffer 107 is appropriately read out and transmitted to a decoding side through a transmission path or a recording medium.
10 [0170]
In.step S118, the rate control unit 117 controls the rate of quantization operation of the quantization unit 105 so as not to cause overflow or underflow based on the encode amount {generated encode amount) of the 15 ■ coded data accumulated in the accumulation buffer 107 by the processing in step S117. In addition, the rate control unit 117 supplies information on the quantization parameter to the quantization'unit 105,
[0171] 20 The encoding process is completed when the
processing in step S118 is ended.
[0172]
[Flow of orthogonal transform skip control
processing] 25 NexL., an example of a flow of the orthogonal
transform sicip control processing to be executed in step
S]08 of Fig, 14 will be described with reference to a
flowchart of Fig. 15,
[0173] 30 When the orthogonal transform ski.p conl".roI

51
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processing is started, the skip determination unit 132 determines in step S131 whether or not to enable a TransformSkip mode in which the orthogonal transform skip is performed, based on the skip enable information 5 {transform_skip_enabled_flag). [0174]
When it is determined that the TransformSkip mode is enabled, the processing proceeds to step S132. In step S132, the skip determination unit 132 allows the
10 TransformSkip mode to be included in a candidate mode.
When the processing in step S132 is ended, the processing
proceeds to step S134.
[0175]
Further, when it is determined in step S132 that
15 the TransformSkip mode is not enabled, the processing proceeds to step S133. In step S133, the skip determination unit 132 eliminates the TransformSkip mode from the candidate mode. When the processing in step S133 is ended, the processing proceeds to step S134.
20 [0176]
In step r>134, the skip encoding unit 131 selects an unprocessed candidate mode. In step S135, the skip encoding unit 131 determines whether the selected mode is the orthogonal transform (TransformSkip) mode.
25 [0177]
When it is determined to be the orthogonal transform (TransformSkip) mode, the processing proceeds to step S136. In step S136, the skip encoding unit 131 generates a weJ.ghting coefficient. When the processing
30 in step S136 is ended, the processing proceeds to step S139.

52
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[0178]
When it is determined that the selected mode is not
the orthogonal transform (Transformskip) mode in step
' '( ' SI35, the processing proceeds to step S137. In step S137,
5 the skip encoding unit 131 performs the orthogonal
transform on the current block.
[0179]
In step S138, the skip encoding unit 131 acquires a
quantization matrix.
10 [0180]
In step S139, the skip encoding unit 131 performs an encoding operation using the orthogonal transform coefficient obtained by the orthogonal transform unit 104 or the pre-orthogonal transform differential value and
15 generates a cost function value with respect to the current mode. [0181]
In step S14 0, the skip encoding unit 131 determines whether all of the candidate modes are processed. When
20 an unproces'sed candidate mode exists, the processing
returns to step S134 and subsequent processing operations are repeatedly executed. That is, each processing operation in step S134 to step S140 is repeatedly executed until the cost function value is generated with
25 respect to all of the modes. [0182]
When it is determined in step S140 that all of the candidate modes are processed, the processing proceeds to step S141. In step 8141, the skip determJ.nation unit 132
30 determines the optimal mode based on the cost function value.

53
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[0183]
In step S142, the skip determination unit 132 generates skip identification information
' i '
(TransformSkipFlag) based on the optimal mode. 5 [0184]
ijijhen the processing in step S142 is ended, the orthogonal transform skip control processing is completed, and the processing returns to the processing operation' illustrated in Fig. 14. 10 [0185]
[Flow of orthogonal transform processing] Next, an example of a flow of orthogonal transform processing to be executed in step S108 of Fig, 14 will be described with reference to a flowchart of Fig. 16. 15 [0186]
When the orthogonal transform processing is started, the orthogonal transform unit 104 determines in step SI51 whether the optimal mode selected by the skip determination unit 132 is the orthogonal transform skip 20 (TransformSkip mode). When it is determined to be the orthogonal transform skip (TransformSkip mode), the processing proceeds to step S152. [0187]
In step S152, the orthogonal transform unit 104 25 skips the orthogonal transform processing and outputs the pre-orthogonal transform differential value of the current block. When the processing in step S152 is ended, the processing returns to the process illustrated in Fig. 14, 30 [0188]
Further, in step S151 of Fig. 16, when it is

54
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determined not to be the orthogonal transform skip (TransformSkip mode), the processing proceeds to step S153. [0189] 5 In step S153, the orthogonal transform unit 104 performs the orthogonal transform on the pre-orthogonal transform differential value of the current block. In step S154, the orthogonal transform unit 104 outputs the obtained orthogonal transform coefficient. When the
10 processing in step SI54 is ended, the processing returns to the process illustrated in Fig. 14. [0190]
[Flow of quantization processing] Next, an example of a flow of the quantization
15 processing to be executed in step SllO of Fig. 14 will be described with reference to a flowchart of Fig. 17. [0191]
When the quantization processing is started, the weighting coefficient generation unit 142 determines, in
20 step S161, whether the optimal mode selected by the skip determination unit 132 is the orthogonal transform skip (TransformSkip mode). When it is determined to be the orthogonal transform skip (TransformSkip mode), the processing proceeds to step S162.
25 [0192]
In step S162, the weighting coefficient generation unit 142 generates a weighting coefficient. When the processing J.n step S162 is ended, the processing proceeds to step S164 .
30 [0193]
Further, when it is determined not to be the

55
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orthogonal transform skip (Transformskip mode) in step
S161, the processing proceeds to step 3163.
[0194]
In step' i5l63, the weighting coefficient generation 5 unit 142 acquires a quantization matrix. When the
processing in step 3163 is ended, the processing proceeds
to step S164.
[0195]
In step Si64, the quantization processing unit 143
10 performs the quantization of the orthogonal transform coefficient of the current block or the pre-orthogonal transform coefficient differential value using the weighting coefficient generated in step S162 and the quantization matrix acquired in step 3163. In step 3165,
15 the quantization processing unit 143 supplies and transmits the quantization matrix and the applied weighting coefficient to the lossless encoding unit 10 6. When the processing in step 3165 is ended, the quantization processing is completed, and the processing
20 returns to the process illustrated in Fig. 14. [0196]
[Flow of deblock:i.ng fil ter processing] Next, an example of a flow of the deblocking filter processing to be executed in step S114 of Fig. 14 will be
25 described with reference to a flowchart o IT F:i.g, 18. [0197]
When the deblocking filter processing is started, the strength adjustment unit 152 acquires mode information, motion vector, reference frame information
30 or the like in step 3171. [0198]

56
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In step S172, the strength adjustment unit 152 detects block boundaries of the TU, PU or the like. In step S173, the strength adjustment unit 152 determines a Bs value based on such information. In step S17'5, the 5 strength adjustment unit 152 calculates a quantization
parameter (boundary QP) in the block boundary by defining quantization parameters of both blocks as QP P and QP Q, as in Formula (3) be].ow. [0199]
10 QP = (QP_P + QP_Q + 1) >> 1 ■■■ .(3) [0200]
In step S175, the strength adjustment unit 152
determines a j3 offset value and a tc offset value using
the boundary QP calculated as described above. In step 15 S17 6, the strength adjustment unit 152 determines filters
(strong, weak, and off) by processing the calculated
offset values.
[0201]
In step S177, the boundary determination unit 151 20 acquires a control signal of the current block from the
skip determination unit 132 and acquires skip
identification information (TransformSkipFlag) of the
peripheral block from the lossless encoding unit 106.
[0202] 25 In step S178, the boundary determination unit 151
determines whether the current block boundary is the
boundary between the orthogonal transform skip block and
the non-orthogonal transform skip block.
[0203] 30 When it is determined that the current block
boundary is the boundary between the orthogonal transform

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skip block and the non-orthogonal transform skip block,
the processing proceeds to step S17 9. In step S179, the
strength adjustment unit 152 adjusts the strength of the
deblocking filter. When the processing in step S17 9 is 5 ended, the processing proceeds to step S180.
[0204]
Further, when it is determined in step S17 8 that
the current block boundary is not the boundary between
the orthogonal transform skip block and the non-10 orthogonal transform skip block, the processing proceeds
to step S180.
[0205]
In step S180, the filtering unit 153 performs the
deblocking filter processing. When the processing in 15 step Si80 is ended, the deblocking filter processing is
completed, and the processing returns to the process
illustrated in Fig. 14.
[0206]
By executing each processing operation as described 20 above, the image encoding device 100 can suppress the
reduction of the encoding efficiency and suppress the
deterioration of the image quality due to the
encoding/decoding.
[0207] 25 <2, Second Embodiment> [Image decodi.ng device] Next, decoding of the coded data (a coded stream)
which is encoded as described above will be described.
Fig. 19 is a block diagram illustrating an example of a 30 main configuration of an i-maqe decoding device
corresponding to the image encoding device 100 in Fig. 1.

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[0208]
An image decoding device 200 illustrated in Fig. 19
decodes the,coded data generated by the image encoding
' i
device 100, using a decoding method corresponding to the 5 coding system thereof. [0209]
As illustrated in Fig, 19, the image decoding device 200 includes an accumulation buffer 201, a lossless decoding unit 202, an' inverse guantization unit
10 203, an inverse orthogonal transform unit 204, a
computation unit 205, a deblocking filter 206, a screen rearrangement buffer 207, and a D/A converter 208, In addition, the image decoding device 200 includes a frame memory 209, a selection unit 210, an intra prediction
15 unit 211, a motion prediction/compensation unit 212, and a selection unit 213. [0210]
Furthermore, the image decoding device 200 includes an inverse orthogonal transform s]<:ip unit 221.
20 [0211]
The accumulation buffer 201 is also a reception uni t for receiving the coded data transmitted thereto. The accumulation buffer 201 receives and accumulates the coded data transmitted therein, and supplies the coded
25 data to the lossless decoding unit 202 at a
predetermining timing. Pieces of information necessary for decoding, such as the prediction mode information, are added to the coded data. The lossless decoding unit 202 decodes the information, which is supplied from the
30 accumulation buffer 201 and encoded by the lossless
encoding unit 106 in Fig. 1, using a method corresponding

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to the coding system of the lossless encoding unit 106. The lossless decoding unit 202 supplies the quantized
coefficient data of a difference image obtained by
■ , ., 1
decoding to the inverse quantization unit 203. 5 [0212]
In addition, the lossless decoding unit 202 determines whether the intra prediction mode is selected or the inter prediction mode is selected, as the optimal prediction mode, and supplies information relating to the
10 optimal prediction mode to one of the intra prediction
unit 211 and the motion prediction/compensation unit 212, which is a mode determined to be selected. In other words, for example, in the case where the inter prediction mode is selected as the optimal prediction
15 mode in the image encoding device 100, the information relating to the optimal prediction mode is supplied to the intra prediction unit 211. In addition, for example, when the inter prediction mode is selected as an optimal prediction mode in the image encoding device 100, the
20 information regarding the optimal prediction mode is
supplied to the motion prediction/compensation uni I. 212. [0213]
Further, the lossless decoding unit 202 supplies information such as, for example, a quantization matrix
25 or a quantization parameter, which is required for
inverse quantization, to the inverse quantization unit 203. Further, the lossless decoding unit 202 supplies information such as, for examp].e, skip enable information (transform_skip_nnabled_flag) or skip .identification
30 information (TransformSkipFJ.ag > , whi.ch is required for an inverse orthogonal trans form, to the inverse orthogonal

60
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transform skip unit 221. [0214]
The inverse quantization unit 203 performs inverse quantization on the quantized coefficient data obtained 5 by decoding of the lossless decoding unit 202 based on
the control of the inverse orthogonal transform skip unit 221, using a method corresponding to the quantization method of the quantization unit 105 in Fig. 1. Further, the inverse quantization unit 203 is a processing unit
10 similar to the inverse quantization-unit 108 of the image encoding device lOO in Fig. 1. That is, the description of the inverse quantization unit 203 can be also applied to that of the inverse quantization unit 108. However, it is necessary to read input/output destination of data
15 by appropriately varying it depending on devices. [0215]
The inverse quantization unit 203 supplies the obtained coefficient data Lo the inverse orthogonal transform unit 204.
20 [0216]
Based on the control of the inverse orthogonaJ. transform skip unit 221, the inverse orthogonal transform unit 204 performs inverse orthogonal transform of the coefficient data {orthogonal transform coefficient or
25 pre-orthogonal transform differential value) to be
supplied from the inverse quantization unit 203 using a method corresponding to the orthogonal transform method of the orthogonal transform unJ-t 104 in Fig. 1, as necessary. Further, the inverse orthogonal transform
30 uni t 20A is a processing uni t simJlar to the inverse orthogonal trans Torm unit 109 oi; the J mage encoding

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device 100 in Fig. 1. That is, the description of the inverse orthogonal transform unit 204 can be also applied to that of the inverse orthogonal transform unit 109. However, it is necessary to read input/output destination 5 of data by appropriately varying it depending on devices. [0217]
The inverse orthogonal transform unit 204 obtains decoded residual data corresponding to the residual data before the orthogonal transform by the inverse orthogonal
10 transform processing in the image encoding device 100. The decoded residual data obtained by the inverse orthogonal transform is supplied to the computation unit 205. Further, a predicted image is supplied to the computation unit 205 through the selection unit 213 from
15 the intra prediction unit 211 or the motion prediction/compensation unit 212 . [0218]
The computation unit 205 adds the decoded residual data and the predicted image and obtains decoded image
20 data corresponding to image data before the predicted image is subtracted by the computation unit 103 of the image encoding device 100. The computation unit 205 supplies the decoded image data to the deblocking filter 206.
25 [0219]
The deblocking filter 206 appropriately performs deblocking filter processing on the supplied decoded image and supplies it to the screen rearrangement buffer 207. By performing the deblocking filter processing on
30 the decoded image, the deblocking filter 206 removes the block distortion of the decoded image. Further, the

52
sps-^sao^wooo
deblocking filter 206 is a processing unit similar to the deblocking filter 111 of the image encoding device 100 in Fig. 1.
[0220] ' ' 5 The deblocking filter 2 06 supplies a filter processing result (a decoded iinage after filter processing) to the screen rearrangement buffer 207 and the frame memory 209. In addition, the decoded iinage output from the computation unit 205 may be supplied to
10 the screen rearrangement buffer 207 or the frame memory 209 without passing through the deblocking filter 206. In other words, the filter processing performed by the deblocking filter 206 may be omitted. [0221]
15 The screen rearrangement buffer 207 rearranges images. In other words, the order of the frames rearranged for the encoding order by the screen rearrangement buffer 102 in Fig. 1 is rearranged in the original display order. The D/A converter 208 D/A-
20 converts the image supplied from the screen rearrangement buffer 207 and outputs the image to a display not illustrated in the drawing to display the image thereon. [0222]
The frame memory 209 stores therein the supplied
25 decoded image and supplies the stored decoded image, as a reference image, to the selection unit 210, at a predetermined timing or on the basis of a request from the outside, such as the intra prediction unit 211 or the motion prediction/compensation unit 212,
30 [0223]

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The selection unit 210 selects the supply destination of the reference image supplied from the frame memory 209. In the case of decoding an intra encoded image,* the selection unit 210 supplies the 5 reference image supplied from the frame memory 209 to the intra prediction unit 211, In addition, in the case of decoding an inter encoded image, the selection unit 210 supplies the reference image supplied from the frame memory 209 to the motion prediction/compensation unit 212.
10 [0224]
To the intra prediction unit 211 is supplied information or the like indicating the, intra prediction mode, which is obtained by decoding header information, appropriately from the lossless decoding unit 2 02. The
15 intra prediction unit 211 performs intra prediction using the reference image acquired from the frame memory 209, in the intra prediction mode used in the intra prediction unit 114 in Fig, 1, and generates a predicted image. The intra prediction unit 211 supplies the generated
20 predicted image to the selection unit 213, [0225]
The motion prediction/compensation unit 212 acquires information (the optimal prediction mode information, the reference image information, and so
25 forth), which is obtained by decoding the header information, from the lossless decoding unit 202. [0226]
The motion prediction/compensation unit 212 performs inter prediction us i.ng the reference image
30 acquired from the frame memory 209, in the inter
prediction mode indj.cated by the optimal prediction mode

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information acquired from the lossless decoding unit 202,
and generates a predicted image,
[0227]
The selection unit 213 supplies the predicted image 5 from the intra prediction unit 211 or the predicted image from the motion prediction/compensation unit 212 to the computation unit 205. In addition, in the computation unit 205, the predicted image generated using the motion vector and the decoded residual data (difference image
10 information} from the inverse orthogonal transform unit 204 are added, and an original image is decoded. In other words, the motion prediction/compensation unit 212, the lossless decoding unit 202, the inverse quantization unit 203, the inverse orthogonal transform unit 204, and
15 the computation unit 205 are also a decoding unit for decoding the coded data using the motion vector and generating the original image. [0228]
The j.nverse orthogonal transform skip unit 221
20 acquires the information supplied from the coding side through the lossless decoding unit 202 and contro.1 .=; execution of the inverse orthogonal transform processing in the inverse orthogonal transform unit 2 04 based on the information. In addition, the inverse orthogonal
25 transform skip unit 221 controls the inverse quantization processing by the inverse quantization unit 203 and the deblocking filter processing by the deblocking filter 206 [0229]
Thus, the image decoding device 200 can
30 appropriately decode the coded data, Accordingly, the
image decoding device 200 can realize the suppression of

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the reduction in the encoding efficiency and can realize
the suppression of the deterioration of the image quality
dude to the encoding/decoding.
[0230] ' ■
5 [Example of configuration of inverse orthogonal
transform skip unit or the like]
Fig. 20 is a block diagram illustrating an example of a main configuration of the inverse orthogonal transform skip unit 221 or the.like. 10 [0231]
As illustrated in Fig. 20, the inverse orthogonal transform skip unit 221 is configured to include a TransfomSkipFlag buffer 231 and a control signal generation unit 232. 15 [0232]
The TransfomSkipFlag buffer 231 acquires and holds the skip enable information (transform_skip_enab,led_flag) or the skip identification information (TransfomSkipFlag) extracted from the coded data {bit stream) in the 20 lossless decoding unit 202. The TransfomSkipFlag buffer 231 Supplies the held the skip enable information (transforrr!_skip_enabled_flag) or the skip identification information (TransfomSkipFlag) to the control signal generation unit 232 at predetermined timing or based on a
2 5 demand,
[0233]
The contro], signal generation unit 232 generates a control signal depending on the skip enable in Eormation {transform_skip enabled flag) or the skip identification
3 0 information (TransfomSkipi^'lag) supplied from the
TransitomSkipFlag buf fyer 231 and supplies the control

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signal to the inverse quantization unit 203, the inverse orthogonal transform unit 204, and the deblocking filter 206. [0231] 5 For example, when the orthogonal transform skip is disabled by the skip enable information {transform_skip_enabled_flag), the control signal generation unit 232 supplies a control signal as follows. That is, the control signal generation unit 232 supplies
10 a control signal for instructing the inverse quantization unit 203 to perform the inverse quantization using the quantization matrix. In addition, the control signal generation unit 232 supplies a control signal for instructing the inverse orthogonal transform unit 204 to
15 perform the inverse orthogonal transform. Further, the control signal generation unit 232 supplies a control signal for notifying the deblocking filter 206 that the current block is not the orthogonal transform skip block. [0235]
20 In addition, for example, when the orthogonal
transform skd.p is enabled by the skip enable information {transJTorm_akip_enabled flag) and it is identified by the skip identification information (TransfomSkipFlag) that the orthogonal transform skip is not app.lied at the time
25 of encoding of the current block, Lihe control signal generation unit 2 32 supplies the control si gnal in following manners, That is, the control signal generation unit 232 supplies the control signal for instructing the inverse quantization unit 203 to perform
30 the inverse quantization i-ising the quantization matrix. In addition, the control signal generation un.Lt 232

Claims
(1) An image processing device including: a
quantization unit that uses a weighting coefficient
applied to an orthogonal transform skip block in which
orthogonal transform processing is skipped and quantizes
5 the orthogonal transform skip block; and an encoding unit that encodes a coefficient of "the orthogonal transform skip block quantized by the quantization unit.
(2) The image processing device described in (1),
wherein the quantization unit uses a spatial domain value
10 as the weighting coefficient.
{3} The image processing device described in (2), wherein the quantization unit uses one of the weighting coefficient.
(4) The image processing device described in (2),
15 wherein the quantization unit uses a DC component of a
quantization matrix used in quantizing an orthogonal transform block in which the orthogonal transform processing is performed, as the weighting coefficient.
(5) The image processing device described in (2),
20 wherein the quantization unit quantizes tho orthogonal
transform skip block using a weighting coefficient matrix
obtained by performing matrix processing on a DC
component of a quantization matrix.
{5) The image processing device described in (1), 25 wherein the quantization unit quantizes the orthogonal
transform skip block usj.ng a weighting coefficient matrix
obtained by performing matrix processing on the weighting
coe Fficient.
(7) The image processing device described in (1), 30 further including a transmission unit that transmits the
weighting coe Tficient as a sequence parameter set or a

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picture parameter set,
(8) The image processing device described in (1),
further including a transmission uni t that transmits skip
enable information indicating whether or not to enable
5 the skip of the orthogonal transform processing as a picture parameter set or as a"slice header.
(9) The image processing device described in (8),
wherein the transmission unit transmits the skip enable
information only when a minimum block size in performing
10 an orthogonal transform is 4 x 4.
(10) The image processing device described in (1),
further including a transmission unit that transmits the
skip enable information as a seguence parameter set only
when a minimum block size in performing an orthogonal
15 transform is 4 x