Technical field
[0001]
　The present disclosure relates to an image processing apparatus and method, and more particularly, to an image processing apparatus and method which make it possible to suppress the reduction of the coding efficiency.
BACKGROUND
[0002]
　Conventionally, in image coding, after performing the primary transform on the prediction residual being the image and the difference of the predicted image, further increasing the energy compaction (to concentrate the conversion factor to the low frequency) for conversion block for each sub-block of the inner, it is disclosed that the application of secondary transformation (e.g., see non-Patent Document 1). Its Non-Patent Document 1 also discloses that signal the secondary conversion identifier CU unit indicating whether to apply any secondary conversion.
[0003]
　Further, in the encoder, based on RDO (Rate-Distortion Optimization), which secondary transform to decide whether to apply the CU units described in Non-Patent Document 1, computational complexity is large, secondary conversion block to signal the secondary conversion flag indicating whether to apply the conversion have been disclosed (e.g., see non-Patent Document 2). Its Non-Patent Document 2, which secondary indicating whether to apply a secondary transform conversion identifier, it is also disclosed that derived based on the primary conversion identifiers and the intra prediction mode.
CITATION
Non-patent literature
[0004]
非特許文献1 : J. Chen, E. Alshina, G. J. Sullivan, J. R. Ohm, J. Boyce, "Algorithm Description of Joint Exploration Test Model 2", JVET-B1001_v3, Joint Video Exploration Team （JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 11 2nd Meeting: San Diego, USA, 20-26 February 2016
非特許文献2 : X.Zhao, A.Said, V.Seregin, M.Karczewicz, J.Chen, R.Joshi, "TU-level non-separable secondary transform", JVET-B0059, Joint Video Exploration Team （JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 11 2nd Meeting: San Diego, USA, 20-26 February 2016
Summary of the Invention
Problems that the Invention is to Solve
[0005]
　However, even in the method according to any of the Non-Patent Documents 1 and 2, 1 is converted skip flag conversion blocks, i.e., to indicate that the application of conversion skip, only converted skip to the primary conversion application It had been. That is, even if the conversion skip only the primary transform is applied, the secondary transform may be applied. Therefore, for example, such as a non-zero coefficient is less sparse residual signal, with respect to a good residual signal better to apply a transform skip, also be applied to convert skipped by conversion skip flag, the secondary transform is applied will be, energy compaction is reduced, the coding efficiency is likely to be reduced.
[0006]
　The present disclosure has been made in view of such circumstances, it is desirable to make it possible to suppress the reduction of the coding efficiency.
Means for Solving the Problems
[0007]
　The image processing apparatus of the first embodiment of the present technology, when to skip a primary transform is a transformation process for prediction residual is the difference between the predicted image of the image with the image, the prediction residual is the primary conversion obtained is a conversion process on the primary transform coefficients secondary conversion is also an image processing apparatus including a control unit to skip.
[0008]
　The image processing method of the first embodiment of the present technology, when to skip a primary transform is a transformation process for prediction residual is the difference between the predicted image of the image with the image, the prediction residual is the primary conversion obtained is a conversion process on the primary transform coefficients secondary conversion is also an image processing method to skip.
[0009]
　If the image processing apparatus of the second embodiment of the present technology, to skip the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual is the difference between the predicted image of the image with the image, the prediction wherein the residual inverse secondary transform that is the inverse of the secondary transform is a transformation process for the primary transformed primary transform coefficients obtained also is an image processing apparatus including a control unit to skip.
[0010]
　If the image processing method of the second embodiment of the present technology, to skip the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual is the difference between the predicted image of the image with the image, the prediction inverse secondary transform that is the inverse of the secondary conversion residual is conversion processing for the primary transform coefficients obtained are the primary conversion is also an image processing method to skip.
[0011]
　If the image processing apparatus of the third embodiment of the present technology, the prediction residual is the difference between the predicted image of the image and the image is secondary conversion is performed on the primary transform coefficients obtained are primary conversion, the primary an image processing apparatus including an encoding unit to skip encoding of first information on a skip conversion.
[0012]
　If the image processing method of the third aspect of the present technology, the prediction residual is the difference between the predicted image of the image and the image is secondary conversion is performed on the primary transform coefficients obtained are primary conversion, the primary the image processing method of skipping the encoding of first information on a skip conversion.
[0013]
　The image processing apparatus of the fourth aspect of the present technique is the inverse of the secondary conversion prediction residual is the difference between the predicted image of the image and the image is a conversion process for the primary transform coefficients obtained are primary converted If the inverse secondary transform is performed, an image processing apparatus including a decoder to skip decoding of the coded data of the first information about the inverse primary transform skip which is the inverse transformation of the primary transformation.
[0014]
　The image processing method of the fourth aspect of the present technique is the inverse of the secondary conversion prediction residual is the difference between the predicted image of the image and the image is a conversion process for the primary transform coefficients obtained are primary converted If the inverse secondary transform is performed, an image processing method to skip decoding of the coded data of the first information about the inverse primary transform skip which is the inverse transformation of the primary transformation.
[0015]
　The image processing apparatus of the fifth aspect of the present technique, when the primary transform is a transformation process for prediction residual is the difference between the predicted image of the image and the image is skipped, the prediction residual is the primary conversion an image processing apparatus including an encoding unit to skip encoding of the first information about skipping secondary transform is a transformation processing on the primary transform coefficients obtained Te.
[0016]
　The image processing method of the fifth aspect of the present technology, when the primary transform is a transformation process for prediction residual is the difference between the predicted image of the image and the image is skipped, the prediction residual is the primary conversion a conversion processing for the primary transform coefficients obtained Te is an image processing method to skip encoding of the first information about skipping the secondary conversion.
[0017]
　If the image processing apparatus of the sixth aspect of the present technology, the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual is the difference between the predicted image of the image and the image is skipped, the image comprising a decoding unit prediction residual skips decoding of the encoded data of the first information about the inverse secondary transform skip which is the inverse of the secondary transform is a transformation processing on the primary transform coefficients obtained are the primary conversion it is a processing apparatus.
[0018]
　If the image processing method of the sixth aspect of the present technology, the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual is the difference between the predicted image of the image and the image is skipped, the is an image processing method to skip decoding of the coded data of the first information about the inverse secondary transform skip in the secondary conversion of inverse transformation is a transformation processing prediction residuals for the primary transform coefficients obtained are the primary conversion .
[0019]
　The image processing apparatus of the seventh aspect of the present technology, the primary conversion is a conversion processing for the prediction residual being the difference between the predicted image of the image with the image, the primary conversion the prediction residual is obtained is the primary conversion secondary transformation is a conversion process for the coefficients, and, when the primary transform coefficients quantized are skipped for secondary transform coefficients obtained are the secondary conversion, the encoding of the first information indicating the contents of the primary conversion an image processing apparatus including an encoding unit to skip.
[0020]
　The image processing method of the seventh aspect of the present technology, the primary conversion is a conversion processing for the prediction residual being the difference between the predicted image of the image with the image, the primary conversion the prediction residual is obtained is the primary conversion secondary transformation is a conversion process for the coefficients, and, when the primary transform coefficients quantized are skipped for secondary transform coefficients obtained are the secondary conversion, the encoding of the first information indicating the contents of the primary conversion the image processing method to skip.
[0021]
　The image processing apparatus of the eighth aspect of the present technique, inverse quantization for the quantized transform coefficient levels of the encoded data is obtained are decoded, the secondary transform coefficients the quantized transform coefficient levels obtained are the inverse quantization the inverse secondary transform that converts the primary transform coefficients, and, when said inverse primary transform to convert the primary transform coefficients to the prediction residual being the difference between the predicted image of the image and the image is skipped, the inverse primary transform an image processing apparatus including a decoder to skip decoding of the encoded data of the first information about the contents.
[0022]
　The image processing method of the eighth aspect of the present technique, inverse quantization for the quantized transform coefficient levels of the encoded data is obtained are decoded, the secondary transform coefficients the quantized transform coefficient levels obtained are the inverse quantization the inverse secondary transform that converts the primary transform coefficients, and, when said inverse primary transform to convert the primary transform coefficients to the prediction residual being the difference between the predicted image of the image and the image is skipped, the inverse primary transform the decoding of the encoded data of the first information about the content is an image processing method of skipping.
[0023]
　In the image processing apparatus and method of the first aspect of the present technology, when the primary transform is a transformation process for prediction residual that is a difference image and the predicted image of the image is skipped, the prediction residual primary conversion secondary transformation is a transformation processing on the primary transform coefficients obtained are also skipped.
[0024]
　In the image processing apparatus and method of the second aspect of the present technology, the image and the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual is the difference between the predicted image of the image is skipped case, the prediction residual is the inverse secondary transform that is the inverse of the secondary transform is a transformation processing on the primary transform coefficients obtained are primary conversion is also skipped.
[0025]
　In the image processing apparatus and method of the third aspect of the present technique, if the image and the prediction residual is the difference between the predicted image of the image secondary conversion is performed on the primary transform coefficients obtained are primary converted , encoding the first information about skipping the primary transform is skipped.
[0026]
　In the image processing apparatus and method of the fourth aspect of the present technology, the image and the secondary conversion inverse prediction residual is the difference between the predicted image of the image is conversion processing for the primary transform coefficients obtained are primary converted If the inverse secondary transform is a transformation is performed, decoding of the coded data of the first information about the skip inverse primary transform is an inverse transformation of the primary transformation is skipped.
[0027]
　In the image processing apparatus and method of the fifth aspect of the present technique, when the primary transform is a transformation process for prediction residual that is a difference image and the predicted image of the image is skipped, the prediction residual primary conversion encoding the first information is skipped regarding secondary conversion skipping a conversion process on the primary transform coefficients obtained are.
[0028]
　In the image processing apparatus and method of the sixth aspect of the present technology, the image and the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual is the difference between the predicted image of the image is skipped If the decoding of the encoded data of the first information about the inverse secondary transform skip which is the inverse of the secondary conversion prediction residual is conversion processing for the primary transform coefficients obtained by the primary transform is skipped.
[0029]
　In the image processing apparatus and method of the seventh aspect of the present technology, the image and the primary transform is a transformation process for prediction residual is the difference between the predicted image of the image, obtained as a prediction residual is primary converted secondary transformation is a transformation processing on the primary transform coefficients, and, if the primary transform coefficients quantized are skipped for secondary transform coefficients obtained by the secondary conversion, encoding of the first information indicating the contents of the primary conversion It is skipped.
[0030]
　In the image processing apparatus and method of the eighth aspect of the present technology, the secondary encoded data is inverse quantization for the quantized transform coefficient levels obtained are decoded, the quantized transform coefficient levels obtained are inverse quantized inverse secondary transform that converts the transform coefficient to the primary transform coefficients, and, if the inverse primary transform is skipped to convert the primary transform coefficients to the prediction residual being the difference image and the predicted image of the image, the inverse primary transform decoding the encoded data of the first information is skipped regarding the content.
Effect of the invention
[0031]
　According to the present disclosure, an image can be processed. In particular, it is possible to suppress the reduction of the coding efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032]
FIG. 1 is an explanatory diagram for explaining the outline of recursive block division for CU.
It is a [2] explanatory diagram for describing the setting of the PU to the CU shown in FIG.
3 is an explanatory diagram for illustrating setting of TU to CU shown in FIG.
FIG. 4 is an explanatory diagram for explaining the scanning order of the CU / PU.
5 is a block diagram showing a main configuration example of an image encoding apparatus.
6 is a block diagram showing a main configuration example of a conversion unit.
Is a diagram showing an example of the scanning method corresponding to FIG. 7 scan identifier.
8 is a diagram showing an example of a matrix of secondary conversion.
Is a flowchart illustrating an example of FIG. 9 the image encoding processing flow.
FIG. 10 is a flowchart illustrating an example of a conversion processing flow.
11 is a block diagram showing a main configuration example of an image decoding apparatus.
It is a block diagram showing a main configuration example of FIG. 12 inverse transform unit.
13 is a flowchart illustrating an example of the flow of the image decoding processing.
14 is a flowchart illustrating an example of the inverse conversion processing flow.
Is a diagram illustrating an example of FIG. 15 syntax.
It is a block diagram showing a main configuration example of FIG. 16 encoding unit.
17 is a flowchart for explaining an example of the encoding process flow.
18 is a block diagram showing a main configuration example of the decoding unit.
19 is a flowchart illustrating an example of a flow of a decoding process.
Is a diagram illustrating an example of FIG. 20 syntax.
21 is a block diagram showing a main configuration example of the encoding unit.
22 is a flowchart for explaining an example of the encoding process flow.
[Figure 23] illustrates an example of encoding processing flow is a flow chart subsequent to FIG.
It is a block diagram showing a main configuration example of FIG. 24 decoder.
Is a flowchart illustrating an example of FIG. 25 decoding process flow.
[Figure 26] illustrates an example flow of a decoding process, a flow chart subsequent to FIG. 25.
Is a diagram illustrating an example of FIG. 27 syntax.
[FIG. 28] is a flowchart illustrating an example of an encoding processing flow.
[Figure 29] illustrates an example of encoding processing flow is a flow chart subsequent to FIG.
Is a flowchart illustrating an example of FIG. 30 decoding process flow.
[Figure 31] illustrates an example flow of a decoding process, a flow chart subsequent to FIG. 30.
[FIG. 32] is a diagram illustrating an example of the way in which the encoding of the primary conversion identifier.
[FIG 33 is a diagram illustrating an example of the way in which the decoding of the primary conversion identifier.
Is a diagram illustrating an example of FIG. 34 syntax.
It is a block diagram showing a main configuration example of FIG. 35 encoding unit.
[FIG. 36] is a flowchart illustrating an example of an encoding processing flow.
FIG 37 is a flowchart illustrating an example of a flow of primary transform identifier encoding process.
Is a diagram illustrating an example of FIG. 38 arithmetic coding and arithmetic decoding corresponding to the context index.
Is a diagram illustrating an example of pseudo-code illustrating how [39] encoding the primary conversion identifier.
It is a block diagram showing a main configuration example of FIG. 40 decoder.
[FIG. 41] is a flowchart illustrating an example of a flow of a decoding process.
FIG 42 is a flowchart illustrating an example of a flow of primary conversion identifier decoding process.
[FIG 43 is a diagram showing an example of a pseudo-code illustrating how decoding of the primary conversion identifier.
[Figure 44] CU, diagrams PU, and TU of the shape will be described.
It is a diagram illustrating an example of FIG. 45 syntax table.
It is a block diagram showing a main configuration example of FIG. 46 encoding unit.
[FIG. 47] is a flowchart illustrating an example of an encoding processing flow.
[Figure 48] illustrates an example of encoding processing flow is a flow chart subsequent to FIG. 47.
[FIG. 49] is a block diagram showing a main configuration example of the decoding unit.
Is a flowchart illustrating an example of FIG. 50 decoding process flow.
[Figure 51] illustrates an example flow of a decoding process, a flow chart subsequent to FIG. 50.
[FIG. 52] is a diagram for explaining a redundant syntax in JEM-4.0.
[FIG. 53] is a diagram for explaining an example of a method of suppressing redundant syntax.
[FIG. 54] is a diagram for explaining a example of the syntax of the conversion unit.
[FIG. 55] is a diagram for explaining an example of the syntax of residual coding.
[FIG. 56] is a block diagram showing a main configuration example of the encoding unit.
[FIG. 57] is a flowchart illustrating an example of an encoding processing flow.
[FIG. 58] is a diagram for explaining an example of the syntax of the conversion unit.
[FIG. 59] is a diagram for explaining an example of the syntax of residual coding.
[FIG. 60] is a diagram for explaining an example of the syntax of residual coding.
[FIG. 61] is a block diagram showing a main configuration example of the decoding unit.
[FIG. 62] is a flowchart illustrating an example of a flow of a decoding process.
[FIG. 63] is a diagram for explaining a redundant syntax in JVET-E0037.
[FIG. 64] is a diagram for explaining an example of a method of suppressing redundant syntax.
It is a diagram for explaining a example of the syntax of FIG. 65] conversion unit.
[FIG. 66] is a diagram for explaining an example of the syntax of residual coding.
[FIG. 67] is a flowchart illustrating an example of an encoding processing flow.
[FIG. 68] is a diagram for explaining an example of the syntax of residual coding.
[FIG. 69] is a flowchart illustrating an example of a flow of a decoding process.
It is a block diagram showing a main configuration example of FIG. 70] computer.
[FIG. 71] is a block diagram showing an example of a schematic configuration of a television device.
[FIG. 72] is a block diagram showing an example of a schematic configuration of a mobile phone.
[FIG. 73] is a block diagram showing an example of a schematic configuration of a recording and reproducing apparatus.
Is a block diagram showing an example of a schematic configuration of FIG. 74] an imaging device.
[FIG. 75] is a block diagram showing an example of a schematic configuration of a video set.
[FIG. 76] is a block diagram showing an example of a schematic configuration of the video processor.
[FIG. 77] is a block diagram showing another example of a schematic configuration of the video processor.
[FIG. 78] is a block diagram showing an example of a schematic configuration of a network system.
DESCRIPTION OF THE INVENTION
[0033]
　The following describes embodiments of the present disclosure (hereinafter referred to as embodiments). The description will be made in the following order.
　1. First Embodiment ((reverse) corresponding to the transform skip (reverse) Skip secondary conversion)
　2. Second Embodiment ((inverse) encoding and decoding skip the conversion the skip flag corresponding to the secondary conversion)
　3. Third Embodiment ((inverse) encoding and decoding skip secondary conversion flag corresponding to the transform skip)
　4. Fourth Embodiment (encoding and decoding skip secondary conversion flag corresponding to the sub-block average of the non-zero coefficients)
　5. Fifth Embodiment (encoding and decoding skipping the primary conversion identifiers corresponding to the bypass transformed and quantized)
　6. Sixth Embodiment (encoding and decoding skip conversion skip flag when the block is a rectangle composed of square or rectangular) of
　7. Seventh Embodiment (control of the adaptive primary conversion flag and conversion skip flag)
　8. Eighth Embodiment (control of the adaptive primary conversion flag and conversion skip flag)
　9. Ninth Embodiment (Other)
[0034]
　<1. First Embodiment>
　　
　The example non-patent document 1, in the image encoding, after the primary transform on the prediction residual being the image and the difference of the predicted image, further, increasing the energy compaction to (low frequency to concentrate the transform coefficients) for each sub-block in the transform block, it is disclosed that applies a secondary transformation. Further, the Non-Patent Document 1 also discloses that signal the secondary conversion identifier CU unit indicating whether to apply any secondary conversion.
[0035]
　Further, for example, in Non-Patent Document 2, in the encoder, based on RDO (Rate-Distortion Optimization), to determine whether to apply any secondary conversion CU units described in Non-Patent Document 1, computational complexity large, it is possible to signal the secondary conversion flag is disclosed which indicates whether to apply the secondary conversion in the conversion block. Further, the Non-Patent Document 2, which secondary indicating whether to apply a secondary transform conversion identifier, it is also disclosed that derived based on the primary conversion identifiers and the intra prediction mode.
[0036]
　However, even in the method according to any of the Non-Patent Documents 1 and 2, 1 is converted skip flag conversion blocks, i.e., to indicate that the application of conversion skip, only converted skip to the primary conversion application It had been. That is, even if the conversion skip only the primary transform is applied, the secondary transform may be applied. Therefore, when the light of the concept of conversion skip can not skip a secondary conversion (optional), the amount of computation there is a possibility to increase. Further, for example, non-zero coefficients (also referred to as non-zero transform coefficients), such as less sparse residual signal, with respect to a good residual signal better to apply a transform skip, to apply a transform skip the conversion skip flag to be, will be the secondary transform is applied, energy compaction is reduced, the coding efficiency is likely to be reduced.
[0037]
　The primary conversion, the horizontal direction of the primary conversion Phor and vertical primary conversion Pver specified by the primary conversion identifier pt_idx is selected, the prediction residual D, for example, a matrix calculation as shown in the following expression (1) performed, transform coefficients after the primary conversion Coeff_P (also referred to as primary transform coefficients) are obtained.
[0038]
　Coeff_P = Phor ・D・Pver T
　・・・（１）
[0039]
　In the equation (1), the operator "·" indicates an operation of performing an inner product of the matrix-matrix (matrix product) operator "T" indicates the operation of the transposed matrix. Primary transform coefficients obtained as described above (Coeff_P) is then secondary conversion. Also, when the primary transformation as described above is skipped (omitted), the prediction residual D is secondary converted.
[0040]
　For example, the prediction residual D is the following formula (2) at the indicated is as a 4 × 4 matrix = [[255,0,0,0], [0,0,0,0], [0,0 , 0,0], a [0,0,0,0]], scan identifier scanIdx to denote the horizontal scanning hor.
[0041]
[Number

　1] ... (2)
[0042]
　Prediction residual D is scanned along the scanning order of the coefficients of the horizontal scan, 1 × 16 dimensional vector X as shown in the following equation (3) 1d is converted to.
[0043]
[Number

　2] · (3)
[0044]
　The 1 × 16 dimensional vector X 1d using the matrix R of the secondary transform is performed matrix operation, such as the following equation (4), the signal Y as shown in the following equation (4) 1d required It is.
[0045]
　Y 1d T = R ・X 1d T
　・・・（４）
[0046]
　Here, the operator "T" represents the operation of the transposed matrix. This matrix operation, for example, the signal Y as shown in the following equation (5) 1d is obtained.
[0047]
[Number

　3] ... (5)
[0048]
　The calculation result Y 1d to normalize the norm of, is performed bit shift operation of N bits, such as the following equation (6), the signal Z after bit shift 1d is obtained.
[0049]
　Z 1d = （ Y 1d )>>N
　・・・（６）
[0050]
　This bit shift operation, for example, the signal Z, as shown in the following equation (7) 1d is obtained.
[0051]
[Formula

　4] ... (7)
[0052]
　Signal Z after norm normalization 1d , based on the scan method specified by the scan identifier scanIdx, 1 × 16 dimensional vector Z 1d converted into 4 × 4 matrix Coeff as is shown in equation (8) below It is.
[0053]
[Formula

　5] · (8)
[0054]
　For expression a-number of zero coefficients is small (sparse residual signal) residual signal (prediction residual) such as (2), skip primary conversion, after them, the case of applying the secondary conversion formula non-zero coefficients as (8) there is a risk spread across the frequency domain. That is, by applying a secondary transform energy compaction is reduced, the coding efficiency is likely to be reduced.
[0055]
　　
　Therefore, when to skip a primary transform is a transformation process for prediction residual that is a difference image and the predicted image of the image, obtained as a prediction residual is primary converted secondary transformation is a transformation processing on the primary transform coefficient so as to skip.
[0056]
　By doing so, since the secondary converted not only the primary conversion is also becomes possible to skip, it is possible to suppress an increase in the calculation amount. Also, as in the example described above, the non-zero coefficients is small, it is possible to suppress the application of the secondary transform to good residual signal better to apply a transformation skip, to suppress the reduction of the energy compaction can. That is, it is possible to suppress the reduction of the coding efficiency.
[0057]
　Also, when to skip the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual that is a difference image and the predicted image of the image, the primary transform the prediction residual is obtained is primary converted also inverse secondary transform that is the inverse of the secondary transform is a transform process for the coefficients so as to skip.
[0058]
　By doing so, since the inverse secondary transform not only the inverse primary transform may be able to be skipped, it is possible to suppress an increase in the calculation amount. Also, as in the example described above, the non-zero coefficients is small, it is possible to suppress the application of an inverse secondary transform to good residual signal better to apply a transform skip suppress reduction in energy compaction be able to. That is, it is possible to suppress the reduction of the coding efficiency.
[0059]
　　
　Incidentally, in MPEG2 (Moving Picture Experts Group 2 ( ISO / IEC 13818-2)) or MPEG-4 Part10 (Advanced Video Coding , hereinafter referred to as AVC) older image encoding method such as an encoding process It is executed in a processing unit called a macroblock. Macro block is a block having a uniform size of 16x16 pixels. In contrast, in HEVC (High Efficiency Video Coding), the encoding processing is executed by the CU (Coding Unit) and referred to the processing unit (coding unit). CU is the maximum coding unit LCU and (Largest Coding Unit) is formed by dividing recursively, a block having a variable size. The maximum size of the selectable CU is 64x64 pixels. The minimum size of the selectable CU is 8x8 pixels. The minimum size of the CU is referred to as the SCU (Smallest Coding Unit). The maximum size of the CU is not limited to 64x64 pixels, larger 128x128 pixels, or as a block size, such as 256x256 pixels.
[0060]
　Thus, the results of CU having a variable size is employed, in HEVC, it is possible to adjust the image quality and encoding efficiency adaptively depending on the content of the image. Prediction process for predictive coding is performed in PU (Prediction Unit) and referred to the processing unit (prediction unit). PU is formed by dividing the CU in one of several split pattern. Further, PU is composed of luminance (Y) and color difference (Cb, Cr) for each of PB (Prediction Block) and referred to the processing unit (prediction block). Further, orthogonal transform processing is executed by the TU (Transform Unit) and referred to the processing unit (conversion unit). TU is formed by dividing to a depth in the CU or PU. Moreover, TU consists luminance (Y) and color difference (Cb, Cr) for each of TB (Transform Block) and referred to the processing unit (transformation blocks).
[0061]
　　
　Figure 1 is an explanatory diagram for explaining the outline of recursive block division of CU in HEVC. Block division of CU is carried out by repeating a division into 4 (= 2x2) sub-blocks of a block recursively, resulting quadtree (Quad-Tree) like a tree structure is formed . The whole of one of the quad-tree is referred to as CTB (Coding Tree Block), a logical unit corresponding to the CTB that CTU (Coding Tree Unit).
[0062]
　At the top of FIG. 1, as an example, C01 is a CU having a size of 64x64 pixels is illustrated. Dividing the depth of the C01 is equal to zero. This means that C01 corresponds to and LCU root of CTU. LCU size may be specified by parameters that are encoded in the SPS (Sequence Parameter Set) or PPS (Picture Parameter Set). A CU C02 is one of the four CU divided from C01, having a size of 32x32 pixels. Dividing the depth of the C02 is equal to 1. A CU C03 is one of the four CU divided from C02, having a size of 16x16 pixels. Dividing the depth of the C03 is equal to 2. A CU C04 is one of the four CU divided from C03, having a size of 8x8 pixels. Dividing the depth of the C04 is equal to 3. Thus, CU is formed by recursively dividing an image to be encoded. The depth of the division is variable. For example, a flat image region such as a blue sky, the larger size (i.e., smaller depth) CU can be set. On the other hand, the steep image area containing many edges, the smaller size (i.e., greater depth) CU can be set. Each of the set CU becomes the processing unit of encoding processing.
[0063]
　　
　PU is a process unit of the prediction process including intra prediction and inter prediction. PU is formed by dividing the CU in one of several split pattern. Figure 2 is an explanatory diagram for illustrating setting of the PU to the CU shown in FIG. The right of FIG. 2, 2Nx2N, 2NxN, Nx2N, NxN, 2NxnU, 2NxnD, that nLx2N and NRx2N, are shown eight division patterns. Of these division patterns, the intra prediction, two 2Nx2N and NxN is selectable (NxN only selectable SCU). The inter prediction In contrast, when an asymmetric motion division is enabled, all eight split patterns can be selected.
[0064]
　　
　TU is a processing unit of orthogonal transform processing. TU is CU (for intra CU, each PU in the CU) is formed by dividing to a depth in the. Figure 3 is an explanatory diagram for describing TU settings to CU shown in FIG. To the right of FIG. 3, there is shown one or more TU that may be set in C02. For example, a TU T01 has a size of 32x32 pixels, the depth of the TU division is equal to zero. A TU T02 has a size of 16x16 pixels, the depth of the TU division is equal to 1. A TU T03 has a size of 8x8 pixels, the depth of the TU division is equal to 2.
[0065]
　Above CU, it is whether to what block division to set the block such PU and TU in the image, is typically determined based on a comparison of influences cost coding efficiency. Encoder, for example, a CU of one 2Mx2M pixel, compare the cost with the CU four MxM pixels, if there is better to set the CU four MxM pixels encoding efficiency is high, the 2Mx2M pixel CU It decides to split into four MxM pixels CU a.
[0066]
　　
　when encoding an image, the image (or slice, tiles) CTB set in a grid pattern in (or LCU) is scanned in a raster scan order. Within one CTB, CU is scanned to follow the quadtree from left to right, top to bottom. When processing a current block, the above information and the left neighboring block is used as input information. Figure 4 is an explanatory diagram for explaining the scanning order of the CU and PU. At the top left of FIG. 4, a four CU that may be included in one of CTB, C10, C11, C12 and C13 are shown. The number in the frame of each CU has represent the order of processing. Encoding process, a top left CU C10, which is the upper right of the CU C11, C12 is a lower left CU, are executed in the order of C13 is CU at the lower right. The right of Figure 4, one or more PU for inter prediction that can be set in C11 is CU are shown. Under 4, one or more PU for intra prediction may be set in C12 is CU are shown. As shown in the figures within the framework of these PU, PU is also scanned to follow from left to right, top to bottom.
[0067]
　In the following, there are (not a block of processing unit) When described with reference to "block" as the partial area and processing unit of an image (picture). The "block" in this case refers to any partial area in the picture, its size, shape, and characteristics, etc. are not limited. That is, the "block" in this case, for example, TB, TU, PB, PU, ​​SCU, CU, LCU (CTB), the sub-block, macroblock, tiles, or slice, etc., any partial region (processing units), It is intended to be included.
[0068]
　　
　FIG. 5 is a block diagram showing an example of a configuration of an image encoding device which is an embodiment of an image processing apparatus to which the present technology is applied. Image encoding apparatus 100 illustrated in FIG. 5, as in the AVC and HEVC, an apparatus for encoding a prediction residual of the image and its prediction picture. For example, the image coding apparatus 100, technologies and proposed in HEVC, implementing the techniques proposed by JVET (Joint Video Exploration Team).
[0069]
　Incidentally, in FIG. 5 shows the main ones, such as the flow of the processing unit and data is not all that shown in Figure 5. That is, in the image encoding apparatus 100, or there is processing unit not shown as a block in FIG. 5, may be or there is a flow of processing and data not shown as arrows or the like in FIG.
[0070]
　The image coding apparatus 100 as shown in Figure 5, the control unit 101, arithmetic unit 111, conversion unit 112, a quantization unit 113, the coding unit 114, an inverse quantization unit 115, inverse transform unit 116, arithmetic unit 117 , a frame memory 118 and the prediction unit 119,.
[0071]
　Control unit 101, based on the external or the block size of the pre-specified processing unit, the block of a processing unit moving image input to the image coding apparatus 100 (CU, PU, ​​transformation block (TB), etc.) to divided, to supply the image I corresponding to the divided block to the calculating unit 111. The control unit 101, coding parameters supplied to each block (header information Hinfo, prediction mode information pinfo, conversion information Tinfo, etc.), for example, determined based on RDO (Rate-Distortion Optimization). Determined coding parameters are supplied to each block.
[0072]
　Header information Hinfo, for example, a video parameter set (VPS (Video Parameter Set)), sequence parameter set (SPS (Sequence Parameter Set)), picture parameter set (PPS (Picture Parameter Set)), the slice header (SH), such as including the information. For example, the header information Hinfo, the image size (width PicWidth, longitudinal width PicHeight), bit depth (brightness BitDepthY, chrominance BitDepthC), the maximum value MaxCUSize / minimum value MinCUSize, maximum MaxTBSize / minimum value of the transform block size of the CU size MinTBSize, (also referred to as maximum conversion skipped block size) maximum MaxTSSize transform skip blocks, (also referred to as valid flag) off flags of the coding tools includes information defining the like.
[0073]
　For example, the on-off flag of the encoding tools included in the header information Hinfo, conversion shown below, there is on-off flag related to the quantization process. Incidentally, off flag of the encoding tools can syntax relating to the encoded tool is interpreted as a flag indicating whether or not present in the encoded data. When the value of the on-off flag is 1 (true) indicates that the coded tool is available, if the value of the on-off flag is 0 (false), that the coded tool is not available show. It should be noted that the interpretation of the flag value is good to be reversed.
[0074]
　As the secondary conversion valid flag (St_enabled_flag) is one of the conversion process and its inverse processing, coding tools or flag indicating whether the encoding tools are available to the inverse transform (inverse secondary transform) thereof the secondary conversion it is. In other words, the secondary conversion enable flag in the data units of interest, the secondary transform or inverse secondary transform (referred (inverse) secondary transform both) is information indicating whether or not it is permitted. In other words further, the secondary conversion enable flag is information regarding permission (inverse) Secondary transformation in the data units of interest.
[0075]
　For example, if the secondary conversion enable flag st_enabled_flag is 1 (true), (it can be performed (inverse) Secondary Transform) that are allowed (inverse) Secondary transformation. Also, if the secondary conversion enable flag st_enabled_flag is 0 (false), (can not be executed (inverse) Secondary transformation) to (inverse) secondary conversion is not permitted.
[0076]
　Transformed and quantized bypass enable flag (Transquant_bypass_enabled_flag) is transformed and quantized, or as one of its inverse processing (inverse transformation and inverse quantization) transform and quantization, or to skip inverse quantization and inverse transform coding tool is a flag indicating whether available. In other words, the transformed and quantized bypass enable flag in the data units of interest, skip transform and quantization, or dequantization and inverse transform ((reverse) also referred to as conversion and (inverse) quantization) ( is information indicating whether or not to permit a bypass). In other words further, the transform quantization bypass valid flag is information about the permission of the data unit of interest (inverse) transformation and (reverse) Skip quantization (bypass).
[0077]
　For example, if the transformed and quantized bypass enable flag transquant_bypass_enabled_flag is 1 (true), are allowed bypass (inverse) transformation and (inverse) quantization. That is, it is possible to bypass (inverse) transformation and (inverse) quantization. Also, in the case of transformed and quantized bypass enable flag transquant_bypass_enabled_flag is 0 (false), it does not allow bypass (inverse) transformation and (inverse) quantization. That is, it is impossible to bypass (inverse) transformation and (inverse) quantization.
[0078]
　Converting skip valid flag (Ts_enabled_flag) as one of the conversion process and its inverse processing, coding tool to skip the (inverse) transform including primary conversion and secondary transform is a flag indicating whether available. In other words, this conversion the skip enable flag in the data units of interest is information indicating whether it is permitted skip (inverse) transform. In other words further, this conversion the skip valid flag is information on skip authorization (inverse) transform the data units of interest.
[0079]
　For example, if the conversion skip enable flag ts_enabled_flag is 1 (true), are allowed skip (inverse) transform. That is, it is possible to skip the (inverse) transform. Also, in the case of conversion the skip valid flag ts_enabled_flag is 0 (false), it does not allow skipped (inverse) transform. That is, it is not possible to skip the (inverse) transform.
[0080]
　In the case of the method described in Non-Patent Document 1 and Non-Patent Document 2, this conversion the skip valid flag, as described above, did not act only on the primary conversion or inverse primary transform ((reverse) referred primary transform both) It was. Therefore, in the present specification, this conversion the skip valid flag, sometimes described regarded as information related to "(inverse) primary conversion". That is, for example, this conversion the skip valid flag, skip "in the data unit of information (target regarding authorization skip" (reverse) Primary conversion "in the data unit of interest," (inverse) primary conversion "is allowed sometimes described as a being information indicating whether or not) "is.
[0081]
　Of course, the contents of the header information Hinfo is optional, any information other than the examples described above may be included in the header information Hinfo.
[0082]
　The prediction mode information pinfo, for example, include the following information.
[0083]
　PU size PUSize is information indicating the PU size to be processed PU (prediction block size). Intra prediction mode information IPinfo (e.g., JCTVC-W1005, 7.3.8.5 Coding Unit syntax in prev_intra_luma_pred_flag, mpm_idx, rem_intra_pred_mode etc.) is information on the intra prediction mode of the block to be processed. Motion prediction information MVinfo (e.g., JCTVC-W1005, 7.3.8.6 Prediction Unit Syntax in merge_idx, merge_flag, inter_pred_idc, ref_idx_LX, mvp_lX_flag, X = {0,1}, mvd, etc.) relates to a motion prediction of a block to be processed is information.
[0084]
　Of course, the content of the prediction mode information pinfo is optional, any information other than the examples described above may be included in the prediction mode information pinfo.
[0085]
　The conversion information Tinfo, for example, include the following information.
[0086]
　Block size TBSize (or logarithm of TBSize that a base of 2 Log2TBSize, also referred to as transform block size) is information indicating a block size of processed transform block.
[0087]
　Transformed and quantized bypass flag (Transquant_bypass_flag), in the data unit of interest is information indicating whether or not (inverse) transformation and (reverse) Skip quantization (bypass) (e.g., JCTVC-W1005, 7.3. 8.5 Coding unit cu_transquant_bypass_flag and the like in the syntax). In other words, the transformed and quantized bypass flag is information about the data units of interest (inverse) transformation and (reverse) Skip quantization (bypass).
[0088]
　For example, the transformed and quantized bypass flag Transquant_bypass _flag cases of 1 (true), (inverse) transformation and (inverse) quantization is bypassed. Further, if the transform quantization bypass valid flag Transquant_bypass _flag of 0 (false), (inverse) transformation and (inverse) quantization is not bypassed.
[0089]
　Conversion skip flag (Ts_flag) are (reverse) is information indicating whether to skip the conversion (e.g., JCTVC-W1005, etc. transfrom_skip_flag in 7.3.8.11 Residual coding syntax syntax). In other words, this conversion the skip flag is information about the skip (inverse) transform the data units of interest.
[0090]
　For example, if the conversion the skip flag ts_flag is 1 (true), (inverse) transform ((inverse) primary transform) is skipped. Also, if the conversion the skip flag ts_flag is 0 (false), (inverse) transform ((inverse) primary transform) is performed.
[0091]
　In the case of the method described in Non-Patent Document 1 and Non-Patent Document 2, this conversion the skip flag, as described above, did not affect only the referred primary transform both (opposite). Therefore, in the present specification, this conversion the skip flag is sometimes described regarded as information related to "(inverse) primary conversion". That is, for example, this conversion the skip flag is in the skip infos (data units of interest of "(reverse) Primary conversion" in the data unit of a "target, whether to skip the" (reverse) Primary conversion " sometimes described as a show information) ".
[0092]
　Primary transformation identifier (Pt_idx), in the data unit of interest, an identifier indicating the vertical direction, and the horizontal direction to apply which (inverse) primary transform (inverse) to the primary conversion (e.g., JVET-B1001, 2.5.1 also referred to as emt_idx In reference to the Adaptive multiple Core transform .JEM2). In other words, the primary conversion identifier is information about the contents of (inverse) primary transform in the data units of interest.
[0093]
　Secondary transformation identifier (St_idx), in the data unit of interest, an identifier indicating whether to apply any (inverse) Secondary transformation (e.g., in reference to JVET-B1001,2.5.2 Secondary Transforms .JEM2, nsst_idx, also referred to as rot_idx). In other words, the secondary transform identifier is information about the contents of (inverse) Secondary transformation in the data units of interest.
[0094]
　For example, secondary converter identifier st_idx, if its value is greater than 0, an identifier for specifying the matrix (inverse) Secondary transformation. In other words, in this case, the secondary transform identifier st_idx shows the execution of (inverse) Secondary transformation. Further, for example, secondary converter identifier st_idx, if its value is 0, indicating the skip (inverse) Secondary transformation.
[0095]
　Scan identifier (scanIdx) is information about the scanning method. Quantization parameter (qp) is the data unit of interest is information indicating the quantization parameter used for (inverse) quantization. Quantization matrices (Scaling_matrix), in the data unit of interest is information indicating the quantization matrix used in the (inverse) quantization (e.g., JCTVC-W1005, 7.3.4 Scaling list data syntax).
[0096]
　Of course, the content of the conversion information TINFO is optional, any information other than the examples described above may be included in the conversion information TINFO.
[0097]
　Header information Hinfo, for example, it is supplied to each block. Prediction mode information Pinfo, for example, is supplied to the coding section 114 and the prediction unit 119. Conversion information Tinfo, for example, conversion unit 112, a quantization unit 113, an encoding unit 114, are supplied to the inverse quantization unit 115, and inverse transform unit 116.
[0098]
　Computing unit 111 from the image I corresponding to the block of the input processing unit, a predicted image P supplied from the prediction unit 119 obtains a prediction residual D is subtracted as shown in equation (9), it and supplies to the converter 112.
[0099]
　Ｄ＝Ｉ－Ｐ
　・・・（９）
[0100]
　Converter 112, based on the conversion information Tinfo supplied from the control unit 101 performs conversion processing on prediction residual D supplied from the arithmetic unit 111, and the transform coefficients Coeff. Conversion unit 112 supplies the transform coefficients Coeff to the quantization unit 113. The conversion unit 112, when converting skip or transformed and quantized bypass, conversion processing (primary conversion and secondary conversion) skipped (omitted), also be supplied to the quantization unit 113 and the prediction residual D as the conversion coefficient Coeff it can.
[0101]
　Quantization unit 113, based on the conversion information Tinfo supplied from the control unit 101, a scaling (quantized) transformation coefficients Coeff supplied from the conversion unit 112. That is, the quantization unit 113, the conversion process is performed transform coefficients Coeff, or quantizes the conversion process skips (optional) transform coefficients Coeff (i.e. prediction residual D). Quantization unit 113, transform coefficients after quantization obtained through the quantization, ie supplies quantized transform coefficient level level to encoding section 114 and the inverse quantization unit 115. Incidentally, the quantization unit 113, when converting the quantization bypass may be quantization processing skips (optional), is supplied to the encoding unit 114 to transform coefficients Coeff as quantized transform coefficient levels level.
[0102]
　Encoding unit 114 encodes the quantized transform coefficient levels level like supplied from the quantization unit 113 in a predetermined manner. For example, the coding unit 114, along with the definition of the syntax table, coding parameters supplied from the control unit 101 (header information Hinfo, prediction mode information pinfo, such conversion information TINFO) and, supplied from the quantization unit 113 the quantized transform coefficient level level that is, converted into the syntax values ​​of each syntax element, coding each syntax value (e.g., arithmetic coding), and generates a bit sequence (encoded data).
[0103]
　The encoding unit 114 derives a residual information rinfo from the quantized transform coefficient levels level, encodes the residual information rinfo, generates a bit sequence (encoded data).
[0104]
　The residual information rinfo, for example, the last non-zero coefficient X-coordinate (last_sig_coeff_x_pos), last non-zero coefficient Y coordinates (last_sig_coeff_y_pos), sub-block non-zero coefficient presence flag (coded_sub_block_flag), non-zero coefficients presence flag (sig_coeff_flag), non level of zero coefficients is flag information indicating whether greater than 1 GR1 flag (gr1_flag), GR2 flag level of the non-zero coefficient is flag information indicating whether greater than 2 (gr2_flag), indicating the sign of non-zero coefficients sign in a sign code (sign_flag), and the like non-zero coefficient residual level is information indicating the residual level of non-zero coefficients (coeff_abs_level_remaining) (e.g., see 7.3.8.11 residual coding syntax of JCTVC-W1005).
[0105]
　Of course, the content of residual information rinfo is optional, any information other than the examples described above may be included in the residual information rinfo.
[0106]
　Encoding unit 114, for example, a bit string of each syntax element is encoded (encoded data) multiplexed, and outputs it as bit stream.
[0107]
　Inverse quantization unit 115, based on the conversion information Tinfo supplied from the control unit 101, the scaling values ​​of the quantized transform coefficient levels level supplied from the quantization unit 113 (inverse quantization) and, after dequantization to derive the conversion coefficient Coeff_IQ. Inverse quantization unit 115 supplies the transform coefficients Coeff_IQ inverse transformation unit 116. Incidentally, the inverse quantization unit 115, when converting the quantization bypass, inverse quantization processing is skipped (omitted), may be supplied to the inverse transform unit 116 a quantized transform coefficient level level as the transformation coefficient Coeff_IQ. Inverse quantization performed by the inverse quantization unit 115, an inverse process of the quantization performed by the quantization unit 113 is the same processing as the inverse quantization performed in the image decoding apparatus described later. Therefore, this inverse quantization will be described later in description of the image decoding apparatus.
[0108]
　Inverse transform unit 116, based on the conversion information Tinfo supplied from the control unit 101 performs inverse transform on the transform coefficients Coeff_IQ supplied from the inverse quantization unit 115 derives a prediction residual D '. Inverse transform unit 116 supplies the prediction residual D 'to the arithmetic unit 117. Incidentally, the inverse transform unit 116, when converting skip or transformed and quantized bypass, the inverse transform processing (inverse secondary transform and inverse primary transform) skipped (omitted), the operation unit conversion coefficient Coeff_IQ as a prediction residual D '117 It can also be supplied to. Inverse conversion performed by the inverse transformation unit 116, an inverse process of conversion performed by the conversion unit 112, an inverse transform and the same processing performed in the image decoding apparatus described later. Therefore, this inverse transform will be described later in description of the image decoding apparatus.
[0109]
　Calculation unit 117, the prediction residual D supplied from the inverse transform unit 116 'and is supplied from the prediction unit 119, the prediction residual D' and the predicted image P (prediction signal) corresponding to the following formula adding to derive the local decoded image Rec as (10). Operation unit 117 supplies the local decoded image Rec in the frame memory 118.
[0110]
　Rec＝Ｄ’＋Ｐ
　・・・（１０）
[0111]
　Frame memory 118, reconstructs the decoded image for each picture unit with a local decoded image Rec supplied from the arithmetic unit 117 is stored in the buffer in the frame memory 118. The frame memory 118 is read out from the buffer the decoded image is designated by the prediction unit 119 as a reference image, and supplies the prediction unit 119. The frame memory 118, the header information Hinfo according to generation of the decoded image, the prediction mode information pinfo, and conversion information TINFO, may be stored in a buffer in the frame memory 118.
[0112]
　Prediction unit 119 is designated by the prediction mode information pinfo, acquires the decoded image stored in the frame memory 118 as a reference image, using the reference image, the predicted image by the prediction method specified by the prediction mode information Pinfo to generate a P. Prediction unit 119 supplies the generated prediction image P in the arithmetic unit 111 and the operation unit 117.
[0113]
　In such an image coding apparatus 100, when to skip a primary transform is a transformation process for prediction residual that is a difference image and the predicted image of the image, the primary transform the prediction residual is obtained it is primary converted secondary transformation is a conversion process for coefficients so that a control unit to skip.
[0114]
　　
　FIG. 6 is a block diagram showing a main configuration example of a conversion unit 112. 6, the conversion unit 112 includes a switch 131, a primary converter section 132 and a secondary converter section 133,.
[0115]
　Switch 131 is one embodiment of a control unit for controlling the execution of the primary converter and a secondary converter. For example, the switch 131, when to skip the primary conversion is controlled to be to skip the secondary conversion. For example, the switch 131 is included in the conversion information TINFO, depending on the value of the conversion the skip flag ts_flag about skipping the primary conversion, controls the supply destination of the prediction residual D supplied from the arithmetic unit 111.
[0116]
　For example, when the value of the conversion the skip flag ts_flag is 0, i.e., if the conversion the skip flag ts_flag indicates execution of the conversion (primary conversion), the switch 131, to perform at least the primary conversion. That is, in this case, the switch 131 supplies the prediction residual D to the primary conversion unit 132.
[0117]
　Further, when the value of the conversion the skip flag Ts_flag is 1, i.e., indicating skip (optional) conversion is converted skip flag Ts_flag (primary conversion), the switch 131, thereby skipping the primary translation and a secondary translation. That is, in this case, the switch 131 supplies the quantization unit 113 and the prediction residual D as the conversion coefficient Coeff.
[0118]
　Thus, converter 112 can be easily suppress unnecessary increase in the processing amount of the conversion.
[0119]
　For example, 4 × 4 prediction residual D matrix = [[255, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0,0,0, 0]], such as, a small number sparse residual signal of non-zero coefficients (prediction residual D) is to suppress the reduction of energy compaction, in order to suppress the reduction of the coding efficiency, conversion skip (primary it is desirable to apply the transform and skip secondary conversion). Switch 131 is, by controlling the execution of the conversion in accordance with the value of the conversion the skip flag ts_flag as described above, especially for a small number sparse residual signal of such non-zero coefficients, more readily primary secondary transformation not only convert also can be skipped to suppress an increase in the processing amount of the conversion, it is possible to suppress the reduction of the coding efficiency.
[0120]
　The switch 131 is included in the conversion information TINFO, according to the value of the transformed and quantized bypass flag Transquant_bypass_flag, may control the destination of the prediction residual D supplied from the arithmetic unit 111.
[0121]
　For example, if the value of the transformed and quantized bypass flag transquant_bypass_flag is 0, i.e., when the transformed and quantized bypass flag transquant_bypass_flag showing the execution of the conversion and quantization, the switch 131, to perform at least the primary conversion. That is, in this case, the switch 131 supplies the prediction residual D to the primary conversion unit 132.
[0122]
　When the value of the transformed and quantized bypass flag transquant_bypass_flag is 1, i.e., when the transformed and quantized bypass flag transquant bypass_flag indicating the skip transform and quantization (optional), switch 131, thereby skipping the primary translation and a secondary translation . That is, in this case, the switch 131 supplies the quantization unit 113 and the prediction residual D as the conversion coefficient Coeff.
[0123]
　By doing so, converter 112, as in the case of conversion the skip, it is possible to easily suppress unnecessary increase in the processing amount of the conversion.
[0124]
　Primary conversion unit 132, the prediction residual D supplied from the switch 131, for example, to perform the primary conversion of the orthogonal transform or the like. In other words, the primary conversion unit 132, under the control of the switches 131, performs primary conversion.
[0125]
　When performing the primary conversion, the primary conversion unit 132 executes, for example, the primary conversion method corresponding to the value of the primary conversion identifier pt_idx is information about the contents of the primary conversion. For example, the primary conversion unit 132 selects the horizontal direction of the primary conversion Phor and vertical primary conversion Pver specified by the primary conversion identifier Pt_idx, the prediction residual D supplied from the switch 131, for example, the following It performs matrix calculation as in equation (11), and the transform coefficients after the primary conversion Coeff_P (also primary transform coefficients referred to).
[0126]
　Coeff_P＝Phor・Ｄ・Pver T
　・・・（１１）
[0127]
　Incidentally, formula (11) may be modified as the following equation (12).
[0128]
　Coeff_P＝Pver・Ｄ・Phor T
　・・・（１２）
[0129]
　Note that the operator "·" represents an operation for performing an inner product of the matrix-matrix (matrix product) operator "T" represents the operation of the transposed matrix. Primary conversion unit 132 supplies the derived primary transform coefficients Coeff_P the secondary conversion unit 133.
[0130]
　Secondary conversion unit 133 converts the primary transform coefficients Coeff_P supplied from the primary conversion unit 132 into one-dimensional vector, performs a matrix operation for the one-dimensional vector, the one-dimensional vector the matrix calculation is performed performs scaling performs secondary transform is a transformation process to the matrix of the one-dimensional vectors that scaling. That is, the secondary conversion unit 133 performs the secondary conversion under the control of the switch 131.
[0131]
　Secondary transformation unit 133, and the secondary conversion identifier st_idx is information about the contents of the secondary conversion, based on the scan identifier scanIdx and is information about the scanning method of the transform coefficients, performs secondary transform to the primary transform coefficients Coeff_P, secondary deriving the transform coefficients Coeff after conversion (also referred to as secondary transform coefficients).
[0132]
　As shown in FIG. 6, the secondary conversion unit 133 includes a rasterizer 141, a matrix computation unit 142, a scaling unit 143, the matrix section 144 and a secondary change selecting section 145,.
[0133]
　Rasterizing unit 141, based on the scan method of transform coefficients that is specified by the scan identifier ScanIdx, for each sub-block (4x4 sub-blocks), the primary transform coefficients Coeff_P at 1 × 16 dimensional supplied from the primary conversion unit 132 vector X 1D to convert to. Rasterizing unit 141, the resulting vector X 1d supplies the matrix calculator 142.
[0134]
　A of FIG. 7 shows a scan type scanType specified by the value of the scan identifier ScanIdx. As will be shown in A of FIG. 7, when the scan identifier scanIdx is zero, it is specified oblique direction scan (up-right diagonal scan), when the scan identifier scanIdx is 1, the horizontal scan (horizontal fast scan) specified, the scan identifier scanIdx the case 2, the vertical scanning (vertical fast scan) is designated. D of B through 7 in FIG. 7 shows a scanning order of coefficients in each scan in 4 × 4 sub-blocks. In D of B through 7 in FIG. 7, number assigned to each coefficient position indicates the order in which the coefficient position is scanned. B of FIG. 7 shows a scanning order of an example of a horizontal scan (horizontal fast scan), C in FIG. 7 shows an example of a scan order vertical scanning (vertical fast scan), D in FIG. 7, an example of a scan order in an oblique direction scan (up-right diagonal scan).
[0135]
　For example, a conversion skip flag ts_flag is 0, the primary transform coefficients Coeff_P supplied from the primary conversion unit 132, and a matrix of 4 × 4 as shown in the following equation (13).
[0136]
[Formula

　6] · (13)
[0137]
　The scan identifier scanIdx to denote the horizontal scanning hor. In this case, the rasterization unit 141, the primary conversion coefficients Coeff_P, scanned along a scanning order of the coefficients of the horizontal scan of B in FIG. 7, 1 × 16 dimensional vector X as shown in the following equation (14) 1d to convert to. Rasterizing unit 141, the vector X determined 1d supplies the matrix calculator 142.
[0138]
[Number

　7] · · · (14)
[0139]
　Secondary change selecting section 145 supplies the matrix R of the secondary conversion, read from the internal memory (not shown) of the secondary change selecting section 145, the matrix calculator 142 which is specified by the secondary conversion identifier St_idx. For example, a secondary change selecting section 145, when the value of a secondary conversion identifier St_idx, as the secondary conversion, reads the matrix R of 16 × 16 as shown in FIG. 8, and supplies the matrix calculator 142.
[0140]
　Incidentally, the secondary change selecting section 145, a secondary conversion identifier st_idx and intra prediction mode information IPinfo (e.g., prediction mode number) in accordance with, may select the matrix R of the secondary conversion. Further, the secondary change selecting section 145, instead of the intra prediction mode information IPinfo, in response to the movement prediction information MVinfo and secondary conversion identifier St_idx, may be selected to convert R.
[0141]
　Matrix calculator 142, a one-dimensional vector X 1d using matrix R and secondary conversion, performs a matrix calculation shown in equation (15) below, the result Y 1d supplies the scaling unit 143.
[0142]
　Y 1d T＝Ｒ・X 1d T
　・・・（１５）
[0143]
　Here, the operator "T" represents the operation of the transposed matrix. For example, the vector X in formula (14) 1d by the matrix product of matrices R secondary conversion shown in FIGS. 8, results Y as the following equation (16) 1d is obtained.
[0144]
[Formula

　8] · (16)
[0145]
　Scaling unit 143, the signal Y supplied from the matrix calculator 142 1d to normalize the norm of, (a natural number N) performs bit shift operation of the bit, such N as shown in the following equation (17), signal Z after bit shifting 1d seek.
[0146]
　Z 1d＝（Y 1d）>>Ｎ
　・・・（１７）
[0147]
　Note that before the shift operation of N bits as shown in the following expression (18), as an offset, 1 << a value of (N-1), the signal Z 1d may be added to each element of.
[0148]
　Z 1d＝（Y 1d＋（（N-1）<<1）・Ｅ）>>Ｎ
　・・・（１８）
[0149]
　In the equation (18), E is the value of all the elements is 1 × 16 dimensional vector of 1. For example, the matrix R of the secondary transform that is shown in Figure 8, since a matrix is 8-bit scaling, the scaling unit 143, the value of N used for the normalization of the norm is 8. For example, the formula (16) signal Y shown in 1d in equation (18), and when calculated as N = 8, results Z as shown in equation (19) 1d is obtained.
[0150]
[Number

　9] · · · (19)
[0151]
　Generally, the matrix R of the secondary conversion, if it is N bits scaling, bit shift amount of the norm normalization is N bits. Scaling unit 143, the signal Z obtained as above 1d supplies the matrixing unit 144.
[0152]
　Matrixing unit 144, based on the scan method specified by the scan identifier scanIdx, 1 × 16 dimensional vector Z after norm normalization 1d converts the into 4 × 4 matrix X. For example, the matrix section 144, 1 × 16 dimensional vector Z shown in formula (19) 1d shown to and matrixing based on the horizontal scan shown in B of FIG. 7, the following equation (20) 4x4 obtaining a transformation coefficient Coeff matrix.
[0153]
[Formula

　10] ... (20)
[0154]
　Matrixing unit 144 supplies the obtained transform coefficient Coeff to the quantization unit 113.
[0155]
　For example, if the conversion the skip flag ts_flag indicates skip conversion process (primary conversion), switch 131 is allowed to skip the primary conversion and secondary conversion, performs quantization quantization unit 113 to the prediction residual D, encoding part 114 encodes the quantized transform coefficient levels and converted skip flag Ts_flag, may generate a bitstream including those encoded data.
[0156]
　　
　Next, an example of the flow of each process executed by the image encoding apparatus 100. First, an example of the flow of the image encoding process will be described with reference to the flowchart of FIG.
[0157]
　When the image coding process is started, in step S101, the control unit 101 performs encoding control processing, performs setting of block division and the coding parameter.
[0158]
　In step S102, the prediction unit 119 performs prediction processing, and generates a prediction image or the like of the optimum prediction mode. For example, in the prediction processing, the prediction unit 119 performs intra prediction to generate a prediction image or the like of the optimum intra prediction mode by performing inter prediction generates a prediction image like the optimal inter prediction mode, their from within, to select an optimal prediction mode based on a cost function value and the like.
[0159]
　In step S103, the calculation unit 111 calculates the difference between the input image, and the prediction image of the selected optimum mode by the prediction processing in step S102. That is, the arithmetic unit 111 generates a prediction residual D between the input image and the prediction image. Prediction residual D obtained in this way, the data amount is reduced as compared to the original image data. Therefore, as compared with the case of directly coding the image, it is possible to compress the data amount.
[0160]
　In step S104, the conversion unit 112 performs conversion processing on the prediction residual D generated by the processing in step S103, and the transform coefficients Coeff. It will be described later in detail the processing in step S104.
[0161]
　In step S105, the quantization unit 113, and the like using the quantization parameters calculated by the control unit 101, the transform coefficient Coeff obtained by the process of step S104 is quantized to derive the quantized transform coefficient level level .
[0162]
　In step S106, the inverse quantization unit 115, the quantized transform coefficient level level generated by the processing in step S105, inverse quantization with characteristics corresponding to the characteristics of the quantization of the step S105, and the transform coefficients Coeff_IQ .
[0163]
　In step S107, the inverse transform unit 116, the transform coefficients Coeff_IQ obtained by the processing in step S106, the inverse transform by a method corresponding to the conversion process in step S104, to derive a prediction residual D '. Incidentally, the inverse transform process is the inverse process of the conversion process in step S104, are performed similarly to the inverse transform processing performed by the image decoding process described below. Therefore, description of the inverse conversion process is carried out in the description of the decoding side.
[0164]
　In step S108, the arithmetic unit 117 processes the prediction residual D 'derived by the step S107, by adding the predicted image obtained by the prediction processing in step S102, the decoded picture which is locally decoded generated.
[0165]
　In step S109, the frame memory 118 is obtained by the processing in step S108, and stores the decoded picture which is locally decoded.
[0166]
　In step S110, the encoding unit 114 encodes the quantized transform coefficient levels level obtained by the processing in step S105. For example, the coding unit 114, the quantized transform coefficient level level is information about the image, coded by arithmetic encoding or the like, to generate encoded data. At this time, the coding unit 114, various coding parameters (header information Hinfo, prediction mode information pinfo, conversion information TINFO) for encoding. Furthermore, the coding unit 114 derives a residual information rinfo from the quantized transform coefficient levels level, encodes the residual information rinfo. Coding section 114, collectively coded data of the generated various kinds of information in this manner, and outputs to the outside of the image coding apparatus 100 as a bit stream. This bit stream, for example, is transmitted to the decoding side through a transmission path or a recording medium.
[0167]
　When the process of step S110 is completed, the image encoding process is completed.
[0168]
　These processes units of each processing is arbitrary, it may not be identical to each other. Accordingly, the process of each step, as appropriate, in parallel with the processing of the other steps, or may be executed by interchanging the processing order.
[0169]
　　
　Next, an example of a conversion processing flow to be executed in step S104 of FIG. 9 will be described with reference to a flowchart of FIG. 10.
[0170]
　Determining the conversion process is started, in step S121, whether the switch 131, converts the skip flag ts_flag is 1 (true). If the conversion the skip flag ts_flag is determined to 1 a (true) (conversion skip flag ts_flag indicating the skip conversion process), the primary converter and a secondary conversion (processing of steps S122 to step S130) is skipped, the conversion process but finished, the process returns to Figure 9. That is, the switch 131 supplies the quantization unit 113 and the prediction residual D as the conversion coefficient Coeff. Further, in step S121, if the conversion the skip flag ts_flag is determined to 0 is (false) (conversion skip flag ts_flag indicating the execution of a conversion process), the process proceeds to step S122.
[0171]
　Note that, in step S121, the switch 131 is further conversion quantization bypass flag transquant_bypass_flag may be determined whether or not 1 (true). At that time, if the conversion quantization bypass flag transquant_bypass_flag is determined 1 is (true) (transformed and quantized bypass flag transquant_bypass_flag indicating the skip of the conversion process and quantization process), the primary converter and the secondary converter (step S122 through the process of step S130) is skipped, the conversion process is completed, the process returns to FIG. That is, the switch 131 supplies the quantization unit 113 and the prediction residual D as the conversion coefficient Coeff. Further, in step S121, when the conversion quantization bypass flag transquant_bypass_flag is determined 0 is (false) (transformed and quantized bypass flag transquant_bypass_flag indicating the execution of the conversion process and quantization process), the process proceeds to step S122 .
[0172]
　In step S122, the primary conversion unit 132, based on the primary transformation identifier Pt_idx, performs primary conversion for the prediction residual D, and deriving a primary transform coefficients Coeff_P.
[0173]
　In step S123, the secondary conversion unit 133 determines whether or not the secondary conversion identifier St_idx applies a secondary conversion (st_idx> 0). If the secondary transform identifier st_idx is 0 (secondary transform identifier st_idx indicates skip secondary conversion) is determined, the secondary conversion (processing of steps S124 to step S130) is skipped, the conversion process is completed, the process Returning to FIG. 9. That is, the secondary conversion unit 133 supplies the quantization unit 113 to the primary transform coefficients Coeff_P as the transformation coefficient Coeff.
[0174]
　Further, in step S123, if the secondary conversion identifier st_idx is determined to be greater than 0 (indicating execution secondary transform identifier st_idx the secondary conversion), the processing proceeds to step S124. Step S124 to the secondary converted by the process of step S130 is executed.
[0175]
　In step S124, the secondary change selecting section 145 selects the matrix R of the secondary transform that is specified by the secondary conversion identifier St_idx.
[0176]
　In step S125, the secondary conversion unit 133 divides the transform block to be processed into sub-blocks, selects an unprocessed sub-block.
[0177]
　In step S126, the rasterization unit 141, based on the scan method specified by the scan identifier ScanIdx, the primary transform coefficients Coeff_P 1 × 16 dimensional vector X 1d is converted to.
[0178]
　In step S127, the matrix computing unit 142, vector X 1d calculates the matrix product of the matrix R and the secondary conversion, vector Y 1d seek.
[0179]
　In step S128, the scaling unit 143, the vector Y 1d normalizes the norm of the vector Z 1d seek.
[0180]
　In step S129, the matrix section 144, based on the scan method specified by the scan identifier ScanIdx, vector Z 1d converts the matrix of 4 × 4, obtaining the conversion coefficient Coeff of processed sub-blocks. The transform coefficient Coeff is supplied to the quantization unit 113.
[0181]
　In step S130, the secondary conversion unit 133 determines whether processing of all of the sub-blocks of transform blocks processed. If unprocessed sub-block is determined to exist, processing returns to step S125, the repeat the process. That is, for each sub-block of transform blocks processed, the processing in steps S125 to step S130 (secondary conversion) is executed. In step S130, if it is determined that the processing of all the sub-blocks (were secondary conversion of all sub blocks), the conversion process is completed, the process returns to FIG.
[0182]
　The conversion process is a feasible range, the processing order and replacement steps, may change the contents of processing. For example, if it is determined that the secondary conversion identifier st_idx = 0 in step S123, 16 matrix of × 16 is selected as the matrix R of the secondary conversion, as the processing in steps S125 through step S130 is executed it may be.
[0183]
　By executing the processes as described above, the image coding apparatus 100 can be skipped even secondary transform not only the primary conversion by indicating the skip conversion process in the conversion the skip flag Ts_flag. Thus, for example, for a small number sparse residual signal of non-zero coefficients it is desirable to apply the transform skip, more easily, reducing the processing amount of the conversion, and suppressing a decrease in energy compaction coding improved conversion efficiency can be performed.
[0184]
　　
　Next, a description will be given decoding of encoded data encoded as described above. Figure 11 is a block diagram showing an example of a configuration of an image decoding apparatus which is an embodiment of an image processing apparatus to which the present technology is applied. The image decoding apparatus 200 shown in FIG. 11 is an image decoding apparatus corresponding to the image encoding apparatus 100 of FIG. 5, the image encoding apparatus 100 is generated encoded data (bit stream), the image coding apparatus 100 decoding by the decoding method corresponding to the encoding method according. For example, the image decoding device 200, technologies and proposed in HEVC, implementing the proposed technique in JVET.
[0185]
　Incidentally, in FIG. 11 shows the main ones, such as the flow of the processing unit and data is not all that shown in Figure 11. That is, the image decoding apparatus 200, or there is processing unit not shown as a block in FIG. 11 may be or there is a flow of processing and data not shown as arrows or the like in FIG. 11.
[0186]
　The image decoding apparatus 200 as shown in FIG. 11 includes a decoding unit 211, an inverse quantization unit 212, inverse transform unit 213, arithmetic unit 214, frame memory 215 and the prediction unit 216,. The image decoding apparatus 200, for example via a transmission medium or a recording medium such as the image coding apparatus 100 or the like is supplied as encoded data generated by, for example, a bit stream or the like.
[0187]
　Decoding unit 211, the encoded data supplied is decoded by a predetermined decoding method corresponding to the coding method. For example, the decoding unit 211, along with the definition of the syntax table, a bit string of the supplied encoded data (bit stream) and decodes the syntax values ​​of each syntax element. The syntax element, for example, header information Hinfo, prediction mode information pinfo, conversion information TINFO, includes information such as the residual information rinfo.
[0188]
　Decoding section 211 refers to the residual information rinfo, to derive the quantized transform coefficient levels level for each coefficient position in each transform block. Decoding unit 211 supplies the prediction mode information Pinfo obtained by decoding the quantized transform coefficient levels level, the conversion information Tinfo to each block. For example, the decoding unit 211 supplies the prediction mode information Pinfo to the prediction unit 216 supplies the quantized transform coefficient level level to the inverse quantization unit 212, a conversion information Tinfo to the inverse quantization unit 212 and inverse transform unit 213 supplies.
[0189]
　Inverse quantization unit 212, based on the conversion information Tinfo supplied from the decoding unit 211, the value of the quantized transform coefficient levels level supplied from the decoding unit 211 scales (inverse quantization) to the dequantized to derive a conversion coefficient Coeff_IQ. The inverse quantization is an inverse process of the quantization performed by the quantization unit 113 of the image coding apparatus 100 (FIG. 5). Incidentally, the inverse quantization unit 115 (FIG. 5) performs the same inverse quantization and the inverse quantization unit 212. Inverse quantization unit 212 supplies the obtained transform coefficient Coeff_IQ the inverse transform unit 213. Incidentally, the inverse quantization unit 212, when converting the quantization bypass, inverse quantization processing is skipped (omitted), may be supplied to the inverse transform unit 213 a quantized transform coefficient level level as the transformation coefficient Coeff_IQ.
[0190]
　Inverse transform unit 213, based on the conversion information Tinfo supplied from the decoding unit 211, inverse transform the transform coefficients Coeff_IQ supplied from the inverse quantization unit 212 derives a prediction residual D '. This inverse transform is the inverse process of the conversion processing performed by the conversion unit 112 of the image coding apparatus 100 (FIG. 5). Incidentally, the inverse transform unit 116 performs the same inverse transform and the inverse transform unit 213. Details of the reverse transformation will be described later. Inverse transform unit 213 supplies the obtained prediction residual D 'to the arithmetic unit 214. Incidentally, the inverse transform unit 213, when converting skip or transformed and quantized bypass, the inverse transform processing (inverse secondary transform and inverse primary transform) skipped (omitted), the calculation unit 214 to transform coefficients Coeff_IQ as prediction residual D ' It can also be supplied.
[0191]
　Calculation unit 214, as shown in the following equation (21), adds the predicted image P (prediction signal) corresponding prediction residual D supplied from the inverse transform unit 213 'and its prediction residual D' in and derives a local decoded image Rec. Calculation unit 214, by using the obtained local decoded image Rec reconstructs the decoded image for each picture unit, and outputs the decoded image obtained on the outside of the image decoding apparatus 200. The arithmetic unit 214 also supplies the local decoded image Rec in the frame memory 215.
[0192]
　Rec＝Ｄ’＋Ｐ
　・・・（２１）
[0193]
　Frame memory 215, reconstructs the decoded image for each picture unit with a local decoded image Rec supplied from the arithmetic unit 214 is stored in a buffer in the frame memory 215. The frame memory 215 is read out from the buffer the decoded image is designated by the prediction mode information Pinfo prediction unit 216 as a reference image, and supplies the prediction unit 216. The frame memory 215, the header information Hinfo according to the generation of the decoded image, the prediction mode information pinfo, may be stored, such as in the buffer in the frame memory 215 converts information TINFO.
[0194]
　Prediction unit 216, is designated by the prediction mode information PInfo supplied from the decoding unit 211, it acquires the decoded image stored in the frame memory 215 as a reference image, using the reference image, by the prediction mode information Pinfo the prediction method is designated to generate the predicted image P. Prediction unit 216 supplies the generated predicted image P, the arithmetic unit 214.
[0195]
　In such an image decoding apparatus 200, when to skip the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual that is a difference image and the predicted image of the image, the prediction residual is the primary inverse secondary transform that is the inverse of the secondary transform is a transformation processing on the primary transform coefficients obtained are converted also to a control unit to skip.
[0196]
　　
　FIG. 12 is a block diagram showing a main configuration example of the inverse transform unit 213 of FIG. 11. As shown in FIG. 12, the inverse transform unit 213, a switch 231, the inverse secondary transform unit 232, and the inverse primary transform unit 233.
[0197]
　Switch 231 is one embodiment of a control unit for controlling the execution of the inverse secondary transform and inverse primary transform. For example, the switch 231, when to skip the inverse primary transform is controlled to reverse secondary transform may be skipped. For example, switch 231 performs such a control in accordance with the value of the value of the conversion the skip flag ts_flag is information about skipping inverse primary transform.
[0198]
　For example, if the value of the conversion the skip flag ts_flag is 0, i.e., when the conversion the skip flag ts_flag indicating the execution of the inverse transform (inverse primary transform), the switch 231, to perform the inverse secondary transform and inverse primary transform. That is, in this case, the switch 231 supplies the transform coefficients Coeff_IQ Conversely secondary conversion unit 232.
[0199]
　In contrast, when the value of the conversion the skip flag ts_flag is 1, i.e., when the conversion the skip flag ts_flag showing skipping inverse transform (inverse primary transform) (optional), switch 231, inverse secondary transform and inverse primary transform It is allowed to skip. That is, in this case, the switch 231 supplies the calculating unit 214 to transform coefficients Coeff_IQ as prediction residual D '.
[0200]
　Accordingly, the inverse transform unit 213 can be easily suppress unnecessary increase of the inverse transform of the processing amount.
[0201]
　For example, 4 × 4 matrix Coeff_IQ = [[255, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0,0,0,0]] of such, fewer sparse residual signal of non-zero coefficients (transform coefficients Coeff_IQ) suppresses the reduction in the energy compaction, in order to suppress the reduction of the coding efficiency, conversion skip (inverse secondary transform and inverse primary it is desirable to apply a skip) conversion. Switch 231, by controlling the execution of the inverse transformation according to the value of the conversion the skip flag ts_flag as described above, especially for a small number sparse residual signal of such non-zero coefficients, easier inverse secondary transform not only the inverse primary transform can also be skipped, suppressing an increase in the inverse transform processing amount, it is possible to suppress the reduction of the coding efficiency.
[0202]
　The switch 231 is included in the conversion information TINFO, according to the value of the transformed and quantized bypass flag Transquant_bypass_flag, may control the destination of the transform coefficients Coeff_IQ supplied from the outside.
[0203]
　For example, if the value of the transformed and quantized bypass flag transquant_bypass_flag is 0, i.e., when the transformed and quantized bypass flag transquant_bypass_flag indicating the execution of the inverse transformation and inverse quantization, the switch 231, the transform coefficients Coeff_IQ Conversely secondary transform unit 232 supplies.
[0204]
　When the value of the transformed and quantized bypass flag transquant_bypass_flag is 1, i.e., when the transformed and quantized bypass flag transquant bypass_flag indicating the skip transform and quantization (optional), switch 231, inverse secondary transform and inverse primary transform to skip. That is, in this case, the switch 231 supplies the calculating unit 214 to transform coefficients Coeff_IQ as prediction residual D '.
[0205]
　Accordingly, the inverse transform unit 213, like the conversion the skip, it is possible to easily suppress unnecessary increase in the processing amount of the conversion.
[0206]
　Inverse secondary transform unit 232, a secondary transform coefficients supplied from the switch 231, i.e., encoded data is decoded, to convert the secondary transform coefficients obtained by inverse quantized to 1-dimensional vectors, one-dimensional vector that It performs matrix operation for, scale the one-dimensional vector that matrix operation is performed, an inverse secondary transform that is a conversion processing for the matrix of a one-dimensional vectors that scaling. In other words, the inverse secondary transform unit 232 performs inverse secondary transform under the control of the switch 231.
[0207]
　Inverse secondary transform unit 232, and the secondary conversion identifier st_idx is information about the contents of the secondary conversion, based on the scan identifier scanIdx and is information about the scanning method of the transform coefficients, performs an inverse secondary transform to the transform coefficients Coeff_IQ, deriving the transform coefficients Coeff_IS after inverse secondary transform (also referred to as primary conversion factor). Inverse secondary transform unit 232, the primary conversion coefficients Coeff_IS, supplies the inverse primary transform unit 233. The details of the inverse secondary transform unit 232 will be described later.
[0208]
　Inverse primary transform unit 233 to the primary transform coefficients Coeff_IS supplied from the inverse secondary transform unit 232, for example, performs an inverse primary transform of the inverse orthogonal transform or the like. In other words, the inverse primary transform unit 233, under the control of the switch 231, an inverse primary transform.
[0209]
　When performing an inverse primary transform, inverse primary transform unit 233, for example, perform an inverse primary transform in a manner corresponding to the value of the primary conversion identifier pt_idx is information about the contents of the inverse primary transform. For example, the inverse primary transform unit 233 selects the horizontal inverse primary transform IPhor and vertical inverse primary transform IPver specified by the primary conversion identifier pt_idx supplied from the decoding unit 211, the converted coefficient Coeff_IS, for example performs matrix operation of equation (22) to derive a prediction residual D '.
[0210]
　Ｄ’＝IPhor・Coeff_IS・IPver T
　・・・（２２）
[0211]
　Here, the operator "·" represents an operation for performing an inner product of the matrix-matrix (matrix product) operator "T" represents the operation of the permutation matrix. The inverse primary transform IPhor in the horizontal direction, an inverse transform in the horizontal direction of the primary conversion Phor, Phor T (= Phor -1 ) also it is expressed. Similarly, the inverse primary transform IPver the vertical direction is the inverse of the vertical direction of the primary conversion PVER, PVER T (= PVER -1 ) also it is expressed. Incidentally, the above-mentioned formula (22) may be modified as the following equation (23).
[0212]
　Ｄ’＝IPver・Coeff_IS・IPhor T
　・・・（２３）
[0213]
　Inverse primary transform unit 233 supplies the obtained prediction residual D 'to the arithmetic unit 214.
[0214]
　Next, a description will be given inverse secondary transform unit 232. As shown in FIG. 12, the inverse secondary transform unit 232 includes a rasterizer 241, a matrix computation unit 242, a scaling unit 243, the matrix unit 244, and the inverse secondary transform selection portion 245.
[0215]
　Rasterizing unit 241, based on the scan method of transform coefficients that is specified by the scan identifier scanIdx supplied from the decoding unit 211, for each sub-block (4 × 4 sub-blocks), the transform coefficients Coeff_IQ supplied from the switch 231 1 × 16 dimensional vector X 1d is converted to. Rasterizing unit 241, the resulting vector X 1d supplies the matrix calculator 242. It should be noted that each scan method corresponding scan identifier scanIdx as is information about scan method of transform coefficients is as described above with reference to FIG.
[0216]
　For example, transform coefficients Coeff_IQ supplied to the inverse transform unit 213, and 4 is a × 4 matrix as shown in the following equation (24).
[0217]
[Number

　11] · (24)
[0218]
　Converting skip flag ts_flag is 0, if the scan identifier scanIdx indicates horizontal scan hor, rasterizing unit 241 scans along the scanning order of the coefficients of the horizontal scan indicated a conversion coefficient Coeff_IQ in B of FIG. 7, the following 1 × 16 dimensional vector X as shown in equation (25) 1d is converted to. The rasterization unit 241, the resulting vector X 1d supplies the matrix calculator 242.
[0219]
[Number

　12] · (25)
[0220]
　Inverse secondary transform selection portion 245 is supplied from the decoding unit 211, inverse secondary transform matrix IR specified by the secondary conversion identifier st_idx is information about the contents of the secondary conversion (= R T a), inverse secondary transform selector 245 read from the internal memory (not shown) to supply the signal to the matrix calculator 242. For example, the inverse secondary transform selection portion 245, when the value of a secondary conversion identifier St_idx, as a matrix IR inverse secondary transform, transpose matrix R matrix R 16 × 16 as shown in FIG. 8 T reads, matrix it and supplies to the computing unit 242.
[0221]
　Incidentally, the inverse secondary transform selection portion 245, for example, secondary converter identifier st_idx and intra prediction mode information IPinfo supplied from the decoding unit 211 (e.g., intra prediction mode number) in accordance with the inverse secondary transform matrix IR (= R T ) may be selected. Further, instead of the intra prediction mode information IPinfo, according to the motion prediction information MVinfo and secondary conversion identifier St_idx, may be inverse transform IR is selected.
[0222]
　Matrix operation unit 242, for each sub-block (4 × 4 sub-blocks), 1 × 16 dimensional vector X 1d and inverse secondary transform matrix IR (= R T shown with a), the following equation (26) It performs matrix calculation as the vector Y as a result 1d to derive.
[0223]
　Y 1d T＝IR・X 1d T＝Ｒ T・X 1d T
　・・・（２６）
[0224]
　Here, the operator "T" represents the operation of the transposed matrix. For example, the matrix calculating unit 242, transposed matrix R of the matrix R of the secondary transform that is shown in the vector X1d and 8 shown in the above Expression (25) T by using the, as shown in equation (26) matrix perform product, vector Y as shown in the following equation (27) 1d derives a. Matrix calculator 242, the resulting vector Y 1d supplies the scaling unit 243.
[0225]
[Number

　13] · (27)
[0226]
　Scaling unit 243, for each sub-block (4 × 4 sub-blocks), the signal Y supplied from the matrix calculator 242 1d to normalize the norm of a Yo, shown in the following equation (28) N ( N is the bit shift operation of a natural number) bit signal Y 1d performed for all elements of the signal Z after bit shifting 1d seek.
[0227]
　Z 1d＝（Y 1d）>>Ｎ
　・・・（２８）
[0228]
　Incidentally, as shown in the following equation (29), before the shift operation of N bits as an offset, the value of 1 << (N-1) is, the signal Z 1d so as to be added to each element of it may be. In the equation (29), the vector E is the value of all the elements is 1 × 16 dimensional vector of 1.
[0229]
　Z1d＝（Y1d＋（（N-1）<<1)・E）>>Ｎ
　・・・（２９）
[0230]
　For example, the matrix IR inverse secondary transform shown in FIG. 8 (= R T ) are the matrices which are 8-bit scaling, the scaling unit 243, the value of N used for the normalization of the norm is 8.
[0231]
　For example, in the formula (29), the result of calculation as N = 8 (signal Z 1d ) is given by the following equation (30).
[0232]
[Formula

　14] ... (30)
[0233]
　Generally, the inverse secondary transform matrix IR (= R T ) is, if it is N bits scaling, bit shift amount of the norm normalization is N bits.
[0234]
　Matrixing unit 244, for each sub-block (4 × 4 sub-blocks), the signal Z after norm normalization 1d as inputs and scan identifier ScanIdx, scanning method specified by the scan identifier ScanIdx supplied from the decoding unit 211 based on, 1 × 16 dimensional vector Z supplied from the scaling unit 243 1d converts the primary transform coefficients Coeff_IS of 4 × 4 matrix.
[0235]
　For example, the matrix unit 244, 1 × 16 dimensional vector Z shown in formula (30) 1d to the, and matrixing based on the horizontal scan shown in B of FIG. 7, shown in the following equation (31) obtaining a primary transform coefficients Coeff_IS such 4 × 4 matrix.
[0236]
[Number

　15] · (31)
[0237]
　Matrixing unit 244 supplies the primary transform coefficients Coeff_IS obtained in inverse primary transform unit 233.
[0238]
　　
　Next, a flow of each process executed by the image decoding apparatus 200 will be described. First, with reference to the flowchart of FIG. 13, an example of a flow of the image decoding processing.
[0239]
　When the image decoding process is started, in step S201, the decoding unit 211 decodes the bit stream supplied to the image decoding apparatus 200 (coded data), the header information Hinfo, prediction mode information pinfo, conversion information TINFO, residual information rinfo, obtain information such as quantized transform coefficient levels level.
[0240]
　In step S202, the inverse quantization unit 212, and the transform coefficients Coeff_IQ inversely quantizes the quantized transform coefficient levels level obtained by the processing in step S201. The inverse quantization is the inverse process of the quantization performed in the image coding process step S105 (FIG. 9), the same processing as the inverse quantization performed in step of the image encoding process S106 (FIG. 9) is there.
[0241]
　In step S203, the inverse transform unit 213 inversely transforms the transform coefficients Coeff_IQ obtained by the processing in step S202, to derive a prediction residual D '. This inverse transform is the inverse process of the conversion process performed in the image encoding process step S104 (FIG. 9), the inverse transform processing similar to that performed in step of the image encoding process S107 (FIG. 9).
[0242]
　In step S204, the prediction unit 216, based on the prediction mode information pinfo, making predictions in the prediction and the same prediction mode for encoding, to the predicted image generation.
[0243]
　In step S205, the arithmetic unit 214, the prediction residual D 'obtained by the processing in step S203, it adds the predicted image obtained by the processing in step S204, obtaining a decoded image.
[0244]
　When the process of step S205 is completed, the image decoding process is terminated.
[0245]
　　
　Next, an example of the inverse conversion processing flow executed in step S203 of FIG. 13 will be described with reference to a flowchart of FIG. 14.
[0246]
　When inverse transform processing is started, in step S221, the switch 231, converts the skip flag ts_flag determines whether a 1 (true). If the conversion the skip flag ts_flag is determined to 1 a (true) (conversion skip flag ts_flag indicating the skip of the inverse transform process), the inverse secondary transform and inverse primary transform (processing of steps S222 to step S230) is skipped , inverse transform processing is completed, the process returns to FIG. 13. That is, the switch 231 supplies the transform coefficients Coeff_IQ, the arithmetic unit 214 as a prediction residual D '. Also, if the conversion the skip flag ts_flag is determined to 0 is (false) (shown transform skip flag ts_flag the execution of the inverse transform process), the process proceeds to step S222.
[0247]
　Note that, in step S221, the switch 231 is further conversion quantization bypass flag transquant_bypass_flag may be determined whether or not 1 (true). At that time, if the conversion quantization bypass flag transquant_bypass_flag is determined 1 is (true) (showing a conversion quantization bypass flag transquant_bypass_flag skip the inverse quantization and inverse transformation processing), the inverse secondary transform and inverse primary transform (the process of step S222 to step S230) is skipped, the inverse transform process is completed, the process returns to FIG. 13. That is, the switch 231 supplies the transform coefficients Coeff_IQ, the arithmetic unit 214 as a prediction residual D '. Also, when the transformed and quantized bypass flag transquant_bypass_flag is determined 0 is (false) (conversion quantization bypass flag transquant_bypass_flag showing the execution of the inverse quantization processing and inverse transform processing), the processing proceeds to step S222.
[0248]
　In step S222, the inverse secondary transform unit 232 determines whether the secondary conversion identifier St_idx applies the inverse secondary transform (st_idx> 0). If the secondary transform identifier st_idx is determined to be 0 (indicating the skip of the secondary transform identifier st_idx inverse secondary transform), inverse secondary transform (processing of steps S223 to step S229) is skipped and the process proceeds to step S230 . In other words, the inverse secondary transform unit 232, the transform coefficients Coeff_IQ as the primary transform coefficients Coeff_P, it supplies the inverse primary transform unit 233.
[0249]
　Further, in step S222, if the secondary conversion identifier st_idx is determined to be greater than 0 (indicating execution of a secondary conversion identifier st_idx inverse secondary transform), the process proceeds to step S223. Inverse secondary transform is performed by the processing of step S223 to step S229.
[0250]
　In step S223, the inverse secondary transform selection unit 245 selects the matrix IR inverse secondary transform that is specified by the secondary conversion identifier St_idx.
[0251]
　In step S224, the inverse secondary transform unit 232 selects the unprocessed sub-blocks included in the conversion block to be processed.
[0252]
　In step S225, the rasterization unit 241, based on the scan method that is specified by the scan identifier ScanIdx, the transform coefficients Coeff_IQ 1 × 16 dimensional vector X 1d is converted to.
[0253]
　In step S226, the matrix computing unit 242, vector X 1d calculates the matrix product of the matrix IR of the inverse secondary transform, vector Y 1d seek.
[0254]
　In step S227, the scaling unit 243, the vector Y 1d normalizes the norm of the vector Z 1d seek.
[0255]
　In step S228, the matrix unit 244, based on the scan method that is specified by the scan identifier ScanIdx, converts vector Z1d to matrix 4 × 4, obtaining the primary transform coefficients Coeff_P of processed sub-blocks.
[0256]
　In step S229, the inverse secondary transform unit 232 determines whether or not to process all the sub-blocks of transform blocks processed. If unprocessed sub-block is determined to exist, processing returns to step S224, and the process thereafter is repeated. That is, for each sub-block of transform blocks processed, the processing in steps S224 to step S229 (the inverse secondary transform) is performed. In step S229, if it is determined that the processing of all the sub-blocks (performed inverse secondary transform of all sub blocks), the process proceeds to step S230.
[0257]
　In step S230, the inverse primary transform unit 233, based on the primary transformation identifier Pt_idx, performs inverse primary transform to the primary transform coefficients Coeff_P, derives the prediction residual D '. The prediction residual D 'is supplied to the arithmetic operation unit 214.
[0258]
　When the process of step S230 is completed, the inverse transform process is completed, the process returns to FIG. 13.
[0259]
　Incidentally, the inverse conversion processing described above, in feasible range, the processing order and replacement steps, may change the contents of processing. For example, if the secondary conversion identifier st_idx is determined to be 0 in step S222, 16 matrix of × 16 is selected as a matrix IR inverse secondary transform, as the processing in steps S223 through step S229 is executed it may be.
[0260]
　By executing the processes as described above, the image decoding apparatus 200 may be inverse secondary transform may skip well inverse primary transform by indicating the skip conversion processing by the conversion skip flag Ts_flag. Thus, for example, for a small number sparse residual signal of non-zero coefficients it is desirable to apply the transform skip, reduction of the inverse transform processing amount, and suppressing a decrease in energy compaction, improving the coding efficiency inverse conversion processing can be performed.
[0261]
　<2. Second Embodiment> of
　　encoding and decoding skip> of
　shows an example of a syntax table describing a pseudo code representing such control in FIG. As shown in the fourth stage from the top in FIG. 15, the coding of the transform skip flag Ts_flag (i.e., decoding of the encoded data of the conversion skip flag Ts_flag) is 1 is conditional secondary conversion identifier st_idx is 0 It becomes bracts. That is, when the secondary conversion identifier st_idx is not 0, i.e., if (inverse) secondary transform is performed, the coding of the transform skip flag Ts_flag (decoding of the encoded data of the conversion the skip flag Ts_flag) is skipped.
[0268]
　　
　In this case the image encoding apparatus 100 also basically has the same configuration as in the first embodiment. However, the image coding apparatus 100 in this case, if the image and the prediction residual is the difference between the predicted image of the image secondary conversion is performed on the primary transform coefficients obtained are primary conversion, the primary conversion comprising an encoding unit to skip encoding of first information on a skip. That is, the encoding unit 114 in this case, if the image and the prediction residual is the difference between the predicted image of the image secondary conversion is performed on the primary transform coefficients obtained are primary transform, skipping the primary conversion skip encoding the first information about the.
[0269]
　Figure 16 is realized by the encoding unit 114 in this case executes the program or the like is a functional block diagram showing an example of major functional related to the coding of the transform skip flag Ts_flag. As shown in FIG. 16, the coding unit 114, by executing a program, as a function related to the coding of the transform skip flag Ts_flag, for example, the secondary conversion enable flag coding unit 301, the secondary transform identifier encoding unit 302 may have a function of converting the skip enable flag coding unit 303, the maximum conversion skip block size coding unit 304, converts the quantized bypass flag coding unit 305, and converts the skip flag encoding unit 306.
[0270]
　Secondary transformation valid flag coding unit 301 performs processing related to the coding of a secondary conversion valid flag st_enabled_flag is information about permission of the secondary conversion. Secondary transformation identifier encoding section 302 performs processing related to the coding of the secondary transform identifier st_idx which is information about the contents of the secondary conversion. Converting skip enable flag coding unit 303 performs processing related to the coding of the transform conversion skip enable flag ts_enabled_flag is information about skipping permission (primary conversion). Maximum conversion skip block size coding unit 304 performs processing related to the coding of the maximum conversion skip block size MaxTSSize indicating the maximum size of the transform block skip conversion (primary conversion) is permitted. Transformed and quantized bypass flag coding unit 305 performs processing relating to conversion (the primary conversion and secondary conversion) as well as the coding of the transformed and quantized bypass flag transquant_bypass_flag is information about skipping quantization (bypass). Converting skip flag coding unit 306 performs processing related to the coding of the transform conversion skip flag ts_flag is information about skipping (primary conversion).
[0271]
　　
　Next, an example of the flow of each process executed by the image encoding apparatus 100. In this case the image coding apparatus 100 performs image encoding processing, as in the case with basically the first embodiment. However, in this case, the image encoding apparatus 100, in step of the image encoding process S110 (FIG. 9), the coding of such conversion the skip flag Ts_flag, performed in accordance with the value or the like of the secondary transform identifier St_idx. The example of the encoding stream, such as the conversion skip flag ts_flag be described with reference to the flowchart of FIG. 17. That is, the encoding processing shown in FIG. 17 is performed as part of the encoding process performed in step S110 of FIG. 9. Encoding the other encoding parameters and the quantized transform coefficient level level is carried out in any way.
[0272]
　When the encoding process is started, in step S301, the secondary conversion enable flag coding unit 301 encodes the secondary conversion valid flag st_enabled_flag included in the header information Hinfo, generates and outputs a bit string (coded data). Coded data in the secondary conversion valid flag st_enabled_flag obtained by this coding is included in a bitstream containing encoded data of the quantized transform coefficient levels level.
[0273]
　In step S302, the secondary transform identifier encoding unit 302, a secondary conversion valid flag st_enabled_flag included in the header information Hinfo determines whether a 1 (true). If the secondary transform valid flag st_enabled_flag is determined to be 1, i.e., if it is determined that the execution of the secondary transform is permitted, the process proceeds to step S303.
[0274]
　In step S303, the secondary transform identifier encoding unit 302 encodes the secondary conversion identifier St_idx, generates and outputs a bit string (coded data). Coded data in the secondary conversion identifier st_idx obtained by this coding is included in a bitstream containing encoded data of the quantized transform coefficient levels level. When the process of step S303 ends, the process proceeds to step S304.
[0275]
　Further, in step S302, if the secondary conversion enable flag st_enabled_flag is determined to be 0 (false), i.e., when the execution of the secondary conversion is determined not to be permitted, the process of step S303 is skipped, and the process It proceeds to step S304.
[0276]
　If the secondary transform is not performed, the secondary transform identifier st_idx is unnecessary. Therefore, in this case, the secondary transform identifier encoding unit 302 skips the encoding of the secondary transform identifier St_idx. In this way, it is possible to skip the encoding of redundant information, it is possible to suppress an increase in the load of the encoding process, it is possible to suppress the reduction of the coding efficiency.
[0277]
　In step S304, the conversion skip enable flag coding unit 303 encodes the transform skip enable flag ts_enabled_flag included in the header information HINFO, generates and outputs a bit string (coded data). Encoded data conversion skip valid flag ts_enabled_flag obtained by this coding is included in a bitstream containing encoded data of the quantized transform coefficient levels level.
[0278]
　In step S305, the maximum conversion skip block size coding unit 304, converts the skip valid flag ts_enabled_flag included in the header information Hinfo determines whether a 1 (true). If the conversion skip enable flag ts_enabled_flag is determined to be 1, i.e., if the conversion skip (skipping the primary conversion and secondary conversion) is determined to be permitted, the process proceeds to step S306.
[0279]
　In step S306, the maximum conversion skip block size coding unit 304, the maximum conversion skipped block size MaxTSSize (or 2 logarithm log2MaxTSSize to base) was coded, and generates and outputs a bit string (coded data). Encoded data of the maximum conversion skip block size MaxTSSize obtained by this coding is included in a bitstream containing encoded data of the quantized transform coefficient levels level. Processing as in step S306 is completed, the process proceeds to step S307.
[0280]
　Further, in step S305, when the conversion skip valid flag ts_enabled_flag it is determined to be 0, i.e., if the conversion skip is determined not to be permitted, the process of step S306 is skipped and the process proceeds to step S307 .
[0281]
　If can convert skip, maximum conversion skipped block size MaxTSSize (or Log2MaxTSSize) is not required. Therefore, in this case, the maximum conversion skip block size coding unit 304 skips the encoding of the maximum conversion skip block size MaxTSSize (or log2MaxTSSize). In this way, it is possible to skip the encoding of redundant information, it is possible to suppress an increase in the load of the encoding process, it is possible to suppress the reduction of the coding efficiency.
[0282]
　In step S307, the transformed and quantized bypass flag coding unit 305, the transform quantization bypass flag transquant_bypass_flag codes, and generates and outputs a bit string (coded data). Coded data of the transformed and quantized bypass flag transquant_bypass_flag obtained by this coding is included in a bitstream containing encoded data of the quantized transform coefficient levels level.
[0283]
　In step S308, conversion skip flag encoding unit 306 converts quantized bypass flag transquant_bypass_flag included in the conversion information Tinfo determines whether a 1 (true). If the conversion quantization bypass flag transquant_bypass_flag is determined to be 1, i.e., the conversion (primary conversion and secondary conversion) and Skip quantization (bypass) Then if it is determined, the processing of steps S309 through step S312 are skipped , the coding process is completed, the process returns to FIG.
[0284]
　If the transform and quantization is bypassed converted skip flag ts_flag is unnecessary. Therefore, in this case, conversion the skip flag encoding unit 306 skips the encoding of the transform skip flag Ts_flag. In this way, it is possible to skip the encoding of redundant information, it is possible to suppress an increase in the load of the encoding process, it is possible to suppress the reduction of the coding efficiency.
[0285]
　In step S308, when the conversion quantization bypass flag transquant_bypass_flag is determined to be 0, i.e., if the conversion and quantization is determined not to skip (bypass), the process proceeds to step S309.
[0286]
　In step S309, the conversion the skip flag coding unit 306 determines a secondary transform identifier value of St_idx is zero or not larger than (st_idx> 0). Greater than the value of the secondary transform identifier st_idx is 0, i.e., if it is determined that the secondary transform is performed, processing in steps S310 through step S312 is skipped, the coding process is completed, the process returns to FIG.
[0287]
　If the secondary transform is performed, since conversion skip is not performed, the value of the conversion the skip flag ts_flag are fixed to zero. Therefore, in this case, there is no need to transmit the converted skip flag Ts_flag to the decoding side, converts the skip flag encoding unit 306 skips the encoding of the transform skip flag Ts_flag. In this way, it is possible to skip the encoding of redundant information, it is possible to suppress an increase in the load of the encoding process, it is possible to suppress the reduction of the coding efficiency.
[0288]
　In step S309, the value of the secondary transform identifier st_idx is 0, i.e., if the secondary conversion is judged to be skipped, the processing proceeds to step S310.
[0289]
　In step S310, the conversion the skip flag coding unit 306, converts the skip valid flag ts_enabled_flag included in the header information HInfo determines whether a 1 (true). Converting skip valid flag ts_enabled_flag is 0, i.e., if the conversion skip is determined not to be permitted, the process of step S311 and step S312 are skipped, the coding process is completed, the process returns to FIG.
[0290]
　If can convert skip, the value of the conversion the skip flag ts_flag are fixed to zero. Therefore, in this case, there is no need to transmit the converted skip flag Ts_flag to the decoding side, converts the skip flag encoding unit 306 skips the encoding of the transform skip flag Ts_flag. In this way, it is possible to skip the encoding of redundant information, it is possible to suppress an increase in the load of the encoding process, it is possible to suppress the reduction of the coding efficiency.
[0291]
　In step S310, the case where the conversion skip valid flag ts_enabled_flag is determined to be 1, i.e., if the conversion skip is determined to be permitted, the process then the procedure advances to Step S311.
[0292]
　In step S311, the conversion the skip flag coding unit 306 determines whether the size TBSize the transform block processed is equal to or less than the maximum conversion skipped block size MaxTSSize the (whether conditional expression TBSize <= MaxTSSize is true) judge. If the size TBSize the transform block processed is determined to be greater than the maximum conversion skipped block size MaxTSSize, i.e., if the conditional expression described above is determined to be 0 (false), the process of step S312 is skipped, coding process is completed, the process returns to FIG.
[0293]
　If the size of the transform block is greater than the maximum conversion skipped block size, since conversion the skip is not allowed, the value of the conversion the skip flag ts_flag are fixed to zero. Therefore, in this case, there is no need to transmit the converted skip flag Ts_flag to the decoding side, converts the skip flag encoding unit 306 skips the encoding of the transform skip flag Ts_flag. In this way, it is possible to skip the encoding of redundant information, it is possible to suppress an increase in the load of the encoding process, it is possible to suppress the reduction of the coding efficiency.
[0294]
　In step S311, if the size TBSize the transform block processed is determined to be less than or equal to the maximum conversion skipped block size MaxTSSize, i.e., if the conditional expression described above is determined to be 1 (true), the process steps the process proceeds to S312.
[0295]
　Note that, in step S311, the conditional expression (TBSize <= MaxTSSize) described above, logarithm log2TrafoSize of TB size base 2 (or Log2TBSize), the logarithm log2MaxTSSize the maximum conversion skip block size MaxTSSize to base 2 used, it may be replaced with a conditional expression (log2TrafroSize <= log2MaxTSSize).
[0296]
　In step S312, the conversion the skip flag coding unit 306, a conversion skip flag ts_flag codes, and generates and outputs a bit string (coded data). Coded data of the conversion the skip flag ts_flag obtained by this coding is included in a bitstream containing encoded data of the quantized transform coefficient levels level.
[0297]
　In other words, the following conditional expression (32) only when a 1 (true), converts the skip flag ts_flag is encoded. This corresponds to the fourth row from the top of the syntax described with reference to FIG. 15.
[0298]
　論理値＝（ts_enabled_flag &&
　　　　　　　!transquant_bypass_flag &&
　　　　　　　（log2TrafoSize <= log2MaxTSSize） &&
　　　　　　　st_idx==0）
　・・・（３２）
[0299]
　When the process of step S312 is completed, the coding process is completed, the process returns to FIG.
[0300]
　By performing the encoding process as described above, the image coding apparatus 100, in case of encoding a secondary transform identifier St_idx in CU units, which indicates that the secondary conversion identifier St_idx applies a secondary conversion (St_idx > 0), it is possible to skip the encoding of the transform skip flag Ts_flag. That is, it is possible to reduce the reduction of the code amount according to the converted skip flag Ts_flag, and the amount of processing according to the encoding.
[0301]
　Incidentally, the above-described encoding process, in feasible range, the processing order and replacement steps, may change the contents of processing. Further, syntax and condition described above (32) is capable of changing the operation in feasible range.
[0302]
　　
　Next image decoding apparatus 200 will be described. In this case the image decoding apparatus 200 also basically has the same configuration as in the first embodiment. However, the image decoding apparatus 200 in this case, the inverse secondary which is the inverse of the secondary transform the prediction residual being the difference image and the predicted image of the image is the conversion for the primary transform coefficients obtained are primary converted If the conversion is carried out, comprises a decoding unit skipping decoding of the encoded data of the first information about skipping inverse primary transform is an inverse transformation of the primary transformation. That is, the decoding unit 211 in this case, image and inverse secondary transform that is the inverse of the secondary conversion prediction residual is the difference is conversion processing for the primary transform coefficients obtained by the primary conversion of the prediction image of the image If is performed, skipping decoding of the encoded data of the first information about skipping inverse primary transform is an inverse transformation of the primary transformation.
[0303]
　Figure 18 is realized by the decoding unit 211 in this case executes the program or the like is a functional block diagram showing an example of main functions relating to decoding of transform skip flag Ts_flag. As shown in FIG. 18, the decoding unit 211 executes the program, as a function relating to decoding of transform skip flag Ts_flag, for example, secondary converter valid flag decoding unit 311, a secondary conversion identifier decoding unit 312, converts the skip effective flag decoding unit 313 may have a function of maximum conversion skip block size decoding unit 314, converts the quantized bypass flag decoding unit 315 and the conversion skip flag decoding unit 316,.
[0304]
　Secondary transformation valid flag decoding unit 311 performs processing relating to decoding of the encoded data of the secondary conversion valid flag st_enabled_flag is information about permission of the inverse secondary transform. Secondary transformation identifier decoding unit 312 performs processing relating to decoding of the encoded data of the secondary transform identifier st_idx is information about the contents of the inverse secondary transform. Converting skip valid flag decoding unit 313 performs processing relating to decoding of the encoded data of the conversion the skip valid flag ts_enabled_flag is information about skipping permission of inverse transform (inverse primary transform). Maximum conversion skipped block size decoding unit 314 performs processing relating to decoding of the maximum conversion skip block size MaxTSSize coded data indicating the maximum size of the transform block skipping inverse transform (inverse primary transform) is permitted. Transformed and quantized bypass flag decoding unit 315 performs inverse transform (inverse secondary transform and inverse primary transform) and processing related to decoding of the encoded data of transformed and quantized bypass flag transquant_bypass_flag is information about skip (bypass) dequantization . Converting skip flag decoding unit 316 performs processing relating to decoding of the encoded data of the conversion the skip flag ts_flag is information about skipping inverse transform (inverse primary transform).
[0305]
　　
　Next, an example of the flow of each process executed by the image decoding apparatus 200. In this case the image decoding apparatus 200 performs image decoding processing, as the case of the essentially first embodiment. However, performed this case, the image decoding apparatus 200, in step of the image decoding process S201 (FIG. 13), the decoding of the encoded data, such as conversion skip flag Ts_flag, depending on the value or the like of the secondary transform identifier St_idx. The example of the decoding of the flow of coded data, such as the conversion skip flag ts_flag be described with reference to the flowchart of FIG. 19. In other words, the decoding process shown in FIG. 19 is performed as part of the decoding process performed in step S201 of FIG. 13. Decoding the encoded data of other coding parameters and the quantized transform coefficient level level is carried out in any way.
[0306]
　When the decoding process starts, in step S331, the secondary conversion valid flag decoding unit 311 decodes the encoded data of the secondary conversion valid flag st_enabled_flag included in the bit stream (encoded data), part of the header information Hinfo and outputs it as.
[0307]
　In step S332, the secondary transform identifier decoding unit 312, a secondary conversion valid flag st_enabled_flag which is the decoded, determines whether a 1 (true). If the secondary transform valid flag st_enabled_flag is determined to be 0, that is, if the execution of the inverse secondary transform is determined not to be permitted, the process proceeds to step S333.
[0308]
　In this case, the inverse secondary transform is skipped, the secondary transform identifier st_idx is not coded. Accordingly, in step S333, the secondary transform identifier decoding unit 312 skips the decoding of the encoded data of the secondary transform identifier St_idx. In this case, since the inverse secondary transform is skipped, the value of the secondary transform identifier st_idx are fixed to zero. Therefore, the secondary transform identifier decoding unit 312, the value of the secondary transform identifier st_idx is estimated to be zero. That is, the secondary transform identifier decoding unit 312 sets the value of the secondary transform identifier St_idx to 0 (st_idx = 0). Processing and the processing of step S333 is completed, the process proceeds to step S335.
[0309]
　Further, in step S332, if the secondary conversion enable flag st_enabled_flag is determined to be 1, the processing which the procedure goes to step S334. In this case, since the execution of the inverse secondary transform is permitted, in step S334, the secondary transform identifier decoding unit 312 decodes the encoded data of the secondary conversion identifier st_idx included in the bit stream (encoded data). Processing and the processing of step S334 is completed, the process proceeds to step S335.
[0310]
　The process according to the decoding of the more secondary conversion identifier st_idx is a feasible range, the processing order and replacement steps, may change the contents of processing.
[0311]
　In step S335, conversion skip valid flag decoding unit 313 decodes the encoded data of the transform skip enable flag ts_enabled_flag included in the bit stream (encoded data), and outputs it as part of the header information Hinfo.
[0312]
　In step S336, the maximum conversion skipped block size decoding unit 314, converts the skip valid flag ts_enabled_flag which is the decoded, determines whether a 1 (true). If the conversion skip enable flag ts_enabled_flag is determined to be 1, that is, if the skip of the inverse transform (inverse secondary transform and inverse primary transform) is determined to be permitted, the process proceeds to step S337.
[0313]
　In step S337, the maximum conversion skipped block size decoding unit 314, the bit stream maximum conversion skipped block size contained in the (encoded data) MaxTSSize (or logarithm log2MaxTSSize to base 2) to decode the encoded data of. Processing and the processing of step S337 is completed, the process proceeds to step S338.
[0314]
　Further, in step S336, when the conversion skip valid flag ts_enabled_flag is determined to be 0, i.e., if the skip of the inverse transform is determined to not permitted, because skipping inverse transform is not performed, the maximum conversion skip block size MaxTSSize is not required. Therefore, in this case, the process of step S337 is skipped and the process proceeds to step S338.
[0315]
　In step S338, conversion quantization bypass flag decoding unit 315 decodes the encoded data of the transformed and quantized bypass flag transquant_bypass_flag included in the bit stream (encoded data), and outputs it as part of the conversion information TINFO.
[0316]
　In step S339, the conversion the skip flag decoding unit 316, the transformed and quantized bypass flag transquant_bypass_flag determines whether a 1 (true). If the conversion quantization bypass flag transquant_bypass_flag is determined to be 1, i.e., the inverse transform (inverse secondary transform and inverse primary transform) and, if the inverse quantization is skipped (bypassed) Then the determination, in step S340 through step S342 processing is skipped and the process proceeds to step S343.
[0317]
　If the inverse transform and quantization are bypassed, converted skip flag ts_flag is unnecessary. Therefore, in this case, conversion the skip flag decoding unit 316 skips the decoding of the encoded data of the conversion the skip flag Ts_flag. By doing so, it is possible to skip the decoding of redundant information, it is possible to suppress an increase in the decoding processing load can be suppressed to reduce the coding efficiency.
[0318]
　Further, in step S339, when the conversion quantization bypass flag transquant_bypass_flag is determined to be 0, i.e., if the inverse transform and quantization is determined not to skip (bypass), the process proceeds to step S340.
[0319]
　In step S340, the conversion the skip flag decoding unit 316 determines the secondary conversion identifier value of St_idx is zero or not larger than (st_idx> 0). Greater than the value of the secondary transform identifier st_idx is 0, i.e., if it is determined that the inverse secondary transform is performed, processing of step S341 and step S342 is skipped and the process proceeds to step S343.
[0320]
　If the secondary transform is performed, since the conversion skip (inverse transform skipping) is not performed, the value of the conversion the skip flag ts_flag are fixed to zero. Therefore, in this case, since the conversion the skip flag Ts_flag is not transmitted from the encoding side, converts the skip flag decoding unit 316 skips the decoding of the encoded data of the conversion the skip flag Ts_flag. By doing so, it is possible to skip the decoding of redundant information, it is possible to suppress an increase in the decoding processing load can be suppressed to reduce the coding efficiency.
[0321]
　In step S340, the value of the secondary transform identifier st_idx is 0, i.e., if the inverse secondary transform is judged to be skipped and the process proceeds to step S341.
[0322]
　In step S341, the conversion the skip flag decoding unit 316, converts the skip valid flag ts_enabled_flag included in the header information HInfo determines whether a 1 (true). If the conversion skip enable flag ts_enabled_flag is determined to be 0, i.e., if the conversion skip is determined not to be permitted, the process of step S342 is skipped and the process proceeds to step S343.
[0323]
　If can convert skip (inverse transform skip), the value of the conversion the skip flag ts_flag are fixed to zero. Therefore, in this case, since the conversion the skip flag Ts_flag is not transmitted from the encoding side, converts the skip flag decoding unit 316 skips the decoding of the encoded data of the conversion the skip flag Ts_flag. In this way, it is possible to skip the encoding of redundant information, it is possible to suppress an increase in the load of the encoding process, it is possible to suppress the reduction of the coding efficiency.
[0324]
　In step S341, when the conversion skip valid flag ts_enabled_flag is determined to be 1, i.e., if the conversion skip (inverse transform skipping) is determined to be permitted, the process proceeds to step S342.
[0325]
　In step S342, conversion skip flag decoding unit 316 determines whether the size TBSize the transform block processed is equal to or less than the maximum conversion skipped block size MaxTSSize (whether conditional expression TBSize <= MaxTSSize is true) to. If the size TBSize the transform block processed is determined to be greater than the maximum conversion skipped block size MaxTSSize, i.e., if the conditional expression described above is determined to be 0 (false), the process proceeds to step S343.
[0326]
　If the size of the transform block is greater than the maximum conversion skipped block size, since conversion the skip is not allowed, the value of the conversion the skip flag ts_flag are fixed to zero. Therefore, in this case, since the conversion the skip flag Ts_flag is not transmitted from the encoding side, converts the skip flag decoding unit 316 skips the decoding of the encoded data of the conversion the skip flag Ts_flag. In this way, it is possible to skip the encoding of redundant information, it is possible to suppress an increase in the load of the encoding process, it is possible to suppress the reduction of the coding efficiency. Note that, in step S342, the conditional expression (TBSize <= MaxTSSize) described above, 2 logarithm log2TrafoSize of TB size that the bottom (or, Log2TBSize), logarithmic value of the maximum conversion skip block size MaxTSSize to base 2 log2MaxTSSize using, it may be replaced by a conditional expression (log2TrafroSize <= log2MaxTSSize).
[0327]
　In step S343, conversion skip flag decoding unit 316 skips the decoding of the encoded data of the conversion the skip flag Ts_flag. In this case, conversion skip (inverse transform skipping) is not performed, i.e., the inverse transform is performed, the value of the conversion the skip flag ts_flag are fixed to zero. Therefore, converting the skip flag decoding unit 316, the value of the conversion the skip flag ts_flag is estimated to be zero. In other words, conversion skip flag decoding unit 316, the value of the conversion the skip flag Ts_flag set to 0 (ts_flag = 0). Decoding processing as the steps S343 ends, the ends and the processing returns to FIG. 13.
[0328]
　Further, in step S342, if the size TBSize the transform block processed is determined to be less than or equal to the maximum conversion skipped block size MaxTSSize, i.e., if the conditional expression described above is determined to be 1 (true), the processing It proceeds to step S344.
[0329]
　In step S344, conversion skip flag decoding unit 316 decodes the encoded data of the transform skip flag Ts_flag.
[0330]
　That is, only if the conditional expressions (32) is 1 (true), the encoded data of the conversion the skip flag ts_flag is decoded. This corresponds to the fourth row from the top of the syntax described with reference to FIG. 15.
[0331]
　When the process of step S344 is finished, the decoding process is completed, the process returns to FIG. 13.
[0332]
　By performing the decoding process as described above, the image decoding apparatus 200, when the secondary conversion identifier St_idx is encoded in CU units, indicating execution of the secondary transform identifier St_idx inverse secondary transform (st_idx> 0), it is possible to skip the decoding of the encoded data of the conversion the skip flag Ts_flag. That is, it is possible to reduce the reduction of the code amount according to the converted skip flag Ts_flag, and the amount of processing according to the decoding.
[0333]
　Incidentally, the decoding processes described above, in feasible range, the processing order and replacement steps, may change the contents of processing. Further, syntax and condition described above (32) is capable of changing the operation in feasible range.
[0334]
　<3. Third Embodiment>
　　
　Non-Patent Document 2, the secondary transform identifier st_idx is to be decoded by the CU units in described in Non-Patent Document 1 Technology (JEM2), and secondary conversion flag st_flag indicating whether to apply a secondary transform to be decoded by the conversion block, on the basis of the intra prediction mode information IPinfo to be decoded by the PU unit, it is described that is derived by the conversion block there.
[0335]
　For example, the relative described in Non-Patent Document 2 technology by applying the present technology described in the first embodiment, the conversion the skip flag ts_flag is 1 (applying a transformation skip) if (reverse) Primary so as to skip the conversion and (reverse) secondary transformation. In this case, conversion the skip flag Ts_flag to be decoded by the transform block units, (opposite) indicating the execution of a skip conversion process (ts_flag = 1), (reverse) because the secondary transform is skipped, execution of the secondary conversion is information related to the coding of a secondary conversion flag st_flag it becomes redundant. Therefore, there is a risk that the encoding efficiency is reduced.
[0336]
　Therefore, if the primary transform is a transformation process for prediction residual that is a difference image and the predicted image of the image is skipped, the conversion processing for the primary transform coefficients the prediction residuals is obtained it is primary converted Secondary so as to skip the encoding of first information on a skip conversion.
[0337]
　By doing so, since it is possible to skip the encoding of the first information if the primary transform is skipped, it is possible to suppress the reduction of the coding efficiency.
[0338]
　Further, if the image and the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual is the difference between the predicted image of the image is skipped, the primary of the prediction residuals is obtained is primary converted so as to skip the decoding of the coded data of the first information about the inverse secondary transform skip in the secondary conversion of inverse transformation is a transformation process for the transform coefficients.
[0339]
　By doing so, since it is possible to reverse the primary transform skip decoding of the encoded data of the first information when it is skipped, it is possible to suppress the reduction of the coding efficiency.
[0340]
　　
　shows an example of a syntax table describing a pseudo code representing such control in FIG. 20. As shown in the seventh stage from the top in FIG. 20, the encoding of the secondary conversion flag St_flag (i.e., decoding of the encoded data of the secondary conversion flag St_flag) is 1 is conditional transform skip flag ts_flag is 0 It becomes bracts. That is, when converting the skip flag ts_flag is 1, i.e., if (inverse) primary transform is skipped, the coding of a secondary conversion flag St_flag (decoding of the encoded data of the secondary conversion flag St_flag) is skipped.
[0341]
　Also, it is transformed and quantized bypass flag transquant_bypass_flag is 0, the coding of a secondary conversion flag St_flag (i.e., decoding of the encoded data of the secondary conversion flag St_flag) becomes one of the conditions. That is, if the conversion quantization bypass flag transquant_bypass_flag of 1, i.e., (reverse) If the conversion and (inverse) quantization is skipped, the coding of a secondary conversion flag St_flag (decoding of the encoded data of the secondary conversion flag St_flag) There are skipped.
[0342]
　　
　In this case the image encoding apparatus 100 also basically has the same configuration as in the first embodiment. In other words, the image coding apparatus 100 described in the first embodiment is, when the primary transform is a transformation process for prediction residual that is a difference image and the predicted image of the image is skipped, the prediction residual There comprising a coding unit for skipping the encoding of first information about skipping secondary transform is a transformation processing on the primary transform coefficients obtained are primary conversion. That is, the encoding unit 114 in this case, if the primary transform is a transformation process for prediction residual that is a difference image and the predicted image of the image is skipped, obtained as a prediction residual is primary converted skip encoding of first information about skipping secondary transform is a transformation processing on the primary transform coefficients.
[0343]
　Figure 21 is realized by the encoding unit 114 in this case executes the program or the like is a functional block diagram showing an example of main functions relating to encoding the secondary conversion flag St_flag. As shown in FIG. 21, the encoding unit 114 in this case, by executing the program, as a function related to the coding of a secondary conversion flag St_flag, for example, the encoding unit 114 described in the second embodiment Similarly with the secondary conversion enable flag coding unit 301, converts the skip enable flag coding unit 303, the maximum conversion skip block size coding unit 304, converts the quantized bypass flag coding unit 305, and converts the skip flag coding unit 306 it is possible to have a function. Furthermore, the coding unit 114, by executing a program, as a function related to the coding of a secondary conversion flag St_flag, for example, can have the function of the secondary conversion flag coding unit 321.
[0344]
　Secondary conversion flag coding unit 321 performs processing related to the coding of a secondary conversion flag st_flag which is information about the execution of the secondary conversion. For example, if the secondary conversion flag st_flag is 1 (true), the secondary transform is performed. For example, when the secondary conversion flag st_flag is 0 (false), the secondary transform is skipped.
[0345]
　　
　Next, an example of the flow of each process executed by the image encoding apparatus 100. In this case the image coding apparatus 100 performs image encoding processing, as in the case with basically the first embodiment. However, in this case, the image encoding apparatus 100, in step of the image encoding process S110 (FIG. 9), the coding of such secondary conversion flag St_flag, performed in accordance with the value or the like of conversion skip flag Ts_flag. The example of the encoding stream, such as the secondary conversion flag st_flag with reference to the flowchart of FIG. 22 and FIG. 23 will be described. That is, the encoding process shown in FIGS. 22 and 23 is performed as part of the encoding process performed in step S110 of FIG. 9. Encoding the other encoding parameters and the quantized transform coefficient level level is carried out in any way.
[0346]
　When the encoding process starts, the processes of steps S361 to step S368 of FIG. 22, step S304 to step S308, and is performed in the same way as the processing in steps S310 to step S312 (Fig. 17).

claims
[Requested item 1]
　Case of skipping the primary conversion is a conversion processing for the prediction residual being the difference between the predicted image of the image with the image, also secondary transform the prediction residual is conversion processing for the primary transform coefficients obtained are the primary conversion control unit to skip
　the image processing apparatus comprising a.
[Requested item 2]
　Case of skipping the primary conversion is a conversion processing for the prediction residual being the difference between the predicted image of the image with the image, also secondary transform the prediction residual is conversion processing for the primary transform coefficients obtained are the primary conversion to skip
　an image processing method.
[Requested item 3]
　Case of skipping the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual is the difference between the predicted image of the image with the image, the primary transform coefficients the prediction residual is obtained is the primary conversion control unit for inverse secondary transform may be skipped, which is the inverse of the secondary transform is a transformation processing on
　the image processing apparatus comprising a.
[Requested item 4]
　Case of skipping the inverse primary transform is an inverse transformation of the primary transformation is a transformation process for prediction residual is the difference between the predicted image of the image with the image, the primary transform coefficients the prediction residual is obtained is the primary conversion is inverse secondary transform may skip which is inverse transformation of the secondary transform is a transformation processing on
　the image processing method.
[Requested item 5]
　When the prediction residual is the difference between the predicted image of the image and the image is secondary conversion is performed on the primary transform coefficients obtained are primary transform, skipping the encoding of first information about skipping the primary conversion encoding unit for
　an image processing apparatus comprising a.
[Requested item 6]
　When the prediction residual is the difference between the predicted image of the image and the image is secondary conversion is performed on the primary transform coefficients obtained are primary transform, skipping the encoding of first information about skipping the primary conversion the
　image processing method.
[Requested item 7]
　When the prediction residual is the difference between the predicted image of the image and the image inverse transform inverse secondary transform that is a secondary transform is a transformation processing on the primary transform coefficients obtained by the primary conversion is performed, the inverse of the primary conversion decoding unit skipping decoding of the coded data of the first information about the inverse primary transform skip which is converting
　the image processing apparatus.
[Requested item 8]
　When the prediction residual is the difference between the predicted image of the image and the image inverse transform inverse secondary transform that is a secondary transform is a transformation processing on the primary transform coefficients obtained by the primary conversion is performed, the inverse of the primary conversion skip decoding the encoded data of the first information about the inverse primary transform skip in the conversion
　image processing method.
[Requested item 9]
　If the primary transform is a transformation process for prediction residual is the difference between the predicted image of the image and the image is skipped, the secondary transform the prediction residual is conversion processing for the primary transform coefficients obtained are the primary conversion coding unit to skip the encoding of the first information on the skip
　an image processing apparatus comprising a.
[Requested item 10]
　If the primary transform is a transformation process for prediction residual is the difference between the predicted image of the image and the image is skipped, the secondary transform the prediction residual is conversion processing for the primary transform coefficients obtained are the primary conversion skip the encoding of the first information on the skip
　image processing method.
[Requested item 11]
　If inverse transform inverse primary transform is a primary conversion is conversion processing for the prediction residual being the difference between the predicted image of the image and the image is skipped, the primary transform the prediction residual is obtained is the primary conversion decoding unit skipping decoding of the coded data of the first information about the inverse secondary transform skip which is the inverse of the secondary transform is a transform process on coefficient
　image processing apparatus comprising a.
[Requested item 12]
　It said decoding unit, based on the horizontal size and vertical size of the transform block of the inverse primary transform and the inverse secondary transform, skipping decoding of the inverse primary transform skip information about skipping the inverse primary transform
　to configured
　image processing apparatus according to claim 11.
[Requested item 13]
　Said decoding unit, when the larger is larger than the predetermined value among the horizontal and vertical size of the transform block, skipping decoding of the inverse primary transform skip information
　configured as
　described in claim 12 image processing apparatus.
[Requested item 14]
　Said decoding unit, said if the sum or the product of horizontal and vertical size of the transform block is greater than a predetermined value, skipping decoding of the inverse primary transform skip information
　configured as
　an image according to claim 12 processing apparatus.
[Requested item 15]
　If inverse transform inverse primary transform is a primary conversion is conversion processing for the prediction residual being the difference between the predicted image of the image and the image is skipped, the primary transform the prediction residual is obtained is the primary conversion skip decoding the encoded data of the first information about the inverse secondary transform skip which is the inverse of the secondary transform is a transform process on coefficient
　image processing method.
[Requested item 16]
　Primary conversion is a conversion processing for the prediction residual being the difference between the predicted image of the image with the image, secondary conversion the prediction residual is conversion processing for the primary transform coefficients obtained are the primary conversion, and the primary If the transform coefficients are quantized is skipped for secondary transform coefficients obtained are the secondary conversion, encoding unit to skip encoding of the first information indicating the content of the primary conversion
　image processing apparatus comprising a.
[Requested item 17]
　Primary conversion is a conversion processing for the prediction residual being the difference between the predicted image of the image with the image, secondary conversion the prediction residual is conversion processing for the primary transform coefficients obtained are the primary conversion, and the primary If the transform coefficients are quantized it is skipped for secondary transform coefficients obtained are the secondary conversion, to skip encoding of the first information indicating the content of the primary conversion
　image processing method.
[Requested item 18]
　Inverse quantization for the quantized transform coefficient levels of the encoded data is obtained are decoded, inverse secondary transform the quantized transform coefficient levels converts the secondary transform coefficients obtained are the inverse quantization to the primary transform coefficients, and, when said inverse primary transform to convert the primary transform coefficients to the prediction residual being the difference between the predicted image of the image and the image is skipped, the decoding of the encoded data of the first information about the content of the inverse primary transform decoder to skip
　the image processing apparatus comprising a.
[Requested item 19]
　Inverse quantization for the quantized transform coefficient levels of the encoded data is obtained are decoded, inverse secondary transform the quantized transform coefficient levels converts the secondary transform coefficients obtained are the inverse quantization to the primary transform coefficients, and, when said inverse primary transform to convert the primary transform coefficients to the prediction residual being the difference between the predicted image of the image and the image is skipped, the decoding of the encoded data of the first information about the content of the inverse primary transform skip
　image processing method.