JP6341067B2 - Image processing apparatus and method - Google Patents

Description

  The present disclosure relates to an image processing apparatus and method, and more particularly, to an image processing apparatus and method capable of suppressing a reduction in encoding efficiency.

  In recent years, with the aim of further improving coding efficiency from MPEG-4 Part10 (Advanced Video Coding, hereinafter referred to as AVC), ITU-T (International Telecommunication Union Telecommunication Standardization Sector) and ISO / IEC (International Organization for Standardization / JCTVC (Joint Collaboration Team-Video Coding), a joint standardization organization of the International Electrotechnical Commission, is standardizing an encoding method called HEVC (High Efficiency Video Coding).

  Also, in HEVC, range extensions are being studied to support high-end formats such as 4: 2: 2 and 4: 4: 4 color difference signal format images and screen content profiles. (For example, refer nonpatent literature 1).

Jill Boyce, Jianle Chen, Ying Chen, David Flynn, Miska M. Hannuksela, Matteo Naccari, Chris Rosewarne, Karl Sharman, Joel Sole, Gary J. Sullivan, Teruhiko Suzuki, Gerhard Tech, Ye-Kui Wang, Krzysztof Wegner, Yan Ye , "Draft high efficiency video coding (HEVC) version 2, combined format range extensions (RExt), scalability (SHVC), and multi-view (MV-HEVC) extensions", JCTVC-R1013_v6, 2014.10.1

  By the way, in this HEVC, TR (Truncated Rice) code (variable length code) is used for the syntax processing of coefficient information data called coeff_abs_level_remaining. In this TR code, five encoding tables are prepared in advance, and the encoding table to be used is updated as needed when each coefficient data is encoded. Furthermore, in the added range extension profile, 21 encoding tables can be prepared.

  However, the update of the coding table used for coding each coefficient data is initialized for each coding sub-block (coded_sub_block) of a predetermined size (for example, 16x16) which is a coding unit, so it is suitable for coefficient data. There is a possibility that an unencoded coding table may be selected, which may reduce the coding efficiency.

  In the added range extension profile, the encoding table used for encoding the first coefficient data of the encoded sub-block (coded_sub_block) is the encoding used for the first coefficient data of the other encoded sub-block. Can be set based on a table. However, in this case as well, the value of the coefficient data at the head of each coding sub-block does not always match or approximate each other. For this reason, there is a possibility that an encoding table that is not suitable for coefficient data may be selected, which may reduce the encoding efficiency.

  This indication is made in view of such a situation, and makes it possible to control reduction of coding efficiency.

One aspect of the present technology provides an encoding table used for encoding current coefficient data, which is a processing target of image data to be encoded, with a plurality of codes used for encoding coefficient data around the current coefficient data. An image processing apparatus comprising: a setting unit that is set based on an encoding table; and an encoding unit that encodes the current coefficient data using the encoding table set by the setting unit.

The setting unit includes, as the plurality of encoding tables, an encoding table used for encoding coefficient data adjacent to the right of the current coefficient data, and encoding of coefficient data adjacent below the current coefficient data. The encoding table used for encoding the current coefficient data can be set based on the encoding table used in the above.

The setting unit includes, as the plurality of encoding tables, an encoding table used for encoding coefficient data adjacent to the right of the current coefficient data, and encoding of coefficient data adjacent below the current coefficient data. The encoding table used for encoding the current coefficient data is set based on the encoding table used for the current coefficient data and the encoding table used for encoding the coefficient data adjacent to the lower right of the current coefficient data. can do.

The setting unit includes, as the plurality of encoding tables, an encoding table used for encoding coefficient data adjacent to the upper right of the current coefficient data, and encoding of coefficient data adjacent to the lower left of the current coefficient data. The encoding table used for encoding the current coefficient data can be set based on the encoding table used in the above.

  The setting unit sets the encoding table as an encoding table used for encoding the current coefficient data when there is a single encoding table used for encoding the peripheral coefficient data that can be used. Can do.

  The setting unit, when there are a plurality of encoding tables used for encoding the peripheral coefficient data that can be used, an encoding table having an average value of table numbers of the plurality of encoding tables as a table number, It can be set as an encoding table used for encoding the current coefficient data.

  When there are a plurality of encoding tables used for encoding the peripheral coefficient data that can be used, the setting unit includes an encoding table having a table number as a median value of the table numbers of the plurality of encoding tables, It can be set as an encoding table used for encoding the current coefficient data.

  When there are a plurality of encoding tables used for encoding the peripheral coefficient data that can be used, the setting unit uses any one of the plurality of encoding tables for encoding the current coefficient data. Can be set as a table.

When the current coefficient data is the first coefficient data in the encoding unit of the image data, the setting unit determines an encoding table used for encoding the current coefficient data based on the plurality of encoding tables. Can be set.

The setting unit can set, for all coefficient data, an encoding table used for encoding the current coefficient data based on the plurality of encoding tables.

The setting unit, as the plurality of encoding tables, is an encoding table used for encoding coefficient data adjacent to the current coefficient data and belonging to an encoding unit different from the encoding unit of the current coefficient data. Based on the above, it is possible to set a coding table used for coding the current coefficient data.

Multiple embodiments of the present technology is also a coding table for use in encoding the current coefficient data to be processed of the image data to be encoded, it was used to encode the coefficient data of the periphery of the current coefficient data And an image processing method for encoding the current coefficient data using the set encoding table.

In one aspect of the present technology, the encoding table used for encoding the current coefficient data that is the processing target of the encoded image data includes a plurality of codes used for encoding the coefficient data around the current coefficient data. The current coefficient data is encoded using the encoding table that is set based on the encoding table.

  According to the present disclosure, it is possible to encode image data. In particular, a reduction in encoding efficiency can be suppressed.

It is a figure explaining the example of an encoding table. It is a figure explaining the example of an encoding table. It is a figure explaining the example of an encoding table. It is a flowchart which shows the example of the mode of a setting of an encoding table. It is a flowchart which shows the example of the mode of a setting of an encoding table. It is a figure which shows the example of the mode of a setting of an encoding table. It is a figure explaining the structural example of a coding unit. It is a block diagram which shows the main structural examples of an image coding apparatus. It is a block diagram which shows the main structural examples of a lossless encoding part. It is a block diagram which shows the main structural examples of a table selection part. It is a figure which shows the example of the mode of a setting of an encoding table. It is a figure which shows the example of the mode of a setting of an encoding table. It is a flowchart explaining the example of the flow of an encoding process. It is a flowchart explaining the example of the flow of TR encoding process. It is a flowchart explaining the example of the flow of an encoding table selection process. It is a figure which shows the other example of the mode of a setting of an encoding table. It is a flowchart explaining the other example of the flow of an encoding table selection process. It is a figure which shows the further another example of the mode of a setting of an encoding table. It is a block diagram which shows the main structural examples of a table selection part. It is a figure which shows the further another example of the mode of a setting of an encoding table. It is a flowchart explaining the other example of the flow of an encoding table selection process. It is a flowchart following FIG. 21 explaining the other example of the flow of an encoding table selection process. It is a figure which shows the example of a multiview image encoding system. It is a figure which shows the main structural examples of the multiview image coding apparatus to which this technique is applied. It is a figure which shows the main structural examples of the multiview image decoding apparatus to which this technique is applied. It is a figure which shows the example of a hierarchy image coding system. It is a figure which shows the main structural examples of the hierarchy image coding apparatus to which this technique is applied. It is a figure which shows the main structural examples of the hierarchy image decoding apparatus to which this technique is applied. And FIG. 20 is a block diagram illustrating a main configuration example of a computer. It is a block diagram which shows an example of a schematic structure of a television apparatus. It is a block diagram which shows an example of a schematic structure of a mobile telephone. It is a block diagram which shows an example of a schematic structure of a recording / reproducing apparatus. It is a block diagram which shows an example of a schematic structure of an imaging device. It is a block diagram which shows an example of a schematic structure of a video set. It is a block diagram which shows an example of a schematic structure of a video processor. It is a block diagram which shows the other example of the schematic structure of a video processor.

Hereinafter, modes for carrying out the present disclosure (hereinafter referred to as embodiments) will be described. The description will be given in the following order.
1. First Embodiment (Image Encoding Device)
2. Second Embodiment (Image Encoding Device)
3. Third embodiment (multi-view image encoding device / multi-view image decoding device)
4). Fourth embodiment (hierarchical image encoding device / hierarchical image decoding device)
5. Fifth embodiment (computer)
6). Sixth embodiment (application example)
7). Seventh embodiment (set unit module processor)

<1. First Embodiment>
<Image coding standardization process>
In recent years, with the aim of further improving coding efficiency from MPEG-4 Part10 (Advanced Video Coding, hereinafter referred to as AVC), ITU-T (International Telecommunication Union Telecommunication Standardization Sector) and ISO / IEC (International Organization for Standardization / JCTVC (Joint Collaboration Team-Video Coding), a joint standardization organization of the International Electrotechnical Commission, is standardizing an encoding method called HEVC (High Efficiency Video Coding).

  Also, in HEVC, range extensions are being studied to support high-end formats such as 4: 2: 2 and 4: 4: 4 color difference signal format images and screen content profiles. (For example, refer nonpatent literature 1).

<TR encoding>
By the way, in this HEVC, TR (Truncated Rice) code (variable length code) is used for the syntax processing of coefficient information data called coeff_abs_level_remaining. In this TR code, five encoding tables are prepared in advance, and the encoding table to be used is updated as needed when each coefficient data is encoded.

  FIGS. 1 to 3 show examples of the five encoding tables (Table 0 to Table 4). As shown in FIGS. 1 to 3, since the value and data length of encoded data obtained by encoding the same coefficient data are basically different for each encoding table, in order to suppress a decrease in encoding efficiency. In addition, it is desirable to select a coding table suitable for the value of the coefficient data.

  Furthermore, in the added range extension profile, 21 encoding tables can be prepared, and the values and data lengths of encoded data obtained by encoding the same coefficient data are further diversified. Therefore, in order to suppress a reduction in encoding efficiency, it is required to select a more appropriate encoding table for the coefficient data value.

  However, the update of the encoding table used for encoding each coefficient data is performed in a predetermined size (for example, 16 × 16) as an encoding unit, as shown in each process of step S1 to step S5 in the flowchart of FIG. Since initialization is performed for each coding sub-block (coded_sub_block), a coding table that is not suitable for coefficient data may be selected, which may lead to a reduction in coding efficiency.

  Note that, in the added range extension profile, as shown in each process of steps S11 to S18 in the flowchart of FIG. 5, a coding table used for coding the coefficient data at the head of the coded subblock (coded_sub_block). Can be set based on the coding table used for the coefficient data at the head of the other coding sub-blocks. However, in this case as well, the value of the coefficient data at the head of each coding sub-block does not always match or approximate each other. For this reason, there is a possibility that an encoding table that is not suitable for coefficient data may be selected, which may reduce the encoding efficiency.

  This will be described in more detail with reference to FIG. A TU (Transform Unit) 10 shown in FIG. 6 is an area (partial area of an image in picture units) that is a unit of orthogonal transform processing in encoded image data. In this example, the TU 10 is configured by 8 × 8 (8 vertical × 8 horizontal) coefficient data. In the TU 10, four encoded sub-blocks (coded_sub_block) (encoded sub-block 11 to encoded sub-block 14) composed of coefficient data of 4 × 4 (4 vertical × 4 horizontal) are formed. That is, in FIG. 6, small squares indicate coefficient data. The numbers shown in the squares of the coefficient data indicate the table numbers of the encoding tables assigned to the coefficient data (used for encoding the coefficient data).

  FIG. 6A shows an example when the encoding table is selected by the method shown in the flowchart of FIG. In this case, first, the table number of the encoding table used for encoding is set to “0” (initialization cRiceParam = 0). Next, using the processed coefficient value, based on the conditional expression (cLastAbsLevel> (3 * (1 << cLastRiceParam))), the table number of the encoding table used for encoding the next coefficient data is Is selected to be the same as the encoding table used for encoding the current coefficient data or the table number of the encoding table used for encoding the current coefficient data (current coefficient data). The By repeating this, an encoding table suitable for the coefficient value to be processed is selected, and the encoding efficiency is improved.

  However, in the case of this method, as shown in FIG. 6A, the coefficient data at the lower right of the encoding sub-block which is the first coefficient data (coefficient data to be processed first) of each encoding sub-block includes a table. The encoding table (Table 0) with number 0 is assigned.

  In general, the value of the coefficient data of TU10 increases from the lower right to the upper left. For this reason, in such a method, there is a possibility that an encoding table that is not suitable for coefficient data may be selected, which may reduce the encoding efficiency.

  FIG. 6B shows an example in which an encoding table is selected by the method shown in the flowchart of FIG. In this case, first, StatCoeff [0] = 0, StatCoeff [1] = 0, StatCoeff [2] = 0, and StatCoeff [3] = 0 are initialized. Next, at the start of the encoding sub-block, the value of sbType is set to any one of “0” to “3” depending on the values of transform_skip_flag and cu_transquant_byppass_flag. A value calculated by StatCoeff [sBtype] / 4 is a table number (cRiceParam = StatCoeff [sbType] / 4). Next, the table number of the coding table used for the processing of the next coding subblock (coded_sub_block) is obtained from the value of the coefficient value processed first in the coding subblock (coded_sub_block) (in step S15). Conditional expression A).

  Next, using the processed coefficient value, based on the conditional expression (cLastAbsLevel> (3 * (1 << cLastRiceParam))), the table number of the encoding table used for encoding the next coefficient data is Is selected to be the same as the encoding table used for encoding the current coefficient data or the table number of the encoding table used for encoding the current coefficient data (current coefficient data). The By repeating this, an encoding table suitable for the coefficient value to be processed is selected, and the encoding efficiency is improved. In the case of this method, as compared with the method of the example of FIG. 4, an encoding table other than the table number “0” can be selected as the initial value, and the encoding efficiency can be improved.

  However, in this method, the code number of the table number set based on the table number of the coding table assigned to the coefficient data of the head of the other coding sub-block is included in the head coefficient data of the coding sub-block. Table will be allocated. Therefore, in this case as well, as shown in FIG. 6B, the table number of the encoding table to which the leading coefficient data of the encoding sub-block 14 is allocated is changed to the coefficient data of the encoding sub-block 11 to the encoding sub-block 13. There is a possibility that the table number is smaller than the assigned encoding table number, which may reduce the encoding efficiency.

<Assignment of encoding table>
Therefore, the encoding table used for encoding the current coefficient data that is the processing target of the image data to be encoded is set based on the encoding table used for encoding the coefficient data around the current coefficient data. The current coefficient data is encoded using the set encoding table.

  For example, in the image processing apparatus, an encoding table used for encoding current coefficient data that is a processing target of image data to be encoded is used as an encoding table used for encoding coefficient data around the current coefficient data. And a coding unit for coding current coefficient data using the coding table set by the setting unit.

  By doing in this way, the encoding table more suitable for current coefficient data can be allocated, and the reduction of encoding efficiency can be suppressed.

  In addition, as an encoding table used for encoding peripheral coefficient data, an encoding table used for encoding coefficient data adjacent to the right of the current coefficient data and coefficient data adjacent below the current coefficient data The encoding table used for encoding may be used. And based on these encoding tables, you may make it set the encoding table used for encoding of current coefficient data.

  In addition, when there is a single encoding table used for encoding available peripheral coefficient data, the encoding table may be set as an encoding table used for encoding current coefficient data.

  Further, when there are a plurality of encoding tables used for encoding the peripheral coefficient data that can be used, an encoding table having an average value of the table numbers of the plurality of encoding tables as a table number is set as the current coefficient data. You may make it set as an encoding table used for an encoding.

  When the current coefficient data is the first coefficient data in the encoding unit of the image data, the encoding table used for encoding the current coefficient data is changed to the encoding table used for encoding the peripheral coefficient data. You may make it set based on.

<Encoding method>
In the following, the present technology will be described by taking as an example the case of application to HEVC (High Efficiency Video Coding) image encoding / decoding.

<Coding unit>
In the AVC (Advanced Video Coding) method, a hierarchical structure is defined by macroblocks and sub-macroblocks. However, a macro block of 16 × 16 pixels is not optimal for a large image frame such as UHD (Ultra High Definition: 4000 pixels × 2000 pixels), which is a target of the next generation encoding method.

  On the other hand, in the HEVC scheme, as shown in FIG. 7, a coding unit (CU (Coding Unit)) is defined.

  CU is also called a Coding Tree Block (CTB), and is a partial area of a picture unit image that plays the same role as a macroblock in the AVC method. The latter is fixed to a size of 16 × 16 pixels, whereas the size of the former is not fixed, and is specified in the image compression information in each sequence.

  For example, in the sequence parameter set (SPS (Sequence Parameter Set)) included in the output encoded data, the maximum size (LCU (Largest Coding Unit)) and minimum size ((SCU (Smallest Coding Unit)) of the CU are specified. Is done.

  Within each LCU, split-flag = 1 can be divided into smaller CUs within a range that does not fall below the SCU size. In the example of FIG. 7, the LCU size is 128, and the maximum hierarchical depth is 5. When the value of split_flag is “1”, the 2Nx2N CU is divided into NxN CUs that are one level below.

  Furthermore, CU is divided into prediction units (Prediction Units (PU)) that are regions (partial regions of images in units of pictures) that are processing units for intra or inter prediction, and are regions that are processing units for orthogonal transformation It is divided into transform units (Transform Units (TU)), which are (partial regions of images in picture units). Currently, in the HEVC system, it is possible to use 16x16 and 32x32 orthogonal transforms in addition to 4x4 and 8x8.

  In the case of an encoding method in which a CU is defined and various processes are performed in units of the CU as in the above HEVC method, a macro block in the AVC method corresponds to an LCU, and a block (sub block) corresponds to a CU. Then you can think. A motion compensation block in the AVC method can be considered to correspond to a PU. However, since the CU has a hierarchical structure, the size of the LCU of the highest hierarchy is generally set larger than the macro block of the AVC method, for example, 128 × 128 pixels.

  Therefore, hereinafter, it is assumed that the LCU also includes a macroblock in the AVC scheme, and the CU also includes a block (sub-block) in the AVC scheme. That is, “block” used in the following description indicates an arbitrary partial area in the picture, and its size, shape, characteristics, and the like are not limited. That is, the “block” includes an arbitrary area (processing unit) such as a TU, PU, SCU, CU, LCU, sub-block, macroblock, or slice. Of course, other partial areas (processing units) are also included. When it is necessary to limit the size, processing unit, etc., it will be described as appropriate.

  Also, in this specification, a CTU (Coding Tree Unit) is a unit including a CTB (Coding Tree Block) of an LCU (maximum number of CUs) and parameters when processing on the basis of the LCU (level). . Also, a CU (Coding Unit) constituting a CTU is a unit including a CB (Coding Block) and a parameter for processing in the CU base (level).

<Image encoding device>
FIG. 8 is a block diagram illustrating an example of a configuration of an image encoding device that is an aspect of an image processing device to which the present technology is applied. The image encoding device 100 illustrated in FIG. 8 encodes moving image image data using, for example, HEVC prediction processing or prediction processing based on the HEVC prediction processing.

  As shown in FIG. 8, the image encoding device 100 includes a screen rearrangement buffer 111, a calculation unit 112, an orthogonal transformation unit 113, a quantization unit 114, a lossless encoding unit 115, a storage buffer 116, an inverse quantization unit 117, And an inverse orthogonal transform unit 118. In addition, the image encoding device 100 includes a calculation unit 119, a loop filter 120, a frame memory 121, an intra prediction unit 122, an inter prediction unit 123, a predicted image selection unit 124, and a rate control unit 125.

  The screen rearrangement buffer 111 stores the image of each frame of the input image data in the display order, and the image of the frame of the stored display order is encoded for encoding according to GOP (Group Of Picture). The images are rearranged in the order of the frames, and the image in which the order of the frames is rearranged is supplied to the calculation unit 112. In addition, the screen rearrangement buffer 111 also supplies the image in which the order of the frames is rearranged to the intra prediction unit 122 and the inter prediction unit 123.

  The calculation unit 112 subtracts the predicted image supplied from the intra prediction unit 122 or the inter prediction unit 123 via the predicted image selection unit 124 from the image read from the screen rearrangement buffer 111, and calculates the difference information (residual). Difference data) is supplied to the orthogonal transform unit 113. For example, in the case of an image on which intra coding is performed, the calculation unit 112 subtracts the prediction image supplied from the intra prediction unit 122 from the image read from the screen rearrangement buffer 111. For example, in the case of an image on which inter coding is performed, the calculation unit 112 subtracts the prediction image supplied from the inter prediction unit 123 from the image read from the screen rearrangement buffer 111.

  The orthogonal transform unit 113 performs orthogonal transform such as discrete cosine transform and Karhunen-Loeve transform on the residual data supplied from the computing unit 112. The orthogonal transform unit 113 supplies the transform coefficient obtained by the orthogonal transform to the quantization unit 114.

  The quantization unit 114 quantizes the transform coefficient supplied from the orthogonal transform unit 113. The quantization unit 114 sets a quantization parameter based on the information regarding the target value of the code amount supplied from the rate control unit 125, and performs the quantization. The quantization unit 114 supplies the quantized transform coefficient to the lossless encoding unit 115.

  The lossless encoding unit 115 encodes the transform coefficient quantized by the quantization unit 114 using an arbitrary encoding method, and generates encoded data (also referred to as an encoded stream). Further, the lossless encoding unit 115 generates header information such as a sequence parameter set, a picture parameter set, and a slice header. Furthermore, the lossless encoding unit 115 acquires information indicating the mode of intra prediction from the intra prediction unit 122, acquires information indicating the mode of inter prediction, difference motion vector information, and the like from the inter prediction unit 123. Various information is included in the header information.

  The lossless encoding unit 115 supplies the encoded data obtained by encoding to the accumulation buffer 116 for accumulation.

  Examples of the encoding method of the lossless encoding unit 115 include variable-length encoding or arithmetic encoding. Examples of variable length coding include H.264. CAVLC (Context-Adaptive Variable Length Coding) defined in the H.264 / AVC format. Also, a TR code is used for the coefficient information data syntax processing called coeff_abs_level_remaining. Examples of arithmetic coding include CABAC (Context-Adaptive Binary Arithmetic Coding).

  The accumulation buffer 116 temporarily holds the encoded data supplied from the lossless encoding unit 115. The accumulation buffer 116 outputs the stored encoded data to the outside of the image encoding device 100 at a predetermined timing. That is, the accumulation buffer 116 is also a transmission unit that transmits encoded data.

  The transform coefficient quantized by the quantization unit 114 is also supplied to the inverse quantization unit 117. The inverse quantization unit 117 inversely quantizes the quantized transform coefficient by a method corresponding to the quantization by the quantization unit 114. The inverse quantization unit 117 supplies the transform coefficient obtained by the inverse quantization to the inverse orthogonal transform unit 118.

  The inverse orthogonal transform unit 118 performs inverse orthogonal transform on the transform coefficient supplied from the inverse quantization unit 117 by a method corresponding to the orthogonal transform processing by the orthogonal transform unit 113. The inverse orthogonal transform unit 118 supplies the output (restored residual data) subjected to the inverse orthogonal transform to the calculation unit 119.

  The calculation unit 119 adds the predicted image supplied from the intra prediction unit 122 or the inter prediction unit 123 via the predicted image selection unit 124 to the restored residual data supplied from the inverse orthogonal transform unit 118, A locally reconstructed image (hereinafter also referred to as a decoded image) is obtained. The decoded image is supplied to the loop filter 120 or the intra prediction unit 122.

  The loop filter 120 appropriately performs a loop filter process on the decoded image supplied from the calculation unit 119. This loop filter process is arbitrary as long as it is a filter process including at least a deblocking filter process. For example, the loop filter 120 performs deblocking filter processing on the decoded image to remove deblocking distortion, and performs image quality improvement by performing adaptive loop filter processing using a Wiener filter (Wiener Filter). May be. Further, the loop filter 120 can supply information such as filter coefficients used for the filter processing to the lossless encoding unit 115 and encode it as necessary. The loop filter 120 supplies the decoded image to which the filter process is appropriately performed to the frame memory 121.

  The frame memory 121 stores the supplied decoded image, and supplies the stored decoded image to the inter prediction unit 123 as a reference image at a predetermined timing.

  The intra prediction unit 122 performs intra prediction (intra-screen prediction) that generates a predicted image using pixel values in a processing target picture that is a decoded image supplied as a reference image from the calculation unit 119. The intra prediction unit 122 performs this intra prediction in a plurality of intra prediction modes prepared in advance.

  The intra prediction unit 122 generates predicted images in all candidate intra prediction modes, evaluates the cost function value of each predicted image using the input image supplied from the screen rearrangement buffer 111, and selects the optimum mode. select. When the intra prediction unit 122 selects the optimal intra prediction mode, the intra prediction unit 122 supplies the predicted image generated in the optimal mode to the predicted image selection unit 124.

  Further, as described above, the intra prediction unit 122 appropriately supplies the intra prediction mode information indicating the adopted intra prediction mode to the lossless encoding unit 115 and performs encoding.

  The inter prediction unit 123 performs inter prediction processing (motion prediction processing and compensation processing) using the input image supplied from the screen rearrangement buffer 111 and the reference image supplied from the frame memory 121. More specifically, the inter prediction unit 123 performs motion compensation processing according to motion vectors detected by performing motion prediction as inter prediction processing, and generates a predicted image (inter predicted image information). The inter prediction unit 123 performs such inter prediction in a plurality of inter prediction modes prepared in advance.

  The inter prediction unit 123 generates a prediction image in all candidate inter prediction modes. The inter prediction unit 123 evaluates the cost function value of each prediction image using the input image supplied from the screen rearrangement buffer 111, information on the generated difference motion vector, and the like, and selects an optimal mode. When the optimal inter prediction mode is selected, the inter prediction unit 123 supplies the predicted image generated in the optimal mode to the predicted image selection unit 124.

  The inter prediction unit 123 supplies information indicating the adopted inter prediction mode, information necessary for performing processing in the inter prediction mode, and the like to the lossless encoding unit 115 when decoding the encoded data, Encode. The necessary information includes, for example, information on the generated differential motion vector and a flag indicating an index of the predicted motion vector as predicted motion vector information.

  The predicted image selection unit 124 selects a supply source of the predicted image supplied to the calculation unit 112 or the calculation unit 119. For example, in the case of intra coding, the predicted image selection unit 124 selects the intra prediction unit 122 as the supply source of the predicted image, and supplies the predicted image supplied from the intra prediction unit 122 to the calculation unit 112 and the calculation unit 119. To do. Further, for example, in the case of inter coding, the prediction image selection unit 124 selects the inter prediction unit 123 as a supply source of the prediction image, and calculates the prediction image supplied from the inter prediction unit 123 as the calculation unit 112 or the calculation unit 119. To supply.

  The rate control unit 125 controls the quantization operation rate of the quantization unit 114 based on the code amount of the encoded data accumulated in the accumulation buffer 116 so that no overflow or underflow occurs.

<Lossless encoding unit>
FIG. 9 is a block diagram illustrating a main configuration example of the lossless encoding unit 115 regarding TR encoding. As illustrated in FIG. 9, the lossless encoding unit 115 includes, for example, a control unit 151, a table selection unit 152, a TR encoding unit 153, and a table designation information buffer 154 as a configuration related to TR encoding.

  The control unit 151 controls each processing unit of the table selection unit 152 to the table designation information buffer 154, respectively.

  The table selection unit 152 acquires coefficient data supplied to the lossless encoding unit 115 and selects an encoding table used for TR encoding for each coefficient data. The table selection unit 152 supplies table designation information indicating the selected table to the TR encoding unit 153 and the table designation information buffer 154.

  The TR encoding unit 153 uses the encoding table selected by the table selection unit 152 (for example, the encoding table specified in the table specification information supplied from the table selection unit 152) to process coefficient data ( Current coefficient data) is encoded. The TR encoding unit 153 outputs encoded data obtained by encoding using the encoding table, for example, to the accumulation buffer 116 or the like.

  The table designation information buffer 154 stores table designation information for each coefficient data supplied from the table selection unit 152. Further, the table designation information buffer 154 supplies the stored table designation information to the table selection unit 152 as coefficient data around the current coefficient data as necessary (for example, according to a request from the table selection unit 152). .

  The table designation information is arbitrary information, but may include a table number, for example. Below, the case where the table number of an encoding table is used as table designation | designated information is demonstrated.

<Table selection part>
FIG. 10 is a block diagram illustrating a main configuration example of the table selection unit 152. As illustrated in FIG. 10, the table selection unit 152 includes a peripheral history calculation unit 161, a table processing unit 162, a selection unit 163, a base level determination unit 164, a calculation unit 165, a calculation unit 166, a selection unit 167, and a shift processing unit. 171, a table selection unit 172, a selection unit 173, a base level determination unit 174, a calculation unit 175, a calculation unit 176, and a selection unit 177.

  As shown in FIG. 10, the table selection unit 152 processes two coefficient data in parallel. The configuration in the upper part of the drawing surrounded by the dotted line 181 is a configuration for processing the first coefficient data, and the configuration in the lower part of the drawing surrounded by the dotted line 182 is a configuration for processing the second coefficient data.

  The peripheral history calculation unit 161 obtains a table number (curr_table No.) of an encoding table used for encoding for current coefficient data (coefficient data to be processed). For example, if the current coefficient data is the first (first processed) coefficient data of a coded sub-block (coded_sub_block) that is one of the coding units of image data, the current coefficient data is stored in the table designation information buffer 154. Obtain the table number (peripheral Table No.) of the encoding table used for encoding the peripheral coefficient data, and use the table number (curr_table No.) of the encoding table of the current coefficient data from the acquired table number. Ask.

  Although details of this calculation method will be described later, for example, when there is no peripheral coefficient data for the current coefficient data, the peripheral history calculation unit 161 uses a predetermined initial value (for example, table number 0) as the current coefficient data. Set as the table number (curr_table No.) of the encoding table.

  The peripheral history calculation unit 161 supplies the set table number (curr_table No.) to the TR encoding unit 153 and the table designation information buffer 154 and also to the selection unit 163.

  If the current coefficient data is not the first coefficient data of the coded sub-block (coded_sub_block), the peripheral history calculation unit 161 selects the table number (next_table_1) selected by the selection unit 177 (that is, the one before the current coefficient data). In the coefficient data processing, a value set as “the table number of the encoding table used for encoding the next coefficient data”) is acquired, and the acquired table number is used as the table of the encoding table of the current coefficient data. The number is supplied to the selection unit 163 as a number (curr_table No.).

  The table processing unit 162 converts the coefficient data supplied to the table selection unit 152 into each encoding table (in the example of FIG. 10, the encoding table (Table_0) with the table number 0 to the encoding table (Table_4) with the table number 4). )) Is used for TR encoding. The table processing unit 162 supplies the TR encoding result using each encoding table to the selection unit 163.

  The selection unit 163 selects the TR encoding result using the encoding table of the table number (curr_table No.) supplied from the peripheral history calculation unit 161 from the TR encoding results supplied from the table processing unit 162. select. The selection unit 163 supplies the selected TR encoding result to the arithmetic unit 165 as coeff_abs_level_remaining.

  The base level determination unit 164 performs processing related to determination of the base level. For example, the base level determination unit 164 determines whether or not scf is 1, which bit of g1_flag [7: 0] corresponds, and when g1_flag = 1, whether g2_flag is 0 or 1 or all g1_flag is output The base level is determined based on conditions such as whether or not. The base level determination unit 164 supplies the determined base level to the calculation unit 165.

  The calculation unit 165 adds the base level (baselevel) determined by the base level determination unit 164 to coeff_abs_level_remaining supplied from the selection unit 163, and supplies the value to the selection unit 167 as cLastAbsLevel.

  The calculation unit 166 adds the value “+1” to the table number (curr_table) of the encoding table used for encoding the current coefficient data. The selection unit 167 is supplied with the table number (curr_table) of the encoding table used for encoding the current coefficient data and the table number added with “+1” by the calculation unit 166.

  Based on the cLastAbsLevel supplied from the operation unit 165, the selection unit 167 adds the table number (curr_table) of the encoding table used for encoding the current coefficient data and “+1” supplied from the operation unit 166. Select one of the table numbers. The selection unit 167 uses the selected table number as the table number (next_table No. (ie, next_table_0)) of the encoding table used for encoding the next coefficient data in the TR encoding unit 153 and the table designation information buffer 154. In addition to the supply, the selection unit 173 is also supplied.

  The coefficient data input to the table selection unit 152 is also supplied to the shift processing unit 171. The shift processing unit 171 shifts the current coefficient data to the next coefficient data. In other words, the shift processing unit 171 supplies the coefficient data next to the coefficient data supplied to the table processing unit 162 to the table processing unit 172.

  The table processing unit 172 converts the coefficient data newly made into current coefficient data by the shift processing unit 171 into each encoding table (in the example of FIG. 10, the encoding table (Table_0) from the table number 0 to the table number 4). Perform TR encoding using the encoding table (Table_4). The table processing unit 172 supplies the TR encoding result using each encoding table to the selection unit 173.

  The selection unit 173 selects a TR encoding result using the encoding table of the table number (next_table_0) supplied from the selection unit 167 from the TR encoding results supplied from the table processing unit 172. The selection unit 173 supplies the selected TR encoding result to the calculation unit 175 as coeff_abs_level_remaining.

  The base level determination unit 174 performs processing related to determination of a base level. For example, the base level determination unit 174 determines whether or not scf is 1, which bit of g1_flag [7: 0] corresponds, and when g1_flag = 1, whether g2_flag is 0 or 1 or all g1_flag is output The base level is determined based on conditions such as whether or not. The base level determination unit 174 supplies the determined base level to the calculation unit 175.

  The calculation unit 175 adds the base level (baselevel) determined by the base level determination unit 174 to coeff_abs_level_remaining supplied from the selection unit 173, and supplies the value to the selection unit 177 as cLastAbsLevel.

  The calculation unit 176 adds the value “+1” to the table number (curr_table) of the encoding table used for encoding the current coefficient data. The selection unit 177 is supplied with the table number (curr_table) of the encoding table used for encoding the current coefficient data and the table number added with “+1” by the calculation unit 176.

  Based on the cLastAbsLevel supplied from the operation unit 175, the selection unit 177 adds the table number (curr_table) of the encoding table used for encoding the current coefficient data and “+1” supplied from the operation unit 176. Select one of the table numbers. The selection unit 177 sets the selected table number as the table number (next_table No. (ie, next_table_1)) of the encoding table used for encoding the next coefficient data in the TR encoding unit 153 and the table designation information buffer 154. Supply.

<Setting method of encoding table>
Next, how to set the encoding table by the peripheral history calculation unit 161 will be described with reference to FIG.

  The TU, which is an orthogonal transform processing unit, is composed of a plurality of coded sub-blocks (coded_sub_block). In the case of the example of FIG. 11A, the TU 190 is configured by 8 × 8 (vertical 8 × horizontal 8) coefficient data, and 2 × 2 encoding sub-blocks (encoding sub-block 191-1 to encoding sub-block 191-4). Is formed. In FIG. 11A, a small square indicates coefficient data. The encoding sub-block 191-1 to the encoding sub-block 191-4 are each composed of coefficient data of 4 × 4 (4 vertical × 4 horizontal). When it is not necessary to distinguish between the encoding sub-block 191-1 to the encoding sub-block 191-4, they are referred to as an encoding sub-block 191.

  The size of the TU 190 is arbitrary and is not limited to 8x8. For example, in HEVC, 4x4, 8x8, 16x16, 32x32, etc. are accepted as TU sizes. Of course, the size may be other than these or may not be square. The encoding sub-block 191 only needs to be smaller than the TU 190, and is not limited to 4x4.

  Within each encoding sub-block 191, each coefficient data is encoded in the order shown in FIG. 11B (up-right_scan order). In FIG. 11B, each small square indicates coefficient data, and the numbers shown therein indicate the processing order. That is, the encoding of each coefficient data of the encoding sub-block 191 proceeds in the order of 0 → 1 → 2 →. That is, the coefficient data at the lower right corner of the encoding sub-block 191 indicated by the hatched pattern is the first coefficient data (coefficient data processed first) in the encoding sub-block 191.

  Also, in this case, in the TU 190 of FIG. 11A, each encoding subblock 191 includes an encoding subblock 191-1, an encoding subblock 191-2, an encoding subblock 191-3, and an encoding subblock 191-4. Are processed in this order.

  The scan order is arbitrary and is not limited to the upright scan order. For example, the order may be horizontal scan (horizontal_scan) order, vertical scan (vertical_scan) order, or any other order.

  For the TU 190 having such a configuration, the peripheral history calculation unit 161 encodes an encoding table (its table number) used for encoding the first coefficient data of the encoding sub-block 191 to encode the peripheral coefficient data. This is set based on the encoding table (table number) used in the above.

  More specifically, the peripheral history calculation unit 161 sets the first coefficient data (coefficient data indicated by “C” in FIG. 11A) of the encoding sub-block 191 as current coefficient data (coefficient data to be processed). The coding table (the table number) used for coding the coefficient data adjacent to the right of the current coefficient data (coefficient data indicated by “A” in FIG. 11A) and the current coefficient data are adjacent to each other. Based on the coding table (the table number) used for coding the coefficient data (coefficient data indicated by “B” in FIG. 11A) (the table number of the coding table used for coding the current coefficient data) ) Is set.

  For example, when the first coefficient data of the encoding sub-block 191-1 is the current coefficient data, as shown in FIG. 11A, the coefficient data adjacent to the right of the current coefficient data (coefficient data indicating “A”) ), There is no coefficient data adjacent to the current coefficient data (coefficient data indicated by “B”). Accordingly, the peripheral history calculation unit 161 sets a predetermined initial value (for example, table number 0) as an encoding table (table number) used for encoding the current coefficient data.

  For example, when the first coefficient data of the encoding sub-block 191-2 is current coefficient data, there is no coefficient data adjacent to the right of the current coefficient data, as shown in FIG. Adjacent coefficient data exists below the coefficient data. Accordingly, the peripheral history calculation unit 161 uses, as an encoding table (table number) used for encoding the current coefficient data, the coefficient data adjacent to the current coefficient data (coefficient data indicating “B”). An encoding table (table number) used for encoding is set.

  Similarly, for example, when the first coefficient data of the encoding sub-block 191-3 is the current coefficient data, there is no coefficient data adjacent to the current coefficient data as shown in FIG. 11A. Adjacent coefficient data exists to the right of the current coefficient data. Therefore, the peripheral history calculation unit 161 uses, as an encoding table (table number) used for encoding the current coefficient data, coefficient data adjacent to the right of the current coefficient data (coefficient data indicating “A”). An encoding table (table number) used for encoding is set.

  Furthermore, for example, when the first coefficient data of the encoding sub-block 191-4 is used as current coefficient data, as shown in FIG. 11A, coefficient data adjacent to the right of the current coefficient data is also the current coefficient data. There is also adjacent coefficient data below. Therefore, the peripheral history calculation unit 161 encodes the coefficient data adjacent to the right of the current coefficient data (coefficient data indicated by “A”) as the table number of the encoding table used for encoding the current coefficient data. The average value of the table number of the encoding table used for the encoding and the table number of the encoding table used for encoding the coefficient data adjacent to the current coefficient data (coefficient data indicated by “B”) Set.

  If the encoding table (table number) used for encoding other coefficient data is set in the same manner as described with reference to the flowchart of FIG. 5, it is used for encoding each coefficient data of TU190. The encoding table (table number) is set as shown in the example of FIG.

  In general, low frequency components are collected at the upper left of the TU 190, and high frequency components are collected at the lower right. In other words, the lower right coefficient data of TU 190 has a smaller value, and the upper left coefficient data tends to have a larger value. Therefore, it is possible to expect an improvement in encoding efficiency by encoding with the encoding table having a smaller table number as the coefficient data at the lower right of the TU 190 and encoding with an encoding table having a larger table number as the upper left coefficient data. it can. In other words, if the lower right coefficient data of the TU 190 is encoded with an encoding table with a larger table number, and the upper left coefficient data is encoded with an encoding table with a smaller table number, the encoding efficiency is increased. May be reduced.

  Further, from the tendency of such value distribution, each coefficient data value is highly correlated with the peripheral coefficient data values. That is, each coefficient data is encoded by using an encoding table having a table number that matches or approximates the table number of the encoding table used for encoding the peripheral coefficient data, thereby improving the encoding efficiency. Can be expected. In other words, if encoding tables having greatly different table numbers are assigned to coefficient data whose positions are close to each other, encoding efficiency may be reduced.

  In the example of FIG. 12, an encoding table having a smaller table number is assigned to the lower right coefficient data of the TU 190 and an encoding table having a larger table number is assigned to the upper left coefficient data than in the case of FIGS. 6A and 6B. Assigned. Further, the example of FIG. 12 has a smaller table number difference between the coding tables assigned to the coefficient data whose positions are closer to each other than in the case of FIGS. 6A and 6B.

  Therefore, the example of FIG. 12 can suppress the reduction in encoding efficiency compared to the cases of FIGS. 6A and 6B.

  In the above description, the coefficient data adjacent to the right of the current coefficient data and the coefficient data adjacent to the current coefficient data are present, that is, used for encoding of the peripheral coefficient data that can be used. In the case where there are a plurality of encoding tables, the table number of the encoding table used for encoding the current coefficient data has been described as setting the average value of the table numbers of these encoding tables. For example, you may make it set the median of the table number of those encoding tables. Further, the result of other calculation may be set as a table number of an encoding table used for encoding current coefficient data.

  Further, for example, any one of the table numbers of the encoding tables may be set as the table number of the encoding table used for encoding the current coefficient data. For example, the maximum value and the minimum value of the table numbers of those encoding tables may be set.

<Flow of encoding process>
Next, an example of the flow of each process executed by the image encoding device 100 will be described. First, an example of the flow of the encoding process will be described with reference to the flowchart of FIG.

  When the encoding process is started, in step S101, the screen rearrangement buffer 111 stores the images of the frames (pictures) of the input moving image in the order in which the images are displayed. Rearrange in the order of conversion.

  In step S102, the intra prediction unit 122 performs intra prediction processing in the intra prediction mode.

  In step S103, the inter prediction unit 123 performs inter prediction processing for performing motion prediction, motion compensation, and the like in the inter prediction mode.

  In step S104, the predicted image selection unit 124 selects either a predicted image generated by the intra prediction in step S102 or a predicted image generated by the inter prediction in step S103, based on the cost function value or the like. .

  In step S105, the calculation unit 112 calculates a difference between the input image whose frame order is rearranged by the process of step S101 and the predicted image selected by the process of step S104. That is, the calculation unit 112 generates residual data between the input image and the predicted image. The residual data obtained in this way is reduced in data amount compared to the original image data. Therefore, the data amount can be compressed as compared with the case where the image is encoded as it is.

  In step S106, the orthogonal transform unit 113 performs orthogonal transform on the residual data generated by the process in step S105.

  In step S107, the quantization unit 114 quantizes the orthogonal transform coefficient obtained by the process in step S106, using the quantization parameter calculated by the rate control unit 125.

  In step S108, the inverse quantization unit 117 inversely quantizes the quantized coefficient (also referred to as a quantization coefficient) generated by the process in step S107 with a characteristic corresponding to the quantization characteristic.

  In step S109, the inverse orthogonal transform unit 118 performs inverse orthogonal transform on the orthogonal transform coefficient obtained by the process of step S108.

  In step S110, the calculation unit 119 generates image data of a decoded image by adding the predicted image selected by the process of step S104 to the residual data restored by the process of step S109.

  In step S111, the loop filter 120 appropriately performs loop filter processing on the image data of the decoded image generated by the processing in step S110.

  In step S112, the frame memory 121 stores the locally decoded decoded image that has undergone the process of step S111.

  In step S113, the lossless encoding unit 115 encodes the quantized coefficient obtained by the process of step S107. That is, lossless encoding such as variable length encoding or arithmetic encoding is performed on data corresponding to the residual data.

  In addition, the lossless encoding unit 115 encodes information related to the prediction mode of the prediction image selected by the processing in step S104 and adds the information to the header information of the encoded data. That is, the lossless encoding unit 115 also encodes the optimal intra prediction mode information supplied from the intra prediction unit 122 or the information corresponding to the optimal inter prediction mode supplied from the inter prediction unit 123, and the like. Add to header information.

  In step S114, the accumulation buffer 116 accumulates the encoded data obtained by the process in step S113. The encoded data or the like stored in the storage buffer 116 is appropriately read as a bit stream and transmitted to the decoding side via a transmission path or a recording medium.

  In step S115, the rate control unit 125 performs step S107 to prevent overflow or underflow based on the code amount (generated code amount) of the encoded data or the like accumulated in the accumulation buffer 116 by the process of step S114. Controls the rate of quantization processing.

  When the process of step S115 ends, the encoding process ends.

<Flow of TR encoding process>
Next, an example of the flow of the TR encoding process executed as the lossless encoding process in step S113 will be described with reference to the flowchart of FIG.

  When the TR encoding process is started, in step S121, the table selection unit 152 selects an encoding table used for encoding coefficient data.

  In step S122, the TR encoding unit 153 encodes the coefficient data using the encoding table selected in step S121.

  In step S123, the table designation information buffer 154 stores table designation information indicating the encoding table (table number) selected in step S121.

  When the process of step S123 ends, the TR encoding process ends.

<Encoding table selection process flow>
Next, an example of the flow of the encoding table selection process executed in step S121 of FIG. 14 will be described with reference to the flowchart of FIG.

  In step S131, the peripheral history calculation unit 161 sets variables StatCoeffA, StatCoeffB, and prevStatCoeff to initial values (for example, “0”).

  The variable StatCoeffA indicates the table number of the encoding table used for encoding the coefficient data adjacent to the right of the current coefficient data. The variable StatCoeffB indicates the table number of the encoding table used for encoding the coefficient data adjacent to the current coefficient data. The variable prevStatCoeff indicates the table number of the encoding table used for encoding the coefficient data processed immediately before.

  In step S132, the control unit 151 selects a coded sub-block (coded_sub_block) to be processed in a predetermined order in the TU. In addition, the control unit 151 selects the first coefficient data in a predetermined scan order as a processing target (current coefficient data) in the selected encoding sub-block.

  In step S133, the peripheral history calculation unit 161 sets a variable initValue depending on the presence / absence of coefficient data around the current coefficient data.

  For example, when the current coefficient data is the first coefficient data (C) of the encoding sub-block 191-1 (FIG. 11A), the coefficient data (A) adjacent to the right of the current coefficient data is also adjacent below. Since the coefficient data (B) is also located outside the TU 190, the values of both the variable StatCoeffA and the variable StatCoeffB are “invalid” (no history).

  Therefore, in this case, the peripheral history calculation unit 161 sets the value of the variable prevStatCoeff to the variable initValue. When this current coefficient data is the first coefficient data of TU 190 (for example, the first coefficient data (C) of the encoding sub-block 191-1), the value of the variable prevStatCoeff is the initial value (for example, the value set in step S131). “0”).

  For example, when the current coefficient data is the first coefficient data (C) of the encoding sub-block 191-2 (FIG. 11A), the coefficient data (A) adjacent to the right of the current coefficient data is the TU190. The value of the variable StatCoeffA is “invalid” (no history). On the other hand, since the coefficient data (B) adjacent to the current coefficient data exists in the TU 190, the value of the variable StatCoeffB is the sign of the coefficient data (B) adjacent to the current coefficient data. This is the table number of the encoding table used for encoding.

  Therefore, in this case, the peripheral history calculation unit 161 sets the value of the variable StatCoeffB in the variable initValue. In the example of FIG. 12, the value of the variable initValue is set to “3”.

  For example, when the current coefficient data is the first coefficient data (C) of the encoding sub-block 191-3 (FIG. 11A), the coefficient data (B) adjacent to the current coefficient data is the TU 190. The value of the variable StatCoeffB is “invalid” (no history). On the other hand, since the coefficient data (A) adjacent to the right of the current coefficient data exists in the TU 190, the value of the variable StatCoeffA is the sign of the coefficient data (A) adjacent to the right of the current coefficient data. This is the table number of the encoding table used for encoding.

  Therefore, in this case, the peripheral history calculation unit 161 sets the value of the variable StatCoeffA in the variable initValue. In the example of FIG. 12, the value of the variable initValue is set to “4”.

  Furthermore, for example, when the current coefficient data is the first coefficient data (C) of the encoding sub-block 191-4 (FIG. 11A), the coefficient data (A) adjacent to the right of the current coefficient data is also below There is also adjacent coefficient data (B). Therefore, the value of the variable StatCoeffA is the table number of the encoding table used for encoding the coefficient data (A) adjacent to the right of the current coefficient data, and the value of the variable StatCoeffB is the value under the current coefficient data. Is the table number of the encoding table used for encoding the coefficient data (B) adjacent to.

  Therefore, in this case, the peripheral history calculation unit 161 sets the average value of the variable StatCoeffA and the variable StatCoeffB as the variable initValue. In the case of the example in FIG. 12, since the variable StatCoeffA and the variable StatCoeffB are both “7”, the value of the variable initValue is set to “7”.

  In step S134, the peripheral history calculation unit 161 sets the variable initValue set as described above to the variable cRiceParam. The variable cRiceParam is a variable indicating the table number of the encoding table used for encoding the current coefficient data. That is, the peripheral history calculation unit 161 sets the encoding table (table number) selected in step S133 as the encoding table (table number) used for encoding the current coefficient data. This variable cRiceParam is supplied to the TR encoding unit 153 and used for encoding. That is, the TR encoding unit 153 encodes the current coefficient data using the encoding table indicated by the variable cRiceParam.

  In step S134, the peripheral history calculation unit 161 sets the variable initValue set as described above to the variable prevStatCoeff. That is, the peripheral history calculation unit 161 sets the coding table (table number) selected in step S133 as the coding table (table number) used for coding the coefficient data processed immediately before. Since the value of this variable prevStatCoeff is used in the process for the next coefficient data, it indicates the encoding table (table number) used for encoding the current current coefficient data.

  In step S135, the control unit 151 determines whether or not unprocessed coefficient data exists in the encoding sub-block to be processed. When it is determined that the data exists, the control unit 151 moves the current coefficient data to the next coefficient data according to a predetermined scan order in the coding sub-block. Then, the process proceeds to step S136.

  In step S136, the selection unit 167 determines whether or not the variable cLastAbsLevel and the variable cLastRiceParam satisfy the following conditional expression (1).

  cLastAbsLevel> (3 * (1 << cLastRiceParam)) (1)

  When it determines with satisfy | filling, a process progresses to step S137. In step S137, the selection unit 167 adds “+1” to the value of the variable cRiceParam. That is, the table used for encoding is changed.

  When the process of step S137 ends, the process returns to step S135, and the subsequent processes are repeated. If it is determined in step S136 that the conditional expression (1) is not satisfied, the process returns to step S135, and the subsequent processes are repeated.

  If it is determined in step S135 that all the coefficient data of the coding sub-block has been processed, the process proceeds to step S138.

  In step S138, the control unit 151 determines whether or not all the encoded sub-blocks have been processed for the TU. If it is determined that there is an unprocessed encoded sub-block, the process returns to step S132, and the subsequent processes are repeated.

  If it is determined in step S138 that all coding sub-blocks have been processed for the TU, the coding table selection process ends, and the process returns to FIG.

  By executing each process as described above, it is possible to suppress a reduction in encoding efficiency.

<Setting method of encoding table>
In the above, as an example of the coefficient data around the current coefficient data, coefficient data (A) adjacent to the right of the current coefficient data (C) and coefficient data (B However, the coefficient data around the current coefficient data is not limited to this example. For example, the coefficient data adjacent to the lower right of the current coefficient data (C) (coefficient data indicated by “D” in FIG. 11A) may be included in the coefficient data around the current coefficient data.

  In this case, when there is no coefficient data around the current coefficient data (C), there is only coefficient data (A) adjacent to the right of the current coefficient data, and coefficient data adjacent below the current coefficient data. The case where only (B) exists is the same as the case described with reference to FIGS.

  On the other hand, for example, when the first coefficient data of the encoding sub-block 191-4 is current coefficient data, as shown in FIG. 11A, coefficient data (A) adjacent to the right of the current coefficient data, The coefficient data (B) adjacent to the current coefficient data and the coefficient data (D) adjacent to the lower right of the current coefficient data all exist. Therefore, the peripheral history calculation unit 161 uses the coefficient data (A) adjacent to the right of the current coefficient data as the table number of the encoding table used for encoding the current coefficient data, and is adjacent to the current coefficient data. An average value of the coefficient data (B) and the table number of the encoding table used for encoding the coefficient data (D) adjacent to the lower right of the current coefficient data is set.

  An example of encoding table allocation in this case is shown in FIG. As shown in FIG. 16, the table number of the encoding table used for encoding the first coefficient data (current coefficient data) of the encoding sub-block 191-4 includes a coefficient adjacent to the right of the current coefficient data. The table number (7) of the encoding table used for encoding the data, the table number (7) of the encoding table used for encoding the coefficient data adjacent to the current coefficient data, and the current An average value ((7 + 7 + 10) / 3 = 8) with the table number (10) of the encoding table used for encoding the adjacent coefficient data is set at the lower right of the coefficient data.

  Therefore, the example of FIG. 16 assigns a smaller table number encoding table to the lower right coefficient data of TU 190 and assigns a larger table number code to the upper left coefficient data than in the case of FIGS. 6A and 6B. Allocating table is assigned. In the example of FIG. 16, the difference between the table numbers of the coding tables assigned to the coefficient data whose positions are close to each other is smaller than in the case of FIGS. 6A and 6B.

  That is, by assigning an encoding table to each coefficient data in this way, it is possible to suppress a reduction in encoding efficiency as compared with the cases of FIGS. 6A and 6B.

  Also in this case, as in the case of the example of FIG. 12, the result of other calculations such as the median may be used instead of the average value. Further, for example, any table number such as the maximum value or the minimum value of the table number of the encoding table used for encoding the peripheral coefficient data may be used.

<Encoding table selection process flow>
An example of the flow of the coding table selection process in this case will be described with reference to the flowchart of FIG.

  When the coding table selection process is started, in step S131, the peripheral history calculation unit 161 sets variables StatCoeffA, StatCoeffB, StatCoeffD, and prevStatCoeff to initial values (for example, “0”). The variable StatCoeffD indicates the table number of the encoding table used for encoding the coefficient data adjacent to the lower right of the current coefficient data.

  The process in step S152 is executed in the same manner as the process in step S132 in FIG.

  In step S153, the peripheral history calculation unit 161 sets a variable initValue depending on the presence / absence of coefficient data around the current coefficient data.

  The current coefficient data is the first coefficient data (C) of the coding sub-block 191-1 (FIG. 11A), the first coefficient data (C) of the coding sub-block 191-2 (FIG. 11A), or the coding sub-block. If it is the first coefficient data (C) of the block 191-3 (FIG. 11A), the variable initValue is set as in the case of the process of step S133 of FIG.

  On the other hand, when the current coefficient data is the first coefficient data (C) of the encoding sub-block 191-4 (FIG. 11A), the coefficient data (A) adjacent to the right of the current coefficient data is also There is also coefficient data (B) adjacent to and coefficient data (D) adjacent to the lower right. Therefore, the value of the variable StatCoeffA is the table number of the encoding table used for encoding the coefficient data (A) adjacent to the right of the current coefficient data, and the value of the variable StatCoeffB is the value under the current coefficient data. Is the table number of the coding table used for coding the coefficient data (B) adjacent to the current coefficient data, and the value of the variable StatCoeffD is used for coding the coefficient data (D) adjacent to the current coefficient data. It becomes the table number of the encoding table.

  Accordingly, in this case, the peripheral history calculation unit 161 sets the average value of the variable StatCoeffA, the variable StatCoeffB, and the variable StatCoeffD as the variable initValue. In the example of FIG. 16, the variable StatCoeffA and the variable StatCoeffB are “7” and the variable StatCoeffD is “10”, so the value of the variable initValue is set to “8”.

  Steps S154 to S158 are executed in the same manner as steps S134 to S138 in FIG.

  By executing the encoding table selection process in this way, it is possible to suppress a decrease in encoding efficiency.

<Setting method of encoding table>
Further, the coefficient data around the current coefficient data may be coefficient data adjacent to the current coefficient data. For example, coefficient data adjacent to the upper right of the current coefficient data (C) (coefficient data indicated by “E” in FIG. 11A) and coefficient data adjacent to the lower left of the current coefficient data (C) (“F” in FIG. 11A). May be used as coefficient data around the current coefficient data.

  As described above, the coefficient data of the TU 190 generally tends to have a smaller value as it is located at the lower right and a larger value as it is located at the upper left. Therefore, the value of each coefficient data is highly correlated in the upper right and lower left diagonal directions. In other words, encoding of the current coefficient data is performed using an encoding table having a table number that matches or approximates the table number of the encoding table used for encoding the coefficient data adjacent to the upper right and the coefficient data adjacent to the lower left. By doing so, an improvement in encoding efficiency can be expected.

  For example, in the example of FIG. 11A, when the first coefficient data of the encoding sub-block 191-1 is current coefficient data, there is no coefficient data adjacent to the upper right and lower left of the current coefficient data. Accordingly, the peripheral history calculation unit 161 sets a predetermined initial value (for example, table number 0) as an encoding table (table number) used for encoding the current coefficient data.

  For example, in the example of FIG. 11A, when the first coefficient data of the encoding sub-block 191-2 is current coefficient data, there is no coefficient data adjacent to the upper right of the current coefficient data, but the current coefficient data There is adjacent coefficient data at the lower left of. Accordingly, the peripheral history calculation unit 161 uses, as an encoding table (table number) used for encoding the current coefficient data, coefficient data adjacent to the lower left of the current coefficient data (coefficient data indicating “F”). An encoding table (table number) used for encoding is set.

  Similarly, for example, in the example of FIG. 11A, when the first coefficient data of the encoding sub-block 191-3 is current coefficient data, there is no coefficient data adjacent to the lower left of the current coefficient data, but the current coefficient There is coefficient data adjacent to the upper right of the data. Therefore, the peripheral history calculation unit 161 uses, as an encoding table (table number) used for encoding the current coefficient data, coefficient data adjacent to the upper right of the current coefficient data (coefficient data indicating “E”). An encoding table (table number) used for encoding is set.

  Furthermore, for example, in the example of FIG. 11A, when the first coefficient data of the encoding sub-block 191-4 is the current coefficient data, the coefficient data adjacent to the upper right of the current coefficient data is also located at the lower left of the current coefficient data. There is also adjacent coefficient data. Therefore, the peripheral history calculation unit 161 encodes the coefficient data adjacent to the upper right of the current coefficient data (coefficient data indicated by “E”) as the table number of the encoding table used for encoding the current coefficient data. The average value of the table number of the encoding table used for the encoding table and the table number of the encoding table used for encoding the coefficient data adjacent to the lower left of the current coefficient data (coefficient data indicating “F”) Set.

  If the encoding table (table number) used for encoding other coefficient data is set in the same manner as described with reference to the flowchart of FIG. 5, it is used for encoding each coefficient data of TU190. The encoding table (table number) is set as shown in the example of FIG.

  In FIG. 18, for example, when the current coefficient data is the first coefficient data of the encoding sub-block 191-1, the initial value “0” is set as the table number of the encoding table used for encoding the current coefficient data. Is set.

  For example, when the current coefficient data is the first coefficient data of the encoding sub-block 191-2, the table number of the encoding table used for encoding the current coefficient data is adjacent to the lower left of the current coefficient data. The table number “7” of the encoding table used for encoding the coefficient data to be set is set.

  Also, for example, when the current coefficient data is the first coefficient data of the encoding sub-block 191-3, it is adjacent to the upper right of the current coefficient data as the table number of the encoding table used for encoding the current coefficient data. The table number “5” of the encoding table used for encoding the coefficient data to be set is set.

  Further, for example, when the current coefficient data is the first coefficient data of the encoding sub-block 191-4, the current coefficient data is adjacent to the upper right of the current coefficient data as the table number of the encoding table used for encoding the current coefficient data. The table number “12” of the encoding table used for encoding the coefficient data to be encoded and the table number “12” of the encoding table used for encoding the coefficient data adjacent to the lower left of the current coefficient data An average value “12” is set.

  In this way, the example of FIG. 18 assigns an encoding table having a smaller table number to the lower right coefficient data of TU 190, and assigns a larger table number to the upper left coefficient data than in the case of FIGS. 6A and 6B. The encoding table is assigned. In the example of FIG. 18, the coding tables assigned to the coefficient data closer to each other than the cases of FIGS. 6A and 6B (particularly, coefficient data closer to the upper right and lower left diagonal directions) The difference in table numbers is small.

  That is, by assigning an encoding table to each coefficient data in this way, it is possible to suppress a reduction in encoding efficiency as compared with the cases of FIGS. 6A and 6B.

  Also in this case, as in the case of the example of FIG. 12, the result of other calculations such as the median may be used instead of the average value. Further, for example, any table number such as the maximum value or the minimum value of the table number of the encoding table used for encoding the peripheral coefficient data may be used.

  Note that the coding table selection process in this case is executed in the same manner as the example described with reference to the flowchart of FIG. 15 except that the positions of the coefficient data around the current coefficient data are different.

  Therefore, also in this case, it is possible to suppress a reduction in encoding efficiency by executing the encoding table selection process.

  The position of the coefficient data around the current coefficient data as described above is arbitrary, and may be a position other than the above-described example. Further, it may not be adjacent to the current coefficient data. The number of coefficient data around the current coefficient data as described above is also arbitrary. For example, the number of coefficient data around the current coefficient data to be used may be four or more. For example, the coefficient data around the current coefficient data in each example described above may be combined. Further, for example, the coefficient data around the current coefficient data in each example described above may be combined with the coefficient data at a position other than each example described above.

<2. Second Embodiment>
<Assignment of encoding table>
In the above description, the encoding table used for encoding the first coefficient data of the encoding sub-block has been described based on the encoding table used for encoding the peripheral coefficient data. Not limited to this, the coding table used for coding coefficient data other than the head of the coding sub-block may be set based on the coding table used for coding the neighboring coefficient data.

  In addition, as a coding table used for coding peripheral coefficient data, a code used for coding coefficient data adjacent to the current coefficient data and belonging to a coding sub-block different from the coding sub-block. An encoding table used for encoding current coefficient data may be set based on the encoding table.

<Table selection part>
FIG. 19 shows a main configuration example of the table selection unit 152 in that case. As shown in FIG. 19, the table selection unit 152 in this case has basically the same configuration as that in FIG. 10, but has a selection unit 211 instead of the selection unit 167 in FIG. The selection unit 212 is provided instead of the selection unit 177.

  In addition to the variable cLastAbsLevel, the table number of the encoding table used for encoding the current coefficient data (curr_table), the table number to which “+1” is added, the selection unit 211 includes the table number of the peripheral coefficient data (the peripheral table No.) and coefficient position information_0 are supplied.

  The coefficient position information_0 is information indicating the position of the current coefficient data in the coding sub-block.

  The selection unit 211 sets an encoding table used for encoding the next current coefficient data based on a table number (peripheral Table No.) of the peripheral coefficient data, or an encoding table used for encoding the current coefficient data. Whether to set the table number (curr_table) or the table number added with “+1” as an encoding table used for encoding the next current coefficient data is selected based on this coefficient position information_0.

  When it is determined that the encoding table used for encoding the next current coefficient data is set based on the table number of the peripheral coefficient data (peripheral Table No.), the selection unit 211 selects the supplied peripheral coefficient data. A table number (neighboring Table No.) is selected, and an encoding table (next_table_0) used for encoding the next current coefficient data is set based on the value.

  In addition, when a table number (curr_table) of an encoding table used for encoding current coefficient data or a table number added with “+1” is set as an encoding table used for encoding the next current coefficient data. When it is determined, the selection unit 211 adds the table number (curr_table) of the encoding table used for encoding the current coefficient data and “+1” supplied from the calculation unit 166 based on the variable cLastAbsLevel. One of the table numbers is selected, and an encoding table (next_table_0) used for encoding the next current coefficient data is set based on the selected value.

  The selection unit 211 supplies the table number (next_table_0) of the encoding table used for encoding the set next coefficient data to the TR encoding unit 153 and the table designation information buffer 154 and also to the selection unit 173. To do.

  Similarly, the selection unit 211 includes a variable cLastAbsLevel, a table number of a coding table used for coding current coefficient data (curr_table), a table number added with “+1”, and a table number of peripheral coefficient data. (Peripheral Table No.) and coefficient position information_1 are supplied.

  The coefficient position information_1 is information indicating the position of the current coefficient data in the coding sub-block.

  The selection unit 211 sets an encoding table used for encoding the next current coefficient data based on a table number (peripheral Table No.) of the peripheral coefficient data, or an encoding table used for encoding the current coefficient data. Whether to set the table number (curr_table) or the table number added with “+1” as the encoding table used for encoding the next current coefficient data is selected based on the coefficient position information_1.

  When it is determined that the encoding table used for encoding the next current coefficient data is set based on the table number of the peripheral coefficient data (peripheral Table No.), the selection unit 211 selects the supplied peripheral coefficient data. A table number (neighboring Table No.) is selected, and an encoding table (next_table_1) used for encoding the next current coefficient data is set based on the value.

  In addition, when a table number (curr_table) of an encoding table used for encoding current coefficient data or a table number added with “+1” is set as an encoding table used for encoding the next current coefficient data. If determined, the selection unit 211 adds the table number (curr_table) of the encoding table used for encoding the current coefficient data and “+1” supplied from the calculation unit 176 based on the variable cLastAbsLevel. One of the table numbers is selected, and an encoding table (next_table_1) used for encoding the next current coefficient data is set based on the value.

  The selection unit 212 supplies the table number (next_table_1) of the encoding table used for encoding the set next coefficient data to the TR encoding unit 153 and the table designation information buffer 154.

<Setting method of encoding table>
Also in this case, the position and number of coefficient data around the current coefficient data are arbitrary. In the following, an example is described in which coefficient data belonging to an encoding sub-block other than the current encoding sub-block that is adjacent to the current coefficient data in the upper right and lower left directions is coefficient data around the current coefficient data. To do.

  That is, coefficient data adjacent to the upper right of the current coefficient data (C) (coefficient data indicated by “E” in FIG. 11A) and coefficient data adjacent to the lower left of the current coefficient data (C) (“F” in FIG. 11A). Is the coefficient data belonging to the encoding sub-block other than the encoding sub-block, the coefficient data is the coefficient data around the current coefficient data.

  In this case, the encoding table (table number) used for encoding each coefficient data of TU 190 is set as shown in the example of FIG.

  When the number of coefficient data around the available current coefficient data is 0, an initial value (for example, “0”) is set as the table number of the encoding table used for encoding the current coefficient data.

  When the number of coefficient data around the available current coefficient data is one, the table number of the encoding table used for encoding the coefficient data is the encoding table used for encoding the current coefficient data. Is set as the table number.

  Furthermore, when the number of coefficient data around the available current coefficient data is two, the average value of the table numbers of the encoding table used for encoding the coefficient data is used for encoding the current coefficient data. This is set as the table number of the encoding table.

  Also in this case, as in the case of the example of FIG. 12, the result of other calculations such as the median may be used instead of the average value. Further, for example, any table number such as the maximum value or the minimum value of the table number of the encoding table used for encoding the peripheral coefficient data may be used.

<Encoding table selection process flow>
An example of the flow of the coding table selection process in this case will be described with reference to the flowcharts of FIGS.

  In step S201, the peripheral history calculation unit 161 sets variables StatCoeffE, StatCoeffF, and prevStatCoeff to initial values (for example, “0”).

  The variable StatCoeffE indicates the table number of the encoding table used for encoding the coefficient data adjacent to the upper right of the current coefficient data. The variable StatCoeffF indicates the table number of the encoding table used for encoding the coefficient data adjacent to the lower left of the current coefficient data.

  The process in step S202 is executed in the same manner as the process in step S132 in FIG.

  In step S203, the peripheral history calculation unit 161 sets a variable initValue depending on the presence / absence of coefficient data around the current coefficient data.

  For example, when the current coefficient data is the first coefficient data (C) of the encoding sub-block 191-1 (FIG. 11A), the coefficient data (E) adjacent to the upper right of the current coefficient data is also adjacent to the lower left. Since the coefficient data (F) is also located outside the TU 190, the values of both the variable StatCoeffE and the variable StatCoeffF are “invalid” (no history).

  Therefore, in this case, the peripheral history calculation unit 161 sets the value of the variable prevStatCoeff to the variable initValue. When this current coefficient data is the first coefficient data of TU 190 (for example, the first coefficient data (C) of the encoding sub-block 191-1), the value of the variable prevStatCoeff is the initial value (for example, the value set in step S201). “0”).

  For example, when the current coefficient data is the first coefficient data (C) of the encoding sub-block 191-2 (FIG. 11A), the coefficient data (E) adjacent to the upper right of the current coefficient data is the TU190. The value of variable StatCoeffE is “invalid” (no history). On the other hand, since the coefficient data (F) adjacent to the lower left of the current coefficient data exists in the TU 190, the value of the variable StatCoeffF is the code of the coefficient data (F) adjacent to the lower left of the current coefficient data. This is the table number of the encoding table used for encoding.

  Therefore, in this case, the peripheral history calculation unit 161 sets the value of the variable StatCoeffF in the variable initValue. In the example of FIG. 20, the value of the variable initValue is set to “7”.

  For example, when the current coefficient data is the first coefficient data (C) of the encoding sub-block 191-3 (FIG. 11A), the coefficient data (F) adjacent to the lower left of the current coefficient data is the TU190. The value of the variable StatCoeffF is “invalid” (no history). On the other hand, since the coefficient data (E) adjacent to the upper right of the current coefficient data exists in the TU 190, the value of the variable StatCoeffE is the sign of the coefficient data (E) adjacent to the upper right of the current coefficient data. This is the table number of the encoding table used for encoding.

  Therefore, in this case, the peripheral history calculation unit 161 sets the value of the variable StatCoeffE in the variable initValue. In the example of FIG. 20, the value of the variable initValue is set to “5”.

  Further, for example, when the current coefficient data is the first coefficient data (C) of the encoding sub-block 191-4 (FIG. 11A), the coefficient data (E) adjacent to the upper right of the current coefficient data is also moved to the lower left. There is also adjacent coefficient data (F). Therefore, the value of the variable StatCoeffE is the table number of the encoding table used for encoding the coefficient data (E) adjacent to the upper right of the current coefficient data, and the value of the variable StatCoeffF is the lower left of the current coefficient data. Is the table number of the encoding table used for encoding the coefficient data (F) adjacent to.

  Therefore, in this case, the peripheral history calculation unit 161 sets the average value of the variable StatCoeffE and the variable StatCoeffF as the variable initValue. In the example of FIG. 20, the variable StatCoeffE is “13” and the variable StatCoeffF is “16”, so the value of the variable initValue is set to “15”.

  Each process of step S204 and step S205 is performed similarly to each process of step S134 and step S135 of FIG.

  If it is determined in step S205 that there is unprocessed coefficient data, the process proceeds to FIG.

  In step S211 in FIG. 22, the selection unit 211 and the selection unit 212 determine whether the coefficient data (E) adjacent to the upper right of the current coefficient data and the coefficient data (F) adjacent to the lower left are outside the TU 190 or the encoding. It is determined whether it is located in the sub-block 191 and cannot be used.

  At least one of the coefficient data (E) adjacent to the upper right of the current coefficient data and the coefficient data (F) adjacent to the lower left is the encoding sub-block 191 other than the TU 190 and the encoding sub-block 191. If it is determined that it is available and available, the process proceeds to step S212.

  In step S212, the peripheral history calculation unit 161 sets a variable cRiceParam according to the presence / absence of coefficient data around the current coefficient data.

  For example, the coefficient data (E) adjacent to the upper right of the current coefficient data is located outside the TU 190 or in the encoding sub-block 191, and the coefficient data (F) adjacent to the lower left of the current coefficient data is the When belonging to a coding subblock 191 other than the coding subblock 191 in the TU 190, the selection unit 211 and the selection unit 212 have a variable cRiceParam and a variable StatCoeffF (that is, coefficient data (F) adjacent to the lower left of the current coefficient data) (The table number of the encoding table used for encoding).

  Also, for example, coefficient data (F) adjacent to the lower left of current coefficient data is located outside the TU 190 or within the encoding sub-block 191 and is adjacent to the upper right of the current coefficient data (E). Belongs to a coding sub-block 191 other than the coding sub-block 191 in the TU 190, the selection unit 211 and the selection unit 212 have the variable cRiceParam and the variable StatCoeffE (that is, the coefficient data adjacent to the upper right of the current coefficient data ( The table number of the encoding table used for the encoding of E) is set.

  Further, for example, both the coefficient data (E) adjacent to the upper right of the current coefficient data and the coefficient data (F) adjacent to the lower left of the current coefficient data are codes other than the encoding sub-block 191 in the TU 190TU190. In the encoding sub-block 191, the selection unit 211 and the selection unit 212 include the encoding table used for encoding the variable StatCoeffE (that is, the coefficient data (E) adjacent to the upper right of the current coefficient data) in the variable cRiceParam. The average value of the variable StatCoeffF (that is, the table number of the encoding table used for encoding the coefficient data (F) adjacent to the lower left of the current coefficient data) is set.

  When the process of step S212 ends, the process returns to step S205 of FIG. 21, and the subsequent processes are repeated.

In step S211, the selection unit 211 and the selection unit 212 determine whether the coefficient data (E) adjacent to the upper right of the current coefficient data and the coefficient data (F) adjacent to the lower left are outside the TU 190 or the encoding sub If it is determined that it is located in the block 191 and cannot be used, the process proceeds to step S213.
Each process of step S213 and step S214 is performed similarly to each process of step S136 and step S137 of FIG.

  When the process of step S214 ends, the process returns to step S205 of FIG.

  If it is determined in step S205 in FIG. 21 that all the coefficient data of the encoding sub-block 191 has been processed, the process proceeds to step S206.

  The process of step S206 is executed in the same manner as the process of step S138 of FIG.

  If it is determined in step S206 that all the encoding sub-blocks in the TU 190 have been processed, the encoding table selection process ends, and the process returns to FIG.

  By executing the coding table selection process as described above, it is possible to suppress a reduction in coding efficiency for coefficient data other than the head of the coding sub-block 191.

  The present technology can be applied to any image processing apparatus that encodes image data.

  Further, the present technology, for example, converts image information into MPEG, H.264, or the like. Compressed by orthogonal transform such as discrete cosine transform and motion compensation, such as 26x, and used when transmitting the bitstream via network media such as satellite broadcasting, cable television, the Internet, or mobile phones It can be applied to an image processing apparatus. In addition, the present technology can be applied to an image processing device used when processing on a storage medium such as an optical, magnetic disk, and flash memory.

<3. Third Embodiment>
<Application to multi-view image encoding / decoding system>
The series of processes described above can be applied to a multi-view image encoding / decoding system. FIG. 23 shows an example of a multi-view image encoding method.

  As shown in FIG. 23, the multi-viewpoint image includes images of a plurality of viewpoints (views). The multiple views of this multi-viewpoint image are encoded using the base view that encodes and decodes using only the image of its own view without using the information of other views, and the information of other views. -It consists of a non-base view that performs decoding. Non-base view encoding / decoding may use base view information or other non-base view information.

  When encoding / decoding a multi-view image as in the example of FIG. 23, the multi-view image is encoded for each viewpoint. When decoding the encoded data thus obtained, the encoded data of each viewpoint is decoded (that is, for each viewpoint). The method described in each of the above embodiments may be applied to such viewpoint encoding / decoding. By doing so, it is possible to suppress a reduction in encoding efficiency. That is, similarly, in the case of a multi-viewpoint image, it is possible to suppress a reduction in encoding efficiency.

<Multi-view image encoding / decoding system>
FIG. 24 is a diagram illustrating a multi-view image encoding apparatus of the multi-view image encoding / decoding system that performs the above-described multi-view image encoding / decoding. As illustrated in FIG. 24, the multi-view image encoding device 600 includes an encoding unit 601, an encoding unit 602, and a multiplexing unit 603.

  The encoding unit 601 encodes the base view image and generates a base view image encoded stream. The encoding unit 602 encodes the non-base view image and generates a non-base view image encoded stream. The multiplexing unit 603 multiplexes the base view image encoded stream generated by the encoding unit 601 and the non-base view image encoded stream generated by the encoding unit 602 to generate a multi-view image encoded stream. To do.

  FIG. 25 is a diagram illustrating a multi-view image decoding apparatus that performs the above-described multi-view image decoding. As illustrated in FIG. 25, the multi-view image decoding device 610 includes a demultiplexing unit 611, a decoding unit 612, and a decoding unit 613.

  The demultiplexing unit 611 demultiplexes the multi-view image encoded stream in which the base view image encoded stream and the non-base view image encoded stream are multiplexed, and the base view image encoded stream and the non-base view image The encoded stream is extracted. The decoding unit 612 decodes the base view image encoded stream extracted by the demultiplexing unit 611 to obtain a base view image. The decoding unit 613 decodes the non-base view image encoded stream extracted by the demultiplexing unit 611 to obtain a non-base view image.

  For example, in such a multi-view image encoding / decoding system, the image encoding device 100 described in each of the above embodiments is applied as the encoding unit 601 and the encoding unit 602 of the multi-view image encoding device 600. May be. By doing so, the method described in each of the above embodiments can be applied to the encoding of multi-viewpoint images. That is, a reduction in encoding efficiency can be suppressed.

<4. Fourth Embodiment>
<Application to hierarchical image encoding / decoding system>
The series of processes described above can be applied to a hierarchical image encoding (scalable encoding) / decoding system. FIG. 26 shows an example of a hierarchical image encoding method.

  Hierarchical image coding (scalable coding) is a method in which image data is divided into a plurality of layers (hierarchized) so as to have a scalability function with respect to a predetermined parameter, and is encoded for each layer. In the hierarchical image decoding, the hierarchical image encoding (scalable decoding) is decoding corresponding to the hierarchical image encoding.

  As shown in FIG. 26, in image hierarchization, one image is divided into a plurality of images (layers) based on a predetermined parameter having a scalability function. That is, the hierarchized image (hierarchical image) includes images of a plurality of hierarchies (layers) having different predetermined parameter values. A plurality of layers of this hierarchical image are encoded / decoded using only the image of the own layer without using the image of the other layer, and encoded / decoded using the image of the other layer. It consists of a non-base layer (also called enhancement layer) that performs decoding. As the non-base layer, an image of the base layer may be used, or an image of another non-base layer may be used.

  In general, the non-base layer is composed of difference image data (difference data) between its own image and an image of another layer so that redundancy is reduced. For example, when one image is divided into two layers of a base layer and a non-base layer (also referred to as an enhancement layer), an image with lower quality than the original image can be obtained using only the base layer data. By synthesizing the base layer data, an original image (that is, a high-quality image) can be obtained.

  By hierarchizing images in this way, it is possible to easily obtain images of various qualities depending on the situation. For example, to a terminal with low processing capability, such as a mobile phone, image compression information of only the base layer is transmitted, and a moving image with low spatiotemporal resolution or poor image quality is reproduced. For terminals with high processing capabilities, such as televisions and personal computers, in addition to the base layer, the image compression information of the enhancement layer is transmitted and the spatial time resolution is high, or Image compression information corresponding to the capabilities of the terminal and the network can be transmitted from the server without performing transcoding processing, such as playing a moving image with high image quality.

  When encoding / decoding a hierarchical image as in the example of FIG. 26, the hierarchical image is encoded for each layer. When decoding the encoded data thus obtained, the encoded data of each layer is decoded (that is, for each layer). The methods described in the above embodiments may be applied to such encoding / decoding of each layer. By doing so, it is possible to suppress a reduction in encoding efficiency. That is, similarly in the case of a hierarchical image, it is possible to suppress a reduction in encoding efficiency.

<Scalable parameters>
In such hierarchical image encoding / hierarchical image decoding (scalable encoding / scalable decoding), parameters having a scalability function are arbitrary. For example, spatial resolution may be used as the parameter (spatial scalability). In the case of this spatial scalability, the resolution of the image is different for each layer.

  In addition, for example, temporal resolution may be applied as a parameter for providing such scalability (temporal scalability). In the case of this temporal scalability, the frame rate is different for each layer.

  Further, for example, a signal-to-noise ratio (SNR) may be applied as a parameter for providing such scalability (SNR scalability). In the case of this SNR scalability (SNR scalability), the SN ratio is different for each layer.

  Of course, the parameters for providing scalability may be other than the example described above. For example, the base layer is composed of an 8-bit image, and by adding an enhancement layer to this, a bit-depth scalability for obtaining a 10-bit image is obtained. is there.

  In addition, the base layer is composed of component images in 4: 2: 0 format, and the enhancement layer (enhancement layer) is added to this, resulting in chroma scalability (chroma) scalability).

<Hierarchical image encoding / decoding system>
FIG. 27 is a diagram illustrating a hierarchical image encoding apparatus of the hierarchical image encoding / decoding system that performs the hierarchical image encoding / decoding described above. As illustrated in FIG. 27, the hierarchical image encoding device 620 includes an encoding unit 621, an encoding unit 622, and a multiplexing unit 623.

  The encoding unit 621 encodes the base layer image and generates a base layer image encoded stream. The encoding unit 622 encodes the non-base layer image and generates a non-base layer image encoded stream. The multiplexing unit 623 multiplexes the base layer image encoded stream generated by the encoding unit 621 and the non-base layer image encoded stream generated by the encoding unit 622 to generate a hierarchical image encoded stream. .

  FIG. 28 is a diagram illustrating a hierarchical image decoding apparatus that performs the hierarchical image decoding described above. As illustrated in FIG. 28, the hierarchical image decoding device 630 includes a demultiplexing unit 631, a decoding unit 632, and a decoding unit 633.

  The demultiplexing unit 631 demultiplexes the hierarchical image encoded stream in which the base layer image encoded stream and the non-base layer image encoded stream are multiplexed, and the base layer image encoded stream and the non-base layer image code Stream. The decoding unit 632 decodes the base layer image encoded stream extracted by the demultiplexing unit 631 to obtain a base layer image. The decoding unit 633 decodes the non-base layer image encoded stream extracted by the demultiplexing unit 631 to obtain a non-base layer image.

  For example, in such a hierarchical image encoding / decoding system, the image encoding device 100 described in each of the above embodiments is applied as the encoding unit 621 and the encoding unit 622 of the hierarchical image encoding device 620. Also good. By doing so, the method described in each of the above embodiments can be applied to the encoding of the hierarchical image. That is, a reduction in encoding efficiency can be suppressed.

<5. Fifth embodiment>
<Computer>
The series of processes described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software is installed in the computer. Here, the computer includes, for example, a general-purpose personal computer that can execute various functions by installing a computer incorporated in dedicated hardware and various programs.

  FIG. 29 is a block diagram illustrating an example of a hardware configuration of a computer that executes the above-described series of processes using a program.

  In a computer 800 shown in FIG. 29, a CPU (Central Processing Unit) 801, a ROM (Read Only Memory) 802, and a RAM (Random Access Memory) 803 are connected to each other via a bus 804.

  An input / output interface 810 is also connected to the bus 804. An input unit 811, an output unit 812, a storage unit 813, a communication unit 814, and a drive 815 are connected to the input / output interface 810.

  The input unit 811 includes, for example, a keyboard, a mouse, a microphone, a touch panel, an input terminal, and the like. The output unit 812 includes, for example, a display, a speaker, an output terminal, and the like. The storage unit 813 includes, for example, a hard disk, a RAM disk, a nonvolatile memory, and the like. The communication unit 814 includes a network interface, for example. The drive 815 drives a removable medium 821 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

  In the computer configured as described above, the CPU 801 loads the program stored in the storage unit 813 into the RAM 803 via the input / output interface 810 and the bus 804 and executes the program, for example. Is performed. The RAM 803 also appropriately stores data necessary for the CPU 801 to execute various processes.

  The program executed by the computer (CPU 801) can be recorded and applied to, for example, a removable medium 821 as a package medium or the like. In that case, the program can be installed in the storage unit 813 via the input / output interface 810 by attaching the removable medium 821 to the drive 815.

  This program can also be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting. In that case, the program can be received by the communication unit 814 and installed in the storage unit 813.

  In addition, this program can be installed in the ROM 802 or the storage unit 813 in advance.

  The program executed by the computer may be a program that is processed in time series in the order described in this specification, or in parallel or at a necessary timing such as when a call is made. It may be a program for processing.

  Further, in the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the described order, but is not necessarily performed in chronological order. It also includes processes that are executed individually.

  In this specification, the system means a set of a plurality of components (devices, modules (parts), etc.), and it does not matter whether all the components are in the same housing. Accordingly, a plurality of devices housed in separate housings and connected via a network and a single device housing a plurality of modules in one housing are all systems. .

  In addition, in the above description, the configuration described as one device (or processing unit) may be divided and configured as a plurality of devices (or processing units). Conversely, the configurations described above as a plurality of devices (or processing units) may be combined into a single device (or processing unit). Of course, a configuration other than that described above may be added to the configuration of each device (or each processing unit). Furthermore, if the configuration and operation of the entire system are substantially the same, a part of the configuration of a certain device (or processing unit) may be included in the configuration of another device (or other processing unit). .

  The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, but the technical scope of the present disclosure is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field of the present disclosure can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that it belongs to the technical scope of the present disclosure.

  For example, the present technology can take a configuration of cloud computing in which one function is shared by a plurality of devices via a network and jointly processed.

  In addition, each step described in the above flowchart can be executed by being shared by a plurality of apparatuses in addition to being executed by one apparatus.

  Further, when a plurality of processes are included in one step, the plurality of processes included in the one step can be executed by being shared by a plurality of apparatuses in addition to being executed by one apparatus.

  The image encoding device 100 according to the above-described embodiment includes, for example, a transmitter or receiver, optical disc, magnetic field in satellite broadcasting, cable broadcasting such as cable TV, distribution on the Internet, and distribution to terminals by cellular communication. The present invention can be applied to various electronic devices such as a recording device that records an image on a medium such as a disk and a flash memory, or a playback device that reproduces an image from the storage medium. Hereinafter, four application examples will be described.

<6. Sixth Embodiment>
<First Application Example: Television Receiver>
FIG. 30 illustrates an example of a schematic configuration of a television device to which the above-described embodiment is applied. The television apparatus 900 includes an antenna 901, a tuner 902, a demultiplexer 903, a decoder 904, a video signal processing unit 905, a display unit 906, an audio signal processing unit 907, a speaker 908, an external interface (I / F) unit 909, and a control unit. 910, a user interface (I / F) unit 911, and a bus 912.

  The tuner 902 extracts a signal of a desired channel from a broadcast signal received via the antenna 901, and demodulates the extracted signal. Then, the tuner 902 outputs the encoded bit stream obtained by the demodulation to the demultiplexer 903. That is, the tuner 902 has a role as a transmission unit in the television device 900 that receives an encoded stream in which an image is encoded.

  The demultiplexer 903 separates the video stream and audio stream of the viewing target program from the encoded bit stream, and outputs each separated stream to the decoder 904. Also, the demultiplexer 903 extracts auxiliary data such as EPG (Electronic Program Guide) from the encoded bit stream, and supplies the extracted data to the control unit 910. Note that the demultiplexer 903 may perform descrambling when the encoded bit stream is scrambled.

  The decoder 904 decodes the video stream and audio stream input from the demultiplexer 903. Then, the decoder 904 outputs the video data generated by the decoding process to the video signal processing unit 905. In addition, the decoder 904 outputs audio data generated by the decoding process to the audio signal processing unit 907.

  The video signal processing unit 905 reproduces the video data input from the decoder 904 and causes the display unit 906 to display the video. In addition, the video signal processing unit 905 may cause the display unit 906 to display an application screen supplied via a network. Further, the video signal processing unit 905 may perform additional processing such as noise removal on the video data according to the setting. Further, the video signal processing unit 905 may generate a GUI (Graphical User Interface) image such as a menu, a button, or a cursor, and superimpose the generated image on the output image.

  The display unit 906 is driven by a drive signal supplied from the video signal processing unit 905, and displays a video on a video screen of a display device (for example, a liquid crystal display, a plasma display, or an OELD (Organic ElectroLuminescence Display) (organic EL display)). Or an image is displayed.

  The audio signal processing unit 907 performs reproduction processing such as D / A conversion and amplification on the audio data input from the decoder 904 and outputs audio from the speaker 908. The audio signal processing unit 907 may perform additional processing such as noise removal on the audio data.

  The external interface unit 909 is an interface for connecting the television apparatus 900 to an external device or a network. For example, a video stream or an audio stream received via the external interface unit 909 may be decoded by the decoder 904. That is, the external interface unit 909 also has a role as a transmission unit in the television apparatus 900 that receives an encoded stream in which an image is encoded.

  The control unit 910 includes a processor such as a CPU and memories such as a RAM and a ROM. The memory stores a program executed by the CPU, program data, EPG data, data acquired via a network, and the like. For example, the program stored in the memory is read and executed by the CPU when the television apparatus 900 is activated. For example, the CPU controls the operation of the television device 900 according to an operation signal input from the user interface unit 911 by executing the program.

  The user interface unit 911 is connected to the control unit 910. The user interface unit 911 includes, for example, buttons and switches for the user to operate the television device 900, a remote control signal receiving unit, and the like. The user interface unit 911 detects an operation by the user via these components, generates an operation signal, and outputs the generated operation signal to the control unit 910.

  The bus 912 connects the tuner 902, the demultiplexer 903, the decoder 904, the video signal processing unit 905, the audio signal processing unit 907, the external interface unit 909, and the control unit 910 to each other.

  In the television apparatus 900 configured as described above, the video signal processing unit 905 encodes the image data supplied from the decoder 904, for example, and the obtained encoded data is transmitted to the television via the external interface unit 909. You may enable it to output to the exterior of the apparatus 900. FIG. The video signal processing unit 905 may have the function of the image encoding device 100 described above. That is, the video signal processing unit 905 may encode the image data supplied from the decoder 904 by the method described in the above embodiments. By doing in this way, the television apparatus 900 can suppress the reduction in the encoding efficiency of the encoded data to be output.

<Second application example: mobile phone>
FIG. 31 shows an example of a schematic configuration of a mobile phone to which the above-described embodiment is applied. A cellular phone 920 includes an antenna 921, a communication unit 922, an audio codec 923, a speaker 924, a microphone 925, a camera unit 926, an image processing unit 927, a demultiplexing unit 928, a recording / reproducing unit 929, a display unit 930, a control unit 931, an operation A portion 932 and a bus 933.

  The antenna 921 is connected to the communication unit 922. The speaker 924 and the microphone 925 are connected to the audio codec 923. The operation unit 932 is connected to the control unit 931. The bus 933 connects the communication unit 922, the audio codec 923, the camera unit 926, the image processing unit 927, the demultiplexing unit 928, the recording / reproducing unit 929, the display unit 930, and the control unit 931 to each other.

  The mobile phone 920 has various operation modes including a voice call mode, a data communication mode, a shooting mode, and a videophone mode, and is used for sending and receiving voice signals, sending and receiving e-mail or image data, taking images, and recording data. Perform the action.

  In the voice call mode, an analog voice signal generated by the microphone 925 is supplied to the voice codec 923. The audio codec 923 converts an analog audio signal into audio data, A / D converts the compressed audio data, and compresses it. Then, the audio codec 923 outputs the compressed audio data to the communication unit 922. The communication unit 922 encodes and modulates the audio data and generates a transmission signal. Then, the communication unit 922 transmits the generated transmission signal to a base station (not shown) via the antenna 921. In addition, the communication unit 922 amplifies a radio signal received via the antenna 921 and performs frequency conversion to acquire a received signal. Then, the communication unit 922 demodulates and decodes the received signal to generate audio data, and outputs the generated audio data to the audio codec 923. The audio codec 923 decompresses the audio data and performs D / A conversion to generate an analog audio signal. Then, the audio codec 923 supplies the generated audio signal to the speaker 924 to output audio.

  Further, in the data communication mode, for example, the control unit 931 generates character data that constitutes an e-mail in response to an operation by the user via the operation unit 932. In addition, the control unit 931 causes the display unit 930 to display characters. In addition, the control unit 931 generates e-mail data in response to a transmission instruction from the user via the operation unit 932, and outputs the generated e-mail data to the communication unit 922. The communication unit 922 encodes and modulates email data and generates a transmission signal. Then, the communication unit 922 transmits the generated transmission signal to a base station (not shown) via the antenna 921. In addition, the communication unit 922 amplifies a radio signal received via the antenna 921 and performs frequency conversion to acquire a received signal. Then, the communication unit 922 demodulates and decodes the received signal to restore the email data, and outputs the restored email data to the control unit 931. The control unit 931 displays the content of the electronic mail on the display unit 930, supplies the electronic mail data to the recording / reproducing unit 929, and writes the data in the storage medium.

  The recording / reproducing unit 929 has an arbitrary readable / writable storage medium. For example, the storage medium may be a built-in storage medium such as RAM or flash memory, and is externally mounted such as a hard disk, magnetic disk, magneto-optical disk, optical disk, USB (Universal Serial Bus) memory, or memory card. It may be a storage medium.

  In the shooting mode, for example, the camera unit 926 captures an image of a subject, generates image data, and outputs the generated image data to the image processing unit 927. The image processing unit 927 encodes the image data input from the camera unit 926, supplies the encoded stream to the recording / reproducing unit 929, and writes the encoded stream in the storage medium.

  Further, in the image display mode, the recording / reproducing unit 929 reads the encoded stream recorded on the storage medium and outputs the encoded stream to the image processing unit 927. The image processing unit 927 decodes the encoded stream input from the recording / reproducing unit 929, supplies the image data to the display unit 930, and displays the image.

  Further, in the videophone mode, for example, the demultiplexing unit 928 multiplexes the video stream encoded by the image processing unit 927 and the audio stream input from the audio codec 923, and the multiplexed stream is the communication unit 922. Output to. The communication unit 922 encodes and modulates the stream and generates a transmission signal. Then, the communication unit 922 transmits the generated transmission signal to a base station (not shown) via the antenna 921. In addition, the communication unit 922 amplifies a radio signal received via the antenna 921 and performs frequency conversion to acquire a received signal. These transmission signal and reception signal may include an encoded bit stream. Then, the communication unit 922 demodulates and decodes the received signal to restore the stream, and outputs the restored stream to the demultiplexing unit 928. The demultiplexing unit 928 separates the video stream and the audio stream from the input stream, and outputs the video stream to the image processing unit 927 and the audio stream to the audio codec 923. The image processing unit 927 decodes the video stream and generates video data. The video data is supplied to the display unit 930, and a series of images is displayed on the display unit 930. The audio codec 923 decompresses the audio stream and performs D / A conversion to generate an analog audio signal. Then, the audio codec 923 supplies the generated audio signal to the speaker 924 to output audio.

  In the mobile phone 920 configured as described above, for example, the image processing unit 927 may have the function of the image encoding device 100. That is, the image processing unit 927 may encode the image data by the method described in each of the above embodiments. In this way, the mobile phone 920 can suppress a reduction in encoding efficiency.

<Third application example: recording / reproducing apparatus>
FIG. 32 shows an example of a schematic configuration of a recording / reproducing apparatus to which the above-described embodiment is applied. For example, the recording / reproducing device 940 encodes audio data and video data of a received broadcast program and records the encoded data on a recording medium. In addition, the recording / reproducing device 940 may encode audio data and video data acquired from another device and record them on a recording medium, for example. In addition, the recording / reproducing device 940 reproduces data recorded on the recording medium on a monitor and a speaker, for example, in accordance with a user instruction. At this time, the recording / reproducing device 940 decodes the audio data and the video data.

  The recording / reproducing apparatus 940 includes a tuner 941, an external interface (I / F) unit 942, an encoder 943, an HDD (Hard Disk Drive) 944, a disk drive 945, a selector 946, a decoder 947, an OSD (On-Screen Display) 948, and a control. Part 949 and a user interface (I / F) part 950.

  The tuner 941 extracts a signal of a desired channel from a broadcast signal received via an antenna (not shown), and demodulates the extracted signal. Then, the tuner 941 outputs the encoded bit stream obtained by the demodulation to the selector 946. That is, the tuner 941 serves as a transmission unit in the recording / reproducing apparatus 940.

  The external interface unit 942 is an interface for connecting the recording / reproducing apparatus 940 to an external device or a network. The external interface unit 942 may be, for example, an IEEE (Institute of Electrical and Electronic Engineers) 1394 interface, a network interface, a USB interface, or a flash memory interface. For example, video data and audio data received via the external interface unit 942 are input to the encoder 943. That is, the external interface unit 942 has a role as a transmission unit in the recording / reproducing apparatus 940.

  The encoder 943 encodes the video data and the audio data when the video data and the audio data input from the external interface unit 942 are not encoded. Then, the encoder 943 outputs the encoded bit stream to the selector 946.

  The HDD 944 records an encoded bit stream in which content data such as video and audio is compressed, various programs, and other data on an internal hard disk. Further, the HDD 944 reads out these data from the hard disk when reproducing video and audio.

  The disk drive 945 performs recording and reading of data with respect to the mounted recording medium. The recording medium loaded in the disk drive 945 is, for example, a DVD (Digital Versatile Disc) disk (DVD-Video, DVD-RAM (DVD-Random Access Memory), DVD-R (DVD-Recordable), DVD-RW (DVD- Rewritable), DVD + R (DVD + Recordable), DVD + RW (DVD + Rewritable), etc.) or Blu-ray (registered trademark) disc.

  The selector 946 selects an encoded bit stream input from the tuner 941 or the encoder 943 when recording video and audio, and outputs the selected encoded bit stream to the HDD 944 or the disk drive 945. In addition, the selector 946 outputs the encoded bit stream input from the HDD 944 or the disk drive 945 to the decoder 947 during video and audio reproduction.

  The decoder 947 decodes the encoded bit stream and generates video data and audio data. Then, the decoder 947 outputs the generated video data to the OSD 948. The decoder 947 outputs the generated audio data to an external speaker.

  The OSD 948 reproduces the video data input from the decoder 947 and displays the video. Further, the OSD 948 may superimpose a GUI image such as a menu, a button, or a cursor on the video to be displayed.

  The control unit 949 includes a processor such as a CPU, and memories such as a RAM and a ROM. The memory stores a program executed by the CPU, program data, and the like. The program stored in the memory is read and executed by the CPU when the recording / reproducing apparatus 940 is activated, for example. The CPU executes the program to control the operation of the recording / reproducing device 940 in accordance with, for example, an operation signal input from the user interface unit 950.

  The user interface unit 950 is connected to the control unit 949. The user interface unit 950 includes, for example, buttons and switches for the user to operate the recording / reproducing device 940, a remote control signal receiving unit, and the like. The user interface unit 950 detects an operation by the user via these components, generates an operation signal, and outputs the generated operation signal to the control unit 949.

  In the recording / reproducing apparatus 940 configured as described above, for example, the encoder 943 may have the function of the image encoding apparatus 100. That is, the encoder 943 may encode the image data by the method described in each of the above embodiments. By doing in this way, the recording / reproducing apparatus 940 can suppress the reduction in encoding efficiency.

<Fourth Application Example: Imaging Device>
FIG. 33 illustrates an example of a schematic configuration of an imaging apparatus to which the above-described embodiment is applied. The imaging device 960 images a subject to generate an image, encodes the image data, and records it on a recording medium.

  The imaging device 960 includes an optical block 961, an imaging unit 962, a signal processing unit 963, an image processing unit 964, a display unit 965, an external interface (I / F) unit 966, a memory unit 967, a media drive 968, an OSD 969, and a control unit 970. A user interface (I / F) unit 971 and a bus 972.

  The optical block 961 is connected to the imaging unit 962. The imaging unit 962 is connected to the signal processing unit 963. The display unit 965 is connected to the image processing unit 964. The user interface unit 971 is connected to the control unit 970. The bus 972 connects the image processing unit 964, the external interface unit 966, the memory unit 967, the media drive 968, the OSD 969, and the control unit 970 to each other.

  The optical block 961 includes a focus lens and a diaphragm mechanism. The optical block 961 forms an optical image of the subject on the imaging surface of the imaging unit 962. The imaging unit 962 includes an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and converts an optical image formed on the imaging surface into an image signal as an electrical signal by photoelectric conversion. Then, the imaging unit 962 outputs the image signal to the signal processing unit 963.

  The signal processing unit 963 performs various camera signal processes such as knee correction, gamma correction, and color correction on the image signal input from the imaging unit 962. The signal processing unit 963 outputs the image data after the camera signal processing to the image processing unit 964.

  The image processing unit 964 encodes the image data input from the signal processing unit 963, and generates encoded data. Then, the image processing unit 964 outputs the generated encoded data to the external interface unit 966 or the media drive 968. In addition, the image processing unit 964 decodes encoded data input from the external interface unit 966 or the media drive 968 to generate image data. Then, the image processing unit 964 outputs the generated image data to the display unit 965. In addition, the image processing unit 964 may display the image by outputting the image data input from the signal processing unit 963 to the display unit 965. Further, the image processing unit 964 may superimpose display data acquired from the OSD 969 on an image output to the display unit 965.

  The OSD 969 generates a GUI image such as a menu, a button, or a cursor, for example, and outputs the generated image to the image processing unit 964.

  The external interface unit 966 is configured as a USB input / output terminal, for example. The external interface unit 966 connects the imaging device 960 and a printer, for example, when printing an image. Further, a drive is connected to the external interface unit 966 as necessary. For example, a removable medium such as a magnetic disk or an optical disk is attached to the drive, and a program read from the removable medium can be installed in the imaging device 960. Furthermore, the external interface unit 966 may be configured as a network interface connected to a network such as a LAN or the Internet. That is, the external interface unit 966 has a role as a transmission unit in the imaging device 960.

  The recording medium mounted on the media drive 968 may be any readable / writable removable medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory. Further, a recording medium may be fixedly attached to the media drive 968, and a non-portable storage unit such as a built-in hard disk drive or an SSD (Solid State Drive) may be configured.

  The control unit 970 includes a processor such as a CPU and memories such as a RAM and a ROM. The memory stores a program executed by the CPU, program data, and the like. The program stored in the memory is read and executed by the CPU when the imaging device 960 is activated, for example. For example, the CPU controls the operation of the imaging device 960 according to an operation signal input from the user interface unit 971 by executing the program.

  The user interface unit 971 is connected to the control unit 970. The user interface unit 971 includes, for example, buttons and switches for the user to operate the imaging device 960. The user interface unit 971 detects an operation by the user via these components, generates an operation signal, and outputs the generated operation signal to the control unit 970.

  In the imaging device 960 configured as described above, for example, the image processing unit 964 may have the function of the image encoding device 100. That is, the image processing unit 964 may encode the image data by the method described in each of the above embodiments. By doing in this way, the imaging device 960 can suppress a reduction in encoding efficiency.

  Note that the present technology is also applicable to HTTP streaming such as MPEG DASH, in which an appropriate one is selected from a plurality of encoded data having different resolutions prepared in advance and used in segment units. Can do. That is, information regarding encoding and decoding can be shared among a plurality of such encoded data.

<7. Seventh Embodiment>
<Other examples of implementation>
In the above, examples of devices and systems to which the present technology is applied have been described. However, the present technology is not limited thereto, and any configuration mounted on such devices or devices constituting the system, for example, a system LSI (Large Scale) Integration) etc., a module using a plurality of processors, etc., a unit using a plurality of modules, etc., a set in which other functions are added to the unit, etc. (that is, a partial configuration of the apparatus) .

<Video set>
An example of implementing the present technology as a set will be described with reference to FIG. FIG. 34 illustrates an example of a schematic configuration of a video set to which the present technology is applied.

  In recent years, multi-functionalization of electronic devices has progressed, and in the development and manufacture, when implementing a part of the configuration as sales or provision, etc., not only when implementing as a configuration having one function, but also related In many cases, a plurality of configurations having functions are combined and implemented as a set having a plurality of functions.

  The video set 1300 shown in FIG. 34 has such a multi-functional configuration, and a device having a function relating to image encoding and decoding (either one or both) can be used for the function. It is a combination of devices having other related functions.

  As shown in FIG. 34, the video set 1300 includes a module group such as a video module 1311, an external memory 1312, a power management module 1313, and a front end module 1314, and an associated module 1321, a camera 1322, a sensor 1323, and the like. And a device having a function.

  A module is a component having a coherent function by combining several component functions related to each other. The specific physical configuration is arbitrary. For example, a plurality of processors each having a function, electronic circuit elements such as resistors and capacitors, and other devices arranged on a wiring board or the like can be considered. . It is also possible to combine the module with another module, a processor, or the like to form a new module.

  In the case of the example in FIG. 34, the video module 1311 is a combination of configurations having functions related to image processing, and includes an application processor, a video processor, a broadband modem 1333, and an RF module 1334.

  The processor is a configuration in which a configuration having a predetermined function is integrated on a semiconductor chip by an SoC (System On a Chip). For example, there is a processor called a system LSI (Large Scale Integration). The configuration having the predetermined function may be a logic circuit (hardware configuration), a CPU, a ROM, a RAM, and the like, and a program (software configuration) executed using them. , Or a combination of both. For example, a processor has a logic circuit and a CPU, ROM, RAM, etc., a part of the function is realized by a logic circuit (hardware configuration), and other functions are executed by the CPU (software configuration) It may be realized by.

  The application processor 1331 in FIG. 34 is a processor that executes an application related to image processing. The application executed in the application processor 1331 not only performs arithmetic processing to realize a predetermined function, but also can control the internal and external configurations of the video module 1311 such as the video processor 1332 as necessary. .

  The video processor 1332 is a processor having a function relating to image encoding / decoding (one or both of them).

  The broadband modem 1333 converts the data (digital signal) transmitted by wired or wireless (or both) broadband communication via a broadband line such as the Internet or a public telephone line network into an analog signal by digitally modulating the data. The analog signal received by the broadband communication is demodulated and converted into data (digital signal). The broadband modem 1333 processes arbitrary information such as image data processed by the video processor 1332, a stream obtained by encoding the image data, an application program, setting data, and the like.

  The RF module 1334 is a module that performs frequency conversion, modulation / demodulation, amplification, filter processing, and the like on an RF (Radio Frequency) signal transmitted and received via an antenna. For example, the RF module 1334 generates an RF signal by performing frequency conversion or the like on the baseband signal generated by the broadband modem 1333. Further, for example, the RF module 1334 generates a baseband signal by performing frequency conversion or the like on the RF signal received via the front end module 1314.

  Note that, as indicated by a dotted line 1341 in FIG. 34, the application processor 1331 and the video processor 1332 may be integrated into a single processor.

  The external memory 1312 is a module having a storage device that is provided outside the video module 1311 and is used by the video module 1311. The storage device of the external memory 1312 may be realized by any physical configuration, but is generally used for storing a large amount of data such as image data in units of frames. For example, it is desirable to realize it by a relatively inexpensive and large-capacity semiconductor memory such as a DRAM (Dynamic Random Access Memory).

  The power management module 1313 manages and controls power supply to the video module 1311 (each component in the video module 1311).

  The front-end module 1314 is a module that provides the RF module 1334 with a front-end function (a circuit on a transmitting / receiving end on the antenna side). As illustrated in FIG. 34, the front end module 1314 includes, for example, an antenna unit 1351, a filter 1352, and an amplification unit 1353.

  The antenna unit 1351 has an antenna that transmits and receives radio signals and a peripheral configuration thereof. The antenna unit 1351 transmits the signal supplied from the amplification unit 1353 as a radio signal, and supplies the received radio signal to the filter 1352 as an electric signal (RF signal). The filter 1352 performs a filtering process on the RF signal received via the antenna unit 1351 and supplies the processed RF signal to the RF module 1334. The amplifying unit 1353 amplifies the RF signal supplied from the RF module 1334 and supplies the amplified RF signal to the antenna unit 1351.

  The connectivity 1321 is a module having a function related to connection with the outside. The physical configuration of the connectivity 1321 is arbitrary. For example, the connectivity 1321 has a configuration having a communication function other than the communication standard supported by the broadband modem 1333, an external input / output terminal, and the like.

  For example, the connectivity 1321 is compliant with wireless communication standards such as Bluetooth (registered trademark), IEEE 802.11 (for example, Wi-Fi (Wireless Fidelity, registered trademark)), NFC (Near Field Communication), IrDA (InfraRed Data Association), etc. You may make it have a module which has a function, an antenna etc. which transmit / receive the signal based on the standard. Further, for example, the connectivity 1321 has a module having a communication function compliant with a wired communication standard such as USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface), and a terminal compliant with the standard. You may do it. Further, for example, the connectivity 1321 may have other data (signal) transmission functions such as analog input / output terminals.

  The connectivity 1321 may include a data (signal) transmission destination device. For example, the drive 1321 reads / writes data to / from a recording medium such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory (not only a removable medium drive, but also a hard disk, SSD (Solid State Drive) And NAS (Network Attached Storage) etc.). In addition, the connectivity 1321 may include an image or audio output device (a monitor, a speaker, or the like).

  The camera 1322 is a module having a function of capturing a subject and obtaining image data of the subject. Image data obtained by imaging by the camera 1322 is supplied to, for example, a video processor 1332 and encoded.

  The sensor 1323 includes, for example, a voice sensor, an ultrasonic sensor, an optical sensor, an illuminance sensor, an infrared sensor, an image sensor, a rotation sensor, an angle sensor, an angular velocity sensor, a velocity sensor, an acceleration sensor, an inclination sensor, a magnetic identification sensor, an impact sensor, It is a module having an arbitrary sensor function such as a temperature sensor. For example, the data detected by the sensor 1323 is supplied to the application processor 1331 and used by an application or the like.

  The configuration described as a module in the above may be realized as a processor, or conversely, the configuration described as a processor may be realized as a module.

  In the video set 1300 having the above configuration, the present technology can be applied to the video processor 1332 as described later. Therefore, the video set 1300 can be implemented as a set to which the present technology is applied.

<Example of video processor configuration>
FIG. 35 illustrates an example of a schematic configuration of a video processor 1332 (FIG. 34) to which the present technology is applied.

  In the case of the example of FIG. 35, the video processor 1332 receives the video signal and the audio signal, encodes them in a predetermined method, decodes the encoded video data and audio data, A function of reproducing and outputting an audio signal.

  As shown in FIG. 35, the video processor 1332 includes a video input processing unit 1401, a first image enlargement / reduction unit 1402, a second image enlargement / reduction unit 1403, a video output processing unit 1404, a frame memory 1405, and a memory control unit 1406. Have The video processor 1332 includes an encoding / decoding engine 1407, video ES (Elementary Stream) buffers 1408A and 1408B, and audio ES buffers 1409A and 1409B. Further, the video processor 1332 includes an audio encoder 1410, an audio decoder 1411, a multiplexing unit (MUX (Multiplexer)) 1412, a demultiplexing unit (DMUX (Demultiplexer)) 1413, and a stream buffer 1414.

  The video input processing unit 1401 acquires a video signal input from, for example, the connectivity 1321 (FIG. 34) and converts it into digital image data. The first image enlargement / reduction unit 1402 performs format conversion, image enlargement / reduction processing, and the like on the image data. The second image enlargement / reduction unit 1403 performs image enlargement / reduction processing on the image data in accordance with the format of the output destination via the video output processing unit 1404, or is the same as the first image enlargement / reduction unit 1402. Format conversion and image enlargement / reduction processing. The video output processing unit 1404 performs format conversion, conversion to an analog signal, and the like on the image data and outputs the reproduced video signal to, for example, the connectivity 1321 or the like.

  The frame memory 1405 is a memory for image data shared by the video input processing unit 1401, the first image scaling unit 1402, the second image scaling unit 1403, the video output processing unit 1404, and the encoding / decoding engine 1407. . The frame memory 1405 is realized as a semiconductor memory such as a DRAM, for example.

  The memory control unit 1406 receives the synchronization signal from the encoding / decoding engine 1407, and controls the writing / reading access to the frame memory 1405 according to the access schedule to the frame memory 1405 written in the access management table 1406A. The access management table 1406A is updated by the memory control unit 1406 in accordance with processing executed by the encoding / decoding engine 1407, the first image enlargement / reduction unit 1402, the second image enlargement / reduction unit 1403, and the like.

  The encoding / decoding engine 1407 performs encoding processing of image data and decoding processing of a video stream which is data obtained by encoding the image data. For example, the encoding / decoding engine 1407 encodes the image data read from the frame memory 1405 and sequentially writes the data as a video stream in the video ES buffer 1408A. Further, for example, the video stream is sequentially read from the video ES buffer 1408B, decoded, and sequentially written in the frame memory 1405 as image data. The encoding / decoding engine 1407 uses the frame memory 1405 as a work area in the encoding and decoding. Also, the encoding / decoding engine 1407 outputs a synchronization signal to the memory control unit 1406, for example, at a timing at which processing for each macroblock is started.

  The video ES buffer 1408A buffers the video stream generated by the encoding / decoding engine 1407 and supplies the buffered video stream to the multiplexing unit (MUX) 1412. The video ES buffer 1408B buffers the video stream supplied from the demultiplexer (DMUX) 1413 and supplies the buffered video stream to the encoding / decoding engine 1407.

  The audio ES buffer 1409A buffers the audio stream generated by the audio encoder 1410 and supplies it to the multiplexing unit (MUX) 1412. The audio ES buffer 1409B buffers the audio stream supplied from the demultiplexer (DMUX) 1413 and supplies the buffered audio stream to the audio decoder 1411.

  The audio encoder 1410 converts, for example, an audio signal input from the connectivity 1321 or the like, for example, into a digital format, and encodes the audio signal using a predetermined method such as an MPEG audio method or an AC3 (Audio Code number 3) method. The audio encoder 1410 sequentially writes an audio stream, which is data obtained by encoding an audio signal, in the audio ES buffer 1409A. The audio decoder 1411 decodes the audio stream supplied from the audio ES buffer 1409B, performs conversion to an analog signal, for example, and supplies the reproduced audio signal to, for example, the connectivity 1321 or the like.

  The multiplexing unit (MUX) 1412 multiplexes the video stream and the audio stream. The multiplexing method (that is, the format of the bit stream generated by multiplexing) is arbitrary. At the time of this multiplexing, the multiplexing unit (MUX) 1412 can also add predetermined header information or the like to the bit stream. That is, the multiplexing unit (MUX) 1412 can convert the stream format by multiplexing. For example, the multiplexing unit (MUX) 1412 multiplexes the video stream and the audio stream to convert it into a transport stream that is a bit stream in a transfer format. Further, for example, the multiplexing unit (MUX) 1412 multiplexes the video stream and the audio stream, thereby converting the data into file format data (file data) for recording.

  The demultiplexing unit (DMUX) 1413 demultiplexes the bit stream in which the video stream and the audio stream are multiplexed by a method corresponding to the multiplexing by the multiplexing unit (MUX) 1412. That is, the demultiplexer (DMUX) 1413 extracts the video stream and the audio stream from the bit stream read from the stream buffer 1414 (separates the video stream and the audio stream). That is, the demultiplexer (DMUX) 1413 can convert the stream format by demultiplexing (inverse conversion of the conversion by the multiplexer (MUX) 1412). For example, the demultiplexing unit (DMUX) 1413 obtains a transport stream supplied from, for example, the connectivity 1321 or the broadband modem 1333 via the stream buffer 1414 and demultiplexes the video stream and the audio stream. And can be converted to Further, for example, the demultiplexer (DMUX) 1413 obtains the file data read from various recording media by the connectivity 1321, for example, via the stream buffer 1414, and demultiplexes the video stream and the audio. Can be converted to a stream.

  The stream buffer 1414 buffers the bit stream. For example, the stream buffer 1414 buffers the transport stream supplied from the multiplexing unit (MUX) 1412 and, for example, in the connectivity 1321 or the broadband modem 1333 at a predetermined timing or based on an external request or the like. Supply.

  Further, for example, the stream buffer 1414 buffers the file data supplied from the multiplexing unit (MUX) 1412 and supplies it to the connectivity 1321 at a predetermined timing or based on an external request, for example. It is recorded on various recording media.

  Further, the stream buffer 1414 buffers a transport stream acquired through, for example, the connectivity 1321 or the broadband modem 1333, and performs a demultiplexing unit (DMUX) at a predetermined timing or based on a request from the outside. 1413.

  Further, the stream buffer 1414 buffers file data read from various recording media in, for example, the connectivity 1321, and the demultiplexer (DMUX) 1413 at a predetermined timing or based on an external request or the like. To supply.

  Next, an example of the operation of the video processor 1332 having such a configuration will be described. For example, a video signal input to the video processor 1332 from the connectivity 1321 or the like is converted into digital image data of a predetermined format such as 4: 2: 2Y / Cb / Cr format by the video input processing unit 1401 and stored in the frame memory 1405. Written sequentially. This digital image data is read by the first image enlargement / reduction unit 1402 or the second image enlargement / reduction unit 1403, and format conversion to a predetermined method such as 4: 2: 0Y / Cb / Cr method and enlargement / reduction processing are performed. Is written again in the frame memory 1405. This image data is encoded by the encoding / decoding engine 1407 and written as a video stream in the video ES buffer 1408A.

  Also, an audio signal input to the video processor 1332 from the connectivity 1321 or the like is encoded by the audio encoder 1410 and written as an audio stream in the audio ES buffer 1409A.

  The video stream of the video ES buffer 1408A and the audio stream of the audio ES buffer 1409A are read and multiplexed by the multiplexing unit (MUX) 1412 and converted into a transport stream or file data. The transport stream generated by the multiplexing unit (MUX) 1412 is buffered in the stream buffer 1414 and then output to the external network via, for example, the connectivity 1321 or the broadband modem 1333. Further, the file data generated by the multiplexing unit (MUX) 1412 is buffered in the stream buffer 1414, and then output to, for example, the connectivity 1321 and recorded on various recording media.

  For example, a transport stream input from an external network to the video processor 1332 via the connectivity 1321 or the broadband modem 1333 is buffered in the stream buffer 1414 and then demultiplexed by the demultiplexer (DMUX) 1413. The Further, for example, file data read from various recording media by the connectivity 1321 and input to the video processor 1332 is buffered by the stream buffer 1414 and then demultiplexed by the demultiplexer (DMUX) 1413. That is, the transport stream or file data input to the video processor 1332 is separated into a video stream and an audio stream by the demultiplexer (DMUX) 1413.

  The audio stream is supplied to the audio decoder 1411 via the audio ES buffer 1409B, decoded, and an audio signal is reproduced. The video stream is written to the video ES buffer 1408B, and then sequentially read and decoded by the encoding / decoding engine 1407, and written to the frame memory 1405. The decoded image data is enlarged / reduced by the second image enlargement / reduction unit 1403 and written to the frame memory 1405. The decoded image data is read out to the video output processing unit 1404, format-converted to a predetermined system such as 4: 2: 2Y / Cb / Cr system, and further converted into an analog signal to be converted into a video signal. Is played out.

  When the present technology is applied to the video processor 1332 configured as described above, the present technology according to each embodiment described above may be applied to the encoding / decoding engine 1407. That is, for example, the encoding / decoding engine 1407 may have the function of the image encoding device 100 described above. By doing so, the video processor 1332 can obtain the same effects as those of the embodiments described above with reference to FIGS. 1 to 22.

  Note that in the encoding / decoding engine 1407, the present technology (that is, the function of the image encoding device 100) may be realized by hardware such as a logic circuit or software such as an embedded program. Alternatively, it may be realized by both of them.

<Other configuration examples of video processor>
FIG. 36 illustrates another example of a schematic configuration of a video processor 1332 to which the present technology is applied. In the case of the example of FIG. 36, the video processor 1332 has a function of encoding / decoding video data by a predetermined method.

  More specifically, as illustrated in FIG. 36, the video processor 1332 includes a control unit 1511, a display interface 1512, a display engine 1513, an image processing engine 1514, and an internal memory 1515. The video processor 1332 includes a codec engine 1516, a memory interface 1517, a multiplexing / demultiplexing unit (MUX DMUX) 1518, a network interface 1519, and a video interface 1520.

  The control unit 1511 controls the operation of each processing unit in the video processor 1332 such as the display interface 1512, the display engine 1513, the image processing engine 1514, and the codec engine 1516.

  As illustrated in FIG. 36, the control unit 1511 includes, for example, a main CPU 1531, a sub CPU 1532, and a system controller 1533. The main CPU 1531 executes a program and the like for controlling the operation of each processing unit in the video processor 1332. The main CPU 1531 generates a control signal according to the program and supplies it to each processing unit (that is, controls the operation of each processing unit). The sub CPU 1532 plays an auxiliary role of the main CPU 1531. For example, the sub CPU 1532 executes a child process such as a program executed by the main CPU 1531, a subroutine, or the like. The system controller 1533 controls operations of the main CPU 1531 and the sub CPU 1532 such as designating a program to be executed by the main CPU 1531 and the sub CPU 1532.

  The display interface 1512 outputs image data to, for example, the connectivity 1321 under the control of the control unit 1511. For example, the display interface 1512 converts image data of digital data into an analog signal, and outputs it to a monitor device or the like of the connectivity 1321 as a reproduced video signal or as image data of the digital data.

  Under the control of the control unit 1511, the display engine 1513 performs various conversion processes such as format conversion, size conversion, color gamut conversion, and the like so as to match the image data with hardware specifications such as a monitor device that displays the image. I do.

  The image processing engine 1514 performs predetermined image processing such as filter processing for improving image quality on the image data under the control of the control unit 1511.

  The internal memory 1515 is a memory provided in the video processor 1332 that is shared by the display engine 1513, the image processing engine 1514, and the codec engine 1516. The internal memory 1515 is used, for example, for data exchange performed between the display engine 1513, the image processing engine 1514, and the codec engine 1516. For example, the internal memory 1515 stores data supplied from the display engine 1513, the image processing engine 1514, or the codec engine 1516, and stores the data as needed (eg, upon request). This is supplied to the image processing engine 1514 or the codec engine 1516. The internal memory 1515 may be realized by any storage device, but is generally used for storing a small amount of data such as image data or parameters in units of blocks. It is desirable to realize it by a semiconductor memory such as a static random access memory that has a relatively small capacity (eg, compared to the external memory 1312) but a high response speed.

  The codec engine 1516 performs processing related to encoding and decoding of image data. The encoding / decoding scheme supported by the codec engine 1516 is arbitrary, and the number thereof may be one or plural. For example, the codec engine 1516 may be provided with codec functions of a plurality of encoding / decoding schemes, and may be configured to perform encoding of image data or decoding of encoded data using one selected from them.

  In the example shown in FIG. 36, the codec engine 1516 includes, for example, MPEG-2 Video 1541, AVC / H.2641542, HEVC / H.2651543, HEVC / H.265 (Scalable) 1544, as functional blocks for codec processing. HEVC / H.265 (Multi-view) 1545 and MPEG-DASH 1551 are included.

  MPEG-2 Video 1541 is a functional block that encodes and decodes image data in the MPEG-2 format. AVC / H.2641542 is a functional block that encodes and decodes image data using the AVC method. HEVC / H.2651543 is a functional block that encodes and decodes image data using the HEVC method. HEVC / H.265 (Scalable) 1544 is a functional block that performs scalable encoding and scalable decoding of image data using the HEVC method. HEVC / H.265 (Multi-view) 1545 is a functional block that multi-view encodes or multi-view decodes image data using the HEVC method.

  MPEG-DASH 1551 is a functional block that transmits and receives image data by the MPEG-DASH (MPEG-Dynamic Adaptive Streaming over HTTP) method. MPEG-DASH is a technology for streaming video using HTTP (HyperText Transfer Protocol), and selects and transmits appropriate data from multiple encoded data with different resolutions prepared in segments. This is one of the features. MPEG-DASH 1551 generates a stream conforming to the standard, controls transmission of the stream, and the like. For encoding / decoding of image data, MPEG-2 Video 1541 to HEVC / H.265 (Multi-view) 1545 described above are used. Is used.

  The memory interface 1517 is an interface for the external memory 1312. Data supplied from the image processing engine 1514 or the codec engine 1516 is supplied to the external memory 1312 via the memory interface 1517. The data read from the external memory 1312 is supplied to the video processor 1332 (the image processing engine 1514 or the codec engine 1516) via the memory interface 1517.

  A multiplexing / demultiplexing unit (MUX DMUX) 1518 multiplexes and demultiplexes various data related to images such as a bit stream of encoded data, image data, and a video signal. This multiplexing / demultiplexing method is arbitrary. For example, at the time of multiplexing, the multiplexing / demultiplexing unit (MUX DMUX) 1518 can not only combine a plurality of data into one but also add predetermined header information or the like to the data. Further, in the demultiplexing, the multiplexing / demultiplexing unit (MUX DMUX) 1518 not only divides one data into a plurality of data but also adds predetermined header information or the like to each divided data. it can. That is, the multiplexing / demultiplexing unit (MUX DMUX) 1518 can convert the data format by multiplexing / demultiplexing. For example, the multiplexing / demultiplexing unit (MUX DMUX) 1518 multiplexes the bit stream, thereby transporting a transport stream that is a bit stream in a transfer format and data in a file format for recording (file data). Can be converted to Of course, the inverse transformation is also possible by demultiplexing.

  The network interface 1519 is an interface for the broadband modem 1333, the connectivity 1321, etc., for example. The video interface 1520 is an interface for the connectivity 1321, the camera 1322, and the like, for example.

  Next, an example of the operation of the video processor 1332 will be described. For example, when a transport stream is received from an external network via the connectivity 1321 or the broadband modem 1333, the transport stream is supplied to a multiplexing / demultiplexing unit (MUX DMUX) 1518 via the network interface 1519. Demultiplexed and decoded by codec engine 1516. For example, the image data obtained by decoding by the codec engine 1516 is subjected to predetermined image processing by the image processing engine 1514, subjected to predetermined conversion by the display engine 1513, and is connected to, for example, the connectivity 1321 through the display interface 1512. And the image is displayed on the monitor. Further, for example, image data obtained by decoding by the codec engine 1516 is re-encoded by the codec engine 1516, multiplexed by a multiplexing / demultiplexing unit (MUX DMUX) 1518, converted into file data, and video data The data is output to, for example, the connectivity 1321 through the interface 1520 and recorded on various recording media.

  Further, for example, encoded data file data obtained by encoding image data read from a recording medium (not shown) by the connectivity 1321 or the like is transmitted via a video interface 1520 via a multiplexing / demultiplexing unit (MUX DMUX). ) 1518 to be demultiplexed and decoded by the codec engine 1516. Image data obtained by decoding by the codec engine 1516 is subjected to predetermined image processing by the image processing engine 1514, subjected to predetermined conversion by the display engine 1513, and supplied to, for example, the connectivity 1321 through the display interface 1512. The image is displayed on the monitor. Further, for example, image data obtained by decoding by the codec engine 1516 is re-encoded by the codec engine 1516, multiplexed by a multiplexing / demultiplexing unit (MUX DMUX) 1518, and converted into a transport stream, The data is supplied to, for example, the connectivity 1321 and the broadband modem 1333 via the network interface 1519 and transmitted to another device (not shown).

  Note that transfer of image data and other data between the processing units in the video processor 1332 is performed using, for example, the internal memory 1515 and the external memory 1312. The power management module 1313 controls power supply to the control unit 1511, for example.

  When the present technology is applied to the video processor 1332 configured as described above, the present technology according to each of the above-described embodiments may be applied to the codec engine 1516. That is, for example, the codec engine 1516 may have a functional block that realizes the above-described image encoding device 100. By doing so, the video processor 1332 can obtain the same effects as those of the embodiments described above with reference to FIGS. 1 to 22.

  In the codec engine 1516, the present technology (that is, the function of the image encoding device 100) may be realized by hardware such as a logic circuit, or may be realized by software such as an embedded program. Alternatively, it may be realized by both of them.

  Two examples of the configuration of the video processor 1332 have been described above, but the configuration of the video processor 1332 is arbitrary and may be other than the two examples described above. The video processor 1332 may be configured as one semiconductor chip, but may be configured as a plurality of semiconductor chips. For example, a three-dimensional stacked LSI in which a plurality of semiconductors are stacked may be used. Further, it may be realized by a plurality of LSIs.

<Application example to equipment>
Video set 1300 can be incorporated into various devices that process image data. For example, the video set 1300 can be incorporated in the television device 900 (FIG. 30), the mobile phone 920 (FIG. 31), the recording / reproducing device 940 (FIG. 32), the imaging device 960 (FIG. 33), or the like. By incorporating the video set 1300, the apparatus can obtain the same effects as those of the embodiments described above with reference to FIGS.

  Note that even a part of each configuration of the video set 1300 described above can be implemented as a configuration to which the present technology is applied as long as it includes the video processor 1332. For example, only the video processor 1332 can be implemented as a video processor to which the present technology is applied. Further, for example, as described above, the processor or the video module 1311 indicated by the dotted line 1341 can be implemented as a processor or a module to which the present technology is applied. Furthermore, for example, the video module 1311, the external memory 1312, the power management module 1313, and the front end module 1314 can be combined and implemented as a video unit 1361 to which the present technology is applied. Regardless of the configuration, the same effects as those of the embodiments described above with reference to FIGS. 1 to 22 can be obtained.

  That is, any configuration including the video processor 1332 can be incorporated into various devices that process image data, as in the case of the video set 1300. For example, a video processor 1332, a processor indicated by a dotted line 1341, a video module 1311, or a video unit 1361, a television device 900 (FIG. 30), a mobile phone 920 (FIG. 31), a recording / playback device 940 (FIG. 32), It can be incorporated in an imaging device 960 (FIG. 33) or the like. Then, by incorporating any configuration to which the present technology is applied, the apparatus obtains the same effects as those of the embodiments described above with reference to FIGS. 1 to 22, as in the case of the video set 1300. be able to.

  Further, in this specification, an example has been described in which various types of information are multiplexed into an encoded stream and transmitted from the encoding side to the decoding side. However, the method for transmitting such information is not limited to such an example. For example, these pieces of information may be transmitted or recorded as separate data associated with the encoded bitstream without being multiplexed into the encoded bitstream. Here, the term “associate” means that an image (which may be a part of an image such as a slice or a block) included in the bitstream and information corresponding to the image can be linked at the time of decoding. Means. That is, information may be transmitted on a transmission path different from that of the image (or bit stream). Information may be recorded on a recording medium (or another recording area of the same recording medium) different from the image (or bit stream). Furthermore, the information and the image (or bit stream) may be associated with each other in an arbitrary unit such as a plurality of frames, one frame, or a part of the frame.

In addition, this technique can also take the following structures.
(1) An encoding table used for encoding current coefficient data that is a processing target of image data to be encoded is set based on an encoding table used for encoding coefficient data around the current coefficient data. A setting section to
An image processing apparatus comprising: an encoding unit that encodes the current coefficient data using an encoding table set by the setting unit.
(2)
The setting unit, as an encoding table used for encoding the peripheral coefficient data, an encoding table used for encoding coefficient data adjacent to the right of the current coefficient data, and the current coefficient data The image processing apparatus according to (1), wherein an encoding table used for encoding the current coefficient data is set based on an encoding table used for encoding the coefficient data adjacent thereto below.
(3) The setting unit includes, as an encoding table used for encoding the peripheral coefficient data, an encoding table used for encoding coefficient data adjacent to the right of the current coefficient data, and the current Based on the encoding table used for encoding the coefficient data adjacent to the coefficient data and the encoding table used for encoding the coefficient data adjacent to the lower right of the current coefficient data, the current The image processing apparatus according to (1) or (2), wherein an encoding table used for encoding coefficient data is set.
(4) The setting unit includes, as an encoding table used for encoding the peripheral coefficient data, an encoding table used for encoding coefficient data adjacent to the upper right of the current coefficient data, and the current The encoding table used for encoding the current coefficient data is set based on the encoding table used for encoding the coefficient data adjacent to the lower left of the coefficient data. (1) to (3) The image processing apparatus described.
(5) In the case where there is a single encoding table used for encoding the peripheral coefficient data that can be used, the setting unit uses the encoding table as an encoding table used for encoding the current coefficient data. The image processing device according to any one of (1) to (4) to be set.
(6) When there are a plurality of encoding tables used for encoding the peripheral coefficient data that can be used, the setting unit performs encoding using an average value of the table numbers of the plurality of encoding tables as a table number. The image processing device according to any one of (1) to (5), wherein the table is set as an encoding table used for encoding the current coefficient data.
(7) When there are a plurality of encoding tables used for encoding the peripheral coefficient data that can be used, the setting unit performs encoding using a median of table numbers of the plurality of encoding tables as a table number. The image processing device according to any one of (1) to (6), wherein the table is set as an encoding table used for encoding the current coefficient data.
(8) When there are a plurality of encoding tables used for encoding the peripheral coefficient data that can be used, the setting unit converts any one of the plurality of encoding tables into the encoding of the current coefficient data. The image processing device according to any one of (1) to (7), which is set as an encoding table to be used.
(9) When the current coefficient data is the first coefficient data in the encoding unit of the image data, the setting unit uses an encoding table used for encoding the current coefficient data as the peripheral coefficient data. The image processing device according to any one of (1) to (8), which is set based on an encoding table used for encoding.
(10) The setting unit sets, for all coefficient data, an encoding table used for encoding the current coefficient data based on the encoding table used for encoding the peripheral coefficient data. The image processing device according to any one of (9) to (9).
(11) The setting unit, as an encoding table used for encoding the peripheral coefficient data, is adjacent to the current coefficient data and belongs to an encoding unit different from the encoding unit of the current coefficient data. The image processing apparatus according to (10), wherein an encoding table used for encoding the current coefficient data is set based on an encoding table used for encoding coefficient data.
(12) An encoding table used for encoding current coefficient data that is a processing target of image data to be encoded is set based on the encoding table used for encoding the coefficient data around the current coefficient data. And
An image processing method for encoding the current coefficient data using a set encoding table.

  DESCRIPTION OF SYMBOLS 100 Image coding apparatus, 115 Lossless encoding part, 151 Control part, 152 Table selection part, 153 TR encoding part, 154 Table designation | designated information buffer, 161 Peripheral history calculation part, 162 Table processing part, 163 Selection part, 164 Base Level determination unit, 165 calculation unit, 166 calculation unit, 167 selection unit, 171 shift processing unit, 172 table processing unit, 173 selection unit, 174 base level determination unit, 175 calculation unit, 176 calculation unit, 177 selection unit, 190 TU , 191 encoding sub-block, 211 selection unit, 212 selection unit

Claims (12)

An encoding table used for encoding current coefficient data which is a processing target of image data to be encoded is set based on a plurality of encoding tables used for encoding the coefficient data around the current coefficient data. A setting section;
An image processing apparatus comprising: an encoding unit that encodes the current coefficient data using an encoding table set by the setting unit. The setting unit includes, as the plurality of encoding tables, an encoding table used for encoding coefficient data adjacent to the right of the current coefficient data, and encoding of coefficient data adjacent below the current coefficient data. The image processing apparatus according to claim 1, wherein an encoding table used for encoding the current coefficient data is set based on the encoding table used in step 1. The setting unit includes, as the plurality of encoding tables, an encoding table used for encoding coefficient data adjacent to the right of the current coefficient data, and encoding of coefficient data adjacent below the current coefficient data. The encoding table used for encoding the current coefficient data is set based on the encoding table used for the current coefficient data and the encoding table used for encoding the coefficient data adjacent to the lower right of the current coefficient data. The image processing apparatus according to claim 1. The setting unit includes, as the plurality of encoding tables, an encoding table used for encoding coefficient data adjacent to the upper right of the current coefficient data, and encoding of coefficient data adjacent to the lower left of the current coefficient data. The image processing apparatus according to claim 1, wherein an encoding table used for encoding the current coefficient data is set based on the encoding table used in step 1. The setting unit sets the encoding table as an encoding table used for encoding the current coefficient data when there is a single encoding table used for encoding the peripheral coefficient data that can be used. Item 8. The image processing apparatus according to Item 1. The setting unit, when there are a plurality of encoding tables used for encoding the peripheral coefficient data that can be used, an encoding table having an average value of table numbers of the plurality of encoding tables as a table number, The image processing apparatus according to claim 1, wherein the image processing apparatus is set as an encoding table used for encoding the current coefficient data. When there are a plurality of encoding tables used for encoding the peripheral coefficient data that can be used, the setting unit includes an encoding table having a table number as a median value of the table numbers of the plurality of encoding tables, The image processing apparatus according to claim 1, wherein the image processing apparatus is set as an encoding table used for encoding the current coefficient data. When there are a plurality of encoding tables used for encoding the peripheral coefficient data that can be used, the setting unit uses any one of the plurality of encoding tables for encoding the current coefficient data. The image processing apparatus according to claim 1, wherein the image processing apparatus is set as a table. When the current coefficient data is the first coefficient data in the encoding unit of the image data, the setting unit determines an encoding table used for encoding the current coefficient data based on the plurality of encoding tables. The image processing apparatus according to claim 1, which is set. The image processing apparatus according to claim 1, wherein the setting unit sets, for all coefficient data, an encoding table used for encoding the current coefficient data based on the plurality of encoding tables. The setting unit, as the plurality of encoding tables, is an encoding table used for encoding coefficient data adjacent to the current coefficient data and belonging to an encoding unit different from the encoding unit of the current coefficient data. The image processing apparatus according to claim 10, wherein an encoding table used for encoding the current coefficient data is set on the basis of the current coefficient data. An encoding table used for encoding current coefficient data to be processed of image data to be encoded is set based on a plurality of encoding tables used for encoding the coefficient data around the current coefficient data. ,
An image processing method for encoding the current coefficient data using a set encoding table.

Images