Image decoding method and device based on block separation structure in image coding system

Abstract

The present invention relates to an image decoding method and apparatus based on a block separation structure in an image coding system. The image decoding method according to the present invention, performed by means of a decoding apparatus, includes the following steps: obtaining first separation information related to a first target block; if a first separation flag indicates that the first target block is to be separated, separating the first target block into a first sub-block; obtaining MPT separation information related to a second target block that is one of the first sub-blocks of the first target block; separating the second target block into a second sub-block based on the MPT separation information; and decoding the second sub-block, wherein the second sub-block is a non-square block.

Description

[0001] This application is a divisional application of the patent application with application number 201880029236.4 (PCT / KR2018 / 003919) filed on November 1, 2019, with an international filing date of April 3, 2018, and the invention name being “Image decoding method and device based on block separation structure in image coding system”. Technical Field

[0002] The present disclosure relates to image encoding technology, and more particularly, to an image decoding method and apparatus according to a block partitioning structure in an image encoding system. Background Art

[0003] The demand for high-resolution, high-quality images, such as high-definition (HD) and ultra-high-definition (UHD), is increasing across various fields. Because image data has high resolution and high quality, the amount of information or bits to be transmitted increases relative to conventional image data. Consequently, when image data is transmitted using a medium such as conventional wired / wireless broadband lines or stored using existing storage media, transmission and storage costs increase.

[0004] Therefore, there is a need for an efficient image compression technology for effectively transmitting, storing, and reproducing information of high-resolution and high-quality images. Summary of the Invention

[0005] Technical Purpose

[0006] The technical purpose of the present disclosure is to provide a method and device that can enhance image coding efficiency.

[0007] Another technical objective of the present disclosure is to provide a method and device that can separate (or partition) a picture according to a multiple partition tree (MPT) structure.

[0008] Yet another technical object of the present disclosure is to provide a method and apparatus that can separate (or partition) a picture into non-square blocks according to a multi-partition tree (MPT) structure and can perform decoding based on each non-square block.

[0009] Technical Solution

[0010] According to an exemplary embodiment of the present disclosure, a video decoding method performed by a decoding device is provided. The method includes the following steps: obtaining first separation information for a first target block, and when a first separation flag indicates that the first target block is separated, separating the first target block into a first sub-block; obtaining multi-partition tree (MPT) separation information for a second target block, wherein the second target block is one of the first sub-blocks of the first target block; separating the second target block into a second sub-block based on the MPT separation information; and decoding the second sub-block, wherein the second sub-block is a non-square block.

[0011] According to another exemplary embodiment of the present disclosure, a decoding device for performing image decoding is provided herein. The decoding device includes: an entropy decoder that obtains first separation information for a first target block through a bitstream and obtains multi-partition tree (MPT) separation information for a second target block through the bitstream, wherein the second target block is one of the first subblocks of the first target block; a picture divider that, when a first separation flag indicates that the first target block is separated, separates the first target block into first subblocks and separates the second target block into second subblocks based on the MPT separation information; and a predictor that decodes the second subblock, wherein the second subblock is a non-square block.

[0012] According to another exemplary embodiment of the present disclosure, a video encoding method performed by an encoding device is provided herein. The method includes the following steps: separating a first target block into first sub-blocks; separating a second target block into second sub-blocks, wherein the second target block is one of the first sub-blocks; decoding the second sub-block; and generating first separation information for the first target block and MPT separation information for the second target block, encoding and outputting the generated information, wherein the second sub-block is a non-square block.

[0013] According to another exemplary embodiment of the present disclosure, a video encoding device is provided herein. The encoding device includes: a picture partitioner that separates a first target block into first sub-blocks and a second target block into second sub-blocks, wherein the second target block is one of the first sub-blocks; a predictor that decodes the second sub-block; and an entropy encoder that generates first separation information for the first target block and MPT separation information for the second target block, and encodes and outputs the generated information, wherein the second sub-block is a non-square block.

[0014] Beneficial effects

[0015] According to the present disclosure, a picture may be separated (or partitioned) into blocks of various shapes according to a multi-partition tree (MPT) structure, and by doing so, prediction efficiency may be enhanced, and overall encoding efficiency may be enhanced.

[0016] According to the present disclosure, a picture may be separated (or partitioned) into blocks of various shapes according to a multi-partition tree (MPT) structure, and by doing so, transformation efficiency may be enhanced, and overall encoding efficiency may be enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram illustrating a configuration of a video encoding device to which the present invention is applicable.

[0018] Figure 2 is a schematic diagram illustrating a configuration of a video decoding device to which the present invention is applicable.

[0019] Figure 3 An example of separating CUs according to a quad-tree binary tree (QTBT) structure and a syntax of the QTBT structure is shown.

[0020] Figure 4 An exemplary transmission of the syntax of the QTBT structure for the target CU is shown.

[0021] Figure 5 An example of separating a target CU according to the QTMPT structure is shown.

[0022] Figure 6 An exemplary transmission of the syntax of the QTMPT structure for the target CU is shown.

[0023] Figure 7 An exemplary transmission of the syntax of the QTMPT structure for the target CU is shown.

[0024] Figure 8 is an overall diagram of a video encoding method performed by an encoding device according to the present invention.

[0025] Figure 9 is an overall diagram of a video decoding method performed by a decoding device according to the present invention. DETAILED DESCRIPTION

[0026] The present disclosure can be modified in various forms, and specific embodiments thereof will be described and illustrated in the accompanying drawings. However, the embodiments are not intended to limit the present disclosure. The terms used in the following description are only used to describe specific embodiments, but are not intended to limit the present disclosure. An expression in the singular includes an expression in the plural as long as it is clearly read in a different way. Terms such as "including" and "having" are intended to indicate the presence of features, numbers, steps, operations, elements, components, or combinations thereof used in the following description, and therefore it should be understood that the presence or addition of one or more different features, numbers, steps, operations, elements, components, or combinations thereof is not excluded.

[0027] On the other hand, for the purpose of explaining different specific functions, the elements in the drawings described in this disclosure are drawn independently, which does not mean that these elements are implemented by independent hardware or independent software. For example, two or more elements in the elements can be combined to form a single element, or an element can be divided into multiple elements. Without departing from the concept of the present disclosure, embodiments in which elements are combined and / or divided belong to the present disclosure.

[0028] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, throughout the drawings, the same reference numerals are used to indicate the same elements, and the same description of the same elements will be omitted.

[0029] In this specification, a picture generally refers to a unit representing an image at a specific time, and a slice is a unit constituting a part of a picture. A picture can be composed of multiple slices, and the terms picture and slice can be mixed with each other as needed.

[0030] A pixel or picture element may refer to the smallest unit that constitutes a picture (or image). In addition, "sample" may be used as a term corresponding to a pixel. A sample may generally represent a pixel or a pixel value, may represent only a pixel (pixel value) of a luma component, or may represent only a pixel (pixel value) of a chroma component.

[0031] A unit refers to a basic unit of image processing. The unit may include at least one of a specific region and information related to the region. Alternatively, the unit may be combined with terms such as block and region. Typically, an M×N block may represent a set of samples or transform coefficients arranged in M ​​columns and N rows.

[0032] Figure 1 The structure of a video encoding device to which the present disclosure is applicable is briefly illustrated.

[0033] refer to Figure 1 The video encoding apparatus (100) may include a picture segmenter (105), a predictor (110), a residual processor (120), an entropy encoder (130), an adder (140), a filter (150), and a memory (160). The residual processor (120) may include a subtractor (121), a transformer (122), a quantizer (123), a rearranger (124), a dequantizer (125), and an inverse transformer (126).

[0034] The picture splitter (105) can separate the input picture into at least one processing unit.

[0035] In the example, the processing unit may be referred to as a coding unit (CU). In this case, the coding unit may be recursively separated from the maximum coding unit (LCU) according to a quadtree binary tree (QTBT) structure. For example, one coding unit may be separated into multiple coding units of a deeper depth based on a quadtree structure and / or a binary tree structure. In this case, for example, the quadtree structure may be applied first, and the binary tree structure may be applied later. Alternatively, the binary tree structure may be applied first. The encoding process according to the present disclosure may be performed based on a final coding unit that is no longer separated further. In this case, depending on image characteristics, the maximum coding unit may be used as the final coding unit based on coding efficiency, etc., or the coding unit may be recursively separated into coding units of a lower depth as needed and a coding unit with an optimal size may be used as the final coding unit. Here, the encoding process may include processes such as prediction, transformation, and reconstruction, which will be described later.

[0036] In another example, a processing unit may include a coding unit (CU), a prediction unit (PU), or a transform unit (TU). A coding unit may be separated from a maximum coding unit (LCU) into coding units of greater depth according to a quadtree structure. In this case, depending on image characteristics, the maximum coding unit may be directly used as the final coding unit based on coding efficiency, etc., or the coding unit may be recursively separated into coding units of greater depth as needed and the coding unit with the optimal size may be used as the final coding unit. When a minimum coding unit (SCU) is set, the coding unit may not be separated into coding units smaller than the minimum coding unit. Here, the final coding unit refers to a coding unit that is partitioned or separated into a prediction unit or a transform unit. A prediction unit is a unit partitioned from a coding unit and may be a unit for sample prediction. Here, a prediction unit may be divided into sub-blocks. A transform unit may be partitioned from a coding unit according to a quadtree structure and may be a unit for deriving a transform coefficient and / or a unit for deriving a residual signal from a transform coefficient. Hereinafter, a coding unit may be referred to as a coding block (CB), a prediction unit may be referred to as a prediction block (PB), and a transform unit may be referred to as a transform block (TB). A prediction block or prediction unit may refer to a specific area in the form of a block in a picture and include an array of prediction samples. In addition, a transform block or transform unit may refer to a specific area in the form of a block in a picture and include an array of transform coefficients or residual samples.

[0037] The predictor (110) may perform prediction on a processing target block (hereinafter, a current block) and may generate a prediction block including prediction samples of the current block. The prediction unit performed in the predictor (110) may be a coding block, a transform block, or a prediction block.

[0038] The predictor (110) may determine whether to apply intra prediction or inter prediction to the current block. For example, the predictor (110) may determine whether to apply intra prediction or inter prediction in units of CUs.

[0039] In the case of intra prediction, the predictor (110) can derive prediction samples of the current block based on reference samples outside the current block in a picture to which the current block belongs (hereinafter, current picture). In this case, the predictor (110) can derive prediction samples based on an average or interpolation of neighboring reference samples of the current block (case (i)), or can derive prediction samples based on reference samples existing in a specific (prediction) direction with respect to the prediction samples among the neighboring reference samples of the current block (case (ii)). Case (i) can be referred to as a non-directional mode or a non-angle mode, and case (ii) can be referred to as a directional mode or an angle mode. In intra prediction, the prediction mode may include, as an example, 33 directional modes and at least two non-directional modes. The non-directional mode may include a DC mode and a planar mode. The predictor (110) can determine the prediction mode to be applied to the current block by using the prediction mode applied to the neighboring block.

[0040] In the case of inter prediction, the predictor (110) can derive the prediction sample of the current block based on the sample specified by the motion vector on the reference picture. The predictor (110) can derive the prediction sample of the current block by applying any one of the skip mode, merge mode and motion vector prediction (MVP) mode. In the case of skip mode and merge mode, the predictor (110) can use the motion information of the neighboring block as the motion information of the current block. In the case of skip mode, unlike merge mode, the difference (residual) between the prediction sample and the original sample is not sent. In the case of MVP mode, the motion vector of the neighboring block is used as a motion vector predictor, and is therefore used as the motion vector predictor of the current block to derive the motion vector of the current block.

[0041] In the case of inter prediction, neighboring blocks may include spatial neighboring blocks present in the current picture and temporal neighboring blocks present in the reference picture. A reference picture including temporal neighboring blocks may also be referred to as a collocated picture (colPic). Motion information may include a motion vector and a reference picture index. Information such as prediction mode information and motion information may be (entropy) encoded and then output as a bitstream.

[0042] When using motion information of temporally neighboring blocks in skip mode and merge mode, the highest picture in the reference picture list can be used as the reference picture. The reference pictures included in the reference picture list can be aligned based on the picture order count (POC) difference between the current picture and the corresponding reference picture. The POC corresponds to the display order and can be distinguished from the coding order.

[0043] The subtractor (121) generates residual samples, which are the difference between the original samples and the predicted samples. If the skip mode is applied, the residual samples may not be generated as described above.

[0044] The transformer (122) transforms the residual samples in units of transform blocks to generate transform coefficients. The transformer (122) may perform the transform based on the size of the corresponding transform block and the prediction mode applied to the coding block or prediction block that spatially overlaps with the transform block. For example, if intra prediction is applied to the coding block or prediction block that overlaps with the transform block and the transform block is a 4×4 residual array, the residual samples may be transformed using a discrete sine transform (DST) transform kernel, and in other cases, the residual samples may be transformed using a discrete cosine transform (DCT) transform kernel.

[0045] The quantizer (123) may quantize the transform coefficients to generate quantized transform coefficients.

[0046] The rearranger (124) rearranges the quantized transform coefficients. The rearranger (124) may rearrange the quantized transform coefficients in block form into a one-dimensional vector by a coefficient scanning method. Although the rearranger (124) is described as a separate component, the rearranger (124) may be part of the quantizer (123).

[0047] The entropy encoder (130) may perform entropy encoding on the quantized transform coefficients. Entropy encoding may include encoding methods such as exponential Golomb, context-adaptive variable length coding (CAVLC), context-adaptive binary arithmetic coding (CABAC), etc. In addition to the quantized transform coefficients, the entropy encoder (130) may encode information required for video reconstruction (e.g., syntax element values, etc.) together or separately. The entropy coded information may be transmitted or stored in units of a network abstraction layer (NAL) in the form of a bitstream.

[0048] The dequantizer (125) dequantizes the value (transform coefficient) quantized by the quantizer (123), and the inverse transformer (126) inversely transforms the value dequantized by the dequantizer (125) to generate residual samples.

[0049] The adder (140) adds the residual samples to the prediction samples to reconstruct the picture. The residual samples can be added to the prediction samples in units of blocks to generate a reconstructed block. Although the adder (140) is described as a separate component, the adder (140) can be part of the predictor (110). At the same time, the adder (140) can be called a reconstructor or a reconstructed block generator.

[0050] The filter (150) may apply deblocking filtering and / or sample adaptive offset to the reconstructed picture. Deblocking filtering and / or sample adaptive offset may be used to correct artifacts at block boundaries or distortion in quantization in the reconstructed picture. After deblocking filtering is completed, sample adaptive offset may be applied on a sample basis. The filter (150) may apply an adaptive loop filter (ALF) to the reconstructed picture. The ALF may be applied to the reconstructed picture to which deblocking filtering and / or sample adaptive offset have been applied.

[0051] The memory (160) can store reconstructed pictures (decoded pictures) or information required for encoding / decoding. Here, the reconstructed pictures can be reconstructed pictures filtered by the filter (150). The stored reconstructed pictures can be used as reference pictures for (inter) prediction of other pictures. For example, the memory (160) can store (reference) pictures used for inter prediction. Here, the pictures used for inter prediction can be specified based on a reference picture set or a reference picture list.

[0052] Figure 2 The structure of a video decoding device to which the present disclosure is applicable is briefly illustrated.

[0053] refer to Figure 2 The video decoding device (200) may include an entropy decoder (210), a residual processor (220), a predictor (230), an adder (240), a filter (250), and a memory (260). The residual processor (220) may include a rearranger (221), a dequantizer (222), and an inverse transformer (223).

[0054] When a bit stream including video information is input, the video decoding apparatus (200) can reconstruct the video in association with a process of processing the video information in the video encoding apparatus.

[0055] For example, the video decoding apparatus (200) may perform video decoding using a processing unit applied in a video encoding apparatus. Thus, the processing unit block of video decoding may be, for example, a coding unit, and in another example, may be a coding unit, a prediction unit, or a transform unit. The coding unit may be separated from the maximum coding unit according to a quadtree structure and / or a binary tree structure.

[0056] In some cases, prediction units and transform units may be further used. In this case, a prediction block is a block derived or partitioned from a coding unit and may be a unit for sample prediction. Here, a prediction unit may be divided into sub-blocks. A transform unit may be separated from a coding unit according to a quadtree structure and may be a unit for deriving transform coefficients or a unit for deriving residual signals from transform coefficients.

[0057] The entropy decoder (210) can parse the bitstream to output information required for video reconstruction or picture reconstruction. For example, the entropy decoder (210) can decode the information in the bitstream based on a coding method such as exponential Golomb coding, CAVLC, CABAC, etc., and can output the values ​​of syntax elements required for video reconstruction and the quantized values ​​of the transform coefficients of the residual.

[0058] More specifically, the CABAC entropy decoding method can receive a bin corresponding to each syntax element in the bitstream, use the decoding target syntax element information and the decoding information of the adjacent and decoding target blocks or the information of the symbol / bin decoded in the previous step to determine the context model, predict the bin generation probability according to the determined context model, and perform arithmetic decoding of the bin to generate a symbol corresponding to each syntax element value. Here, the CABAC entropy decoding method can update the context model using the information of the symbol / bin decoded by the context model for the next symbol / bin after determining the context model.

[0059] Information about prediction among the information decoded in the entropy decoder (210) can be provided to the predictor (250), and the residual value that has been entropy-decoded by the entropy decoder (210), that is, the quantized transform coefficient, can be input to the rearranger (221).

[0060] The rearranger (221) may rearrange the quantized transform coefficients into a two-dimensional block form. The rearranger (221) may perform rearrangement corresponding to coefficient scanning performed by the encoding device. Although the rearranger (221) is described as a separate component, the rearranger (221) may be part of the dequantizer (222).

[0061] The dequantizer (222) may dequantize the quantized transform coefficient based on the (de)quantization parameter to output the transform coefficient. In this case, information for deriving the quantization parameter may be signaled from the encoding device.

[0062] The inverse transformer (223) may inversely transform the transform coefficients to derive residual samples.

[0063] The predictor (230) may perform prediction on the current block and may generate a prediction block including prediction samples of the current block. The unit of prediction performed in the predictor (230) may be a coding block, or may be a transform block or may be a prediction block.

[0064] The predictor (230) may determine whether to apply intra prediction or inter prediction based on the information about the prediction. In this case, the unit for determining which one to use between intra prediction and inter prediction may be different from the unit for generating prediction samples. In addition, the unit for generating prediction samples may also be different in inter prediction and intra prediction. For example, it may be determined which one to use between inter prediction and intra prediction in units of CUs. In addition, for example, in inter prediction, prediction samples may be generated by determining a prediction mode in units of PUs, and in intra prediction, prediction samples may be generated in units of TUs by determining a prediction mode in units of PUs.

[0065] In the case of intra prediction, the predictor (230) may derive prediction samples of the current block based on neighboring reference samples in the current picture. The predictor (230) may derive prediction samples of the current block by applying a directional mode or a non-directional mode based on the neighboring reference samples of the current block. In this case, the prediction mode to be applied to the current block may be determined by using the intra prediction mode of the neighboring block.

[0066] In the case of inter prediction, the predictor (230) may derive prediction samples of the current block based on samples specified in the reference picture according to the motion vector. The predictor (230) may derive prediction samples of the current block using one of the skip mode, merge mode, and MVP mode. Here, motion information required for inter prediction of the current block provided by the video encoding device, such as a motion vector and information about a reference picture index, may be acquired or derived based on information about prediction.

[0067] In skip mode and merge mode, motion information of a neighboring block may be used as motion information of the current block. Here, the neighboring block may include a spatial neighboring block and a temporal neighboring block.

[0068] The predictor (230) may construct a merge candidate list using motion information of available neighboring blocks and use information indicated by a merge index on the merge candidate list as a motion vector for the current block. The merge index may be signaled by the encoding device. The motion information may include a motion vector and a reference picture. When using motion information of temporally neighboring blocks in skip mode and merge mode, the highest picture in the reference picture list may be used as a reference picture.

[0069] In the case of skip mode, the difference (residual) between the predicted sample and the original sample is not sent, unlike the merge mode.

[0070] In the case of MVP mode, the motion vector of the current block can be derived using the motion vector of the neighboring block as a motion vector predictor. Here, the neighboring block may include a spatial neighboring block and a temporal neighboring block.

[0071] When the merge mode is applied, for example, a merge candidate list may be generated using the motion vector of the reconstructed spatial neighboring block and / or the motion vector corresponding to the Col block which is the temporal neighboring block. The motion vector of the candidate block selected from the merge candidate list is used as the motion vector of the current block in the merge mode. The above-mentioned information on prediction may include a merge index indicating the candidate block having the best motion vector selected from the candidate blocks included in the merge candidate list. Here, the predictor (230) may derive the motion vector of the current block using the merge index.

[0072] When the motion vector prediction (MVP) mode is applied as another example, a motion vector predictor candidate list can be generated using the motion vectors of the reconstructed spatial neighboring blocks and / or the motion vectors corresponding to the Col blocks as the temporal neighboring blocks. That is, the motion vectors of the reconstructed spatial neighboring blocks and / or the motion vectors corresponding to the Col blocks as the temporal neighboring blocks can be used as motion vector candidates. The above-mentioned information on prediction may include a predicted motion vector index indicating the best motion vector selected from the motion vector candidates included in the list. Here, the predictor (230) can select the predicted motion vector of the current block from the motion vector candidates included in the motion vector candidate list using the motion vector index. The predictor of the encoding device can obtain a motion vector difference (MVD) between the motion vector of the current block and the motion vector predictor, encode the MVD and output the encoded MVD in the form of a bitstream. That is, the MVD can be obtained by subtracting the motion vector predictor from the motion vector of the current block. Here, the predictor (230) can obtain the motion vector included in the information on prediction and derive the motion vector of the current block by adding the motion vector difference to the motion vector predictor. In addition, the predictor can obtain or derive a reference picture index indicating a reference picture from the above-mentioned information on prediction.

[0073] The adder (240) may add the residual samples to the prediction samples to reconstruct the current block or current picture. The adder (240) may reconstruct the current picture by adding the residual samples to the prediction samples in units of blocks. When the skip mode is applied, the residual is not sent, and thus the prediction samples may become reconstructed samples. Although the adder (240) is described as a separate component, the adder (240) may be part of the predictor (230). At the same time, the adder (240) may be referred to as a reconstructor or a reconstructed block generator.

[0074] The filter (250) may apply deblocking filtering, sample adaptive offset, and / or ALF to the reconstructed picture. Here, sample adaptive offset may be applied on a sample-by-sample basis after deblocking filtering. ALF may be applied after deblocking filtering and / or applying sample adaptive offset.

[0075] The memory (260) can store reconstructed pictures (decoded pictures) or information required for decoding. Here, the reconstructed pictures can be reconstructed pictures filtered by the filter (250). For example, the memory (260) can store pictures used for inter prediction. Here, the pictures used for inter prediction can be specified based on a reference picture set or a reference picture list. The reconstructed pictures can be used as reference pictures for other pictures. The memory (260) can output the reconstructed pictures in an output order.

[0076] When encoding an input picture as described above, encoding can be performed based on a single processing unit. This processing unit can be referred to as a coding unit (CU). Since encoding is performed based on regions within the picture that contain similar information, transform efficiency can be improved. This can also improve overall coding efficiency. Furthermore, since encoding is performed based on regions within the picture that contain similar information, prediction efficiency can be improved. This can also improve overall coding efficiency. However, when a picture is separated (or partitioned) into square CUs using a quadtree (QT) structure, there may be limitations on how the separation (or partitioning) can be performed so that the CUs can accurately contain similar information. For example, information indicating a specific entity within a picture may be widely located along a diagonal direction. In this case, if information indicating a specific entity is included using only one CU, a wider range of other information can be included in addition to the information indicating the specific entity. Furthermore, if information indicating a specific entity is included using multiple square CUs, encoding will be performed on each of the multiple CUs. Consequently, coding efficiency may be reduced. In this case, separating the picture into non-square CUs that contain information indicating the specific entity can further improve coding efficiency. Therefore, the present disclosure proposes a method for separating (or partitioning) an input picture into square CUs and non-square CUs by using another separation structure and a quadtree (QT) structure. By doing so, the picture can be separated into CUs of different shapes according to the information included in the picture, and encoding can be performed more efficiently.

[0077] Figure 3 An example of separating CUs according to a quad-tree binary tree (QTBT) structure and a syntax of the QTBT structure is shown.

[0078] The QTBT structure may indicate a structure in which a CU (or CTU) is separated (or split) according to a QT structure, and then separated according to a binary tree (BT) structure. More specifically, the QTBT structure may indicate a separation structure configured in a combination of a QT structure and a BT structure. Here, in the case of encoding a picture in units of CTU, the CTU may be separated (or split) according to the QT structure, and the leaf nodes of the QT structure may be additionally separated according to the BT structure. Here, the leaf node may indicate a CU that is no longer separated in the QT structure, and the leaf node may also be referred to as a terminal node. In addition, the QT structure may indicate the separation of a 2N×2N sized CU (or CTU) into 4 N×N sized sub-CUs, and the BT structure may indicate the separation of a 2N×2N sized CU into 2 N×2N sized sub-CUs, or 2 2N×N sub-CUs. Reference Figure 3 (a) A CU may be separated into square CUs of a lower depth according to the QT structure, and further, among the square CUs, a specific CU may be separated into non-square CUs of a lower depth according to the BT structure.

[0079] Figure 3 (b) may illustrate an exemplary transmission of the syntax of a QTBT structure. Figure 3 As shown in (b), the solid line may indicate the QT structure, while the dotted line may indicate the BT structure. In addition, starting from the top and extending downward (i.e., from the top to the bottom direction), the syntax for the CU starting from the higher depth to the lower depth may be indicated. In addition, starting from the left end toward the right end (i.e., from the left to the right direction), the syntax for the upper left CU, the upper right CU, the lower left CU and the lower right CU may be indicated respectively. More specifically, the index shown at the highest (or topmost) position may indicate the syntax for the n-depth CU, and the index shown at the second highest position may indicate the syntax for the (n+1)-depth CU, and the index shown at the third position from the top may indicate the syntax for the (n+2)-depth CU, and the index shown at the fourth position from the top may indicate the syntax for the (n+3)-depth CU. In addition, the index marked with bold may indicate the value of the syntax corresponding to the QT structure, and the index not marked with bold may indicate the value of the syntax corresponding to the BT structure.

[0080] refer to Figure 3(b) A QT split flag indicating whether the CU is to be separated (or split) according to the QT structure may be sent. More specifically, a flag indicating whether a CU of size 2N×2N is to be separated into 4 sub-CUs of size N×N may be sent. QT_split_flag may indicate a syntax element for the QT split flag. For example, when the value of the QT split flag is equal to 1, the CI may be separated into 4 sub-CUs. And, when the value of the QT split flag is equal to 0, the CU may not be separated. In addition, in order to adjust the QT structure corresponding to the input image, information about the maximum CU size, minimum CU size, maximum depth, etc. within the QT structure may be sent. The above information about the QT structure may be sent separately for each slice type or for each image component (luminance component, chrominance component, etc.).

[0081] refer to Figure 3 (b) , information about the BT structure may be sent for a terminal node that is no longer separated in the QT structure. More specifically, information about the BT structure may be sent for a CU corresponding to a terminal node in the QT structure. Here, information including information about the BT structure may be referred to as MPT information. For example, a BT separation flag indicating whether to perform separation (or splitting) of the CU according to the BT structure, that is, whether to apply the BT structure for the CU, may be sent. BT_split_flag may indicate a syntax element for the BT separation flag. More specifically, when the value of the BT separation flag is equal to 1, the CU may be separated into 2 sub-CUs, and when the value of the BT separation flag is equal to 0, the CU may not be separated. In addition, in order to adjust the BT structure corresponding to the input image, information about the maximum CU size, minimum CU size, maximum depth, etc. within the BT structure may be sent. The above information about the QT structure may be sent separately for each slice type or for each image component. In the case of separating the CU according to the BT structure, the CU may be separated horizontally or vertically. In other words, a 2N×2N CU can be separated into 2 N×N sub-CUs, or a 2N×2N CU can be separated into N×2N sub-CUs. A BT split mode index indicating the direction along which the CU is to be separated, that is, the separation type of the CU, can be sent. BT_split_mode can indicate the syntax element used for the BT split mode index. For example, when the value of the BT split mode index is equal to 1, the CU can be separated in the vertical direction, that is, separated into N×2N sub-CUs, and when the value of the BT split mode index is equal to 0, the CU can be separated in the horizontal direction, that is, separated into 2N×N sub-CUs.

[0082] Figure 4 An exemplary transmission of the syntax of the QTBT structure for the target CU is shown.

[0083] refer to Figure 4 , QT_split_flag for the target CU may be sent. As described above, QT_split_flag may indicate whether the target CU is split according to the QT structure. More specifically, QT_split_flag may indicate whether the target CU is split into sub-CUs having a size corresponding to half the height and half the width of the target CU.

[0084] More specifically, for example, when the value of the QT_split_flag of the target CU is equal to 1, that is, when the QT_split_flag indicates that the target CU is split into sub-CUs each having a size corresponding to half the height and half the width of the target CU, the target CU can be split into the corresponding sub-CUs. In this case, the QT_split_flag corresponding to the sub-CU can be transmitted. More specifically, the target CU can be recursively split into CUs of lower depth, thereby deriving a CU of a terminal node that can no longer be split.

[0085] Meanwhile, when the value of the QT_split_flag of the target CU of the terminal node is equal to 0, that is, when the QT_split_flag indicates that the target CU is not separated into sub-CUs each having a size corresponding to half the height and half the width of the target CU, the BT_split_flag corresponding to the target CU may be transmitted. As described above, the BT_split_flag may indicate whether the target CU is separated according to the BT structure. More specifically, for example, the BT_split_flag indicates whether a target CU of size 2N×2N is separated into sub-CUs of size N×2N or sub-CUs of size 2N×N. When the BT structure is applied to the target CU, the shape of the CU separated from the target CU may be determined according to the BT_split_flag and BT_split_mode values.

[0086] More specifically, when the value of BT_split_flag is equal to 1, the target CU can be separated into N×2N sub-CUs or 2N×N sub-CUs, and if the value of the BT split flag is equal to 0, the target CU cannot be separated. Also, when BT_split_flag indicates that the target CU is separated according to the BT structure, BT_split_mode for the target CU can be sent. BT_split_mode can indicate the direction along which the CU will be separated, that is, the separation type of the CU. For example, when the value of BT_split_mode is equal to 1, the CU can be separated in the vertical direction, that is, separated into N×2N sub-CUs, and when the value of BT_split_mode is equal to 0, the CU can be separated in the horizontal direction, that is, separated into 2N×N sub-CUs.

[0087] Additionally, the syntax of the QTBT structure may be indicated as shown in the following table.

[0088] [Table 1]

[0089]

[0090]

[0091] Here, QT_split_flag may indicate a syntax element of the QT split flag, BT_split_flag may indicate a syntax element of the BT split flag, and BT_split_mode may indicate a syntax element of the BT split mode index.

[0092] The CU may be separated, and the leaf nodes of the QT structure may be further separated according to the MPT structure.

[0093] According to the above QTBT structure, the 2N×2N target CU corresponding to the leaf node of the QT structure can be separated into two N×2N sub-CUs, or can be separated into two 2N×N sub-CUs. Figure 5 As shown in (a) to (j) of FIG, the target CU corresponding to the leaf node of the QT structure can be separated into 2, 3 or 4 sub-CUs of different shapes. More specifically, the MPT structure can represent a structure in which the target CU is separated into multiple non-square sub-CUs of different shapes.

[0094] More specifically, refer to Figure 5(a) and (b), according to the MPT structure, the target CU can be separated into two sub-CUs in the vertical direction or the horizontal direction. More specifically, according to the MPT structure, the target CU of 2N×2N size can be separated into two sub-CUs of N×2N size, or can be separated into two sub-CUs of 2N×N size.

[0095] In addition, reference Figure 5 (c) to (h), according to the MPT structure, the target CU can be separated into 3 sub-CUs in the vertical direction or the horizontal direction. If the target CU is separated into 3 sub-CUs, the target CU can be separated into one large-sized sub-CU and two small-sized sub-CUs, or the target CU can be equally separated into 3 sub-CUs, that is, the target CU can be separated into 3 sub-CUs of equal size. The scheme for separating the target CU into one large-sized sub-CU and two small-sized sub-CUs may include a variety of separation (or partitioning) methods depending on the position of the large-sized sub-CU.

[0096] For example, Figure 5 As shown in (c), according to the MPT structure, the target CU of size 2N×2N can be separated into a sub-CU of size N / 2×2N, an N×2N sub-CU and an N / 2×2N sub-CU. Figure 5 As shown in (c), the target CU of 2N×2N size can be separated in the order of an N / 2×2N sub-CU, an N×2N CU, and an N / 2×2N sub-CU from left to right according to the MPT structure.

[0097] Alternatively, for example, Figure 5 As shown in (d), according to the MPT structure, the target CU of size 2N×2N can be separated into a sub-CU of size N / 2×2N, a sub-CU of size N / 2×2N, and a sub-CU of size N×2N. More specifically, as Figure 5 As shown in (d), the target CU of 2N×2N size can be separated in the order of an N / 2×2N sub-CU, an N / 2×2N sub-CU, and an N×2N sub-CU from left to right according to the MPT structure.

[0098] Alternatively, for example, Figure 5 As shown in (e), according to the MPT structure, the target CU of size 2N×2N can be separated into a sub-CU of size N×2N, a sub-CU of size N / 2×2N, and a sub-CU of size N / 2×2N. More specifically, as Figure 5 As shown in (e), the target CU of 2N×2N size can be separated in the order of an N×2N sub-CU, an N / 2×2N sub-CU, and an N / 2×2N sub-CU from left to right according to the MPT structure.

[0099] Alternatively, for example, Figure 5 As shown in (f), according to the MPT structure, the target CU of size 2N×2N can be separated into a sub-CU of size 2N×N / 2, a 2N×N sub-CU and a 2N×N / 2 sub-CU. More specifically, as Figure 5 As shown in (f), the target CU of 2N×2N size can be separated in the order of a 2N×N / 2 sub-CU, a 2N×N sub-CU, and a 2N×N / 2 sub-CU from top to bottom according to the MPT structure.

[0100] Alternatively, for example, Figure 5 As shown in (g), according to the MPT structure, the target CU of size 2N×2N can be separated into a sub-CU of size 2N×N / 2, a sub-CU of size 2N×N / 2, and a sub-CU of size 2N×N. More specifically, as Figure 5 As shown in (g), the target CU of 2N×2N size can be separated in the order of a 2N×N / 2 sub-CU, a 2N×N / 2 sub-CU, and a 2N×N sub-CU from top to bottom according to the MPT structure.

[0101] Alternatively, for example, Figure 5 As shown in (h), according to the MPT structure, the target CU of size 2N×2N can be separated into a sub-CU of size 2N×N, a sub-CU of size 2N×N / 2, and a sub-CU of size 2N×N / 2. More specifically, as Figure 5 As shown in (h), the target CU of 2N×2N size can be separated in the order of 1 2N×N sub-CU, 1 2N×N / 2 sub-CU and 1 2N×N / 2 sub-CU from top to bottom according to the MPT structure.

[0102] Alternatively, for example, Figure 5 As shown in (i) and (j) of FIG, according to the MPT structure, the target CU of 2N×2N size can be separated into 4 sub-CUs along the vertical direction or the horizontal direction. More specifically, the target CU of 2N×2N size can be separated into 4 sub-CUs of N / 2×2N size, or it can be separated into 4 sub-CUs of 2N×N / 2 size. At the same time, if the separation according to the BT structure is recursively applied to the target CU and the sub-CUs of the target CU, it can be as follows Figure 5 However, in the MPT structure, the target CU can be separated into 4 sub-CUs through a single separation process without repeating the separation process.

[0103] At the same time, in order to adjust the MPT structure corresponding to the input image, information about the maximum CU size, minimum CU size, maximum depth, etc. within the MPT structure can be transmitted. The above information about the MPT structure can be transmitted separately for each slice type or for each image component (luminance component, chrominance component, etc.). Alternatively, the above information about the MPT structure can be transmitted separately through a sequence parameter set (SPS), a picture parameter set (PPS), or a slice segment header.

[0104] Figure 6 An exemplary transmission of the syntax of the QTMPT structure for the target CU is shown.

[0105] refer to Figure 6 , QT_split_flag for the target CU may be sent. As described above, QT_split_flag may indicate whether the target CU is split according to the QT structure. More specifically, QT_split_flag may indicate whether the target CU is split into sub-CUs having a size corresponding to half the height and half the width of the target CU.

[0106] More specifically, for example, when the value of the QT_split_flag of the target CU is equal to 1, that is, when the QT_split_flag indicates that the target CU is split into sub-CUs each having a size corresponding to half the height and half the width of the target CU, the target CU can be split into the corresponding sub-CUs. In this case, the QT_split_flag corresponding to the sub-CU can be transmitted. More specifically, the target CU can be recursively split into CUs of lower depth, thereby deriving a CU of a terminal node that can no longer be split.

[0107] Meanwhile, when the value of QT_split_flag for the target CU of the terminal node is equal to 0, that is, when QT_split_flag indicates that the target CU is not split into sub-CUs each having a size corresponding to half the height and half the width of the target CU, information about the MPT structure corresponding to the target CU of the terminal node may be transmitted. Here, information including information about the MPT structure may be referred to as MPT split information. For example, the MPT split information may include MPT split type information corresponding to the target CU. More specifically, when the value of QT_split_flag corresponding to the target CU of the terminal node is equal to 0, MPT_split_type for the target CU may be transmitted. MPT_split_type may indicate the syntax used for MPT split type information. MPT_split_type may, for example, indicate whether a 2N×2N target CU is split into multiple non-square sub-CUs of various shapes. Non-square sub-CUs may include N / 2×2N sub-CUs, N×2N sub-CUs, 2N×N / 2 sub-CUs, and / or 2N×N sub-CUs.

[0108] More specifically, for example, when the value of MPT_split_type of the target CU is equal to 0, the target CU may not be split. In addition, when the value of MPT_split_type of the target CU is not equal to 0, the shape of the sub-CU separated from the target CU may be determined according to MPT_split_type and MPT_split_mode. More specifically, the MPT split information may include MPT split type information and MPT split direction information corresponding to the target CU. Here, MPT_split_type may indicate the syntax corresponding to the MPT split type information, and MPT_split_mode may indicate the syntax corresponding to the MPT split direction information.

[0109] For example, if the value of MPT_split_type is equal to 1, the target CU can be split into 2 sub-CUs. More specifically, when the value of MPT_split_type is equal to 1 and the value of MPT_split_mode is equal to 1, the target CU can be split into 2 N×2N sub-CUs, as described above. Figure 5 In addition, when the value of MPT_split_type is equal to 1 and the value of MPT_split_mode is equal to 0, the target CU can be separated into two 2N×N sub-CUs, as described above. Figure 5 As shown in (b).

[0110] In addition, for example, when the value of MPT_split_type is equal to 2, the target CU can be separated into 3 sub-CUs. In addition, when the value of MPT_split_type is equal to 2 and the value of MPT_split_mode is equal to 1, the target CU can be separated into 3 sub-CUs along the vertical direction. In addition, when the value of MPT_split_type is equal to 2 and the value of MPT_split_mode is equal to 0, the target CU can be separated into 3 sub-CUs along the horizontal direction. In the case of deriving the separation direction of the target CU based on MPT_split_type, MPT_sub_split_type corresponding to the target CU can be sent, and MPT_sub_split_type can indicate sub-separation information of the target CU. The MPT separation information can include the MPT sub-separation type information corresponding to the target CU. And, herein, MPT_sub_split_type can indicate the syntax for the MPT sub-separation type information.

[0111] More specifically, in the case of splitting the target CU into 3 sub-CUs, sub-split information of the target CU may be derived based on MPT_sub_split_type.

[0112] More specifically, when the value of MPT_split_type is equal to 2, the value of MPT_split_mode is equal to 1, and the value of MPT_sub_split_type is equal to 0, the target CU can be separated into a left sub-CU of N / 2×2N size, a central sub-CU of N×2N size, and a right sub-CU of N / 2×2N size, as described above. Figure 5 In addition, when the value of MPT_split_type is equal to 2, the value of MPT_split_mode is equal to 1, and MPT_sub_split_type is equal to 1, the target CU can be separated into a left sub-CU of N / 2×2N size, a central sub-CU of N / 2×2N size, and a right sub-CU of N×2N size, as described above. Figure 5 In addition, when the value of MPT_split_type is equal to 2, the value of MPT_split_mode is equal to 1, and MPT_sub_split_type is equal to 2, the target CU can be separated into a left sub-CU of N×2N size, a central sub-CU of N / 2×2N size, and a right sub-CU of N / 2×2N size, as described above. Figure 5In addition, when the value of MPT_split_type is equal to 2, the value of MPT_split_mode is equal to 0, and the value of MPT_sub_split_type is equal to 0, the target CU can be separated into an upper sub-CU of 2N×N / 2 size, a central sub-CU of 2N×N size, and a lower sub-CU of 2N×N / 2 size, as described above. Figure 5 In addition, when the value of MPT_split_type is equal to 2, the value of MPT_split_mode is equal to 0, and the value of MPT_sub_split_type is equal to 1, the target CU can be split into an upper sub-CU of 2N×N / 2 size, a central sub-CU of 2N×N / 2 size, and a lower sub-CU of 2N×N size, as described above. Figure 5 In addition, when the value of MPT_split_type is equal to 2, the value of MPT_split_mode is equal to 0, and MPT_sub_split_type is equal to 2, the target CU can be separated into an upper sub-CU of 2N×N size, a central sub-CU of 2N×N / 2 size, and a lower sub-CU of 2N×N / 2 size, as described above. Figure 5 As shown in (h).

[0113] In addition, for example, when the value of MPT_split_type is equal to 3, the target CU can be separated into 4 sub-CUs. More specifically, when the value of MPT_split_type is equal to 3 and the value of MPT_split_mode is equal to 1, the target CU can be separated into 4 sub-CUs of N / 2×2N size, as described above. Figure 5 In addition, when the value of MPT_split_type is equal to 3 and the value of MPT_split_mode is equal to 0, the target CU can be separated into 4 sub-CUs of 2N×N / 2 size, as described above. Figure 5 As shown in (j).

[0114] Meanwhile, although the syntax of the QTMPT structure may be transmitted as described above, exemplary transmission of the syntax of another QTMPT structure may be proposed as described below.

[0115] Figure 7 FIG. 4 shows an exemplary transmission of the syntax of the QTMPT structure for the target CU. Figure 6 In the above description, in the case where the value of MPT_split_type is not equal to 0, MPT_split_mode can be sent together. Figure 7, MPT_split_mode can be parsed earlier than MPT_split_type.

[0116] refer to Figure 7 , QT_split_flag for the target CU may be sent. As described above, QT_split_flag may indicate whether the target CU is split according to the QT structure. More specifically, QT_split_flag may indicate whether the target CU is split into sub-CUs having a size corresponding to half the height and half the width of the target CU.

[0117] More specifically, for example, when the value of the QT_split_flag of the target CU is equal to 1, that is, when the QT_split_flag indicates that the target CU is split into sub-CUs each having a size corresponding to half the height and half the width of the target CU, the target CU can be split into the corresponding sub-CUs. In this case, the QT_split_flag corresponding to the sub-CU can be transmitted. More specifically, the target CU can be recursively split into CUs of lower depth, thereby deriving a CU of a terminal node that can no longer be split.

[0118] Meanwhile, when the value of QT_split_flag of the target CU of the terminal node is equal to 0, that is, when QT_split_flag indicates that the target CU is not to be separated into sub-CUs having a size corresponding to half the height and half the width of the target CU, the MPT separation information may include the MPT separation flag of the target CU. More specifically, when the value of QT_split_flag for the target CU of the terminal node is equal to 0, the MPT_split_flag for the target CU may be transmitted. MPT_split_flag may indicate the syntax for the MPT separation flag. MPT_split_flag may indicate whether the target CU is to be separated according to the MPT structure. More specifically, for example, MPT_split_flag may indicate whether a 2N×2N target CU is to be separated into non-square sub-CUs of various shapes. Non-square sub-CUs may include N / 2×2N sub-CUs, N×2N sub-CUs, 2N×N / 2 sub-CUs, and / or 2N×N sub-CUs. When the value of MPT_split_flag is 0, the target CU may not be separated. In addition, when the value of MPT_split_flag is 1, the target CU may be separated according to the MPT structure, and MPT_split_mode and MPT_split_type may be transmitted. When the value of MPT_split_flag is 1, that is, when the target CU is separated according to the MPT structure, the shape of the CU separated from the target CU may be determined according to MPT_split_mode and MPT_split_type.

[0119] More specifically, when the value of MPT_split_flag is equal to 1, that is, when the target CU is separated according to the MPT structure, the separation direction of the target CU can be derived based on MPT_split_mode. For example, when the value of MPT_split_mode is equal to 1, the target CU can be separated in the vertical direction, and when the value of MPT_split_mode is equal to 0, the target CU can be separated in the horizontal direction.

[0120] Subsequently, the separation type of the target CU can be derived based on MPT_split_type. For example, when the value of MPT_split_type is equal to 0, the target CU can be separated into 2 sub-CUs. More specifically, when the value of MPT_split_mode is equal to 1 and the value of MPT_split_type is equal to 0, the target CU can be separated into 2 N×2N sub-CUs, as described above. Figure 5In addition, when the value of MPT_split_mode is equal to 0 and the value of MPT_split_type is equal to 0, the target CU can be separated into two 2N×N sub-CUs, as described above. Figure 5 as described in (b).

[0121] In addition, as another example, when the value of MPT_split_type is equal to 1, the target CU can be split into 3 sub-CUs. When the value of MPT_split_type is equal to 1, that is, when the target CU is split into 3 sub-CUs, MPT_sub_split_type for the target CU can be transmitted, and MPT_sub_split_type can indicate sub-split information of the target CU. More specifically, when the target CU is split into 3 sub-CUs, the sub-split information of the target CU can be derived based on MPT_sub_split_type.

[0122] More specifically, when the value of MPT_split_mode is equal to 1, the value of MPT_split_type is equal to 1, and the value of MPT_sub_split_type is equal to 0, the target CU can be separated into a left sub-CU of N / 2×2N size, a center sub-CU of N×2N size, and a right sub-CU of N / 2×2N size, as described above. Figure 5 In addition, when the value of MPT_split_mode is equal to 1, the value of MPT_split_type is equal to 1, and the value of MPT_sub_split_type is equal to 1, the target CU can be separated into a left CU of N / 2×2N size, a center sub-CU of N / 2×2N size, and a right sub-CU of N×2N size, as described above. Figure 5 In addition, when the value of MPT_split_mode is equal to 1, the value of MPT_split_type is equal to 1, and the value of MPT_sub_split_type is equal to 2, the target CU can be separated into a left sub-CU of N×2N size, a central sub-CU of N / 2×2N size, and a right sub-CU of N / 2×2N size, as described above. Figure 5 In addition, when the value of MPT_split_mode is equal to 0, the value of MPT_split_type is equal to 1, and the value of MPT_sub_split_type is equal to 0, the target CU can be split into an upper sub-CU of 2N×N / 2 size, a center sub-CU of 2N×N size, and a lower sub-CU of 2N×N / 2 size, as described above in Figure 5In addition, when the value of MPT_split_mode is equal to 0, the value of MPT_split_type is equal to 1, and the value of MPT_sub_split_type is equal to 1, the target CU can be split into an upper sub-CU of 2N×N / 2 size, a center sub-CU of 2N×N / 2 size, and a lower sub-CU of 2N×N size, as described above in Figure 5 In addition, when the value of MPT_split_mode is equal to 0, the value of MPT_split_type is equal to 1, and the value of MPT_sub_split_type is equal to 2, the target CU can be separated into an upper sub-CU of 2N×N size, a central sub-CU of 2N×N / 2 size, and a lower sub-CU of 2N×N / 2 size, as described above in Figure 5 as described in (h).

[0123] In addition, as another example, when the value of MPT_split_type is equal to 2, the target CU can be separated into 4 sub-CUs. More specifically, when the value of MPT_split_mode is equal to 1 and the value of MPT_split_type is equal to 2, the target CU can be separated into 4 sub-CUs of N / 2×2N size, as shown above. Figure 5 In addition, when the value of MPT_split_mode is equal to 0 and the value of MPT_split_type is equal to 2, the target CU can be separated into 4 sub-CUs of 2N×N / 2 size, as described above in Figure 5 As described in (j).

[0124] As described above, the number of sub-CUs derived by separating the target CU can be derived based on MPT_split_type. Meanwhile, generally, depending on the input image, the number of partitions into which the block is separated, that is, the situation of the separation type of the generated block may be different. More specifically, the ratio (or proportion) of the block separation type may vary according to the input image. For example, the ratio of the block type according to which the block is separated into 2 partitions may be high, or the ratio of the block type according to which the block is separated into 3 partitions may be high, or the ratio of the block type according to which the block is separated into 4 partitions may be high. Therefore, the encoding efficiency can be improved by using a binarization method that assigns a binarization string with a small number of bits to a syntax with a high ratio of a separation type.

[0125] Therefore, for the Figure 5The binarized character strings of the above-described separation types of MPT_slice_type and MPT_sub_slice_type shown in (a) to (j) can be derived as shown in the following table.

[0126] [Table 2]

[0127] Binarization method 1 Binarization method 2 Binarization method 3 MPT-2(5(a),5(b)) 0 00 0 MPT-3 Type 0 (5(c), 5(f)) 100 10 10 MPT-3 Type 1 (5(d), 5(g)) 1010 110 1110 MPT-3 Type 2 (5(e), 5(h)) 1011 111 1111 MPT-4(5(i),5(j)) 11 01 110

[0128] Here, MPT-2 indicates a separation type according to which a block is separated (or partitioned) into 2 sub-blocks, such as Figure 5 MPT-3 type 0 indicates a separation type, according to which the block is separated (or divided) into 3 sub-blocks, such as Figure 5 As shown and described in (c) and (f) of , and here, MPT-3 type 0 indicates that the central sub-block corresponds to a sub-block having a larger size. MPT-3 type 1 indicates a separation type according to which one block is separated (or partitioned) into 3 sub-blocks, such as Figure 5 As shown and described in (d) and (g) of FIG, and here, MPT-3 type 1 indicates that the right sub-block or the lower sub-block corresponds to a sub-block having a larger size. MPT-3 type 2 indicates a separation type according to which a block is separated (or divided) into 3 sub-blocks, as in Figure 5 As shown and described in (e) and (h) of , and here, MPT-3 type 2 indicates that the left subblock or the upper subblock corresponds to a subblock having a larger size. And, MPT-4 indicates a separation type according to which a block is separated into 4 subblocks, as in Figure 5 As shown and described in (i) and (j).

[0129] Referring to Table 2, binarization method 1 may first determine whether the separation type corresponds to MPT-2. More specifically, when the first value of the syntax of the acquired information on the MPT structure of the target block is equal to 0, the separation type of the target block may be determined to be MPT-2.

[0130] If the target block's separation type does not correspond to MPT-2, that is, if the first value of the syntax of the target block's MPT structure information is not equal to 0, MPT-4 and MPT-4 can be distinguished from each other based on the second value of the syntax of the target block's MPT structure information. More specifically, if the second value of the syntax of the target block's MPT structure information is equal to 0, the target block's separation type can be determined to be MPT-3. Furthermore, if the second value of the syntax of the target block's MPT structure information is equal to 1, the target block's separation type can be determined to be MPT-4. The syntax can also indicate the aforementioned MPT_split_type. More specifically, according to binarization method 1, if MPT_split_type is equal to 0, the target block's separation type can be derived as MPT-2. If MPT_split_type is equal to 10, the target block's separation type can be derived as MPT-3. Furthermore, if MPT_split_type is equal to 11, the target block's separation type can be derived as MPT-4.

[0131] In addition, the separation type of the target block is determined to be MPT-3, that is, when MPT_split_type is equal to 10, the MPT_sub_split_type of the target block can be additionally transmitted. Based on MPT_sub_split_type, the separation type of the target block can be determined as MPT-3 type 0, MPT-3 type 1, or MPT-3 type 2. According to binarization method 1, when MPT_sub_split_type is equal to 0, the separation type of the target block can be derived as MPT-3 type 0. When MPT_sub_split_type is equal to 10, the separation type of the target block can be derived as MPT-3 type 1. And, when MPT_sub_split_type is equal to 11, the separation type of the target block can be derived as MPT-3 type 2. Therefore, according to binarization method 1, when the separation type of the target block corresponds to MPT-3 type 0, the binarization string indicating the syntax of the MPT structure of the target block can be indicated as 100. When the separation type of the target block corresponds to MPT-3 type 1, the binary string indicating the syntax of the MPT structure of the target block can be indicated as 1010. When the separation type of the target block corresponds to MPT-3 type 2, the binary string indicating the syntax of the MPT structure of the target block can be indicated as 1011. The binarization method can be used when the proportion (or ratio) of blocks with the MPT-2 separation type and the proportion (or ratio) of blocks with the MPT-4 separation type within the input image are high. Therefore, encoding efficiency can be improved.

[0132] Furthermore, referring to Table 2, binarization method 2 can first determine whether the separation type corresponds to MPT-2 or MPT-4. More specifically, if the first value of the syntax of the acquired information regarding the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-2 or MPT-4. Furthermore, if the first value of the syntax of the acquired information regarding the MPT structure of the target block is not equal to 0, the separation type of the target block can be determined to be MPT-3. More specifically, if the separation type of the target block is determined to be MPT-2 or MPT-4, that is, if the first value of the syntax of the acquired information regarding the MPT structure of the target block is equal to 0, MPT-2 and MPT-4 can be distinguished from each other based on the second value of the syntax of the information regarding the MPT structure of the target block. More specifically, if the second value of the syntax of the information regarding the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-2. Furthermore, if the second value of the syntax of the information regarding the MPT structure of the target block is equal to 1, the separation type of the target block can be determined to be MPT-4. At the same time, the syntax may indicate the above-mentioned MPT_split_type. More specifically, according to binarization method 2, when MPT_split_type is equal to 00, the separation type of the target block can be derived as MPT-2. When MPT_split_type is equal to 1, the separation type of the target block can be derived as MPT-3. And, when MPT_split_type is equal to 01, the separation type of the target block can be derived as MPT-4.

[0133] In addition, when the separation type of the target block is determined to be MPT-3, that is, when MPT_split_type is equal to 1, the MPT_sub_split_type of the target block may be additionally transmitted. Based on MPT_sub_split_type, the separation type of the target block may be determined to be MPT-3 type 0, MPT-3 type 1, or MPT-3 type 2. According to binarization method 2, when MPT_sub_split_type is equal to 0, the separation type of the target block may be derived as MPT-3 type 0. When MPT_sub_split_type is equal to 10, the separation type of the target block may be derived as MPT-3 type 1. And, when MPT_sub_split_type is equal to 11, the separation type of the target block may be derived as MPT-3 type 2. Therefore, according to binarization method 2, when the separation type of the target block corresponds to MPT-3 type 0, the binarized string indicating the syntax of the MPT structure of the target block may be indicated as 10. When the separation type of the target block corresponds to MPT-3 type 1, the binary string indicating the syntax of the MPT structure of the target block can be indicated as 110. When the separation type of the target block corresponds to MPT-3 type 2, the binary string indicating the syntax of the MPT structure of the target block can be expressed as 111. When the ratio (or rate) of blocks having the MPT-3 separation type within the input image is greater than the ratio of blocks having the MPT-2 separation type, binarization method 2 can be used. Therefore, encoding efficiency can be improved.

[0134] In addition, referring to Table 2, the binarization method 3 may first determine whether the separation type corresponds to MPT-2. For example, when the first value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block may be determined to be MPT-2.

[0135] In a case where the separation type of the target block does not correspond to MPT-2, that is, in a case where the first value of the syntax of the acquired information about the MPT structure of the target block is not equal to 0, based on the second value of the syntax of the acquired information about the MPT structure of the target block, it can be determined whether the separation type of the target block corresponds to MPT-3 type 0. For example, in a case where the second value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-3 type 0.

[0136] If the separation type of the target block does not correspond to MPT-3 type 0, that is, if the second value of the syntax of the information about the MPT structure of the target block is not equal to 0, it can be determined whether the separation type of the target block corresponds to MPT-4 based on the third value of the syntax of the information about the MPT structure of the target block. For example, if the third value of the syntax of the information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-4.

[0137] If the target block's separation type does not correspond to MPT-4, that is, if the third value of the syntax of the acquired information regarding the MPT structure of the target block is not equal to 0, whether the target block's separation type corresponds to MPT-3 Type 1 or MPT-3 Type 2 can be determined based on the remaining value of the syntax of the information regarding the MPT structure of the target block. For example, if the remaining value of the syntax of the acquired information regarding the MPT structure of the target block is equal to 10, the target block's separation type can be determined to be MPT-3 Type 1. Furthermore, if the remaining value of the syntax of the acquired information regarding the MPT structure of the target block is equal to 11, the target block's separation type can be determined to be MPT-3 Type 2. If the proportion (or ratio) of blocks having an MPT-3 Type 0 separation type within the input image is higher than the proportion (or ratio) of blocks having an MPT-4 separation type, binarization method 3 can be used. Consequently, encoding efficiency can be improved.

[0138] Meanwhile, a binarization method of the information indicating the separation type of the target block according to the MPT structure may be adaptively selected in units of a sequence parameter set (SPS), a picture parameter set (PPS), a slice, or a block, etc., and transmission may be performed in units of an SPS, a PPS, a slice, or a block, etc. Alternatively, a binarization method of the information indicating the separation type of the target block according to the MPT structure may be adaptively derived in units of a slice or a block.

[0139] Alternatively, as another example, it may be determined first whether to perform separation on the target block according to the MPT. In this case, a binarized character string indicating MPT separation (or segmentation) information may be derived as shown in the following table.

[0140] [Table 3]

[0141] Binarization method 1 Binarization method 2 Binarization method 3 No separation 0 0 0 MPT-2(5(a),5(b)) 1 0 1 00 1 0 MPT-3 Type 0 (5(c), 5(f)) 1 10 0 1 10 1 10 MPT-3 Type 1 (5(d), 5(g)) 1 10 10 1 11 0 1 11 10 MPT-3 Type 2 (5(e), 5(h)) 1 10 11 1 11 1 1 11 11 MPT-4(5(i),5(j)) 1 11 1 01 1 11 0

[0142] Here, MPT-2 indicates a separation type according to which a block is separated (or partitioned) into 2 sub-blocks, as in Figure 5 MPT-3 type 0 indicates a separation type according to which a block is separated (or partitioned) into 3 sub-blocks, such as Figure 5As shown and described in (c) and (f) of FIG, and here, MPT-3 type 0 indicates that the central sub-block has a larger size. MPT-3 type 1 indicates a separation type according to which the block is separated (or divided) into 3 sub-blocks, as shown above Figure 5 As shown and described in (d) and (g) of FIG, and here, MPT-3 type 1 indicates that the right sub-block or the lower sub-block has a larger size. MPT-3 type 2 indicates a separation type according to which the block is separated (or divided) into 3 sub-blocks, as shown above in Figure 5 As shown and described in (e) and (h) of FIG. 1 , and here, MPT-3 type 2 indicates that the left sub-block or the upper sub-block has a larger size. And, MPT-4 indicates a separation type according to which a block is separated into 4 sub-blocks, as shown above in FIG. Figure 5 As shown and described in (i) and (j).

[0143] Referring to the binarization method 1 of Table 3, it may first be determined whether to perform separation (or segmentation) according to MPT. More specifically, when the first value of the syntax of the acquired information on the MPT structure of the target block is equal to 0, the target block may not be separated according to MPT.

[0144] In the case of separating the target block according to the MPT, that is, in the case where the first value of the syntax of the information on the MPT structure of the target block is not equal to 0, it can be determined based on the second value of the syntax of the information on the MPT structure of the target block whether the separation type corresponds to MPT-2. More specifically, in the case where the second value of the syntax of the acquired information on the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-2.

[0145] If the target block's separation type does not correspond to MPT-2, that is, if the second value of the syntax of the target block's MPT structure information is not equal to 0, MPT-3 and MPT-4 can be distinguished from each other based on the third value of the syntax of the target block's MPT structure information. More specifically, if the third value of the syntax of the target block's MPT structure information is equal to 0, the target block's separation type can be determined to be MPT-3. Furthermore, if the third value of the syntax of the target block's MPT structure information is equal to 1, the target block's separation type can be determined to be MPT-4. The syntax can also indicate the aforementioned MPT_split_type. More specifically, according to binarization method 1, if MPT_split_type is equal to 10, the target block's separation type can be derived as MPT-2. If MPT_split_type is equal to 110, the target block's separation type can be derived as MPT-3. Furthermore, if MPT_split_type is equal to 111, the target block's separation type can be derived as MPT-4.

[0146] In addition, the target block's separation type is determined to be MPT-3. That is, when MPT_split_type is equal to 110, the target block's MPT_sub_split_type may be additionally transmitted. Based on MPT_sub_split_type, the target block's separation type may be determined to be MPT-3 type 0, MPT-3 type 1, or MPT-3 type 2. According to binarization method 1, when MPT_sub_split_type is equal to 0, the target block's separation type may be derived as MPT-3 type 0. When MPT_sub_split_type is equal to 10, the target block's separation type may be derived as MPT-3 type 1. And, when MPT_sub_split_type is equal to 11, the target block's separation type may be derived as MPT-3 type 2. Therefore, according to binarization method 1, when the target block's separation type corresponds to MPT-3 type 0, the binarized string indicating the syntax of the target block's MPT structure may be indicated as 1100. When the separation type of the target block corresponds to MPT-3 type 1, the binary string indicating the syntax of the MPT structure of the target block can be indicated as 11010. When the separation type of the target block corresponds to MPT-3 type 2, the binary string indicating the syntax of the MPT structure of the target block can be expressed as 11011. When the ratio (or rate) of blocks with MPT-2 separation type and the ratio of blocks with MPT-4 separation type are both high within the input image, binarization method 1 can be used. Therefore, encoding efficiency can be improved.

[0147] In addition, referring to the binarization method 2 of Table 3, it may be determined whether to perform separation (or segmentation) according to MPT. More specifically, when the first value of the syntax of the acquired information on the MPT structure of the target block is equal to 0, the target block may not be separated according to MPT.

[0148] When the target block is separated according to the MPT, that is, when the first value of the syntax of the information regarding the MPT structure of the target block is not equal to 0, it is first possible to determine whether the separation type corresponds to MPT-2 or MPT-4 based on the second value of the syntax of the information regarding the MPT structure of the target block. More specifically, when the second value of the syntax of the acquired information regarding the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-2 or MPT-4. Furthermore, when the second value of the syntax of the acquired information regarding the MPT structure of the target block is not equal to 0, the separation type of the target block can be determined to be MPT-3. More specifically, when the separation type of the target block is determined to be MPT-2 or MPT-4, that is, when the second value of the syntax of the information regarding the MPT structure of the target block is equal to 0, MPT-2 and MPT-4 can be distinguished from each other based on the third value of the syntax of the information regarding the MPT structure of the target block. More specifically, when the third value of the syntax of the information regarding the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-2. Furthermore, when the third value of the syntax of the information regarding the MPT structure of the target block is equal to 1, the separation type of the target block can be determined to be MPT-4. At the same time, the syntax can indicate the aforementioned MPT_split_type. More specifically, according to binarization method 2, when MPT_split_type is equal to 100, the separation type of the target block can be derived as MPT-2. When MPT_split_type is equal to 11, the separation type of the target block can be derived as MPT-3. Furthermore, when MPT_split_type is equal to 101, the separation type of the target block can be derived as MPT-4.

[0149] In addition, when the separation type of the target block is determined to be MPT-3, that is, when MPT_split_type is equal to 11, MPT_sub_split_type for the target block may be additionally transmitted. Based on MPT_sub_split_type, the separation type of the target block may be determined to be MPT-3 type 0, MPT-3 type 1, or MPT-3 type 2. According to binarization method 2, when MPT_sub_split_type is equal to 0, the separation type of the target block may be derived as MPT-3 type 0. When MPT_sub_split_type is equal to 10, the separation type of the target block may be derived as MPT-3 type 1. And, when MPT_sub_split_type is equal to 11, the separation type of the target block may be derived as MPT-3 type 2. Therefore, according to binarization method 2, when the separation type of the target block corresponds to MPT-3 type 0, the binarized string indicating the syntax of the MPT structure of the target block may be indicated as 110. When the separation type of the target block corresponds to MPT-3 type 1, the binary string indicating the syntax of the MPT structure of the target block may be indicated as 1110. When the separation type of the target block corresponds to MPT-3 type 2, the binary string indicating the syntax of the MPT structure of the target block may be indicated as 1111. When the ratio (or rate) of blocks having the MPT-3 separation type within the input image is greater than the ratio of blocks having the MPT-2 separation type, binarization method 2 may be used. Therefore, encoding efficiency can be improved.

[0150] Furthermore, referring to the binarization method 3 of Table 3, it may be first determined whether to perform separation of the target block according to the MPT. More specifically, when the first value of the syntax of the acquired information on the MPT structure of the target block is equal to 0, the target block may not be separated according to the MPT.

[0151] When the target block is separated according to the MPT, that is, when the first value of the syntax of the acquired information about the MPT structure of the target block is not equal to 0, it can be determined whether the separation type corresponds to MPT-2 based on the second value of the syntax of the information about the MPT structure of the target block. For example, when the second value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-2.

[0152] In a case where the separation type of the target block does not correspond to MPT-2, that is, in a case where the second value of the syntax of the acquired information about the MPT structure of the target block is not equal to 0, based on the third value of the syntax of the acquired information about the MPT structure of the target block, it can be determined whether the separation type of the target block corresponds to MPT-3 type 0. For example, in a case where the third value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-3 type 0.

[0153] If the separation type of the target block does not correspond to MPT-3 type 0, that is, if the third value of the syntax of the information about the MPT structure of the target block is not equal to 0, it can be determined whether the separation type of the target block corresponds to MPT-4 based on the fourth value of the syntax of the information about the MPT structure of the target block. For example, if the fourth value of the syntax of the information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-4.

[0154] If the separation type of the target block does not correspond to MPT-4, that is, if the fourth value of the syntax of the acquired information regarding the MPT structure of the target block is not equal to 0, it is possible to determine whether the separation type of the target block corresponds to MPT-3 Type 1 or MPT-3 Type 2 based on the remaining value of the syntax of the information regarding the MPT structure of the target block. For example, if the remaining value of the syntax of the acquired information regarding the MPT structure of the target block is equal to 10, the separation type of the target block can be determined to be MPT-3 Type 1. Furthermore, if the remaining value of the syntax of the acquired information regarding the MPT structure of the target block is equal to 11, the separation type of the target block can be determined to be MPT-3 Type 2. If the proportion (or ratio) of blocks having an MPT-3 Type 0 separation type within the input image is higher than the proportion of blocks having an MPT-4 separation type, binarization method 3 can be used. Consequently, encoding efficiency can be improved.

[0155] Meanwhile, a binarization method of information indicating the separation type of a target block according to the MPT structure may be adaptively selected in units of a sequence parameter set (SPS), a picture parameter set (PPS), a slice, or a block, and transmission may be performed in units of an SPS, a PPS, a slice, or a block, etc. Alternatively, a binarization method of information indicating the separation type of a target block according to the MPT structure may be adaptively derived in units of a slice or a block.

[0156] Alternatively, among the above separation types, an MPT structure may be applied that uses only MPT-2, MPT-3 type 0, and MPT-4 and does not include MPT-3 type 1 and MPT-3 type 2. In this case, a binary string of MPT_slice_type and MPT_sub_slice_type of the separation type may be derived as shown in the following table.

[0157] [Table 4]

[0158] Binarization method 4 Binarization method 5 Binarization method 6 MPT-2(5(a),5(b)) 0 10 10 MPT-3 Type 0 (5(c), 5(f)) 10 0 11 MPT-4(5(i),5(j)) 11 11 0

[0159] Here, MPT-2 indicates the separation type according to which a block is separated (or divided) into 2 sub-blocks, as shown above in Figure 5 MPT-3 type 0 indicates a separation type, according to which a block is separated (or partitioned) into 3 sub-blocks, such as Figure 5 As shown and described in (c) and (f) of FIG. 1 , and here, MPT-3 type 0 indicates that the central sub-block has a larger size. And, MPT-4 indicates a separation type according to which a block is separated into 4 sub-blocks, as shown in the above Figure 5 As shown and described in (i) and (j).

[0160] Referring to the binarization method 4 of Table 4, it can be first determined whether the separation type of the target block corresponds to MPT-2. More specifically, when the first value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-2.

[0161] If the target block's separation type does not correspond to MPT-2, that is, if the first value of the syntax of the information regarding the target block's MPT structure is not equal to 0, MPT-3 Type 0 and MPT-4 can be distinguished from each other based on the second value of the syntax of the information regarding the target block's MPT structure. More specifically, if the second value of the syntax of the information regarding the target block's MPT structure is equal to 0, the target block's separation type can be determined to be MPT-3 Type 0. Furthermore, if the second value of the syntax of the information regarding the target block's MPT structure is equal to 1, the target block's separation type can be determined to be MPT-4. The syntax can also indicate the aforementioned MPT_split_type. More specifically, according to binarization method 4, if MPT_split_type is equal to 0, the target block's separation type can be derived as MPT-2. If MPT_split_type is equal to 10, the target block's separation type can be derived as MPT-3 Type 0. Furthermore, if MPT_split_type is equal to 11, the target block's separation type can be derived as MPT-4. In the case where the ratio (or rate) of blocks having separation type MPT-2 within the input image is high, the binarization method 4 can be used. Therefore, the encoding efficiency can be improved.

[0162] In addition, referring to the binarization method 5 of Table 4, it can be first determined whether the separation type of the target block corresponds to MPT-3 type 0. More specifically, in a case where the first value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-3 type 0.

[0163] If the target block's separation type does not correspond to MPT-3 Type 0, that is, if the first value of the syntax for the target block's MPT structure information is not equal to 0, MPT-2 and MPT-4 can be distinguished from each other based on the second value of the syntax for the target block's MPT structure information. More specifically, if the second value of the syntax for the target block's MPT structure information is equal to 0, the target block's separation type can be determined to be MPT-2. Furthermore, if the second value of the syntax for the target block's MPT structure information is equal to 1, the target block's separation type can be determined to be MPT-4. The syntax can also indicate the aforementioned MPT_split_type. More specifically, according to binarization method 5, if MPT_split_type is equal to 0, the target block's separation type can be derived as MPT-3 Type 0. If MPT_split_type is equal to 10, the target block's separation type can be derived as MPT-2. Furthermore, if MPT_split_type is equal to 11, the target block's separation type can be derived as MPT-4. In the case where the ratio (or rate) of blocks having the separation type of MPT-3 type 0 within the input image is high, the binarization method 5 can be used. Therefore, the encoding efficiency can be improved.

[0164] In addition, referring to the binarization method 6 of Table 4, it can be first determined whether the separation type of the target block corresponds to MPT-4. More specifically, when the first value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-4.

[0165] If the target block's separation type does not correspond to MPT-4, that is, if the first value of the syntax for the target block's MPT structure information is not equal to 0, MPT-2 and MPT-3 Type 0 can be distinguished from each other based on the second value of the syntax for the target block's MPT structure information. More specifically, if the second value of the syntax for the target block's MPT structure information is equal to 0, the target block's separation type can be determined to be MPT-2. Furthermore, if the second value of the syntax for the target block's MPT structure information is equal to 1, the target block's separation type can be determined to be MPT-3 Type 0. The syntax can also indicate the aforementioned MPT_split_type. More specifically, according to binarization method 6, if MPT_split_type is equal to 0, the target block's separation type can be derived as MPT-4. If MPT_split_type is equal to 10, the target block's separation type can be derived as MPT-2. Furthermore, if MPT_split_type is equal to 11, the target block's separation type can be derived as MPT-3 Type 0. In the case where the ratio (or rate) of blocks having separation type MPT-4 within the input image is high, the binarization method 6 can be used. Therefore, the encoding efficiency can be improved.

[0166] Meanwhile, a binarization method of information indicating the separation type of a target block according to the MPT structure may be adaptively selected in units of a sequence parameter set (SPS), a picture parameter set (PPS), a slice, or a block, and transmission may be performed in units of an SPS, a PPS, a slice, or a block, etc. Alternatively, a binarization method of information indicating the separation type of a target block according to the MPT structure may be adaptively derived in units of a slice or a block.

[0167] Alternatively, as another example, binarized character strings of MPT_slice_type and MPT_sub_slice_type for the separation type may be derived as shown in the following table.

[0168] [Table 5]

[0169] Binarization method 4 Binarization method 5 Binarization method 6 No separation 0 0 0 MPT-2(5(a),5(b)) 1 0 1 10 1 10 MPT-3 Type 0 (5(c), 5(f)) 1 10 1 0 1 11 MPT-4(5(i),5(j)) 111 111 10

[0170] Here, MPT-2 indicates the separation type according to which a block is separated (or divided) into 2 sub-blocks, as in the above Figure 5 MPT-3 type 0 indicates a separation type, according to which the block is separated (or split) into 3 sub-blocks, as shown and described in (a) and (b) above. Figure 5 As shown in (c) and (f), and here, MPT-3 type 0 indicates that the central sub-block has a larger size. And, MPT-4 indicates a separation type that separates the block into 4 sub-blocks, as shown in the above Figure 5 As shown and described in (i) and (j).

[0171] Referring to the binarization method 4 of Table 5, it may be first determined whether to perform separation (or segmentation) according to MPT. More specifically, when the first value of the syntax of the acquired information on the MPT structure of the target block is equal to 0, the target block may not be separated according to MPT.

[0172] In the case of separating the target block according to the MPT, that is, in the case where the first value of the syntax of the acquired information about the MPT structure of the target block is not equal to 0, it can be first determined whether the separation type corresponds to MPT-2 based on the second value of the syntax of the information about the MPT structure of the target block. More specifically, in the case where the second value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-2.

[0173] If the target block's separation type does not correspond to MPT-2, that is, if the second value of the syntax of the target block's MPT structure information is not equal to 0, MPT-3 Type 0 and MPT-4 can be distinguished from each other based on the third value of the syntax of the target block's MPT structure information. More specifically, if the third value of the syntax of the target block's MPT structure information is equal to 0, the target block's separation type can be determined to be MPT-3 Type 0. Furthermore, if the third value of the syntax of the target block's MPT structure information is equal to 1, the target block's separation type can be determined to be MPT-4. Furthermore, the syntax can indicate the aforementioned MPT_split_type. More specifically, according to binarization method 4, if MPT_split_type is equal to 10, the target block's separation type can be derived as MPT-2. If MPT_split_type is equal to 110, the target block's separation type can be derived as MPT-3 Type 0. Furthermore, if MPT_split_type is equal to 111, the target block's separation type can be derived as MPT-4. In the case where the ratio (or rate) of blocks having separation type MPT-2 within the input image is high, the binarization method 4 can be used. Therefore, the encoding efficiency can be improved.

[0174] Referring to the binarization method 5 of Table 5, it may be first determined whether to perform separation (or segmentation) according to MPT. More specifically, when the first value of the syntax of the acquired information on the MPT structure of the target block is equal to 0, the target block may not be separated according to MPT.

[0175] In the case where the target block is separated according to the MPT, that is, in the case where the first value of the syntax of the information about the MPT structure of the target block is not equal to 0, based on the second value of the syntax of the acquired information about the MPT structure of the target block, it can be determined whether the separation type of the target block corresponds to MPT-3 Type 0. More specifically, in the case where the second value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-3 Type 0.

[0176] If the target block's separation type does not correspond to MPT-3 Type 0, that is, if the second value of the syntax of the target block's MPT structure information is not equal to 0, MPT-2 and MPT-4 can be distinguished from each other based on the third value of the syntax of the target block's MPT structure information. More specifically, if the third value of the syntax of the target block's MPT structure information is equal to 0, the target block's separation type can be determined to be MPT-2. Furthermore, if the third value of the syntax of the target block's MPT structure information is equal to 1, the target block's separation type can be determined to be MPT-4. The syntax can also indicate the aforementioned MPT_split_type. More specifically, according to binarization method 5, if MPT_split_type is equal to 10, the target block's separation type can be derived as MPT-3 Type 0. If MPT_split_type is equal to 110, the target block's separation type can be derived as MPT-2. Furthermore, if MPT_split_type is equal to 111, the target block's separation type can be derived as MPT-4. In the case where the ratio (or rate) of blocks having the separation type of MPT-3 type 0 within the input image is high, the binarization method 5 can be used. Therefore, the encoding efficiency can be improved.

[0177] Efficiency can be enhanced.

[0178] Referring to the binarization method 6 of Table 5, it may be first determined whether to perform separation (or segmentation) according to MPT. More specifically, when the first value of the syntax of the acquired information on the MPT structure of the target block is equal to 0, the target block may not be separated according to MPT.

[0179] When the target block is separated according to the MPT, that is, when the first value of the syntax of the information on the MPT structure of the target block is not equal to 0, based on the second value of the syntax of the acquired information on the MPT structure of the target block, it can be determined whether the separation type of the target block corresponds to MPT-4. More specifically, when the second value of the syntax of the acquired information on the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-4.

[0180] If the target block's separation type does not correspond to MPT-4, that is, if the second value of the syntax of the acquired information regarding the MPT structure of the target block is not equal to 0, MPT-2 and MPT-3 Type 0 can be distinguished from each other using the third value of the syntax based on the information regarding the MPT structure of the target block. More specifically, if the third value of the syntax of the acquired information regarding the MPT structure of the target block is equal to 0, the target block's separation type can be determined to be MPT-2. Furthermore, if the third value of the syntax of the acquired information regarding the MPT structure of the target block is equal to 1, the target block's separation type can be determined to be MPT-3 Type 0. At the same time, the syntax can indicate the aforementioned MPT_split_type. More specifically, according to binarization method 6, if MPT_split_type is equal to 10, the target block's separation type can be derived as MPT-4. If MPT_split_type is equal to 110, the target block's separation type can be derived as MPT-2. Furthermore, when MPT_split_type is equal to 111, the split type of the target block can be derived as MPT-3 type 0. When the ratio (or rate) of blocks having the split type MPT-4 within the input image is high, binarization method 6 can be used. Therefore, encoding efficiency can be improved.

[0181] Meanwhile, a binarization method of information indicating the separation type of a target block according to the MPT structure may be adaptively selected in units of a sequence parameter set (SPS), a picture parameter set (PPS), a slice, or a block, and transmission may be performed in units of an SPS, a PPS, a slice, or a block, etc. Alternatively, a binarization method of information indicating the separation type of a target block according to the MPT structure may be adaptively derived in units of a slice or a block.

[0182] Alternatively, among the above-mentioned separation types, an MPT structure using only MPT-2 and MPT-3 type 0 may be applied. In this case, a binarized character string of MPT_slice_type for the separation type may be derived as shown in the following table.

[0183] [Table 6]

[0184] Binarization method 7 No separation 0 MPT-2(3(a),3(b)) 1 0 MPT-3 Type 0 (3(c), 3(f)) 1 1

[0185] Here, MPT-2 indicates a separation type according to which a block is separated (or divided) into 2 sub-blocks, as shown above Figure 5 And, MPT-3 type 0 indicates a separation type, according to which the block is separated (or split) into 3 sub-blocks, as shown and described in (a) and (b) above. Figure 5As shown and described in (c) and (f) of , and herein, MPT-3 type 0 indicates a separation type in which a center sub-block corresponds to a sub-block having a larger size.

[0186] Referring to the binarization method 7 of Table 6, it can be first determined whether separation (or segmentation) is performed according to MPT. More specifically, when the first value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block indicates that MPT separation (or segmentation) is not performed.

[0187] In a case where the separation type of the target block does not correspond to MPT separation, that is, in a case where the first value of the syntax of the information about the MPT structure of the target block is not equal to 0, based on the second value of the syntax of the acquired information about the MPT structure of the target block, it can be first determined whether the separation type of the target block corresponds to MPT-2 or MPT-3 type 0. More specifically, in a case where the second value of the syntax of the acquired information about the MPT structure of the target block is equal to 0, the separation type of the target block can be determined to be MPT-2.

[0188] If the target block separation type does not correspond to MPT-2, that is, if the second value of the syntax for acquiring information about the MPT structure of the target block is not equal to 0, the separation target block type may be determined to be MPT-3 type 0. Meanwhile, the syntax may indicate the above-mentioned MPT_split_type.

[0189] More specifically, according to the binarization method 7 of Table 6, when MPT_split_type is equal to 10, the separation type of the target block can be derived as MPT-2. When MPT_split_type is equal to 11, the separation type of the target block can be derived as MPT-3 type 0.

[0190] Figure 8 is an overall diagram of a video encoding method performed by an encoding device according to the present invention. Figure 8 The method shown in Figure 1 More specifically, for example, Figure 8 Steps S800 to S810 may be performed by a picture divider of the encoding device, step S820 may be performed by a predictor of the encoding device, and step S830 may be performed by an entropy encoder of the encoding device.

[0191] The encoding device separates (or divides) the first target block into first sub-blocks (S800). The encoding device may separate the first target block into the first sub-blocks according to a quadtree (QT) structure. More specifically, for example, the encoding device may separate the first target block into four first sub-blocks. The first sub-blocks may each have a size corresponding to half the height and half the width of the target block. At the same time, the encoding device may generate a quadtree (QT) separation flag corresponding to the first target block. The QT separation flag may indicate whether to separate the target block into sub-blocks having a size corresponding to half the height and half the width of the target block.

[0192] The encoding device separates the second target block, which is one of the first sub-blocks, into second sub-blocks (S810). The second target block may not be separated according to the QT structure. In the case where the second target block is not separated according to the QT structure, the encoding device may separate the second target block into second sub-blocks. The second sub-blocks may correspond to non-square blocks.

[0193] The second target block can be separated into second sub-blocks according to a multi-partition tree (MPT) structure. In this case, the second target block can be separated into second sub-blocks corresponding to a plurality of non-square blocks of different shapes. The second target block can be separated in a vertical direction or in a horizontal direction.

[0194] For example, according to the MPT separation structure, the second target block can be separated into 2, 3, or 4 second sub-blocks in the vertical direction or horizontal direction. More specifically, when the size of the second target block corresponds to 2N×2N, the second target block can be separated into 2 N×2N second sub-blocks, 2 2N×N second sub-blocks, 1 N×2N second sub-block and 2 N / 2×2N second sub-blocks, 1 2N×N second sub-block and 2 2N×N / 2 second sub-blocks, 4 N / 2×2N second sub-blocks, or 4 2N×N / 2 second sub-blocks. Here, when the second target block is separated into 1 N×2N second sub-block and 2 N / 2×2N second sub-blocks, the N×2N second sub-block can be derived as a left second sub-block, a center second sub-block, or a right second sub-block. In addition, when the second target block is separated into one second sub-block of 2N×N size and two second sub-blocks of 2N×N / 2 size, the second sub-block of 2N×N size can be derived as an upper second sub-block, a center second sub-block, or a lower second sub-block. At the same time, the encoding device can generate MPT separation information indicating the MPT separation type of the second target block. The number of bits in the binary string indicating the MPT separation information can vary based on the separation type of the second target block. For example, the binary string of the MPT separation information indicating the separation type most frequently applied to the block among the separation types within the input image (or target picture) can be derived as a binary string with the smallest number of bits among the number of bits in the binary string indicating the separation type. As shown in Table 2 or Table 3 above, the binary string of the MPT separation information derived based on the separation type can be derived. For example, when the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binary string of the MPT separation information can be equal to 0. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binary string of the MPT separation information may be equal to 100, where the second sub-block of size N×2N or 2N×N corresponds to the left or upper second sub-block. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binary string of the MPT separation information may be equal to 1010, where the second sub-block of size N×2N or 2N×N corresponds to the center second sub-block. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binary string of the MPT separation information may be equal to 1011, where the second sub-block of size N×2N or 2N×N corresponds to the right or lower second sub-block. When the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binary string of the MPT separation information may be equal to 11.Alternatively, when the second target block is separated into two second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 00. When the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 10, where the second sub-block of size N×2N or 2N×N corresponds to the left or upper second sub-block. When the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 110, where the second sub-block of size N×2N or 2N×N corresponds to the center second sub-block. When the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 111, where the second sub-block of size N×2N or 2N×N corresponds to the right or lower second sub-block. When the second target block is separated into four second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 01. Alternatively, if the second target block is separated into two second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 0. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 10, where the N×2N or 2N×N second sub-block corresponds to the left or upper second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1110, where the N×2N or 2N×N second sub-block corresponds to the center second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1111, where the N×2N or 2N×N second sub-block corresponds to the right or lower second sub-block. If the second target block is separated into four second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 110. Alternatively, when the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. When the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 1100, where the second sub-block of N×2N size or 2N×N size corresponds to the left or upper second sub-block.If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 11010, where the second sub-block of size N×2N or 2N×N corresponds to the center second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 11011, where the second sub-block of size N×2N or 2N×N corresponds to the right or bottom second sub-block. If the second target block is separated into four second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 111. Alternatively, if the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. If the second target block is separated into two second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 100. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 110, where the N×2N or 2N×N second sub-block corresponds to the left or upper second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1110, where the N×2N or 2N×N second sub-block corresponds to the center second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1111, where the N×2N or 2N×N second sub-block corresponds to the right or lower second sub-block. If the second target block is separated into four second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 101. Alternatively, if the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. In the case where the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10. In the case where the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 110, where the second sub-block of N×2N size or 2N×N size corresponds to the left or upper second sub-block. In the case where the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 11110, where the second sub-block of N×2N size or 2N×N size corresponds to the center second sub-block. In the case where the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 11111, where the second sub-block of N×2N size or 2N×N size corresponds to the right or lower second sub-block.In a case where the second target block is separated into four second sub-blocks in a vertical direction or a horizontal direction, the binarized character string of the MPT separation information may be equal to 1110.

[0195] Alternatively, as another example, according to the MPT separation structure, the second target block can be separated into 2, 3, or 4 second sub-blocks along the vertical direction or the horizontal direction. More specifically, when the size of the second target block corresponds to 2N×2N, the second target block can be separated into 2 N×2N second sub-blocks, 2 2N×N second sub-blocks, 1 N×2N second sub-block and 2 N / 2×2N second sub-blocks, 1 2N×N second sub-block and 2 2N×N / 2 second sub-blocks, 4 N / 2×2N second sub-blocks, or 4 2N×N / 2 second sub-blocks. Here, when the second target block is separated into 1 N×2N second sub-block and 2 N / 2×2N second sub-blocks, the N×2N second sub-block can be derived as the center second sub-block. Furthermore, when the second target block is separated into one 2N×N second sub-block and two 2N×N / 2 second sub-blocks, the 2N×N second sub-block can be derived as the center second sub-block. Simultaneously, the encoding device can generate MPT separation information indicating the MPT separation type of the second target block. The number of bits indicating the MPT separation information in the binary string can vary based on the separation type of the second target block. In this case, for example, as shown in Table 4 or Table 5 above, a binary string of MPT separation information derived based on the separation type can be derived. For example, when the second target block is separated into two second sub-blocks vertically or horizontally, the binary string of MPT separation information can be equal to 0. When the second target block is separated into three second sub-blocks vertically or horizontally, the binary string of MPT separation information can be equal to 10. When the second target block is separated into four second sub-blocks vertically or horizontally, the binary string of MPT separation information can be equal to 11. Alternatively, when the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 0. When the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 11. Alternatively, when the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 11. When the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 0.Alternatively, if the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. If the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10. If the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 110. If the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 111. Alternatively, if the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. If the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 110. If the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10. In the case where the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 111. Alternatively, in the case where the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. In the case where the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 110. In the case where the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 111. In the case where the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10.

[0196] Alternatively, as another example, based on the MPT separation structure, the second target block can be separated into two or three second sub-blocks in the vertical or horizontal direction. More specifically, based on the MPT separation information, the second target block can be separated into two or three second sub-blocks in the vertical or horizontal direction. Here, if the size of the second target block corresponds to 2N×2N and the second target block is separated into two second sub-blocks in the vertical direction, the second target block can be separated into second sub-blocks of N×2N size. Furthermore, if the size of the second target block corresponds to 2N×2N and the second target block is separated into two second sub-blocks in the horizontal direction, the second target block can be separated into second sub-blocks of 2N×N size. Furthermore, if the size of the second target block corresponds to 2N×2N and the second target block is separated into three second sub-blocks in the vertical direction, the second target block can be separated into a left second sub-block of N / 2×2N size, a center second sub-block of N×2N size, and a right second sub-block of N / 2×2N size. Furthermore, if the size of the second target block corresponds to 2N×2N and the second target block is separated into three second sub-blocks in the horizontal direction, the second target block may be separated into an upper second sub-block of 2N×N / 2, a center second sub-block of 2N×N, and a lower second sub-block of 2N×N / 2. The encoding device may also generate MPT separation information indicating the MPT separation type of the second target block. The number of bits indicating the MPT separation information in the binarized string may vary depending on the separation type of the second target block. In this case, for example, the binarized string of the MPT separation information derived based on the separation type may be derived as shown in Table 6 above. For example, if the second target block is separated into two second sub-blocks in the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 10. Furthermore, if the second target block is separated into three second sub-blocks in the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 11. Furthermore, if the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0.

[0197] The encoding device decodes the second sub-block (S820). The encoding device may perform processes such as transformation, intra / inter prediction, etc. on the second sub-block and may generate reconstructed samples corresponding to the second sub-block. And, then, the encoding device may generate a reconstructed picture based on the generated reconstructed samples.

[0198] The encoding device generates first separation information for the first target block and generates MPT separation information for the second target block, and encodes and outputs the generated information (S830). The encoding device can encode the first separation information and the MPT separation information corresponding to the second target block, and can output the encoded information through a bit stream, and the bit stream can be stored in a recording medium (non-transitory computer-readable medium). The encoding device can generate first separation information corresponding to the first target block. The first separation information may include a quadtree (QT) separation flag corresponding to the first target block. The QT separation flag may indicate whether the target block is separated into sub-blocks having a size corresponding to half the height and half the width of the target block. In addition, the encoding device can generate second separation information corresponding to the second target block, and the second separation information may include a QT separation flag corresponding to the second target block.

[0199] In addition, the encoding device may generate MPT separation information corresponding to the second target block. Meanwhile, the MPT separation information may be generated when the second target block is separated based on the QT separation information corresponding to the second target block. More specifically, the MPT separation information may be generated when the second target block is not separated according to the QT structure.

[0200] For example, the MPT separation information may include multi-partition tree (MPT) separation type information and MPT separation direction information corresponding to the second target block. The MPT separation type information may indicate the number of second sub-blocks into which the second target block is separated. Furthermore, the MPT separation direction information may indicate the separation direction of the second target block. More specifically, if the value of the MPT separation type information is 0, the MPT separation type information may indicate that the second target block is not separated. If the value of the MPT separation type information is 1, the MPT separation type information may indicate that the number of second sub-blocks is 2. If the value of the MPT separation type information is 2, the MPT separation type information may indicate that the number of second sub-blocks is 3. Furthermore, if the value of the MPT separation type information is 3, the MPT separation type information may indicate that the number of second sub-blocks is 4. Furthermore, if the value of the MPT separation direction information is 0, this may indicate that the separation direction of the second target block corresponds to the horizontal direction. Furthermore, if the value of the MPT separation direction information is 1, this may indicate that the separation direction of the second target block corresponds to the vertical direction.

[0201] Furthermore, when the number of second sub-blocks indicated by the MPT separation type information is 3 and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the MPT separation information may include MPT sub-separation type information corresponding to the second target block. When the number of second sub-blocks indicated by the MPT separation type information is 3 and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the MPT separation information may indicate whether the separation type of the second target block is type 0, type 1, or type 2. More specifically, when the value of the MPT sub-separation type information is 0, the MPT sub-separation type information may indicate type 0. When the value of the MPT sub-separation type information is 1, the MPT sub-separation type information may indicate type 1. When the value of the MPT sub-separation type information is 2, the MPT sub-separation type information may indicate type 2. When the MPT sub-separation type information indicates type 0, the left second sub-block among the second sub-blocks may be derived as an N×2N second sub-block. When the MPT sub-separation type information indicates type 1, the center second sub-block among the second sub-blocks may be derived as an N×2N second sub-block. In the case where the MPT sub-separation type information indicates type 2, in the second sub-block, the second sub-block on the right may be derived as a second sub-block of N×2N size.

[0202] Furthermore, when the number of second sub-blocks indicated by the MPT separation type information is 3 and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the MPT separation information may include MPT sub-separation type information corresponding to the second target block. When the number of second sub-blocks indicated by the MPT separation type information is 3 and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the MPT separation information may indicate whether the separation type of the second target block is Type 0, Type 1, or Type 2. More specifically, when the value of the MPT sub-separation type information is 0, the MPT sub-separation type information may indicate Type 0. When the value of the MPT sub-separation type information is 1, the MPT sub-separation type information may indicate Type 1. When the value of the MPT sub-separation type information is 2, the MPT sub-separation type information may indicate Type 2. When the MPT sub-separation type information indicates Type 0, the upper second sub-block may be derived as a 2N×N second sub-block among the second sub-blocks. When the MPT sub-separation type information indicates Type 1, the center second sub-block may be derived as a 2N×N second sub-block among the second sub-blocks. In case that the MPT sub-separation type information indicates type 2, among the second sub-blocks, the lower second sub-block may be derived as a second sub-block of 2N×N size.

[0203] In addition, as another example, the MPT separation information may include a multi-partition tree (MPT) separation flag for the second target block. The MPT separation flag may indicate whether the second target block is separated into second sub-blocks corresponding to non-square blocks. More specifically, when the value of the MPT separation flag is 0, the MPT separation flag may indicate that the second target block is not separated. And, when the value of the MPT separation flag is 1, the MPT separation flag may indicate that the second target block is separated into second sub-blocks according to the MPT structure. More specifically, when the value of the MPT separation flag is 1, the MPT separation flag may indicate that the second target block is separated into second sub-blocks corresponding to non-square blocks.

[0204] In addition, when the value of the MPT separation flag is 1, the MPT separation information may include MPT separation direction information and MPT separation type information for the second target block. The MPT separation direction information may indicate the separation direction of the second target block. Furthermore, the MPT separation type information may indicate the number of second sub-blocks into which the second target block is separated. More specifically, when the value of the MPT separation direction information is 0, this may indicate that the separation direction of the second target block corresponds to the horizontal direction. Furthermore, when the value of the MPT separation direction information is 1, this may indicate that the separation direction of the second target block corresponds to the vertical direction. Furthermore, when the value of the MPT separation type information is 0, the MPT separation type information may indicate that the number of second sub-blocks is 2. When the value of the MPT separation type information is 1, the MPT separation type information may indicate that the number of second sub-blocks is 3. Furthermore, when the value of the MPT separation type information is 2, the MPT separation type information may indicate that the number of second sub-blocks is 4.

[0205] Furthermore, when the number of second sub-blocks indicated by the MPT separation type information is 3 and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the MPT separation information may include MPT sub-separation type information corresponding to the second target block. When the number of second sub-blocks indicated by the MPT separation type information is 3 and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the MPT separation information may indicate whether the separation type of the second target block is type 0, type 1, or type 2. More specifically, when the value of the MPT sub-separation type information is 0, the MPT sub-separation type information may indicate type 0. When the value of the MPT sub-separation type information is 1, the MPT sub-separation type information may indicate type 1. When the value of the MPT sub-separation type information is 2, the MPT sub-separation type information may indicate type 2. When the MPT sub-separation type information indicates type 0, the left second sub-block may be derived as an N×2N second sub-block among the second sub-blocks. When the MPT sub-separation type information indicates type 1, the center second sub-block may be derived as an N×2N second sub-block among the second sub-blocks. In the case where the MPT sub-separation type information indicates type 2, in the second sub-block, the second sub-block on the right may be derived as a second sub-block of N×2N size.

[0206] Furthermore, when the number of second sub-blocks indicated by the MPT separation type information is 3 and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the MPT separation information may include MPT sub-separation type information corresponding to the second target block. When the number of second sub-blocks indicated by the MPT separation type information is 3 and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the MPT separation information may indicate whether the separation type of the second target block is Type 0, Type 1, or Type 2. More specifically, when the value of the MPT sub-separation type information is 0, the MPT sub-separation type information may indicate Type 0. When the value of the MPT sub-separation type information is 1, the MPT sub-separation type information may indicate Type 1. When the value of the MPT sub-separation type information is 2, the MPT sub-separation type information may indicate Type 2. When the MPT sub-separation type information indicates Type 0, the upper second sub-block may be derived as a 2N×N second sub-block among the second sub-blocks. When the MPT sub-separation type information indicates Type 1, the center second sub-block may be derived as a 2N×N second sub-block among the second sub-blocks. In the case where the MPT sub-separation type information indicates type 2, in the second sub-block, the lower second sub-block may be derived as a second sub-block of 2N×N size.

[0207] Meanwhile, MPT separation information may be signaled via a sequence parameter set (SPS), a picture parameter set (PPS), or a slice segment header, etc.

[0208] In addition, the number of bits in the binary string indicating the MPT separation information can vary based on the separation type of the second target block. For example, the binary string indicating the MPT separation information of the separation type most frequently applied to the block among the separation types within the input image (or target picture) can be derived as the binary string with the smallest number of bits among the number of bits in the binary string indicating the separation type. The binary string of the MPT separation information derived based on the separation type can be derived as shown in Table 2, Table 3, Table 4, Table 5 or Table 6 above. At the same time, the bit stream including the MPT separation information can be sent to the decoding device via a network or a (digital) storage medium. Here, the network can include a broadcast network and / or a communication network, etc., and the digital storage medium can include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD, SSD, etc.

[0209] Figure 9 is an overall diagram of a video decoding method performed by a decoding device according to the present invention. Figure 9 The method shown can be used by Figure 2 More specifically, for example, steps S900 and S920 may be performed by an entropy decoder of the decoding device, steps S910 and S930 may be performed by a picture segmenter of the decoding device, and step S940 may be performed by a predictor of the decoding device.

[0210] The decoding device obtains first separation information for a first target block through a bitstream (S900). The decoding device may obtain the first separation information corresponding to the first target block through the bitstream. The first information may include a quadtree (QT) separation flag corresponding to the first target block. The QT separation flag may indicate whether to separate the target block into sub-blocks having a size corresponding to half the height and half the width of the target block.

[0211] When the first separation information indicates that the first target block is separated, the decoding device separates the first target block into first sub-blocks (S910). In the case where the QT separation flag included in the first separation information indicates that the first target block is being separated, the decoding device may separate the first target block into the first sub-blocks. For example, the first target block may be separated into four first sub-blocks, and the first sub-blocks may correspond to sub-blocks having a size corresponding to half the height and half the width of the target block.

[0212] The decoding device obtains MPT separation information of a second target block, the second target block being one of the first subblocks of the first target block (S920). The decoding device may obtain the MPT separation information of the second target block through a bitstream. In addition, the MPT separation information may be transmitted via a sequence parameter set (SPS), a picture parameter set (PPS), or a slice segment header.

[0213] The decoding device separates the second target block into second sub-blocks based on the MPT separation information (S930). The decoding device may separate the second target block into second sub-blocks according to a multi-partition tree (MPT) separation type, which is derived based on the MPT separation information. At the same time, the second separation information corresponding to the second target block can be obtained through the bitstream, and the second target block can be separated into second sub-blocks based on the MPT separation information without separating the second target block based on the second separation information corresponding to the second target block. More specifically, the second separation information may include a QT separation flag for the second target block. The MPT separation information can be obtained when the QT separation flag corresponding to the second target block indicates that the second target block is not separated into sub-blocks having a size corresponding to half the height and half the width of the second target block. More specifically, the MPT separation information can be obtained when the second target block is not separated based on the QT separation flag corresponding to the second target block.

[0214] For example, the second target block can be separated into 2, 3, or 4 second sub-blocks in the vertical direction or horizontal direction based on the MPT separation information. More specifically, when the size of the second target block corresponds to 2N×2N, the second target block can be separated into 2 N×2N second sub-blocks, 2 2N×N second sub-blocks, 1 N×2N second sub-block and 2 N / 2×2N second sub-blocks, 1 2N×N second sub-block and 2 2N×N / 2 second sub-blocks, 4 N / 2×2N second sub-blocks, or 4 2N×N / 2 second sub-blocks. Here, when the second target block is separated into 1 N×2N second sub-block and 2 N / 2×2N second sub-blocks, the N×2N second sub-block can be derived as the left second sub-block, the center second sub-block, or the right second sub-block. In addition, when the second target block is separated into one second sub-block of 2N×N size and two second sub-blocks of 2N×N / 2 size, the second sub-block of 2N×N size can be derived as the upper second sub-block, the center second sub-block, or the lower second sub-block. At the same time, the number of bits in the binary string indicating the MPT separation information can vary based on the separation type of the second target block. For example, the binary string of the MPT separation information indicating the separation type most frequently applied to the block among the separation types within the input image (or target picture) can be used as the binary string with the smallest number of bits among the binary strings indicating the separation type. As shown in Table 2 or Table 3 above, the binary string of the MPT separation information derived based on the separation type can be derived. For example, in the case where the second target block is separated into two second sub-blocks in the vertical direction or the horizontal direction, the binary string of the MPT separation information can be equal to 0. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 100, where the second sub-block of size N×2N or 2N×N corresponds to the left or upper second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1010, where the second sub-block of size N×2N or 2N×N corresponds to the center second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1011, where the second sub-block of size N×2N or 2N×N corresponds to the right or lower second sub-block. If the second target block is separated into four second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 11. Alternatively, if the second target block is separated into two second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 00.If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 10, where the second sub-block of size N×2N or 2N×N corresponds to the left or upper second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 110, where the second sub-block of size N×2N or 2N×N corresponds to the center second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 111, where the second sub-block of size N×2N or 2N×N corresponds to the right or lower second sub-block. If the second target block is separated into four second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 01. Alternatively, if the second target block is separated into two second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 0. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 10, where the N×2N or 2N×N second sub-block corresponds to the left or upper second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1110, where the N×2N or 2N×N second sub-block corresponds to the center second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1111, where the N×2N or 2N×N second sub-block corresponds to the right or lower second sub-block. If the second target block is separated into four second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 110. Alternatively, if the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. When the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 1100, where the second sub-block of N×2N size or 2N×N size corresponds to the left or upper second sub-block. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 11010, where the second sub-block of N×2N size or 2N×N size corresponds to the center second sub-block.When the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 11011, where the second sub-block of N×2N or 2N×N size corresponds to the right or lower second sub-block. When the second target block is separated into four second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 111. Alternatively, when the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. When the second target block is separated into two second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 100. When the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 110, where the second sub-block of N×2N or 2N×N size corresponds to the left or upper second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1110, where the second sub-block of size N×2N or 2N×N corresponds to the center second sub-block. If the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1111, where the second sub-block of size N×2N or 2N×N corresponds to the right or bottom second sub-block. If the second target block is separated into four second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 101. Alternatively, if the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. If the second target block is separated into two second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 10. When the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 110, wherein the second sub-block of size N×2N or 2N×N corresponds to the left or upper second sub-block. When the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 11110, wherein the second sub-block of size N×2N or 2N×N corresponds to the center second sub-block. When the second target block is separated into three second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 11111, wherein the second sub-block of size N×2N or 2N×N corresponds to the right or lower second sub-block. When the second target block is separated into four second sub-blocks along the vertical or horizontal direction, the binarized string of the MPT separation information may be equal to 1110.

[0215] Alternatively, as another example, according to the MPT separation structure, the second target block can be separated into 2, 3, or 4 second sub-blocks in the vertical direction or horizontal direction. More specifically, when the size of the second target block corresponds to 2N×2N, the second target block can be separated into 2 N×2N second sub-blocks, 2 2N×N second sub-blocks, 1 N×2N second sub-block and 2 N / 2×2N second sub-blocks, 1 2N×N second sub-block and 2 2N×N / 2 second sub-blocks, 4 N / 2×2N second sub-blocks, or 4 2N×N / 2 second sub-blocks. Here, when the second target block is separated into 1 N×2N second sub-block and 2 N / 2×2N second sub-blocks, the N×2N second sub-block can be derived as the center second sub-block. Furthermore, when the second target block is separated into one 2N×N second sub-block and two 2N×N / 2 second sub-blocks, the 2N×N second sub-block can be derived as the center second sub-block. The number of bits in the binary string indicating the MPT separation information can vary based on the separation type of the second target block. In this case, for example, as shown in Table 4 or Table 5 above, the binary string of the MPT separation information can be derived based on the separation type. For example, when the second target block is separated into two second sub-blocks vertically or horizontally, the binary string of the MPT separation information can be equal to 0. When the second target block is separated into three second sub-blocks vertically or horizontally, the binary string of the MPT separation information can be equal to 10. When the second target block is separated into four second sub-blocks vertically or horizontally, the binary string of the MPT separation information can be equal to 11. Alternatively, when the second target block is separated into two second sub-blocks vertically or horizontally, the binary string of the MPT separation information can be equal to 10. In the case where the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 0. In the case where the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 11. Alternatively, in the case where the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10. In the case where the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 11. In the case where the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 0. Alternatively, in the case where the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0.When the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 110. When the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 111. Alternatively, when the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. When the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 110. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10. When the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 111. Alternatively, when the second target block is not separated according to the MPT, the binarized string of the MPT separation information may be equal to 0. When the second target block is separated into two second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 110. When the second target block is separated into three second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 111. When the second target block is separated into four second sub-blocks along the vertical direction or the horizontal direction, the binarized string of the MPT separation information may be equal to 10.

[0216] Alternatively, as another example, the second target block can be separated into two or three second sub-blocks along the vertical or horizontal direction based on the MPT separation information. More specifically, based on the MPT separation information, the second target block can be separated into two or three second sub-blocks along the vertical or horizontal direction. Here, if the size of the second target block corresponds to 2N×2N and the second target block is separated into two second sub-blocks along the vertical direction, the second target block can be separated into second sub-blocks of N×2N size. Furthermore, if the size of the second target block corresponds to 2N×2N and the second target block is separated into two second sub-blocks along the horizontal direction, the second target block can be separated into second sub-blocks of 2N×N size. Furthermore, if the size of the second target block corresponds to 2N×2N and the second target block is separated into three second sub-blocks along the vertical direction, the second target block can be separated into a left second sub-block of N / 2×2N size, a center second sub-block of N×2N size, and a right second sub-block of N / 2×2N size. Furthermore, if the size of the second target block corresponds to 2N×2N and the second target block is separated into three second sub-blocks in the horizontal direction, the second target block may be separated into an upper second sub-block of 2N×N / 2, a center second sub-block of 2N×N, and a lower second sub-block of 2N×N / 2. The number of bits in the binary string indicating the MPT separation information may vary based on the separation type of the second target block. In this case, for example, the binary string of the MPT separation information derived based on the separation type may be derived as shown in Table 6 above. For example, if the second target block is separated into two second sub-blocks in the vertical or horizontal direction, the binary string of the MPT separation information may be equal to 10. Furthermore, if the second target block is separated into three second sub-blocks in the vertical or horizontal direction, the binary string of the MPT separation information may be equal to 11. Furthermore, if the second target block is not separated according to the MPT, the binary string of the MPT separation information may be equal to 0.

[0217] Meanwhile, the MPT separation information may include the following information.

[0218] For example, the MPT separation information may include multi-partition tree (MPT) separation type information and MPT separation direction information corresponding to the second target block. The MPT separation type information may indicate the number of second sub-blocks into which the second target block is separated. Furthermore, the MPT separation direction information may indicate the separation direction of the second target block. More specifically, if the value of the MPT separation type information is 0, the MPT separation type information may indicate that the second target block is not separated. If the value of the MPT separation type information is 1, the MPT separation type information may indicate that the number of second sub-blocks is 2. If the value of the MPT separation type information is 2, the MPT separation type information may indicate that the number of second sub-blocks is 3. Furthermore, if the value of the MPT separation type information is 3, the MPT separation type information may indicate that the number of second sub-blocks is 4. Furthermore, if the value of the MPT separation direction information is 0, this may indicate that the separation direction of the second target block corresponds to the horizontal direction. Furthermore, if the value of the MPT separation direction information is 1, this may indicate that the separation direction of the second target block corresponds to the vertical direction. The second target block may be separated into second sub-blocks based on the MPT separation information.

[0219] Here, in a case where the size of the second target block corresponds to 2N×2N and the number of second sub-blocks indicated by the MPT separation information is equal to 2, and in a case where the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the second target block may be separated into second sub-blocks of N×2N size. Also, in a case where the size of the second target block corresponds to 2N×2N and the number of second sub-blocks along the direction indicated by the MPT separation information is equal to 2, and in a case where the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the second target block may be separated into second sub-blocks of 2N×N size.

[0220] As another example, if the size of the second target block is 2N×2N, the number of second sub-blocks indicated by the MPT separation type information is 3, and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the second target block can be separated into an N×2N second sub-block and an N / 2×2N second sub-block. Furthermore, if the size of the second target block is 2N×2N, the number of second sub-blocks indicated by the MPT separation type information is 3, and the separation direction of the second target block indicated by the second separation direction information corresponds to the horizontal direction, the second target block can be separated into a 2N×N second sub-block and a 2N×N / 2 second sub-block. In this case, for example, if the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the center second sub-block in the second sub-block can be derived as an N×2N second sub-block. Furthermore, if the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the center second sub-block in the second sub-block can be derived as a 2N×N second sub-block. Meanwhile, when the size of the second target block is 2N×2N, when the number of second sub-blocks indicated by the MPT separation type information is 3, and when the second target block separation direction indicated by the MPT separation direction information corresponds to the vertical direction, the MPT separation information may include MPT sub-separation type information. If the value of the MPT sub-separation type information is 0, the MPT sub-separation type information may indicate type 0. If the value of the MPT sub-separation type information is 1, the MPT sub-separation type information may indicate type 1. Furthermore, if the value of the MPT sub-separation type information is 2, the MPT sub-separation type information may indicate type 2. If the MPT sub-separation type information indicates type 0, the left second sub-block within the second sub-block may be derived as an N×2N second sub-block. If the MPT sub-separation type information indicates type 1, the center second sub-block within the second sub-block may be derived as an N×2N second sub-block. Furthermore, if the MPT sub-separation type information indicates type 2, the right second sub-block within the second sub-block may be derived as an N×2N second sub-block. In addition, when the size of the second target block is equal to 2N×2N, when the number of second sub-blocks indicated by the MPT separation type information is equal to 3, and when the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the MPT separation information may include MPT sub-separation type information. When the value of the MPT sub-separation type information is equal to 0, the MPT sub-separation type information may indicate type 0. When the value of the MPT sub-separation type information is equal to 1, the MPT sub-separation type information may indicate type 1.Furthermore, when the value of the MPT sub-separation type information is 2, the MPT sub-separation type information may indicate type 2. When the MPT sub-separation type information indicates type 0, the upper second sub-block among the second sub-blocks may be derived as a second sub-block of 2N×N size. When the MPT sub-separation type information indicates type 1, the central second sub-block among the second sub-blocks may be derived as a second sub-block of 2N×N size. Furthermore, when the MPT sub-separation type information indicates type 2, the lower second sub-block among the second sub-blocks may be derived as a second sub-block of 2N×N size.

[0221] Here, in a case where the size of the second target block corresponds to 2N×2N and the number of second sub-blocks indicated by the MPT separation information is equal to 4, and in a case where the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the second target block can be separated into second sub-blocks of N / 2×2N size. Also, in a case where the size of the second target block corresponds to 2N×2N and the number of second sub-blocks indicated by the MPT separation information is equal to 4, and in a case where the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the second target block can be separated into second sub-blocks of 2N×N / 2 size.

[0222] Meanwhile, as another example, the MPT separation information may include a multi-partition tree (MPT) separation flag for the second target block. The MPT separation flag may indicate whether the second target block is being separated into second sub-blocks corresponding to non-square blocks. More specifically, when the value of the MPT separation flag is 0, the MPT separation flag may indicate that the second target block is not separated. And, when the value of the MPT separation flag is 1, the MPT separation flag may indicate that the second target block is separated into second sub-blocks according to the MPT structure. More specifically, when the value of the MPT separation flag is 1, the MPT separation flag may indicate that the second target block is separated into second sub-blocks corresponding to non-square blocks.

[0223] Furthermore, when the value of the MPT separation flag is 1, the MPT separation information may include MPT separation direction information and MPT separation type information for the second target block. The MPT separation direction information may indicate the separation direction of the second target block. Furthermore, the MPT separation type information may indicate the number of second sub-blocks into which the second target block is separated. More specifically, when the value of the MPT separation direction information is 0, this may indicate that the separation direction of the second target block corresponds to the horizontal direction. Furthermore, when the value of the MPT separation direction information is 1, this may indicate that the separation direction of the second target block corresponds to the vertical direction. Furthermore, when the value of the MPT separation type information is 0, the MPT separation type information may indicate that the number of second sub-blocks is 2. When the value of the MPT separation type information is 1, the MPT separation type information may indicate that the number of second sub-blocks is 3. Furthermore, when the value of the MPT separation type information is 2, the MPT separation type information may indicate that the number of second sub-blocks is 4. The second target block may be separated into second sub-blocks based on the MPT separation information.

[0224] Here, in a case where the size of the second target block corresponds to 2N×2N and the number of second sub-blocks along the second target block indicated by the MPT separation information is equal to 2, and in a case where the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the second target block may be separated into second sub-blocks of N×2N size. Also, in a case where the size of the second target block corresponds to 2N×2N and the number of second sub-blocks along the second target block indicated by the MPT separation information is equal to 2, and in a case where the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the second target block may be separated into second sub-blocks of 2N×N size.

[0225] As another example, if the size of the second target block is 2N×2N, the number of second sub-blocks indicated by the MPT separation type information is 3, and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the second target block can be separated into a second sub-block of N×2N and a second sub-block of N / 2×2N. Furthermore, if the size of the second target block is 2N×2N, the number of second sub-blocks indicated by the MPT separation type information is 3, and the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the second target block can be separated into a second sub-block of 2N×N and a second sub-block of 2N×N / 2. In this case, for example, if the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the center second sub-block can be derived as an N×2N second sub-block among the second sub-blocks. Furthermore, if the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the center second sub-block can be derived as a 2N×N second sub-block among the second sub-blocks. Meanwhile, when the size of the second target block is 2N×2N, when the number of second sub-blocks indicated by the MPT separation type information is 3, and when the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the MPT separation information may include MPT sub-separation type information. If the value of the MPT sub-separation type information is 0, the MPT sub-separation type information may indicate type 0. If the value of the MPT sub-separation type information is 1, the MPT sub-separation type information may indicate type 1. And, if the value of the MPT sub-separation type information is 2, the MPT sub-separation type information may indicate type 2. If the MPT sub-separation type information indicates type 0, the left second sub-block among the second sub-blocks may be derived as a second sub-block of N×2N size. If the MPT sub-separation type information indicates type 1, the center second sub-block among the second sub-blocks may be derived as a second sub-block of N×2N size. And, if the MPT sub-separation type information indicates type 2, the right second sub-block among the second sub-blocks may be derived as a second sub-block of N×2N size. In addition, when the size of the second target block is equal to 2N×2N, when the number of second sub-blocks indicated by the MPT separation type information is equal to 3, and when the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the MPT separation information may include MPT sub-separation type information. When the value of the MPT sub-separation type information is equal to 0, the MPT sub-separation type information may indicate type 0. When the value of the MPT sub-separation type information is equal to 1, the MPT sub-separation type information may indicate type 1.Furthermore, when the value of the MPT sub-separation type information is 2, the MPT sub-separation type information may indicate type 2. When the MPT sub-separation type information indicates type 0, the upper second sub-block among the second sub-blocks may be derived as a second sub-block of 2N×N size. When the MPT sub-separation type information indicates type 1, the central second sub-block among the second sub-blocks may be derived as a second sub-block of 2N×N size. Furthermore, when the MPT sub-separation type information indicates type 2, the lower second sub-block among the second sub-blocks may be derived as a second sub-block of 2N×N size.

[0226] Here, in a case where the size of the second target block corresponds to 2N×2N and the number of second sub-blocks indicated by the MPT separation information is equal to 4, and in a case where the separation direction of the second target block indicated by the MPT separation direction information corresponds to the vertical direction, the second target block can be separated into second sub-blocks of N / 2×2N size. Also, in a case where the size of the second target block corresponds to 2N×2N and the number of second sub-blocks indicated by the MPT separation information is equal to 4, and in a case where the separation direction of the second target block indicated by the MPT separation direction information corresponds to the horizontal direction, the second target block can be separated into second sub-blocks of 2N×N / 2 size.

[0227] At the same time, the number of bits in the binary string indicating the MPT separation information based on the separation type of the second target block can be variable. For example, the binary string indicating the MPT separation information that is most frequently applied to the block among the separation types within the input image (or target picture) can be derived as the binary string having the smallest number of bits among the binary strings indicating the separation type. The binary string of the MPT separation information derived based on the separation type can be derived as shown in Table 2, Table 3, Table 4, Table 5, or Table 6.

[0228] The decoding device decodes the second sub-block (S940). The decoding device may decode the second sub-block. More specifically, the decoding device may generate prediction samples of the second sub-block by performing intra or inter prediction on the second sub-block. Thereafter, the decoding device may generate reconstructed (or restored) samples corresponding to the second sub-block based on the prediction samples, and then may generate a reconstructed picture based on the generated reconstructed samples.

[0229] Meanwhile, although not shown in the accompanying drawings, the decoding device may directly use the predicted samples as reconstructed (or restored) samples according to the prediction mode, or the decoding device may generate reconstructed samples by adding residual samples to the predicted samples. In the presence of residual samples for the target block, the decoding device may receive information about the residual of the target block, and the information about the residual may include information about the phase. The information about the residual may include transform coefficients corresponding to the residual samples. The decoding device may derive residual samples (or residual sample arrays) corresponding to the target block based on the residual information. The decoding device may generate reconstructed samples based on the predicted samples and the residual samples. And, then, the decoding device may derive a reconstructed block or a reconstructed picture based on the restored samples. Thereafter, as described above, the decoding device may apply a loop filtering process such as a deblocking filter and / or an SAO process to the restored picture as needed to enhance subjective / objective image quality.

[0230] According to the present disclosure described above, a picture can be separated (or partitioned) into blocks of various shapes according to a multi-partition tree (MPT) structure, and by doing so, prediction efficiency can be improved and overall encoding efficiency can be enhanced.

[0231] In addition, according to the present disclosure, a picture can be separated (or partitioned) into blocks of various shapes according to a multi-partition tree (MPT) structure, and by doing so, transformation efficiency can be enhanced, and overall encoding efficiency can be enhanced.

[0232] In the above embodiments, the method is described based on a flow chart having a series of steps or blocks. The present disclosure is not limited to the order of the above steps or blocks. As described above, some steps or blocks may occur simultaneously or in a different order than other steps or blocks. In addition, it will be understood by those skilled in the art that the steps shown in the above flow chart are not exclusive and may include other steps, or one or more steps in the flow chart may be deleted without affecting the scope of the present disclosure.

[0233] The above method according to the present disclosure can be implemented by software. The encoding device and / or decoding device according to the present disclosure can be included in a device that performs image processing, such as a television, a computer, a smart phone, a set-top box, or a display device.

[0234] When the embodiments of the present disclosure are implemented in software, the above methods can be implemented by modules (procedures, functions, etc.) that perform the above functions. Such modules can be stored in a memory and executed by a processor. The memory can be inside or outside the processor, and various well-known means can be used to couple the memory to the processor. The processor may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. The memory may include ROM (read-only memory), RAM (random access memory), flash memory, memory cards, storage media, and / or other storage devices.

Claims

1. A video decoding method performed by a decoding device, comprising: obtaining first separation information for a first target block through a bitstream; When the first separation information indicates that the first target block is separated, separating the first target block into first sub-blocks; obtaining, through the bitstream, multi-partition tree (MPT) separation information for a second target block, wherein the second target block is one of the first sub-blocks of the first target block; separating the second target block into second sub-blocks based on the MPT separation information; and decoding the second sub-block, The second sub-block is a non-square block. The MPT separation information includes an MPT separation flag for the second target block, The MPT separation flag indicates whether the second target block is separated into the second sub-blocks of the non-square blocks. When the value of the MPT separation flag is equal to 1, the MPT separation information includes MPT separation direction information and MPT separation type information for the second target block. The MPT separation direction information indicates the separation direction of the second target block. The MPT separation type information indicates the number of the second sub-blocks into which the second target block is separated. wherein, based on the size of the second target block being 2Nx2N, the value of the MPT separation direction information being equal to 1, and the value of the MPT separation type information being equal to 1, the second target block is separated into second sub-blocks of size Nx2N; wherein, based on the size of the second target block being 2Nx2N, the value of the MPT separation direction information being equal to 0, and the value of the MPT separation type information being equal to 1, the second target block is separated into second sub-blocks of a size of 2NxN; wherein information on the MPT structure including the 2-split type and the 3-split type is obtained through the first high-level syntax (HLS) and the second HLS, wherein the first HLS is a sequence parameter set (SPS), and the second HLS is a lower syntax structure of the SPS, wherein the 2-split type is a type in which a block is separated into 2 sub-blocks, wherein the 3-split type is a type in which a block is separated into 3 sub-blocks, and The information about the MPT structure includes information about the maximum depth of intra-frame slices in the MPT structure, information about the maximum block size of intra-frame slices in the MPT structure, information about the maximum depth of inter-frame slices in the MPT structure, and information about the maximum block size of inter-frame slices in the MPT structure.

2. A video encoding method performed by an encoding device, comprising: separating the first target block into first sub-blocks; separating a second target block, which is one of the first sub-blocks, into second sub-blocks; as well as generating and encoding first separation information for the first target block and multi-partition tree (MPT) separation information for the second target block, The second sub-block is a non-square block. The MPT separation information includes an MPT separation flag, MPT separation direction information, and MPT separation type information for the second target block. The MPT separation flag indicates whether the second target block is separated into the second sub-blocks of the non-square blocks. The MPT separation direction information indicates the separation direction of the second target block. The MPT separation type information indicates the number of the second sub-blocks into which the second target block is separated. wherein, based on the size of the second target block being 2Nx2N, the value of the MPT separation direction information being equal to 1 and the value of the MPT separation type information being equal to 1, the second target block is separated into second sub-blocks of size Nx2N; wherein, based on the size of the second target block being 2Nx2N, the value of the MPT separation direction information being equal to 0 and the value of the MPT separation type information being equal to 1, the second target block is separated into second sub-blocks of a size of 2NxN; wherein information on the MPT structure including the 2-split type and the 3-split type is obtained through the first high-level syntax (HLS) and the second HLS, wherein the first HLS is a sequence parameter set (SPS), and the second HLS is a lower syntax structure of the SPS, wherein the 2-split type is a type in which a block is separated into 2 sub-blocks, wherein the 3-split type is a type in which a block is separated into 3 sub-blocks, and The information about the MPT structure includes information about the maximum depth of intra-frame slices in the MPT structure, information about the maximum block size of intra-frame slices in the MPT structure, information about the maximum depth of inter-frame slices in the MPT structure, and information about the maximum block size of inter-frame slices in the MPT structure.

3. A computer-readable storage medium storing instructions that, when executed by a processor, configure the processor to perform a video encoding method, the video encoding method comprising: separating the first target block into first sub-blocks; separating a second target block, which is one of the first sub-blocks, into second sub-blocks; as well as generating and encoding first separation information for the first target block and multi-partition tree (MPT) separation information for the second target block, The second sub-block is a non-square block. The MPT separation information includes an MPT separation flag, MPT separation direction information, and MPT separation type information for the second target block. The MPT separation flag indicates whether the second target block is separated into the second sub-blocks of the non-square blocks. The MPT separation direction information indicates the separation direction of the second target block. The MPT separation type information indicates the number of the second sub-blocks into which the second target block is separated. wherein, based on the size of the second target block being 2Nx2N, the value of the MPT separation direction information being equal to 1 and the value of the MPT separation type information being equal to 1, the second target block is separated into second sub-blocks of size Nx2N; wherein, based on the size of the second target block being 2Nx2N, the value of the MPT separation direction information being equal to 0 and the value of the MPT separation type information being equal to 1, the second target block is separated into second sub-blocks of a size of 2NxN; wherein information on the MPT structure including the 2-split type and the 3-split type is obtained through the first high-level syntax (HLS) and the second HLS, wherein the first HLS is a sequence parameter set (SPS), and the second HLS is a lower syntax structure of the SPS, wherein the 2-split type is a type in which a block is separated into 2 sub-blocks, wherein the 3-split type is a type in which a block is separated into 3 sub-blocks, and The information about the MPT structure includes information about the maximum depth of intra-frame slices in the MPT structure, information about the maximum block size of intra-frame slices in the MPT structure, information about the maximum depth of inter-frame slices in the MPT structure, and information about the maximum block size of inter-frame slices in the MPT structure.

4. A method for transmitting video data, the method comprising: Obtaining a bitstream of a video, wherein the bitstream is generated based on: separating a first target block into first sub-blocks, separating a second target block that is one of the first sub-blocks into second sub-blocks, and generating and encoding first separation information for the first target block and multi-partition tree (MPT) separation information for the second target block; and sending data comprising said bitstream, The second sub-block is a non-square block. The MPT separation information includes an MPT separation flag, MPT separation direction information, and MPT separation type information for the second target block. The MPT separation flag indicates whether the second target block is separated into the second sub-blocks of the non-square blocks. The MPT separation direction information indicates the separation direction of the second target block. The MPT separation type information indicates the number of the second sub-blocks into which the second target block is separated. wherein, based on the size of the second target block being 2Nx2N, the value of the MPT separation direction information being equal to 1 and the value of the MPT separation type information being equal to 1, the second target block is separated into second sub-blocks of size Nx2N; wherein, based on the size of the second target block being 2Nx2N, the value of the MPT separation direction information being equal to 0 and the value of the MPT separation type information being equal to 1, the second target block is separated into second sub-blocks of a size of 2NxN; wherein information on the MPT structure including the 2-split type and the 3-split type is obtained through the first high-level syntax (HLS) and the second HLS, wherein the first HLS is a sequence parameter set (SPS), and the second HLS is a lower syntax structure of the SPS, wherein the 2-split type is a type in which a block is separated into 2 sub-blocks, wherein the 3-split type is a type in which a block is separated into 3 sub-blocks, and The information about the MPT structure includes information about the maximum depth of intra-frame slices in the MPT structure, information about the maximum block size of intra-frame slices in the MPT structure, information about the maximum depth of inter-frame slices in the MPT structure, and information about the maximum block size of inter-frame slices in the MPT structure.

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