RU2816865C1 - Encoding method and apparatus therefor, and decoding method and apparatus therefor - Google Patents

Abstract

FIELD: image encoding and decoding.

SUBSTANCE: determining the predicted quantization parameter of the current quantization group determined according to at least one of the block breakdown information and the block size information, determining a quantization parameter of the difference of the current quantization group, determining the quantisation parameter of the current quantisation group based on the predicted quantisation parameter and the quantisation parameter of the difference of the current quantisation group and performing inverse quantization of the current block included in the current quantization group according to the quantization parameter of the current quantization group.

EFFECT: creation of methods of encoding and decoding image data with minimum deterioration of image quality and increased degree of compression.

3 cl, 32 dwg

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

[0001] The disclosure relates to a method for encoding and a method for decoding images, and in particular, to a method for efficiently encoding and decoding motion vector information.

BACKGROUND OF THE ART

[0002] When a high quality image is encoded, a large amount of data is required. However, since the frequency band available for transmitting image data is limited, the data rate applied to transmitting image data may be limited. Thus, for efficient transmission of image data, there is a need for methods for encoding and decoding image data with minimal degradation of image quality and increased compression ratio.

[0003] Image data can be compressed by removing spatial redundancies and temporal redundancies between pixels. Since adjacent pixels generally have common characteristics, the encoding of the information of a data element consisting of pixels is transmitted to remove redundancies between adjacent pixels.

[0004] The pixel values of the pixels included in the data element are not transmitted directly, but information about the method for obtaining the pixel values is transmitted. A prediction method in which a pixel value that is similar to the original value is predicted is determined for each data element, and encoding information about the prediction method is transmitted from the encoder to the decoder. Since the prediction value is not exactly equal to the original value, residual data of the difference between the original value and the prediction value is transmitted from the encoder to the decoder.

[0005] When the prediction is accurate, the size of the encoding information for determining the prediction method increases, but the size of the residual data decreases. Thus, the prediction method is determined taking into account the sizes of the encoding information and the residual data. In particular, the data elements into which a frame is divided have different sizes, and in this regard, when the size of the data element increases, there is an increased probability that the prediction accuracy decreases while the size of the encoding information decreases. Thus, the block size is determined according to the characteristics of the frame.

[0006] The prediction method includes intra prediction and inter prediction. Intra-frame prediction is a method of predicting the pixels of a block from pixels adjacent to the block. Inter-frame prediction is a method of predicting pixels by referring to pixels of another referenced frame for a frame including a block. Thus, spatial redundancy is removed by intra-frame prediction, and temporal redundancy is removed by inter-frame prediction.

[0007] When the number of prediction methods increases, the amount of encoding information for indicating the prediction method increases. Thus, the amount of encoding information can be reduced by predicting, from another block, encoding information to be applied to the block.

[0008] Since the loss of image data is allowed to the extent that the human eye cannot recognize the loss, the residual data can be lossily compressed according to the conversion and quantization processes, and thus the amount of residual data can be reduced.

DESCRIPTION OF IMPLEMENTATION OPTIONS

TECHNICAL PROBLEM

[0009] An image encoding method and an image encoding apparatus for determining a quantization parameter of a quantization group based on block division information and block size information are provided. An image decoding method and an image decoding device are proposed for determining a quantization parameter of a quantization group based on block division information and block size information.

[0010] An image encoding method and an image encoding apparatus are provided for matching a current block with a current quantization parameter element based on at least one of a position and a size of the current block. An image decoding method and an image decoding device are proposed for matching a current block with a current quantization parameter element based on at least one of a position and a size of the current block.

[0011] Further provided is a computer-readable storage medium having a program recorded thereon for executing, on a computer, an image encoding method and an image decoding method according to one embodiment of the disclosure.

SOLUTION

[0012] An image decoding method is provided, including the steps of: determining a predicted quantization parameter of a current quantization group determined according to at least one of block division information and block size information; determining a difference quantization parameter of the current quantization group; determining a quantization parameter of the current quantization group based on the predicted quantization parameter and a difference quantization parameter of the current quantization group; and reverse quantization of the current block included in the current quantization group according to the quantization parameter of the current quantization group.

[0013] An image decoding device is provided, including a processor configured to determine a predicted quantization parameter of a current quantization group determined according to at least one of block division information and block size information, determine a difference quantization parameter of the current quantization group, determine a quantization parameter the current quantization group based on the predicted quantization parameter and the difference quantization parameter of the current quantization group, and reverse quantize the current block included in the current quantization group according to the quantization parameter of the current quantization group.

[0014] A method for decoding images is provided, including the steps of: mapping a current block to a current quantization parameter element based on at least one of a position and a size of the current block; obtaining a predicted quantization parameter with respect to the current quantization parameter element; obtaining a difference quantization parameter with respect to the current quantization parameter element; determining a quantization parameter of the current quantization parameter element based on the predicted quantization parameter and the difference quantization parameter; and reverse quantization of the current block according to the quantization parameter of the current quantization parameter element.

[0015] An image decoding apparatus is provided, including a processor configured to map a current block to a current quantization parameter element based on at least one of a position and a size of the current block, obtain a predicted quantization parameter with respect to the current quantization parameter element, obtain a difference quantization parameter with respect to the current quantization parameter element, determine a quantization parameter of the current quantization parameter element based on the predicted quantization parameter and the difference quantization parameter, and reverse quantize the current block according to the quantization parameter of the current quantization parameter element.

[0016] A computer-readable storage medium is provided having a program recorded thereon for executing an image encoding method and an image decoding method.

[0017] The technical problems to be achieved by the present disclosure are not limited to the technical features described above, and other technical problems can be inferred from the embodiments below.

ADVANTAGEOUS EFFECTS OF DISCLOSURE

[0018] The quantization parameter of the blocks is determined according to the quantization group or the quantization parameter element so that information necessary for determining the quantization parameter can be efficiently compressed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1A depicts a block diagram of an image encoding apparatus based on encoding elements according to a tree structure according to one embodiment of the disclosure.

[0020] FIG. 1B is a block diagram of an image decoding apparatus based on tree encoding elements according to one embodiment.

[0021] FIG. 2 depicts a process by which an image decoding apparatus determines at least one encoding element by splitting a current encoding element according to one embodiment.

[0022] FIG. 3 depicts a process for determining at least one encoding element by partitioning a non-square encoding element according to one embodiment.

[0023] FIG. 4 depicts a process of dividing an encoding element based on at least one of block shape information and partition shape information according to one embodiment.

[0024] FIG. 5 depicts a method for determining a preset encoding element from an odd number of encoding elements according to one embodiment.

[0025] FIG. 6 depicts a processing order of multiple encoding elements when the plurality of encoding elements is determined by partitioning the current encoding element, according to one embodiment.

[0026] FIG. 7 depicts a process for determining that a current encoding element should be divided into an odd number of encoding elements when encoding blocks are not processed in a predetermined order, according to one embodiment.

[0027] FIG. 8 depicts a process for determining at least one encoding element by partitioning a first encoding element according to one embodiment.

[0028] FIG. 9 depicts that the shape into which the second encoding element is capable of being partitioned is limited when the second encoding element having a non-square shape, which is determined by partitioning the first encoding element, satisfies a preset condition, according to one embodiment.

[0029] FIG. 10 depicts a process of splitting a square encoding element when the partitioning shape information indicates that the square encoding element should not be divided into four square encoding elements, according to one embodiment.

[0030] FIG. 11 depicts that the processing order between multiple encoding elements may be changed depending on the encoding element partitioning process, according to one embodiment.

[0031] FIG. 12 depicts a process for determining the depth of an encoding element as the shape and size of the encoding element changes when the encoding element is recursively divided so that a plurality of encoding elements are determined, according to one embodiment.

[0032] FIG. 13 depicts depths that are capable of being determined based on shapes and sizes of encoding elements and part indices (PIDs) that are intended to distinguish encoding elements, according to one embodiment.

[0033] FIG. 14 depicts that a plurality of encoding elements is determined based on a plurality of preset data elements included in a frame, according to one embodiment.

[0034] FIG. 15 depicts a processing unit functioning as an element for determining the order of determining reference encoding elements included in a frame, according to one embodiment.

[0035] FIG. 16 depicts an image decoding apparatus for determining a block quantization parameter and decoding residual block data according to the determined quantization parameter.

[0036] FIGS. 17A to 17D show diagrams of embodiments in which a quantization group is determined according to the number of times of quadtree partitioning.

[0037] FIGS. 18A-18C depict an embodiment of a method for determining a quantization group in a largest coding block to which non-quadtree partitioning is applied.

[0038] FIG. 19 depicts a syntax structure regarding a method for decoding a difference quantization parameter included in a bit stream when quadtree partitioning and non-quad tree partitioning are enabled.

[0039] FIG. 20 depicts a method for decoding images by determining a block quantization parameter according to a quantization group and decoding residual block data according to the determined quantization parameter.

[0040] FIG. 21 depicts an embodiment of a quantization parameter element structure and a tree structure of a coding block.

[0041] FIGS. 22A and 22B depict a method for determining a quantization parameter element corresponding to a current block.

[0042] FIGS. 23A and 23B depict the correlation between a block and a quantization parameter element.

[0043] FIG. 24 depicts a method for decoding images by determining a block quantization parameter according to a quantization parameter element and decoding residual block data according to the determined quantization parameter.

BEST OPTION

[0044] An image decoding method is provided, including the steps of: determining a predicted quantization parameter of a current quantization group determined according to at least one of block division information and block size information; determining a difference quantization parameter of the current quantization group; determining a quantization parameter of the current quantization group based on the predicted quantization parameter and a difference quantization parameter of the current quantization group; and reverse quantization of the current block included in the current quantization group according to the quantization parameter of the current quantization group. An image decoding apparatus is also provided, including a process for performing an image decoding method.

[0045] A method for decoding images is provided, including the steps of: mapping a current block to a current quantization parameter element based on at least one of a position and a size of the current block; obtaining a predicted quantization parameter with respect to the current quantization parameter element; obtaining a difference quantization parameter with respect to the current quantization parameter element; determining a quantization parameter of the current quantization parameter element based on the predicted quantization parameter and the difference quantization parameter; and reverse quantization of the current block according to the quantization parameter of the current quantization parameter element. An image decoding apparatus is also provided, including a process for performing an image decoding method.

DISCLOSURE OPTION

[0046] The advantages and features of the embodiments and methods for achieving them can be more easily understood by reference to the embodiments and the accompanying drawings. In this regard, the disclosure may take various forms and should not be construed as limited to the embodiments set forth herein. Indeed, these embodiments are provided so that this disclosure is comprehensive and complete, and will fully convey the concepts of the disclosure to one of ordinary skill in the art.

[0047] Terms used in the technical description will be briefly defined, and embodiments will be described in detail.

[0048] All terms, including descriptive or technical terms, that are used in the technical description should be construed to have meanings that are apparent to one of ordinary skill in the art. However, the terms may have different meanings according to the intent of one of ordinary skill in the art, precedent cases, or the emergence of new technologies. Also, certain terms may be arbitrarily selected by the applicant, in which case the meaning of the selected terms will be described in detail in the detailed description of the disclosure. Therefore, terms used in the disclosure should not be interpreted based on their names alone, but rather should be defined based on the meanings of the terms along with descriptions throughout the technical specification.

[0049] In the following technical description, singular forms include plural forms unless the context clearly indicates otherwise.

[0050] When a part "includes" or "contains" an element, unless specifically described to the contrary, the part may further include other elements without excluding other elements. In the following descriptions, terms such as "element" indicate a software or hardware component, such as a field programmable gate array (FPGA) or application specific semiconductor (ASIC), and the "element" performs specific functions. However, the "element" is not limited to software or hardware. An "item" may be configured to reside in an addressable storage medium, or may be configured to operate on one or more processors. Thus, for example, the term "element" may refer to components such as software components, object-oriented software components, class components, and task components, and may include processes, functions, attributes, procedures, routines, code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays or variables. The function provided by the components and "elements" may be associated with fewer components and "elements" or may be divided into additional components and "elements".

[0051] The term "current block" indicates one of a current encoding element to be encoded or decoded, a prediction element, and a transform element. For convenience of description, when it is desired to distinguish between other types of blocks, such as a prediction element, a transform element, or the like, the terms "current encoding block", "current prediction block", "current transform block" may be used. In addition, a "lower level block" denotes a data element obtained by splitting the "current block". "Top-level block" denotes a data element including the "current block".

[0052] Hereinafter, “sample” refers to data assigned to the image sampling position, i.e. data to be processed. For example, the pixel values of an image in the spatial domain and the transform coefficients in the transform domain may be discrete samples. An element including at least one such sample may be defined as a block.

[0053] The disclosure will now be described more fully with reference to the accompanying drawings so that one of ordinary skill in the art will be able to carry out the embodiments without any difficulty. Additionally, parts not relevant to the description will be omitted in the drawings for the sake of clear description of the disclosure.

[0054] FIG. 1A depicts a block diagram of an image encoding apparatus 100 based on encoding elements according to a tree structure according to one embodiment of the disclosure.

[0055] The image encoding apparatus 100 may include an encoder 110 and a bitstream generator 120 .

[0056] The encoder 110 partitions a frame or slice included in the frame into a plurality of largest encoding elements according to the sizes of the largest encoding elements. The largest encoding units may be data units having a size of 32×32, 64×64, 128×128, 256×256, or the like, and each of them may be a square data unit having a width and a length equal to powers of 2. The encoder 110 may provide the bit stream generator 120 with largest element size information indicating the size of the largest element. Bit stream generator 120 may add largest element size information to the bit stream.

[0057] Encoder 110 determines encoding elements by splitting the largest encoding element. Whether to split a coding element is determined according to whether it is efficient to split the coding element by optimizing the rate-to-distortion ratio. Additionally, splitting information indicating whether an encoding element is split may be generated. The partitioning information may be in the form of a flag.

[0058] An encoding element can be divided in various ways. For example, a square encoding element can be divided into four square encoding elements whose width and height are half that of the square encoding element. A square encoding element may be split into two rectangular encoding elements having half the width of a square encoding element. A square encoding element may be split into two rectangular encoding elements having half the height of a square encoding element. A square encoding element can be split into three encoding elements by dividing its width or height in a ratio of 1:2:1.

[0059] A rectangular encoding element having a width twice its height can be divided into two square encoding elements. A rectangular encoding element having a width twice its height can be split into two square encoding elements having a width four times its height. A rectangular encoding element having a width twice its height can be split into two rectangular encoding elements and one square encoding element by dividing the width of the rectangular encoding element in a ratio of 1:2:1.

[0060] Likewise, a rectangular encoding element having a height twice its width can be divided into two square encoding elements. A rectangular encoding element having a height twice its width can be split into two rectangular encoding elements having a height four times its width. Likewise, a rectangular encoding element having a height twice its width can be split into two rectangular encoding elements and one square encoding element by splitting the height of the rectangular encoding element in a ratio of 1:2:1.

[0061] When two or more partitioning methods are applicable to the image encoding device 100, information about the partitioning method applicable to the encoding element from among the partitioning methods applicable to the image encoding device 100 can be determined for each frame. Thus, only specific partitioning methods can be specified for use on a per-frame basis. When the image encoding device 100 uses only one partitioning method, information about the partitioning method applicable to the encoding element is not further determined.

[0062] An encoding element of a particular size may be divided by a particular partitioning method. For example, when the encoding element size is 256×265, the encoding element can be set to be divided into only four square encoding elements whose width and height are half that of the encoding element.

[0063] When the encoding element splitting information indicates that the encoding element is to be split, splitting shape information indicating how the encoding element is split may be generated. When there is only one splitting method applicable to the frame to which the encoding element belongs, splitting shape information may not be generated. When the partitioning method is adaptively determined based on the encoding information about the proximity of the encoding element, the partitioning shape information may not be generated.

[0064] As described above, the image data of the current frame is divided into largest encoding elements according to the maximum encoding element size. The largest encoding element may include encoding elements that are hierarchically subdivided from the largest encoding element. The shape and position of the lower level encoding element can be determined based on the partition shape of the upper level encoding element. A minimum encoding element size that limits the partitioning of an encoding element may be preset.

[0065] Encoder 110 compares encoding efficiency when the encoding element is hierarchically partitioned with encoding efficiency when the encoding element is not partitioned. The encoder 110 then determines whether to split the encoding element according to the comparison result. When it is determined that it is more efficient to split the encoding element, the encoder 110 hierarchically splits the encoding element. An encoding element is not split when the result of the comparison demonstrates that it is more efficient to not split the encoding element. Whether to split an encoding element can be determined regardless of whether to split other encoding elements adjacent to that encoding element.

[0066] The coding element that is split last may be predicted in view of intra-frame prediction or inter-frame prediction. Intra-frame prediction is a method of predicting prediction element samples by reference samples around the prediction element. Inter-frame prediction is a method of predicting prediction element samples by obtaining a reference sample from a reference frame referenced for the current frame.

[0067] For intra prediction, encoder 110 may select the most efficient intra prediction method by applying a plurality of intra prediction methods to the prediction element. Intra prediction methods include DC mode, planar mode, directional mode such as vertical mode and horizontal mode, or the like.

[0068] Intra-frame prediction may be performed for each prediction element when the reconstructed sample around the encoding element is used as a reference sample. However, when a reconstructed sample in an encoding element is used as a reference sample, the reference sample in an encoding element must first be reconstructed, and thus the prediction order of the prediction element may be subject to the transform order of the transform element. That is, when a reconstructed sample in a coding element is used as a reference sample, only the intra-prediction method for transform elements corresponding to the prediction element is determined for the prediction element, and intra-prediction can be performed on substantially each transform element.

[0069] Encoder 110 may select the most efficient inter-frame prediction method to determine the optimal motion vector and reference frame. For inter-frame prediction, encoder 110 may determine a plurality of potentially candidate motion vectors from coding elements spatially and temporally adjacent to a current coding element, and determine the most effective motion vector as a motion vector among the plurality of candidate motion vectors. Likewise, a plurality of potentially suitable reference frames can be determined from among encoding elements spatially and temporally adjacent to the current coding element, and the most effective reference frame can be determined among the plurality of potentially suitable reference frames. In one embodiment, the reference frame may be determined from a list of reference frames defined in advance for the current frame. In one embodiment, for accurate prediction, the most effective motion vector from a plurality of potentially suitable motion vectors may be determined to be the predicted motion vector, and the motion vector may be determined by correcting the predicted motion vector. Inter-frame prediction may be performed in parallel for each prediction element included in the coding element.

[0070] The encoder 110 can recover the encoding element by obtaining only the information representing the motion vector and the reference frame according to the skip mode. According to the skip mode, all encoding information including the residual signal is omitted except information representing the motion vector and the reference frame. Since the residual signal is omitted, the skip mode is applicable when the prediction accuracy is very high.

[0071] The division mode to be used may be limited according to the prediction method for the prediction element. For example, only the division mode for prediction elements having sizes 2Nx2N and NxN can be applied to intra-frame prediction, while the division mode for prediction elements having sizes 2Nx2N, 2NxN, Nx2N and NxN can be applied to inter-frame prediction. Additionally, only the division mode for a prediction element having a size of 2Nx2N can be applied to the skip mode from inter-frame prediction. The division mode enabled for each prediction method in the image encoding apparatus 100 can be changed according to the encoding efficiency.

[0072] The image encoding apparatus 100 may perform conversion based on the encoding element. The image encoding apparatus 100 can convert residual data, which are differences between the original values of pixels included in the encoding element and their prediction values, by a predetermined process. For example, image encoding apparatus 100 may perform lossy compression on residual data by quantization and discrete cosine transform (DCT)/discrete sine transform (DST). Alternatively, image encoding apparatus 100 may perform lossless compression on the residual data without quantization.

[0073] Finally, encoder 110 determines the most efficient prediction method for the current encoding element from a plurality of intra-prediction methods and inter-prediction methods. Then, the encoder 110 determines a prediction method of the current encoding element based on the encoding efficiency according to the prediction result. Likewise, the encoder 110 may determine the transformation method based on the coding efficiency according to the prediction result. Based on the most effective prediction method and transformation method determining the scheme with respect to the encoding element, the encoding efficiency of the encoding element is finally determined. The encoder 110 determines the hierarchical structure of the largest encoding element according to the encoding efficiency of the finally split encoding element.

[0074] The encoder 110 may measure coding efficiency of coding elements, prediction efficiency of prediction methods, etc. through a rate-to-distortion ratio optimization technique based on Lagrange multipliers.

[0075] The encoder 110 may generate partitioning information indicating whether an encoding element is partitioned based on the determined hierarchical structure of the largest encoding element. The encoder 110 may generate split mode information to determine a prediction element and transform the split element information to determine a transform element with respect to the split encoding element. When there are two or more ways to split an encoding element, the encoder 110 may generate split shape information indicating the splitting method along with the split information. Then, the encoder 110 can generate information about the prediction method and the transformation method used for the prediction element and the transformation element.

[0076] The bitstream generator 120 may output the information generated by the encoder 110 in the form of a bitstream based on the hierarchical structure of the largest encoding element.

[0077] A method for determining an encoding element, a prediction element and a transform element according to a tree structure of the largest encoding element according to one embodiment will be described in detail with reference to FIGS. 3-12 below.

[0078] FIG. 1B depicts a block diagram of an image decoding apparatus 150 based on tree encoding elements according to one embodiment.

[0079] The image decoding apparatus 150 includes a receiver 160 and a decoder 170.

[0080] Various terms such as "encoding element", "prediction element", "transform element" and various "partition information" related to the decoding operation of the image decoding apparatus 150 according to one embodiment are as described above with references. 1 and an image encoding device 100. Additionally, the image decoding apparatus 150 is configured to recover image data, and thus, various encoding methods used on the image encoding apparatus 100 are applicable to the image decoding apparatus 150.

[0081] Receiver 160 receives and parses the bit stream of the encoded image. Receiver 160 extracts the information necessary to decode each largest encoding element from the parsed bitstream and provides the information to decoder 170. Receiver 160 may extract information about the maximum encoding element size of the current frame from a header, sequence parameter set, or frame parameter set for the current frame. .

[0082] Receiver 160 extracts, from the parsed bit stream, encoding element splitting information of the tree structure for each largest encoding element. The extracted splitting information is output to the decoder 170. The decoder 170 may determine a tree structure of the largest encoding element by splitting the largest encoding element according to the extracted splitting information.

[0083] The partitioning information extracted by the decoder 170 is the partitioning information of a tree structure determined by the image encoding apparatus 100 to generate a minimum encoding error. Thus, the image decoding apparatus 150 can reconstruct an image by decoding data according to an encoding method that generates a minimum encoding error.

[0084] The decoder 170 may extract split information about a data element, such as a prediction element and a transform element included in an encoding element. For example, decoder 170 may extract information about the most efficient division mode for a prediction element. The decoder 170 may extract transform split information of the tree structure that is most effective at the transform element.

[0085] The decoder 170 may obtain prediction method information that is most effective in the prediction elements split from the encoding element. Decoder 170 may obtain transform method information that is most effective in the transform elements obtained by splitting from the encoding element.

[0086] The decoder 170 extracts information from the bitstream according to the bitstream configuring method of the bitstream generator 120 of the image encoding device 100.

[0087] Decoder 170 may split the largest encoding element into encoding elements of the most efficient tree structure based on the partitioning information. The decoder 170 may split the encoding element into prediction elements according to the division mode information. The decoder 170 may split the encoding element into transform elements according to the transform splitting information.

[0088] The decoder 170 can predict the prediction element according to the prediction method information. The decoder 170 may perform inverse quantization and inverse transform on the residual data corresponding to the difference between the original value and the prediction value of the pixel based on information about the transform element transform method. Additionally, the decoder 170 can restore the pixels of the encoding element according to the prediction result of the prediction element and the transform result of the transform element.

[0089] FIG. 2 depicts a process by which image decoding apparatus 150 determines at least one encoding element by splitting the current encoding element, according to one embodiment.

[0090] According to one embodiment, the image decoding apparatus 150 can determine the shape of an encoding element by means of block shape information, and can determine the shape into which the encoding element should be divided by means of the partitioning shape information. That is, a method of dividing an encoding element, where the method is indicated by the division type information, can be determined based on the block shape indicated by the block shape information operated by the image decoding device 150.

[0091] According to one embodiment, the image decoding apparatus 150 may use block shape information indicating that the current encoding element has a square shape. For example, the image decoding apparatus 150 may determine whether to split a square coding element, whether to vertically split a square coding element, whether to horizontally split a square coding element, or whether to split a square coding element into four coding elements, based on the split shape information. Referring to FIG. 2, when the block shape information of the current encoding element 200 indicates a square shape, the decoder 180 can determine that the encoding element 210a having the same size as the current encoding element 200 is not split based on the split shape information indicating not to perform partitioning, or may determine encoding elements 210b, 210c or 210d to be partitioned based on partition shape information indicating a predetermined partitioning method.

[0092] Referring to FIG. 2, according to one embodiment, the image decoding apparatus 150 can determine two encoding elements 210b obtained by dividing the current encoding element 200 in the vertical direction based on the partition shape information indicating to perform partitioning in the vertical direction. The image decoding apparatus 150 can determine two encoding elements 210c obtained by dividing the current encoding element 200 in the horizontal direction based on the partition shape information indicating to perform partitioning in the horizontal direction. The image decoding apparatus 150 can determine four encoding elements 210d obtained by dividing the current encoding element 200 in the vertical and horizontal directions based on the partition shape information indicating to perform the partitioning in the vertical and horizontal directions. However, methods for dividing a square encoding element are not limited to the above-described methods, and the partition shape information may indicate various methods. The predetermined broken shapes into which a square encoding element is to be broken will be described in detail below with respect to various embodiments.

[0093] FIG. 3 depicts a process performed by the image decoding apparatus 150 to determine at least one encoding element by splitting a non-square encoding element according to one embodiment.

[0094] According to one embodiment, the image decoding apparatus 150 may use block shape information indicating that the current encoding element has a non-square shape. The image decoding apparatus 150 can determine whether to split the non-square current encoding element or whether to split the non-square current encoding element by a predetermined dividing method based on the dividing shape information. Referring to FIG. 3, when the block shape information of the current encoding element 300 or 350 indicates a non-square shape, the image decoding apparatus 150 can determine that the encoding element 310 or 360 having the same size as the current encoding element 300 or 350 is not split based on split shape information indicating not to split, or determine encoding elements 320a and 320b, 330a-330c, 370a and 370b or 380a-380c split based on split shape information indicating a predetermined splitting method. Preset partitioning methods for partitioning a non-square encoding element will be described in detail below with respect to various embodiments.

[0095] According to one embodiment, the image decoding apparatus 150 may determine a method of dividing an encoding element through the partitioning shape information, and in this case, the partitioning shape information may indicate the number of one or more encoding elements generated by dividing the encoding element. Referring to FIG. 3, when the split shape information indicates to split the current encoding element 300 or 350 into two encoding elements, the image decoding apparatus 150 may determine two encoding elements 320a and 320b or 370a and 370b included in the current encoding element 300 or 350. by splitting the current encoding element 300 or 350 based on the split shape information.

[0096] According to one embodiment, when the image decoding apparatus 150 splits the non-square current encoding element 300 or 350 based on the partition shape information, the current encoding element may be divided taking into account the position of the long side of the non-square current encoding element 300 or 350. For example, the image decoding apparatus 150 may determine a plurality of encoding elements by dividing a long side of the current encoding element 300 or 350 taking into account the shape of the current encoding element 300 or 350.

[0097] According to one embodiment, when the partition shape information indicates to divide an encoding element into an odd number of blocks, the image decoding apparatus 150 can determine the odd number of encoding elements included in the current encoding element 300 or 350. For example, when the split shape information indicates to split the current encoding element 300 or 350 into three encoding elements, the image decoding apparatus 150 may split the current encoding element 300 or 350 into three encoding elements 330a, 330b and 330c or 380a, 380b and 380c. According to one embodiment, image decoding apparatus 150 may determine an odd number of encoding elements included in the current encoding element 300 or 350, and not all determined encoding elements may be the same size. For example, a preset encoding element 330b or 380b from a certain odd number of encoding elements 330a, 330b and 330c or 380a, 380b and 380c may have a size different from the size of the other encoding elements 330a and 330c or 380a and 380c. That is, the encoding elements, which may be determined by partitioning the current encoding element 300 or 350, may have a plurality of sizes, and, in some cases, all of the odd number of encoding elements 330a, 330b, and 330c or 380a, 380b, and 380c may have different sizes. .

[0098] According to one embodiment, when the partition shape information indicates to split an encoding element into an odd number of blocks, the image decoding apparatus 150 may determine the odd number of encoding elements included in the current encoding element 300 or 350, and may impose a predetermined limit on at least at least one encoding element from an odd number of encoding elements generated by splitting the current encoding element 300 or 350. Referring to FIG. 3, the image decoding apparatus 150 may allow the decoding method of the encoding element 330b or 380b to be different from the decoding method of the other encoding elements 330a and 330c or 380a and 380c, where the encoding element 330b or 380b is at the center position of the three elements 330a. , 330b and 330c or 380a, 380b and 380c, generated by splitting the current encoding element 300 or 350. For example, the image decoding apparatus 150 may constrain the encoding element 330b or 380b to a central position so that it is no longer broken or is only broken a predetermined number of times, unlike the other encoding elements 330a and 330c or 380a and 380c.

[0099] FIG. 4 depicts a process performed by the image decoding apparatus 150 for dividing an encoding element based on at least one of block shape information and partition shape information according to one embodiment.

[00100] According to one embodiment, the image decoding apparatus 150 can determine whether or not to split the square first encoding element 400 into encoding elements based on at least one of the block shape information and the partition shape information. According to one embodiment, when the partition shape information indicates to partition the first encoding element 400 in the horizontal direction, the image decoding apparatus 150 can determine the second encoding element 410 by dividing the first encoding element 400 in the horizontal direction. The first encoding element, the second encoding element, and the third encoding element, as used according to one embodiment, are terms used to understand the relationship before and after splitting the encoding element. For example, a second encoding element may be determined by partitioning the first encoding element, and a third encoding element may be determined by partitioning the second encoding element. It will be understood that the relationship between the first encoding element, the second encoding element and the third encoding element follows the above descriptions.

[00101] According to one embodiment, the image decoding apparatus 150 can determine whether or not to split a certain second encoding element 410 into encoding elements based on at least one of block shape information and partition shape information. Referring to FIG. 4, the image decoding apparatus 150 may or may not split the non-square second encoding element 410, which is determined by dividing the first encoding element 400, into one or more third encoding elements 420a or 420b, 420c and 420d based on at least one of block shape information and partition shape information. The image decoding apparatus 150 may obtain at least one of block shape information and partition shape information and determine a plurality of differently shaped second encoding elements (e.g., 410) by dividing the first encoding element 400 based on the obtained at least one of the block shape information and partition shape information, and the second encoding element 410 may be partitioned by a method of partitioning the first encoding element 400 based on at least one of the block shape information and partition shape information. According to one embodiment, when the first encoding element 400 is partitioned into second encoding elements 410 based on at least one of the block shape information and the partition shape information of the first encoding element 400, the second encoding element 410 may also be partitioned into third elements 420a or 420b. 420c and 420d encoding based on at least one of block shape information and partition shape information of the second encoding element 410. That is, the encoding element may be recursively partitioned based on at least one of the block shape information and the partition shape information of each encoding element. A method that can be used to recursively split an encoding element will be described below with respect to various embodiments.

[00102] According to one embodiment, image decoding apparatus 150 may decide to split each of the third encoding elements 420a or 420b, 420c and 420d into encoding elements or not to split the second encoding element 410 based on at least one of block shape information and information forms of partition. According to one embodiment, image decoding apparatus 150 may split the non-square second encoding element 410 into an odd number of third encoding elements 420b, 420c and 420d. The image decoding apparatus 150 may impose a preset constraint on a preset third encoding element from an odd number of third encoding elements 420b, 420c, and 420d. For example, the image decoding apparatus 150 may constrain the third encoding element 420c to a central position from an odd number of third encoding elements 420b, 420c, and 420d so that it is no longer broken or broken a set number of times. Referring to FIG. 4, the image decoding apparatus 150 may constrain the third encoding element 420c, which is at the center position of an odd number of third encoding elements 420b, 420c, and 420d included in the non-square second encoding element 410, so that it is no longer split, split by a predetermined partitioning method (eg, partitioned only into four encoding elements or partitioned by the partitioning method of the second encoding element 410) or partitioned only a predetermined number of times (eg, partitioned only n times (where n>0)). However, restrictions on the third center position encoding element 420c are not limited to the above-described examples and may include various restrictions for decoding the third center position encoding element 420c in a different manner from the other third encoding elements 420b and 420d.

[00103] According to one embodiment, the image decoding apparatus 150 can obtain at least one of block shape information and partition shape information that is used to partition the current encoding element from a preset position in the current encoding element.

[00104] According to one embodiment, when the current encoding element is divided into a predetermined number of encoding elements, the image decoding apparatus 150 may select one of the encoding elements. Various methods may be used to select one of a variety of encoding elements, as will be described below with respect to various embodiments.

[00105] According to one embodiment, the image decoding apparatus 150 can split the current encoding element into a plurality of encoding elements and can determine the encoding element at a predetermined position.

[00106] FIG. 5 depicts a method performed by the image decoding apparatus 150 for determining a preset position encoding element from an odd number of encoding elements according to one embodiment.

[00107] According to one embodiment, the image decoding apparatus 150 may use information indicating positions of an odd number of encoding elements to determine an encoding element at a central position of the odd number of encoding elements. Referring to FIG. 5, the image decoding apparatus 150 may determine an odd number of encoding elements 520a, 520b, and 520c by dividing the current encoding element 500. The image decoding apparatus 150 can determine the encoding element 520b at the center position by information about the positions of an odd number of encoding elements 520a, 520b and 520c. For example, the image decoding apparatus 150 may determine the center position encoding element 520b by determining the positions of the encoding elements 520a, 520b and 520c based on information indicating the positions of preset samples included in the encoding elements 520a, 520b and 520c. In detail, the image decoding apparatus 150 can determine the encoding element 520b at the center position by determining the positions of the encoding elements 520a, 520b and 520c based on information indicating the positions of the upper left samples 530a, 530b and 530c of the encoding elements 520a, 520b and 520c.

[00108] According to one embodiment, information indicating the positions of the top left samples 530a, 530b, and 530c that are included in encoding elements 520a, 520b, and 520c, respectively, may include information about the positions or coordinates of elements 520a, 520b, and 520c coding in the frame. According to one embodiment, information indicating the positions of the top left samples 530a, 530b, and 530c that are included in encoding elements 520a, 520b, and 520c, respectively, may include information indicating the widths or heights of encoding elements 520a, 520b, and 520c, included in the current encoding element 500, and the width or height may correspond to information indicating differences between the coordinates of encoding elements 520a, 520b and 520c in the frame. That is, the image decoding apparatus 150 can determine the encoding element 520b at the center position by directly using information about the positions or coordinates of the encoding elements 520a, 520b and 520c in the frame or by information about the widths or heights of the encoding elements that correspond to the difference in values between the coordinates.

[00109] According to one embodiment, information indicating the position of the upper left sample 530a of the upper upper layer encoding element 520a may include (xa, ya) coordinates, information indicating the position of the upper left sample 530b of the middle encoding element 520b may include coordinates (xb, yb), and information indicating the position of the upper left sample 530c of the lower encoding element 520c may include coordinates (xc, yc). The image decoding apparatus 150 may determine the middle encoding element 520b by the coordinates of the upper left samples 530a, 530b, and 530c that are included in the encoding elements 520a, 520b, and 520c, respectively. For example, when the coordinates of the upper left samples 530a, 530b, and 530c are sorted in ascending or descending order, the encoding element 520b including the coordinates (xb, yb) of the sample 530b at the center position may be defined as the encoding element at the center position among encoding elements 520a, 520b and 520c determined by splitting the current encoding element 500. However, the coordinates indicating the positions of the top left samples 530a, 530b and 530c may include coordinates indicating absolute positions in the frame, or may use coordinates (dxb, dyb) indicating the relative position of the top left sample 530b of the middle encoding element 520b, and coordinates (dxc, dyc) indicating the relative position of the upper left sample 530c of the lower encoding element 520c with reference to the position of the upper left sample 530a of the upper encoding element 520a. The method of determining an encoding element at a predetermined position by the coordinates of a sample sample included in the encoding element as information indicating the position of the sample sample is not limited to the above-described method, and may include various arithmetic methods capable of using the coordinates of the sample sample.

[00110] According to one embodiment, the image decoding apparatus 150 may partition the current encoding element 500 into a plurality of encoding elements 520a, 520b, and 520c, and may select one of the encoding elements 520a, 520b, and 520c based on a predetermined criterion. For example, the image decoding apparatus 150 may select an encoding element 520b that has a different size from the others from the encoding elements 520a, 520b, and 520c.

[00111] According to one embodiment, the image decoding apparatus 150 may determine the widths or heights of the encoding elements 520a, 520b, and 520c by coordinates (xa, ya) indicating the position of the top left sample 530a of the top encoding element 520a, coordinates (xb, yb) , indicating the position of the upper left sample 530b of the middle encoding element 520b, and coordinates (xc, yc) indicating the position of the upper left sample 530c of the lower encoding element 520c. The image decoding apparatus 150 can determine the respective sizes of the encoding elements 520a, 520b and 520c by coordinates (xa, ya), (xb, yb) and (xc, yc) indicating the positions of the encoding elements 520a, 520b and 520c.

[00112] According to one embodiment, the image decoding apparatus 150 may determine the width of the upper encoding element 520a as xb-xa and determine its height as yb-ya. According to one embodiment, the image decoding apparatus 150 may determine the width of the middle encoding element 520b as xc-xb and determine its height as yc-yb. According to one embodiment, the image decoding apparatus 150 may determine the width or height of the bottom encoding element 520c by the width or height of the current encoding element 500 or the widths or heights of the upper and middle encoding elements 520a and 520b. The image decoding apparatus 150 may determine an encoding element that has a different size from the others based on the determined widths and heights of the encoding elements 520a, 520b, and 520c. Referring to FIG. 5, the image decoding apparatus 150 may determine the middle encoding element 520b, which has a size different from the size of the upper and lower encoding elements 520a and 520c, as the preset position encoding element. However, the above-described method performed by the image decoding apparatus 150 of determining an encoding element having a size different from the size of other encoding elements corresponds only to the example of determining an encoding element at a predetermined position by the sizes of encoding elements that are determined based on the sample coordinates, and thus Thus, various methods for determining an encoding element at a predetermined position by comparing the sizes of encoding elements that are determined based on the coordinates of predetermined sample samples can be used.

[00113] However, the positions of the sample samples taken into account to determine the positions of the encoding elements are not limited to the above-described upper left positions, and information about the random positions of the sample samples included in the encoding elements can be used.

[00114] According to one embodiment, the image decoding apparatus 150 may select an encoding element at a preset position from an odd number of encoding elements determined by dividing the current encoding element, taking into account the shape of the current encoding element. For example, when the current encoding element has a non-square shape whose width is longer than the height, the image decoding apparatus 150 can determine the encoding element at a predetermined position in the horizontal direction. That is, the image decoding apparatus 150 can determine one of the encoding elements at different positions in the horizontal direction and impose a constraint on the encoding element. When the current encoding element has a non-square shape whose height is longer than the width, the image decoding apparatus 150 can determine the encoding element at a predetermined position in the vertical direction. That is, the image decoding apparatus 150 can determine one of the encoding elements at different positions in the vertical direction and can impose a constraint on the encoding element.

[00115] According to one embodiment, the image decoding apparatus 150 may use information indicating the corresponding positions of an even number of encoding elements to determine an encoding element at a predetermined position of an even number of encoding elements. The image decoding apparatus 150 can determine an even number of encoding elements by dividing the current encoding element, and can determine an encoding element at a preset position by information about the positions of the even number of encoding elements. The operation related thereto may correspond to the operation of determining an encoding element at a predetermined position (eg, a center position) from an odd number of encoding elements, which was described in detail above with respect to FIG. 5, and thus detailed descriptions thereof are not provided here. .

[00116] According to one embodiment, when a non-square current encoding element is divided into a plurality of encoding elements, preset information about the encoding element at a preset position can be used in a partitioning operation to determine the encoding element at a preset position from the plurality of encoding elements. For example, the image decoding apparatus 150 may use at least one of the block shape information and the split shape information that is stored in a sample included in the center position encoding element in a split operation to determine the center position encoding element from a plurality of encoding elements , defined by splitting the current encoding element.

[00117] Referring to FIG. 5, the image decoding apparatus 150 may partition the current encoding element 500 into a plurality of encoding elements 520a, 520b, and 520c based on at least one of block shape information and partition shape information, and may determine encoding element 520b. at a central position of a plurality of encoding elements 520a, 520b and 520c. In addition, the image decoding apparatus 150 may determine the encoding element 520b at a central position taking into account the position from which at least one of the block shape information and the split shape information is obtained. That is, at least one of the block shape information and the partition shape information of the current encoding element 500 can be obtained from the sample 540 at the center position of the current encoding element 500, and when the current encoding element 500 is divided into a plurality of encoding elements 520a, 520b and 520c based on at least one of the block shape information and the partition shape information, the encoding element 520b including the sample 540 can be determined to be the encoding element at the center position. However, the information used to determine the encoding element at the center position is not limited to at least one of block shape information and split shape information, and various types of information may be used to determine the encoding element at the center position.

[00118] According to one embodiment, preset information for identifying an encoding element at a preset position can be obtained from a preset sample included in the encoding element to be determined. Referring to FIG. 5, the image decoding apparatus 150 may use at least one of block shape information and partition shape information that is obtained from a sample at a preset position in the current encoding element 500 (for example, a sample at the center position of the current element 500 encoding) to determine an encoding element at a predetermined position from a plurality of encoding elements 520a, 520b and 520c determined by splitting the current encoding element 500 (eg, an encoding element at a central position from a plurality of divided encoding elements). That is, the image decoding apparatus 150 may determine a sample at a preset position based on the block shape of the current encoding element 500, determine an encoding element 520b including the sample from which the preset information (for example, at least one of the block shape information and partition shape information) may be obtained from a plurality of encoding elements 520a, 520b, and 520c determined by dividing the current encoding element 500, and may impose a predetermined constraint on encoding element 520b. Referring to FIG. 5, according to one embodiment, the image decoding apparatus 150 can determine a sample 540 at the center position of the current encoding element 500 as a sample from which preset information can be obtained, and can impose a preset constraint on the element encoding 520b, including sample 540, in a decoding operation. However, the position of the sampled sample from which the preset information can be obtained is not limited to the above-described position, and may include arbitrary positions of the sampled samples included in the encoding element 520b to be determined for limitation.

[00119] According to one embodiment, the position of the sample from which preset information can be obtained can be determined based on the shape of the current encoding element 500. According to one embodiment, the block shape information may indicate whether the current encoding element has a square or non-square shape, and the sample position from which the preset information can be obtained can be determined based on the shape. For example, the image decoding apparatus 150 may determine a sample located at a boundary for dividing at least one of the width and height of the current encoding element in half as a sample from which preset information can be obtained by at least one of the information about the width of the current encoding element and information about the height of the current encoding element. As another example, when the block shape information of the current encoding element indicates a non-square shape, the image decoding apparatus 150 may determine one of the samples adjacent to the boundary for bisecting the long side of the current encoding element as a sample from which the preset information can be received.

[00120] According to one embodiment, when the current encoding element is divided into a plurality of encoding elements, the image decoding apparatus 150 may use at least one of the block shape information and the split shape information to determine the encoding element at a predetermined position from the plurality of encoding elements. According to one embodiment, the image decoding apparatus 150 can obtain at least one of block shape information and partition shape information from a sample at a predetermined position in an encoding element, and can split a plurality of encoding elements that are generated by dividing the current encoding element by at least one of partition shape information and block shape information that is obtained from a sample of a predetermined position in each of the plurality of encoding elements. That is, the encoding element may be recursively divided based on at least one of block shape information and partition shape information that is obtained from a sample at a predetermined position in each encoding element. The operation of recursively splitting an encoding element has been described above with respect to FIG. 4, and thus detailed descriptions thereof will not be given here.

[00121] According to one embodiment, the image decoding apparatus 150 may determine one or more encoding elements by partitioning the current encoding element, and may determine the decoding order of the one or more encoding elements based on a preset block (eg, the current encoding element).

[00122] FIG. 6 depicts a processing order of multiple encoding elements when the image decoding apparatus 150 determines a plurality of encoding elements by splitting the current encoding element according to one embodiment.

[00123] According to one embodiment, image decoding apparatus 150 may determine second encoding elements 610a and 610b by dividing the first encoding element 600 in the vertical direction, may determine second encoding elements 630a and 630b by dividing the first encoding element 600 in the horizontal direction, or may determine second encoding elements 650a, 650b, 650c and 650d by dividing the first encoding element 600 in the vertical and horizontal directions based on the block shape information and the partition shape information.

[00124] Referring to FIG. 6, the image decoding apparatus 150 may determine to process the second encoding elements 610A and 610b, which are determined by dividing the first encoding element 600 in the vertical direction, in the horizontal direction order 610c. The image decoding apparatus 150 may decide to process the second encoding elements 630A and 630b, which are determined by splitting the first encoding element 600 in the horizontal direction, in the order of the vertical direction 630c. The image decoding apparatus 150 may decide to process the second encoding elements 650a, 650b, 650c and 650d, which are determined by dividing the first encoding element 600 in the vertical and horizontal directions according to a predetermined order (for example, a raster scan order or a Z-scan order 650e), whereby the encoding elements in a line are processed, and then the encoding elements in the next line are processed.

[00125] According to one embodiment, image decoding apparatus 150 may recursively split encoding elements. Referring to FIG. 6, the image decoding apparatus 150 may determine a plurality of encoding elements 610a, 610b, 630a, 630b, 650a, 650b, 650c, and 650d by dividing the first encoding element 600, and may recursively partition each of the determined plurality of elements 610a, 610b. 630a, 630b, 650a, 650b, 650c and 650d encoding. The partitioning method of the plurality of encoding elements 610a, 610b, 630a, 630b, 650a, 650b, 650c and 650d may correspond to the partitioning method of the first encoding element 600. Thus, each of the plurality of encoding elements 610a, 610b, 630a, 630b, 650a, 650b, 650c and 650d can be independently divided into a plurality of encoding elements. Referring to FIG. 6, the image decoding apparatus 150 can determine the second encoding elements 610A and 610b by splitting the first encoding element 600 in the vertical direction, and can independently determine whether or not to split each of the second encoding elements 610a and 610b.

[00126] According to one embodiment, the image decoding apparatus 150 may determine the third encoding elements 620a and 620b by splitting the left second encoding element 610a in the horizontal direction and may not split the right second encoding element 610b.

[00127] According to one embodiment, the processing order of the encoding elements may be determined based on the operation of splitting the encoding element. In other words, the processing order of the split encoding elements can be determined based on the processing order of the encoding elements immediately before the split. The image decoding apparatus 150 may determine the processing order of the third encoding elements 620a and 620b determined by splitting the left second encoding element 610a independently of the right second encoding element 610b. Since the third encoding elements 620A and 620b are determined by splitting the left second encoding element 610a in the horizontal direction, the third encoding elements 620a and 620b can be processed in the vertical direction order 620c. Since the left and right second encoding elements 610a and 610b are processed in the horizontal direction order 610c, the right second encoding element 610b can be processed after the third encoding elements 620a and 620b included in the left second encoding element 610a are processed in the vertical direction order 620c. The operation of determining the processing order of encoding elements based on the encoding element before partitioning is not limited to the above example, and various methods can be used to independently process encoding elements that are partitioned and determined with different shapes in a predetermined order.

[00128] FIG. 7 depicts a process performed by the image decoding apparatus 150 to determine that a current encoding element should be divided into an odd number of encoding elements when the encoding elements are not capable of being processed in a predetermined order, according to one embodiment.

[00129] According to one embodiment, the image decoding apparatus 150 can determine whether the current encoding element should be divided into an odd number of encoding elements based on the obtained block shape information and the partition shape information. Referring to FIG. 7, the square first encoding element 700 may be divided into non-square second encoding elements 710a and 710b, and the second encoding elements 710a and 710b may be independently divided into third encoding elements 720a and 720b, and 720c-720e. According to one embodiment, the image decoding apparatus 150 can determine a plurality of third encoding elements 720a and 720b by dividing the left second encoding element 710a in the horizontal direction, and can partition the right second encoding element 710b into an odd number of third encoding elements 720c-720e.

[00130] According to one embodiment, image decoding apparatus 150 can determine whether any encoding element should be split into an odd number of encoding elements by determining whether third encoding elements 720a and 720b, and 720c-720e can be processed in pre- in the prescribed manner. Referring to FIG. 7, the image decoding apparatus 150 may determine the third encoding elements 720a and 720b, and 720c-720e by recursively splitting the first encoding element 700. The image decoding apparatus 150 may determine whether any of the first encoding element 700 should the second encoding elements 710a and 710b and the third encoding elements 720a and 720b, and 720c, 720d and 720e be split into an odd number of encoding elements based on at least one of the block shape information and the partition shape information. For example, the second encoding element located to the right of the second encoding elements 710a and 710b may be divided into an odd number of third encoding elements 720c, 720d and 720e. The processing order of the plurality of encoding elements included in the first encoding element 700 may be a predetermined order (for example, the order of the Z-scan 730), and the image decoding apparatus 70 may determine whether the third encoding elements 720c, 720d, and 720e, which are determined by dividing the right second encoding element 710B into an odd number of encoding elements, conditioned to be processed in a predetermined order.

[00131] According to one embodiment, the image decoding apparatus 150 can determine whether the third encoding elements 720a and 720b, and 720c, 720d and 720e included in the first encoding element 700 satisfy a condition for processing in a predetermined order, and the condition refers to whether at least one of the width and height of the second encoding elements 710a and 710b should be bisected along the boundary of the third encoding elements 720a and 720b, and 720c, 720d and 720e. For example, third encoding elements 720a and 720b determined by dividing the height of the non-square left second encoding element 710a in half satisfy the condition. However, since the boundaries of the third encoding elements 720c, 720d and 720e determined by dividing the right second encoding element 710b into three encoding elements do not bisect the width or height of the right second encoding element 710b, it can be determined that the third encoding elements 720c, 720d and 720e do not satisfy the condition. When the condition is not satisfied as described above, the image decoding apparatus 150 may decide to decouple the scan order and determine that the right second encoding element 710b should be divided into an odd number of encoding elements based on the result of the decision. According to one embodiment, when a coding element is divided into an odd number of coding elements, the image decoding apparatus 150 may impose a preset constraint on the coding element at a preset position of the coding elements. The limitation or predetermined position has been described above with respect to various embodiments, and thus, detailed descriptions thereof will not be given here.

[00132] FIG. 8 depicts a process performed by the image decoding apparatus 150 to determine at least one encoding element by splitting the first encoding element 800 according to one embodiment. According to one embodiment, the image decoding apparatus 150 may split the first encoding element 800 based on at least one of block shape information and partition shape information that is obtained by the receiver 160. The square first encoding element 800 may be divided into four square encoding elements or may be broken down into many non-square coding elements. For example, with reference to FIG. 8, when the block shape information indicates that the first encoding element 800 has a square shape, and the partition shape information indicates to divide the first encoding element 800 into non-square encoding elements, the image decoding apparatus 150 may partition the first encoding element 800 into set of non-square coding elements. In detail, when the partitioning shape information indicates to determine an odd number of encoding elements by dividing the first encoding element 800 in the horizontal direction or the vertical direction, the image decoding apparatus 150 may divide the square first encoding element 800 into an odd number of encoding elements, for example, second elements 810a, 810b and encoding elements 810c determined by dividing the square first encoding element 800 in the vertical direction, or second encoding elements 820a, 820b and 820c determined by dividing the square first encoding element 800 in the horizontal direction.

[00133] According to one embodiment, the image decoding apparatus 150 can determine whether the second encoding elements 810a, 810b, 810c, 820a, 820b, and 820c included in the first encoding element 800 satisfy a condition for processing in a predetermined order, and the condition applies to whether at least one of the width and height of the first encoding element 800 should be bisected along the boundary of the second encoding elements 810a, 810b, 810c, 820a, 820b and 820c. Referring to FIG. 8, since the boundaries of the second encoding elements 810a, 810b, and 810c determined by dividing the square first encoding element 800 in the vertical direction do not bisect the height of the first encoding element 800, it can be determined that the first encoding element 800 does not satisfy condition for processing in a predetermined manner. Additionally, since the boundaries of the second encoding elements 820a, 820b, and 820c determined by dividing the square first encoding element 800 in the horizontal direction do not bisect the width of the first encoding element 800, it can be determined that the first encoding element 800 does not satisfy the condition for preprocessing. in the prescribed manner. When the condition is not satisfied as described above, the image decoding apparatus 150 may decide to decompose the scan order and may determine that the first encoding element 800 should be divided into an odd number of encoding elements based on the decision result. According to one embodiment, when a coding element is split into an odd number of coding elements, the image decoding apparatus 150 may impose a preset constraint on the coding element at a predetermined position of the split coding elements. The limitation or predetermined position has been described above with respect to various embodiments, and thus, detailed descriptions thereof will not be given here.

[00134] According to one embodiment, the image decoding apparatus 150 can determine encoding elements of different shapes by splitting the first encoding element.

[00135] Referring to FIG. 8, the image decoding apparatus 150 may split the square first encoding element 800 or the non-square first encoding element 830 or 850 into encoding elements of various shapes.

[00136] FIG. 9 depicts that the shape into which the second encoding element is able to be divided by the image decoding apparatus 150 is limited when the second encoding element having a non-square shape, which is determined by dividing the first encoding element 900, satisfies a preset condition according to one embodiment.

[00137] According to one embodiment, the image decoding apparatus 150 may decide to split the square first encoding element 900 into non-square second encoding elements 910a, 910b, 920a, and 920b based on at least one of block shape information and partition shape information that is obtained receiver 160. Second encoding elements 910a, 910b, 920a, and 920b may be independently split. That is, the image decoding apparatus 150 can decide whether or not to split the first encoding element 900 into a plurality of encoding elements based on at least one of the block shape information and the partition shape information of each of the second encoding elements 910a, 910b, 920a and 920b . According to one embodiment, the image decoding apparatus 150 may determine the third encoding elements 912a and 912b by splitting the non-square left second encoding element 910a, which is determined by dividing the first encoding element 900 in the vertical direction, in the horizontal direction. However, when the left second encoding element 910a is split in the horizontal direction, the image decoding apparatus 150 may limit the right second encoding element 910b to not be split in the horizontal direction in which the left second encoding element 910a is split. When the third encoding elements 914a and 914b are determined by partitioning the right second encoding element 910b in the same direction, since the left and right second encoding elements 910a and 910b are independently partitioned in the horizontal direction, the third encoding elements 912a, 912b, 914a and 914b can be defined. However, this case also serves as a case in which the image decoding apparatus 150 splits the first encoding element 900 into four square second encoding elements 930a, 930b, 930c and 930d based on at least one of the block shape information and the partition shape information, and may be ineffective in decoding images.

[00138] According to one embodiment, image decoding apparatus 150 may determine third encoding elements 922a, 922b, 924a, and 924b by dividing a non-square second encoding element 920a or 920b, which is determined by dividing the first encoding element 900 in the horizontal direction, in the vertical direction. However, when the second encoding element (for example, the upper second encoding element 920a) is split in the vertical direction, for the reason described above, the image decoding apparatus 150 may limit the other second encoding element (for example, the lower second encoding element 920b) so that it is not split in the vertical direction. , in which the upper second encoding element 920a is split.

[00139] FIG. 18 depicts a process performed by the image decoding apparatus 150 for splitting a square encoding element when the partitioning shape information indicates that the square encoding element should not be divided into four square encoding elements, according to one embodiment.

[00140] According to one embodiment, the image decoding apparatus 150 may determine second encoding elements 1010a, 1010b, 1020a, 1020b, etc. by dividing the first encoding element 1000 based on at least one of block shape information and partition shape information. The partitioning shape information may include information about different ways of partitioning an encoding element, but the information about different ways of partitioning may not include information for dividing an encoding element into four square encoding elements. According to such partitioning shape information, the image decoding apparatus 150 may not partition the first square encoding element 1000 into four square second encoding elements 1030a, 1030b, 1030c and 1030d. The image decoding apparatus 150 may determine non-square second encoding elements 1010a, 1010b, 1020a, 1020b, etc. based on the split shape information.

[00141] According to one embodiment, image decoding apparatus 150 may independently decompose non-square second encoding elements 1010a, 1010b, 1020a, 1020b, etc. Each of the second elements 1010a, 1010b, 1020a, 1020b, etc. encoding may be recursively partitioned in a predetermined order, and this partitioning method may correspond to a partitioning method of the first encoding element 1000 based on at least one of the block shape information and the partition shape information.

[00142] For example, the image decoding apparatus 150 may determine the square third encoding elements 1012a and 1012b by dividing the left second encoding element 1010a in the horizontal direction, and may determine the square third encoding elements 1014a and 1014b by dividing the right second encoding element 1010b in the horizontal direction. In addition, the image decoding apparatus 150 can determine the square third encoding elements 1016a, 1016b, 1016c and 1016d by dividing both of the left and right second encoding elements 1010a and 1010b in the horizontal direction. In this case, encoding elements having the same shape as the four square second encoding elements 1030a, 1030b, 1030c and 1030d split from the first encoding element 1000 can be determined.

[00143] As another example, image decoding apparatus 150 may determine square third encoding elements 1022a and 1022b by dividing the upper second encoding element 1020a in the vertical direction, and may determine square third encoding elements 1024a and 1024b by dividing the lower second encoding element 1020b in the vertical direction direction. In addition, the image decoding apparatus 150 can determine the square third encoding elements 1022a, 1022b, 1024a and 1024b by dividing both of the upper and lower second encoding elements 1020a and 1020b in the vertical direction. In this case, encoding elements having the same shape as the four square second encoding elements 1030a, 1030b, 1030c and 1030d split from the first encoding element 1000 can be determined.

[00144] FIG. 11 depicts that the processing order between multiple encoding elements may be changed depending on the encoding element partitioning process according to one embodiment.

[00145] According to one embodiment, the image decoding apparatus 150 may split the first encoding element 1100 based on the block shape information and the split shape information. When the block shape information indicates a square shape and the partition shape information indicates to partition the first encoding element 1100 in at least one of the horizontal and vertical directions, the image decoding apparatus 150 can determine the second encoding elements 1110a, 1110b, 1120a and 1120b by dividing the first encoding element 1100 . Referring to FIG. 11, the non-square second encoding elements 1110a, 1110b, 1120a and 1120b determined by dividing the first encoding element 1100 only in the horizontal direction or vertical direction can be independently partitioned based on the block shape information and the partitioning shape information of each encoding element. For example, the image decoding apparatus 150 may determine the third encoding elements 1116a, 1116b, 1116c, and 1116d by dividing the second encoding elements 1110a and 1110b, which are generated by dividing the first encoding element 1100 in the vertical direction, in the horizontal direction, and may determine the third elements 1126a. 1126b, 1126c and 1126d encoding by dividing the second encoding elements 1120a and 1120b, which are generated by dividing the first encoding element 1100 in the horizontal direction, in the vertical direction. The operation of dividing the second encoding elements 1110a, 1110b, 1120a and 1120b has been described above with respect to FIG. 9, and thus detailed descriptions thereof will not be given here.

[00146] According to one embodiment, the image decoding apparatus 150 may process encoding elements in a predetermined order. The operation of processing encoding elements in a predetermined order has been described above with respect to FIG. 6, and thus detailed descriptions thereof will not be given here. Referring to FIG. 11, the image decoding apparatus 150 can determine four square third encoding elements 1116a, 1116b, 1116c and 1116d, and 1126a, 1126b, 1126c and 1126d by dividing the square first encoding element 1100. According to one embodiment, the image decoding apparatus 150 may determine the processing orders of the third encoding elements 1116a, 1116b, 1116c and 1116d, and 1126a, 1126b, 1126c and 1126d based on the way the first encoding element 1100 is partitioned.

[00147] According to one embodiment, the image decoding apparatus 150 can determine the third encoding elements 1116a, 1116b, 1116c, and 1116d by splitting the second encoding elements 1110a and 1110b generated by splitting the first encoding element 1100 in the vertical direction, in the horizontal direction, and can process third encoding elements 1116a, 1116b, 1116c and 1116d in the processing order 1117 for initially processing third encoding elements 1116a that are included in the left second encoding element 1110a in the vertical direction and then processing third encoding elements 1116b and 1116d that are included in the right second element 1110b encoding, in vertical direction.

[00148] According to one embodiment, the image decoding apparatus 150 can determine the third encoding elements 1126a, 1126b, 1126c, and 1126d by splitting the second encoding elements 1120a and 1120b generated by splitting the first encoding element 1100 in the horizontal direction, in the vertical direction, and can process third encoding elements 1126a, 1126b, 1126c and 1126d in the processing order 1127 for initially processing third encoding elements 1126a and 1126b that are included in the upper second encoding element 1120a in the horizontal direction and then processing third encoding elements 1126c and 1126d that are included in the lower a second encoding element 1120b, in the horizontal direction.

[00149] Referring to FIG. 11, square third encoding elements 1116a, 1116b, 1116c and 1116d, and 1126a, 1126b, 1126c and 1126d can be determined by partitioning the second encoding elements 1110a, 1110b, 1120a and 1120b, respectively. Although the second encoding elements 1110a and 1110b are determined by dividing the first encoding element 1100 in the vertical direction in a different manner from the second encoding elements 1120a and 1120b, which are determined by dividing the first encoding element 1100 in the horizontal direction, the third elements 1116a, 1116b, 1116c and 1116d, and The encodings 1126a, 1126b, 1126c and 1126d split from them ultimately show encoding elements of the same shape split from the first coding element 1100. Thus, by recursively dividing an encoding element in various ways based on at least one of the block shape information and the partitioning shape information, the image decoding apparatus 150 can process multiple encoding elements in different orders, even when the encoding elements are ultimately determined to have one and the same shape.

[00150] FIG. 12 depicts a process for determining the depth of an encoding element as the shape and size of the encoding element changes when the encoding element is recursively divided so that a plurality of encoding elements are determined, according to one embodiment.

[00151] According to one embodiment, the image decoding apparatus 150 can determine the depth of an encoding element based on a predetermined criterion. For example, the preset criterion may be the length of the long side of the encoding element. When the long side length of a pre-divided encoding element is 2n times (n>0) greater than the long side length of the split current encoding element, the image decoding apparatus 150 can determine that the depth of the current encoding element is increased relative to the depth of the pre-divided encoding element by n. In the following description, an encoding element having an increased depth is expressed as a higher depth encoding element.

[00152] Referring to FIG. 12, according to one embodiment, the image decoding apparatus 150 can determine the second encoding element 1202 and the third deeper encoding element 1204 by dividing the square of the first encoding element 1200 based on the block shape information indicating the square shape ( for example, block shape information can be expressed as "0: SQUARE"). Assuming that the size of the square first encoding element 1200 is 2N×2N, the second encoding element 1202 determined by dividing the width and height of the first encoding element 1200 by 2 may have a size of N×N. In addition, the third encoding element 1204, determined by dividing the width and height of the second encoding element 1202 by 2, may have a size of N/2×N/2. In this case, the width and height of the third encoding element 1204 are 1/2 of the width and height of the first encoding element 1200. When the depth of the first encoding element 1200 is D, the depth of the second encoding element 1202, whose width and height are 1/2 of the width and height of the first encoding element 1200, may be D+1, and the depth of the third encoding element 1204, whose width and height equal to 1/2 of the width and height of the first encoding element 1200, may be equal to D+2.

[00153] According to one embodiment, image decoding apparatus 150 may determine a second encoding element 1212 or 1222 and a third deeper encoding element 1214 or 1224 by splitting the non-square first encoding element 1210 or 1220 based on block shape information indicating the non-square shape (e.g. , the block shape information can be expressed as "1:NS_VER", which indicates a non-square shape whose height is longer than the width, or as "2:NS_HOR", which indicates a non-square shape whose width is longer than the height).

[00154] The image decoding apparatus 150 may determine the second encoding element 1202, 1212, or 1222 by dividing at least one of the width and height of the first encoding element 1210 having a size of N×2N. That is, the image decoding apparatus 150 may determine the second encoding element 1202 having size N×N or the second encoding element 1222 having size N×N/2 by dividing the first encoding element 1210 in the horizontal direction, or may determine the second encoding element 1212 having a size of N/2×N by dividing the first encoding element 1210 in the horizontal and vertical directions.

[00155] According to one embodiment, image decoding apparatus 150 may determine a second encoding element 1202, 1212, or 1222 by dividing at least one of the width and height of the first encoding element 1220 having a size of 2N×N. That is, the image decoding apparatus 150 may determine the second encoding element 1202 having size N×N or the second encoding element 1212 having size N/2×N by dividing the first encoding element 1220 in the vertical direction, or may determine the second encoding element 1222 having a size of N×N/2, by dividing the first encoding element 1220 in the horizontal and vertical directions.

[00156] According to one embodiment, image decoding apparatus 150 may determine a third encoding element 1204, 1214, or 1224 by dividing at least one of the width and height of the second encoding element 1202 having an N×N size. That is, the image decoding apparatus 150 may determine a third encoding element 1204 having a size of N/2×N/2, a third encoding element 1214 having a size N/2×N/2, or a third encoding element 1224 having a size N/2× N/2, by splitting the second encoding element 1202 in the vertical and horizontal directions.

[00157] According to one embodiment, image decoding apparatus 150 may determine a third encoding element 1204, 1214, or 1224 by dividing at least one of the width and height of the second encoding element 1212 having a size of N/2×N. That is, the image decoding apparatus 150 may determine the third encoding element 1204 having size N/2×N/2 or the third encoding element 1224 having size N/2×N/2 by dividing the second encoding element 1212 in the horizontal direction, or may determine a third encoding element 1214 having a size of N/2×N/2 by splitting the second encoding element 1212 in the vertical and horizontal directions.

[00158] According to one embodiment, image decoding apparatus 150 may determine a third encoding element 1204, 1214, or 1224 by dividing at least one of the width and height of the second encoding element 1212 having a size of N×N/2. That is, the image decoding apparatus 150 may determine the third encoding element 1204 having size N/2×N/2 or the third encoding element 1214 having size N/2×N/2 by dividing the second encoding element 1222 in the vertical direction, or may determine a third encoding element 1224 having a size of N/2×N/2 by dividing the second encoding element 1222 in the vertical and horizontal directions.

[00159] According to one embodiment, the image decoding apparatus 150 may split the square encoding element 1200, 1202, or 1204 in the horizontal or vertical direction. For example, the image decoding apparatus 150 may determine the first encoding element 1210 having size N×2N by dividing the first encoding element 1200 having size 2N×2N in the vertical direction, or may determine the first encoding element 1220 having size 2N×N. by splitting the first encoding element 1200 in the horizontal direction. According to one embodiment, when the depth is determined based on the length of the longest side of the encoding element, the depth of the encoding element determined by dividing the first encoding element 1200, 1202 or 1204 having a size of 2N×2N in the horizontal or vertical direction may be the same , as the depth of the first element is 1200, 1202 or 1204 encoding.

[00160] According to one embodiment, the width and height of the third encoding element 1214 or 1224 may be 1/2 the width and height of the first encoding element 1210 or 1220. When the depth of the first encoding element 1210 or 1220 is D, the depth of the second encoding element 1212 or 1222, whose width and height are 1/2 the width and height of the first encoding element 1210 or 1220, may be D+1, and the depth of the third element 1214 or An encoding 1224 whose width and height are 1/2 the width and height of the first encoding element 1210 or 1220 may be D+2.

[00161] FIG. 13 depicts depths that are capable of being determined based on shapes and sizes of encoding elements, and part indices (PIDs) that are present to distinguish encoding elements, according to one embodiment.

[00162] According to one embodiment, the image decoding apparatus 150 can determine second encoding elements of different shapes by dividing the square of the first encoding element 1300. Referring to FIG. 13, the image decoding apparatus 150 may determine second encoding elements 1302a and 1302b, 1304a and 1304b, and 1306a, 1306b, 1306c and 1306d by dividing the first encoding element 1300 in at least one of the vertical and horizontal directions based on partition form information. That is, the image decoding apparatus 150 can determine the second encoding elements 1302a and 1302b, 1304a and 1304b, and 1306a, 1306b, 1306c and 1306d based on the split shape information of the first encoding element 1300.

[00163] According to one embodiment, the depth of the second encoding elements 1302a and 1302b, 1304a and 1304b, and 1306a, 1306b, 1306c and 1306d, which are determined based on the partition shape information of the square first encoding element 1300, can be determined based on the length of their long sides. For example, since the side length of the square first encoding element 1300 is equal to the long side length of the non-square second encoding elements 1302a and 1302b, and 1304a and 1304b, the first encoding element 1300 and the non-square second encoding elements 1302a and 1302b, and 1304a and 1304b may have the same depth, such as D. However, when the image decoding apparatus 150 partitions the first encoding element 1300 into four square second encoding elements 1306a, 1306b, 1306c and 1306d based on the split shape information, since the side length of the square second encoding elements 1306a, 1306b, 1306c and 1306d is 1/2 of the side length of the first encoding element 1300, the depth of the second encoding elements 1306a, 1306b, 1306c and 1306d may be D+1, which is deeper than the depth D of the first encoding element 1300 by 1.

[00164] According to one embodiment, the image decoding apparatus 150 may determine a plurality of second encoding elements 1312a and 1312b, and 1314a, 1314b and 1314c by dividing the first encoding element 1310 whose height is longer than its width in the horizontal direction based on the partition shape information. According to one embodiment, the image decoding apparatus 150 may determine a plurality of second encoding elements 1322a and 1322b, and 1324a, 1324b and 1324c by dividing the first encoding element 1320 whose width is longer than its height in the vertical direction based on the partition shape information.

[00165] According to one embodiment, the depth of second encoding elements 1312a and 1312b, 1314a, 1314b and 1314c, 1322a and 1322b and 1324a, 1324b and 1324c, which are determined based on the partition shape information of the non-square first encoding element 1310 or 1320, can be determined based on the length of their long side. For example, since the side length of the square second encoding elements 1312a and 1312b is 1/2 that of the long side of the first encoding element 1310 having a non-square shape whose height is longer than the width, the depth of the square second encoding elements 1312a and 1312b is D+1, which is deeper than the depth D of the non-square first encoding element 1310 by 1.

[00166] In addition, the image decoding apparatus 150 may partition the non-square first encoding element 1310 into an odd number of second encoding elements 1314a, 1314b and 1314c based on the partition shape information. The odd number of second encoding elements 1314a, 1314b and 1314c may include non-square second encoding elements 1314a and 1314c and square second encoding element 1314b. In this case, since the long side length of the non-square second encoding elements 1314a and 1314c and the side length of the square second encoding element 1314b are 1/2 of the long side length of the first encoding element 1310, the depth of the second encoding elements 1314a, 1314b and 1314c can be equal to D+ 1, which is deeper than the depth D of the non-square first encoding element 1310 by 1. The image decoding apparatus 150 can determine the depths of encoding elements divided from the first encoding element 1320 having a non-square shape, the width of which is longer than the height, by the above-described method for determining the depths of encoding elements divided from first encoding element 1310.

[00167] According to one embodiment, the image decoding apparatus 150 may determine a PID for identifying broken encoding elements based on the size relationship between encoding elements when an odd number of broken encoding elements do not have equal sizes. Referring to FIG. 13, the center position encoding element 1314b of an odd number of split encoding elements 1314a, 1314b and 1314c may have a width equal to the width of the other encoding elements 1314a and 1314c, and a height that is twice the height of the other encoding elements 1314a and 1314c. That is, in this case, the encoding element 1314b at the center position may include two of the other encoding elements 1314a or 1314c. Thus, when the PID of the encoding element 1314b at the center position is 1 based on the scan order, the PID of the encoding element 1314c located next to the encoding element 1314b may be increased by 2 and thus may be equal to 3. That is, a discontinuity in PID values may be present. According to one embodiment, the image decoding apparatus 150 can determine whether an odd number of split encoding elements are not of equal size based on whether a discontinuity is present in the PID for identifying the split encoding elements.

[00168] According to one embodiment, the image decoding apparatus 150 can determine whether to use a particular partitioning method based on PID values to identify a plurality of encoding elements determined by partitioning the current encoding element. Referring to FIG. 13, the image decoding apparatus 150 can determine an even number of encoding elements 1312a and 1312b or an odd number of encoding elements 1314a, 1314b and 1314c by dividing the first encoding element 1310 having a rectangular shape whose height is longer than its width. The image decoding apparatus 150 may use the PID to identify corresponding encoding elements. According to one embodiment, the PID may be obtained from a sample of the preset position of each encoding element (eg, the top left sample).

[00169] According to one embodiment, the image decoding apparatus 150 can determine an encoding element at a preset position from the split encoding elements by a PID to distinguish encoding elements. According to one embodiment, when the partition shape information of the first encoding element 1310 having a rectangular shape whose height is longer than the width indicates to split the encoding element into three encoding elements, the image decoding apparatus 150 may divide the first encoding element 1310 into three elements 1314a, 1314b and 1314c coding. The image decoding apparatus 150 may assign a PID to each of the three encoding elements 1314a, 1314b and 1314c. The image decoding apparatus 150 may compare the PIDs of an odd number of split encoding elements to determine an encoding element at a central position among the encoding elements. The image decoding apparatus 150 may determine an encoding element 1314b having a PID corresponding to the average of the PIDs of the encoding elements as an encoding element at a central position among the encoding elements determined by dividing the first encoding element 1310. According to one embodiment, the image decoding apparatus 150 may determine a PID to distinguish split encoding elements based on the size relationship between encoding elements when the resulting split encoding elements do not have equal sizes. Referring to FIG. 13, the encoding element 1314b generated by splitting the first encoding element 1310 may have a width equal to the width of the other encoding elements 1314a and 1314c, and a height that is twice the height of the other encoding elements 1314a and 1314c. In this case, when the PID of the encoding element 1314b at the center position is 1, the PID of the encoding element 1314c located next after the encoding element 1314b may be increased by 2 and thus may be equal to 3. When the PID is non-uniformly increased as described above , the image decoding apparatus 150 may determine that an encoding element is divided into a plurality of encoding elements including an encoding element having a size different from the size of other encoding elements. According to one embodiment, when the split shape information indicates to split a coding element into an odd number of coding elements, the image decoding apparatus 150 may split the current coding element such that the coding element at a predetermined position of the odd number of coding elements (for example, the coding element at the central position) has a different size from other coding elements. In this case, the image decoding apparatus 150 can determine a coding element at the center position that has a different size by means of the PIDs of the coding elements. However, the PID and size or position of the encoding element at a preset position is not limited to the above-described examples, and other PIDs and other positions and sizes of encoding elements may be used.

[00170] According to one embodiment, image decoding apparatus 150 may use a preset data element where the encoding element begins to be recursively split.

[00171] FIG. 14 depicts that a plurality of encoding elements is determined based on a plurality of preset data elements included in a frame, according to one embodiment.

[00172] According to one embodiment, a preset data element may be determined as a data element where an encoding element begins to be recursively split by at least one of block shape information and split shape information. That is, the preset data element may correspond to an uppermost depth coding element that is used to determine a plurality of coding elements split from the current frame. In the following descriptions, for convenience of explanation, the preset data item is called a reference data item.

[00173] According to one embodiment, the reference data element may have a preset size and a preset size shape. According to one embodiment, a reference encoding element may include M×N samples. Here, M and N may be equal to each other and may be integer values expressed as powers of 2. That is, the reference data element may have a square or non-square shape and may be divided into an integer number of encoding elements.

[00174] According to one embodiment, image decoding apparatus 150 may partition the current frame into a plurality of reference data elements. According to one embodiment, the image decoding apparatus 150 can split the plurality of reference data elements into which the current frame is divided by splitting information about each reference data element. The operation of splitting a reference data element may correspond to a splitting operation using a quadtree structure.

[00175] According to one embodiment, image decoding apparatus 150 may previously determine the minimum size allowed for reference data elements included in the current frame. Accordingly, the image decoding apparatus 150 can determine various reference data elements having sizes greater than or equal to the minimum size, and can determine one or more encoding elements by block shape information and partition shape information with references to a specific reference data element.

[00176] Referring to FIG. 14, the image decoding apparatus 150 may use a square encoding reference element 1400 or a non-square encoding reference element 1402. According to one embodiment, the shape and size of the encoding reference elements may be determined based on various data elements, possibly including one or more encoding reference elements (eg, sequences, frames, slices, slice segments, largest encoding elements, or the like).

[00177] According to one embodiment, the receiver 160 of the image decoding device 150 can obtain, from the bit stream, at least one of the encoding reference element shape information and the encoding reference element size information with respect to each of the different data elements. The operation of dividing a square reference encoding element 1400 into one or more encoding elements has been described above with respect to the operation of dividing the current encoding element 1000 of FIG. 10, and the operation of dividing a non-square reference encoding element 1402 into one or more encoding elements has been described above with respect to the operation of dividing current encoding element 1100 or 1150 of FIG. Therefore, their detailed descriptions will not be given here.

[00178] According to one embodiment, the image decoding apparatus 150 may use the PID to identify the size and shape of the reference encoding elements to determine the size and shape of the reference encoding elements according to some data elements previously determined based on a preset condition. That is, the receiver 160 may obtain from the bitstream only a PID to identify the size and shape of reference encoding elements with respect to each slice, slice segment, or largest encoding element that is a data element that satisfies a predetermined condition (for example, a data element having a size that less than or equal to slice), from various data elements (eg, sequences, frames, slices, slice segments, largest encoding elements, or the like). The image decoding apparatus 150 may determine the size and shape of reference data elements with respect to each data element that satisfies a preset condition by a PID. When the encoding reference element shape information and the encoding reference element size information are obtained and used from the bit stream according to each data element having a relatively small size, the bit stream utilization efficiency may not be high, and thus only the PID can be obtained and used instead directly obtaining the encoding reference element shape information and the encoding reference element size information. In this case, at least one of the size and shape of the reference encoding elements corresponding to the PID for identifying the size and shape of the reference encoding elements may be previously determined. That is, the image decoding apparatus 150 can determine at least one of the size and shape of the reference encoding elements included in a data element functioning as an element for obtaining a PID by selecting the previously determined at least one of the size and shape of the reference encoding elements based on the PID .

[00179] According to one embodiment, image decoding apparatus 150 may use one or more reference encoding elements included in the largest encoding element. That is, the largest encoding element divided into a frame may include one or more reference encoding elements, and the encoding elements may be determined by recursively dividing each reference encoding element. According to one embodiment, at least one of the width and height of the largest encoding element may be equal to an integer multiplied by at least one of the width and height of the reference encoding elements. According to one embodiment, the size of the reference encoding elements can be obtained by splitting the largest encoding element n times based on the quadtree structure. That is, the image decoding apparatus 150 can determine reference encoding elements by dividing the largest encoding element n times based on the quadtree structure, and can divide the reference encoding element based on at least one of block shape information and partition shape information according to various embodiments.

[00180] FIG. 15 depicts a processing unit functioning as an element for determining the order of determination of reference encoding elements included in frame 1500, according to one embodiment.

[00181] According to one embodiment, image decoding apparatus 150 may determine one or more processing blocks divided from a frame. A processing block is a data element including one or more reference encoding elements divided from a frame, and one or more reference encoding elements included in the processing block may be determined according to a particular order. That is, the order of determining one or more reference encoding elements defined in each processing block may correspond to one of various types of orders for determining the reference encoding elements and may vary depending on the processing block. The order of determining reference encoding elements that is determined with respect to each processing unit may be one of various orders, such as raster scan order, Z-scan, N-scan, top right diagonal scan, horizontal scan and vertical scan, but is not limited to the above-mentioned orders scanning.

[00182] According to one embodiment, the image decoding apparatus 150 may obtain processing block size information and may determine the size of one or more processing blocks included in a frame. The image decoding apparatus 150 may obtain processing block size information from the bitstream and may determine the size of one or more processing blocks included in a frame. The size of the processing blocks may be a preset size of data elements, which is indicated by the processing block size information.

[00183] According to one embodiment, the receiver 160 of the image decoding device 150 can obtain processing block size information from the bit stream according to each specific data element. For example, processing block size information may be obtained from a bitstream in a data element such as an image, sequence, frame, slice, or slice segment. That is, the receiver 160 can obtain processing block size information from the bitstream according to each of the various data elements, and the image decoding apparatus 150 can determine the size of one or more processing blocks into which a frame is divided by the obtained processing block size information. The size of the processing units may be multiplied by an integer by the size of the reference encoding elements.

[00184] According to one embodiment, image decoding apparatus 150 may determine the size of processing blocks 1502 and 1512 included in frame 1500. For example, image decoding apparatus 150 may determine the size of processing blocks based on processing block size information obtained from the bit stream. Referring to FIG. 15, according to one embodiment, the image decoding apparatus 150 may determine the width of the processing blocks 1502 and 1512 to be four times the width of the reference encoding elements, and may determine the height of the processing blocks 1502 and 1512 to be four times the height of the reference elements. coding. The image decoding apparatus 150 may determine an order in which one or more reference encoding elements are determined in one or more processing blocks.

[00185] According to one embodiment, image decoding apparatus 150 may determine processing blocks 1502 and 1512 that are included in frame 1500 based on the size of processing blocks and may determine the order in which one or more reference encoding elements are determined in processing blocks 1502 and 1512. According to one embodiment, determining the reference encoding elements may include determining the size of the reference encoding elements.

[00186] According to one embodiment, the image decoding apparatus 150 can obtain from the bit stream information about the determination order of one or more reference encoding elements included in one or more processing blocks, and can determine the determination order with respect to the one or more reference encoding elements based on the information received regarding the determination order. The determination order information may be defined as an order or direction for determining reference encoding elements in a processing block. That is, the order of determining the reference encoding elements can be independently determined with respect to each processing block.

[00187] According to one embodiment, the image decoding apparatus 150 can obtain from the bitstream information about the order of determining reference encoding elements according to each specific data element. For example, receiver 160 may obtain reference encoding element determination order information from the bitstream according to each data element such as an image, sequence, frame, slice, slice segment, or processing block. Since the determination order information of the reference encoding elements indicates an order for determining the reference encoding elements in a processing block, the determination order information can be obtained with respect to each specific data element including an integer number of processing blocks.

[00188] According to one embodiment, image decoding apparatus 150 may determine one or more reference encoding elements based on a determined determination order.

[00189] According to one embodiment, the receiver 160 may obtain reference encoding element determination order information from the bit stream as information related to processing blocks 1502 and 1512, and the image decoding apparatus 150 may determine the determination order of one or more reference encoding elements included to processing units 1502 and 1512, and determine one or more reference encoding elements that are included in frame 1500 based on the order of determination. Referring to FIG. 15, image decoding apparatus 150 may determine determination orders 1504 and 1514 of one or more reference encoding elements in processing blocks 1502 and 1512, respectively. For example, when reference encoding element determination order information is obtained with respect to each processing block, different types of reference encoding element determination order information may be obtained for processing blocks 1502 and 1512. When the order 1504 of determining the reference encoding elements in the processing block 1502 is a raster scan order, the reference encoding elements included in the processing block 1502 can be determined according to the raster scan order. Conversely, when the order 1514 of determining reference encoding elements in another processing block 1512 is the reverse raster scan order, the reference encoding elements included in the processing block 1512 can be determined according to the reverse raster scan order.

[00190] FIGS. 1 to 15 depict a method of dividing an image into a largest encoding element and dividing the largest encoding element into encoding elements of a hierarchical tree structure. FIGS. 16 to 24 show a method for determining a quantization parameter of a current block.

[00191] The image encoding apparatus 100 of FIG. 1 can convert, through a predetermined procedure, residual data that is the difference between the original values of pixels included in an encoding element and their prediction values. In this regard, the image encoding apparatus 100 can reduce the size of the residual data instead of losing the residual data by quantizing the transformed residual data.

[00192] Quantization of the residual data is performed based on the quantization parameter. The quantization parameter denotes the index used to find the scaling matrix needed for quantizing the residual data of the current block. When the quantization parameter is large, the scaling matrix where the elements are relatively large is found. Thus, when the quantization parameter is large, the residual data is lost in large amounts, but the compression ratio of the residual data is increased. Conversely, when the quantization parameter is small, the scaling matrix where the elements are relatively small is found. Thus, when the quantization parameter is small, the residual data is lost in small amounts, but the compression ratio of the residual data is reduced.

[00193] That is, in the case where the subjective degradation of image quality is small, even when the compression ratio of the residual data is increased, a large quantization parameter can be used. However, in the case where subjective degradation of image quality is detected when the compression ratio of the residual data is increased, a small quantization parameter should be used. Thus, different quantization parameters must be used for blocks of the same frame, taking into account the degradation in image quality.

[00194] FIG. 16 depicts an image decoding apparatus for determining a block quantization parameter and decoding residual block data according to the determined quantization parameter.

[00195] The image decoding apparatus 1600 includes a quantization parameter determiner 1610 and an inverse quantizer 1620. In FIG. 16, the quantization parameter determiner 1610 and the inverse quantizer 1620 are illustrated as separate components, but in another embodiment, the quantization parameter determiner 1610 and the inverse Quantizer 1620 can be combined into one component.

[00196] In FIG. 16, quantization parameter determiner 1610 and inverse quantizer 1620 are illustrated as being included in a single device, but the devices performing the respective functions of quantization parameter determiner 1610 and inverse quantizer 1620 may not necessarily be physically adjacent to each other. Thus, in another embodiment, the quantization parameter determiner 1610 and the inverse quantizer 1620 may be separated.

[00197] The quantization parameter determiner 1610 and the inverse quantizer 1620 may be implemented by a single processor according to one embodiment. In another embodiment, quantization parameter determiner 1610 and inverse quantizer 1620 may be implemented by multiple processors.

[00198] The image decoding apparatus 1600 may perform inverse quantization based on a quantization group including one or more blocks. Next, the inverse quantization method based on the quantization group will be described.

[00199] When the quantization parameter is varied in each block, the quantization parameter information is increased. Thus, when the quantization parameter is determined with respect to a block element, coding efficiency may decrease. Thus, in order to increase coding efficiency, a method for determining the same quantization parameter with respect to multiple blocks is being considered.

[00200] In general, adjacent blocks have the same or similar quantization parameters. Thus, the image decoding apparatus 1600 can use the same quantization parameter for adjacent blocks. A set of blocks that are adjacent to each other and use the same quantization parameter are called a quantization group.

[00201] The quantization group may be determined based on the largest encoding element. For example, the quantization group may be set to blocks divided from the largest encoding element a predetermined number of times. When a block for which a quantization group is set is not further divided, the quantization parameter of the quantization group is applied only to the block for which the quantization group is set. Conversely, when a block corresponding to a quantization group is further divided, the quantization parameter of the quantization group may be applied to all subblocks that are generated by dividing the block for which the quantization group is set.

[00202] Alternatively, the quantization group may be determined based on size. For example, when the block size is less than or equal to the reference quantization group size, a quantization group may be set for the block. When a block for which a quantization group is set is not further divided, the quantization parameter of the quantization group is applied only to one block for which the quantization group is set. Conversely, the block corresponding to the quantization group is further split, the quantization parameter of the quantization group can be applied to all sub-blocks that are generated by splitting the block for which the quantization group is set. Accordingly, the block quantization parameter is determined based on the quantization block so that the quantization parameter information is reduced.

[00203] The quantization parameter determiner 1610 may obtain a difference quantization parameter enable flag with respect to the top-level data element of the current quantization group. When the difference quantization parameter enable flag indicates that it is allowed to determine the quantization parameter according to the difference quantization parameter, the quantization parameter determining means 1610 may obtain the difference quantization parameter of the current block.

[00204] The top layer data element may be one of a video parameter set (VPS), a sequence parameter set (SPS), and a frame parameter set (PPS). Thus, the quantization parameter determining means 1610 may apply the quantization parameter determining method based on the quantization group to all blocks included in the top-layer data element.

[00205] The quantization parameter determiner 1610 may obtain quantization group information regarding the top-level data element of the current quantization group. The quantization group information indicates how the quantization group is determined. For example, the quantization group information may include block division information or block size information. When the difference quantization parameter enable flag enables the difference quantization parameter, the quantization parameter determiner 1610 can obtain quantization group information.

[00206] The quantization parameter determining means 1610 may determine a predicted quantization parameter of a current quantization group, wherein the predicted quantization parameter is determined according to at least one of block division information and block size information.

[00207] The block splitting information may include the number of times of splitting with a quadtree and the number of times of splitting without a quadtree. The number of times of quadtree splitting indicates how many times the quadtree splitting is performed to obtain the current quantization group from the largest encoding element. For example, the block partition 210d of FIG. 2 corresponds to a quad-tree partition.

[00208] The number of times of non-quadtree partitioning indicates how many times a partition that is not a quadtree partition is performed to obtain the current quantization group from the largest encoding element. For example, the partitioning method shown in FIG. 3 corresponds to partitioning without a quadtree.

[00209] The block size information may include a block area or a binary logarithm (log) value of the block area. Additionally, the block height and width, or binary logarithm values of the block height and width, can be included here.

[00210] According to one embodiment, the quantization parameter determiner 1610 may determine the current quantization group according to the number of times of quadtree partitioning. When only quadtree partitioning is used to partition the largest encoding element, a quantization group can be set to a block having at least a preset size according to the number of times of quadtree partitioning. For example, when the size of the largest encoding element is 256×256 and the number of times of quadtree partitioning is 2, the quantization group can be set to a block whose size is 64×64 or more.

[00211] FIGS. 17A to 17D show diagrams of embodiments in which a quantization group is determined according to the number of times of quadtree partitioning.

[00212] Referring to FIG. 17A, the largest encoding block 1700 is divided into four blocks 1702, 1704, 1706 and 1708 according to a quadtree partition. The number of times the blocks 1702, 1704, 1706, and 1708 are quadtreed is set to 1. Block 1704 is split into four blocks 1710, 1712, 1714, and 1716 according to the quadtree split. The number of times the blocks 1710, 1712, 1714, and 1716 are quadtreed is set to 2. Block 1716 is split into four blocks 1718, 1720, 1722, and 1724 according to the quadtree split. The number of times the quadtree splits blocks 1718, 1720, 1722, and 1724 is set to 3. Based on blocks 1702, 1706, 1708, 1710, 1712, 1714, 1718, 1720, 1722, and 1724 determined when splitting the largest block 1700 code the process is completed, predictive and transform encoding and decoding can be performed.

[00213] As shown in FIG. 17A, when the number of times of quadtree partitioning increases by 1, the size of the partitioned block is reduced by half. Thus, only when quad-tree partitioning is enabled, the block size can be determined according to the number of times of quad-tree partitioning.

[00214] FIG. 17B depicts an embodiment in which a quantization group is determined with respect to a block for which the number of times of quadtree partitioning is 1. Referring to FIG. 17B, quantization groups are set with respect to four blocks 1702, 1704, 1706, and 1708 , for which the number of times of partitioning with a quadtree is 1.

[00215] Each of blocks 1702, 1706, and 1708 is individually included in each of the quantization groups for blocks 1702, 1706, and 1708. However, the quantization group of block 1704 includes subblocks 1710, 1712, 1714, 1718, 1720, 1722, and 1724 of block 1704 Thus, quantization and inverse quantization according to the same quantization parameter may be applied to subblocks 1710, 1712, 1714, 1718, 1720, 1722, and 1724 of block 1704.

[00216] FIG. 17C depicts an embodiment in which a quantization group is determined with respect to a block for which the number of times of quadtree partitioning is 2. Referring to FIG. 17C, quantization groups are set with respect to blocks 1702, 1706, 1708, 1710, 1712, 1714 and 1716, for which the number of times of quadtree splitting is less than or equal to 2. For blocks 1702, 1706 and 1708, the number of times of quadtree splitting is 1, but blocks 1702, 1706 and 1708 are not further split, so that the quantization group is established for blocks 1702, 1706 and 1708.

[00217] Each of blocks 1702, 1706, 1708, 1710, 1712 and 1714 is individually included in each of the quantization groups for it. However, the quantization group of block 1716 includes subblocks 1718, 1720, 1722, and 1724 of block 1716. Thus, quantization and inverse quantization according to the same quantization parameter can be applied to subblocks 1718, 1720, 1722, and 1724 of block 1716.

[00218] FIG. 17D depicts an embodiment in which a quantization group is determined with respect to a block for which the number of quadtree partitioning times is 3. Since the block for which the number of quadtree partitioning times is 4 is not present in FIG. 17D, the group quantization is set to all blocks 1702, 1706, 1708, 1710, 1712, 1714, 1718, 1720, 1722 and 1724.

[00219] Referring to FIGS. 17A to 17D, when the number of times of quadtree partitioning from the block partitioning information increases, the size of the quantization group decreases. Conversely, when the number of times of partitioning with a quadtree from the block partitioning information decreases, the size of the quantization group increases. Thus, the size of the quantization parameter information can be increased or decreased based on the number of times of quadtree partitioning from the block partitioning information.

[00220] The quantization parameter determiner 1610 may determine the current quantization group according to the number of times of partitioning with a quadtree and the number of times of partitioning without a quadtree. When both of quadtree partitioning and non-quadratree partitioning are applied to block partitioning, the quantization group determination method shown in FIGS. 17A to 17D is not used. Thus, the quantization group can be determined by further taking into account the number of times of partitioning without a quadtree, or the method of determining the quantization group based on the size of the quantization group can be applied to it. FIGS. 18A-18C depict an embodiment of a method for determining a quantization group in a largest coding block to which non-quadtree partitioning is applied.

[00221] FIG. 18A depicts how the largest coding block 1800 is broken up. The number marked in each block indicates the number of times the partitioning is performed on the largest coding block 1800.

[00222] The largest encoding block 1800 is a quadtree divided into four blocks 1802, 1804, 1806 and 1808. Since the block 1802 is not further divided, the number of times the block 1802 is divided is 1. It is further assumed that the size of the largest encoding block 1800 is 4Nx4N.

[00223] Block 1804 is split into two 2NxN blocks 1810 and 1812. Block 1810 is then split into two NxN blocks 1814 and 1816, and block 1812 is split into two N/2xN blocks 1818 and 1822 and one NxN block 1820. The number of times subblocks 1814, 1816, 1818, 1820, 1822 of block 1804 are split is 3 in total.

[00224] Block 1806 is split into two Nx2N blocks 1824 and 1826. Block 1824 is then split into two NxN blocks 1828 and 1830, and block 1826 is split into two NxN/2 blocks 1840 and 1844 and one NxN block 1842. Block 1828 is split into two blocks 1832 and 1834 N/2xN. Block 1834 is split into two blocks 1836 and 1838 N/2xN/2. The number of times subblocks 1828, 1830, 1840, 1842, and 1844 of block 1806 are split is 3. The number of times block 1832 split from block 1828 is split is 4, and the number of times blocks 1836 and 1838 are split is 5.

[00225] Block 1808 is split into four NxN blocks 1846, 1848, 1850 and 1852. Block 1846 is split into four blocks 1854, 1856, 1858 and 1860 NxN. Also, block 1848 is split into two Nx2N blocks 1862 and 1864, and block 1862 is split into two NxN blocks 1866 and 1868. The number of times to split blocks 1850 and 1852 is 2, and the number of times to split blocks 1854, 1856, 1858, 1860 and 1864 is 3. The number of times to split blocks 1866 and 1868 is 4.

[00226] When the quantization group is determined according to the number of times the block is divided, the size of the quantization group may not be uniform. In detail, with reference to Fig. 18B, the heterogeneity in the size of the quantization group will now be described.

[00227] FIG. 18B depicts an embodiment in which a quantization group is set with respect to blocks whose partitioning number is 3. Referring to FIG. 18B, the quantization group is set with respect to blocks 1802, 1814, 1816, 1818, 1820, 1822 , 1828, 1830, 1840, 1842, 1844, 1850, 1852, 1854, 1856, 1858, 1860, 1862 and 1864, the number of split times of which is 3.

[00228] However, the number of times the block 1814 is divided and the number of times the block 1854 is divided are equal, but the size of block 1814 is four times the size of block 1854. Although the size of 1836 is equal to the size of 1854, the quantization parameter of the quantization group corresponding to block 1828 is applied at that time as the quantization parameter of the quantization group corresponding to block 1854 is applied to block 1854.

[00229] Only when quadtree partitioning is performed, as in the embodiments of FIGS. 17A-17D, are the sizes of the quantization groups the same. However, as described above, in the case where the quantization groups are set according to the number of times of partitioning, when the quadtree-free partitioning is performed, the sizes of the quantization groups are different.

[00230] FIG. 18C depicts methods for solving the problem. For example, the quantization parameter determiner 1610 may determine the current quantization group according to the weighted sum of the number of times of partitioning with a quadtree and the number of times of partitioning without a quadtree. Quadtree partitioning is the same because vertical partitioning and horizontal partitioning are applied sequentially. Thus, one partition with a quadtree is essentially the same as two partitions without a quadtree.

[00231] Thus, the quantization parameter determination means 1610 divides the number of partitioning times into the number of partitioning times with a quadtree and the number of partitioning times without a quadtree, and can set the quantization group based on the weighted sum of the number of times of partitioning with a quadtree and the number of partitioning times without a quadtree according to the weight 2 :1.

[00232] For example, block 1814 is generated in view of one quadtree split and two non-quadtree splits from the largest encoding element 1800. Thus, the weighted sum of the number of times of quadtree splitting and the number of splitting times without quadtree according to the 2:1 weight with respect to block 1814 is 4. Block 1846 is generated in view of two quadtree splits from the largest encoding element 1800. Thus, the weighted sum of the number of times of partitioning with a quadtree and the number of times of partitioning without a quadtree according to the 2:1 weight with respect to block 1846 is 4. Thus, when a quantization group is set with respect to a block whose weighted sum is 4, unlike in FIG. 18B, in FIG. 18C, block 1854 receives a quantization parameter from a quantization group set to block 1846.

[00233] According to another embodiment, the quantization parameter determiner 1610 may determine the current quantization group based on the sum of the block height and width or the average of the block height and width. For example, when a quantization group is set with respect to a block of size NxN, quantization groups are set with respect to block 1814 and block 1846. Thus, unlike in FIG. 18B, in FIG. 18C block 1854 obtains a quantization parameter from the quantization group set for the block 1846 Since top level blocks 1812 and 1826 are larger than NxN size and thus there is no quantization group corresponding to them, even when blocks 1818, 1822, 1840 and 1844 are smaller than NxN size, quantization groups are set for them.

[00234] Likewise, quantization parameter determiner 1610 may determine the current quantization group based on the sum of the binary logarithm values of the block height and width or the average of the binary logarithm values of the block height and width. Alternatively, quantization parameter determiner 1610 may determine the current quantization group based on a block area or a binary logarithm value of the area.

[00235] The quantization parameter determiner 1610 may determine a predicted quantization parameter of the current block based on the quantization parameter of the top adjacent block of the current quantization group, the quantization parameter of the left adjacent block of the current quantization group, and the quantization parameter of the quantization group that was decoded immediately before the current quantization group.

[00236] For example, the quantization parameter determining means 1610 may determine, as the quantization parameter of the current quantization group, the average value of the quantization parameter of the upper adjacent block and the quantization parameter of the left adjacent block. When the quantization parameter of the upper adjacent block does not exist, the quantization parameter determiner 1610 may use, instead of the quantization parameter of the upper adjacent block, the quantization parameter of a quantization group that was decoded immediately before the current quantization group to determine the quantization parameter of the current quantization group. Likewise, when a left adjacent block quantization parameter does not exist, the quantization parameter determiner 1610 may use, instead of the left adjacent block quantization parameter, the quantization parameter of a quantization group that was decoded immediately before the current quantization group to determine the quantization parameter of the current quantization group.

[00237] Also, the quantization parameter determiner 1610 may determine the default quantization parameter of the slice or frame as the predicted quantization parameter. For example, when the quantization parameter of the top adjacent block, the quantization parameter of the left adjacent block, and the quantization parameter of the quantization group that was decoded immediately before the current quantization group referenced by the current quantization group do not exist, the default quantization parameter can be used.

[00238] The quantization parameter determination means 1610 determines the difference quantization parameter of the current quantization group. The quantization parameter determining means 1610 may obtain, from the bit stream, absolute value information of the difference quantization parameter and sign information of the difference quantization parameter. The quantization parameter determining means 1610 may determine the difference quantization parameter of the current quantization group based on the absolute value information of the difference quantization parameter and the sign information of the difference quantization parameter.

[00239] When the current quantization group includes two or more blocks, the quantization parameter determiner 1610 may obtain absolute value information of the difference quantization parameter and sign information of the difference quantization parameter regarding the block to be decoded first in the scanning order. Then, the quantization parameter determining means 1610 does not obtain the absolute value information of the difference quantization parameter and the sign information of the difference quantization parameter with respect to the remaining blocks of the current quantization group, and applies the quantization parameter to the remaining blocks, the quantization parameter being determined with respect to the block to be decoded first. Thus, as a result, the quantization parameter determiner 1610 applies the same quantization parameter to all blocks of the current quantization group.

[00240] When the quantization parameter determiner 1610 decodes all blocks of the current quantization group and then decodes a block of the new quantization group, the quantization parameter determiner 1610 may initiate the difference quantization parameter and difference quantization parameter-related information. The difference quantization parameter-related information may include difference quantization parameter decoding information indicating whether the difference quantization parameter has already been decoded, and quantization group position information indicating the position of the quantization group.

[00241] The quantization parameter determining means 1610 may initiate the difference quantization parameter and difference quantization parameter-related information, and may obtain new absolute value information of the difference quantization parameter and new sign information of the difference quantization parameter from the bit stream.

[00242] The quantization parameter determining means 1610 determines the quantization parameter of the current quantization group based on the predicted quantization parameter and the difference quantization parameter of the current quantization group. In detail, the quantization parameter determiner 1610 may determine the quantization parameter based on the sum of the predicted quantization parameter and the difference quantization parameter of the current quantization group. According to one embodiment, the quantization parameter determining means 1610 can obtain the quantization parameter offset information from the bit stream and can adjust the determined quantization parameter according to the quantization parameter offset information.

[00243] The inverse quantizer 1620 inversely quantizes the current block included in the current quantization group based on the quantization parameter of the current quantization group.

[00244] FIG. 19 depicts a syntax structure regarding a method for decoding a difference quantization parameter included in a bit stream when quadtree partitioning and non-quad tree partitioning are enabled.

[00245] The table at the top of FIG. 19 depicts the syntax structure of a quadtree partition (coding_quadtree). The quadtree partitioning syntax structure of FIG. 19 provides a configuration for determining whether to initiate a difference quantization parameter and information related to the difference quantization parameter before determining whether to perform quadtree partitioning.

[00246] In the quadtree splitting syntax structure of FIG. 19, "cu_qp_delta_enabled_flag" indicates a difference quantization parameter enable flag, "cqtDepth" indicates the number of times of quadtree splitting, and "diff_cu_qp_delta_depth" indicates block splitting information. "CuQpDeltaVal" indicates the difference quantization parameter, "IsCuQpDeltaCoded" indicates the difference quantization parameter decoding information, and "CuQgTopLeftX" and "CuQgTopLeftY" indicate the quantization group position information.

[00247] With reference to FIG. 19, when "cu_qp_delta_enabled_flag" indicates 1 and "cqtDepth" is less than or equal to "diff_cu_qp_delta_depth", "CuQpDeltaVal" and "IsCuQpDeltaCoded" are determined to be 0, and "CuQgTopLeftX" and "CuQgTopLeftY" are determined to be x0 and y0, which indicate the position of the top left sample of the current block.

[00248] When "cu_qp_delta_enabled_flag" indicates 1, it means that it is possible to obtain the difference quantization parameter.

[00249] When "cqtDepth" is less than or equal to "diff_cu_qp_delta_depth", it means that the number of times of partitioning with the current block's quadtree is less than or equal to the number of times of partitioning, which is the quantization group reference indicated by the block partitioning information. The sign that the number of times of partitioning with the quadtree of the current block is less than or equal to the number of times of partitioning, which is a quantization group reference, means that the current block is not included in the quantization group of the block decoded before the current block.

[00250] When the above conditions are satisfied, "CuQpDeltaVal" and "IsCuQpDeltaCoded" are determined to be 0, and a new difference quantization parameter with respect to the quantization group located in "CuQgTopLeftX" and "CuQgTopLeftY" is obtained based on the difference quantization parameter information that just obtained from the bit stream.

[00251] The table in the middle of Fig. 19 depicts the syntax structure of partitioning without a quadtree. The non-quadtree partitioning syntax structure of FIG. 19 provides a configuration for determining whether to initiate a difference quantization parameter and information related to the difference quantization parameter before determining whether to perform non-quadtree partitioning.

[00252] In the non-quadtree partitioning syntax structure of FIG. 19, "cu_qp_delta_enabled_flag" indicates a difference quantization parameter enable flag, "cqtDepth" indicates the number of times of quadtree partitioning, "mttDepth" indicates the number of times of non-quadtree partitioning, and "diff_cu_qp_delta_depth" indicates information block splitting. "CuQpDeltaVal" indicates the difference quantization parameter, "IsCuQpDeltaCoded" indicates the difference quantization parameter decoding information, and "CuQgTopLeftX" and "CuQgTopLeftY" indicate the quantization group position information.

[00253] With reference to FIG. 19, when "cu_qp_delta_enabled_flag" indicates 1 and the sum of "cqtDepth" and "mttDepth" is less than or equal to "diff_cu_qp_delta_depth", "CuQpDeltaVal" and "IsCuQpDeltaCoded" are determined to be 0, and "CuQgTopLeftX" and "CuQgTopLe" ftY " are defined as x0 and y0, which indicate the position of the top-left sample of the current block.

[00254] Similar to the quadtree partitioning syntax structure, even in the non-quadtree partitioning syntax structure, the difference quantization parameter and the difference quantization parameter-related information are initiated. However, unlike the quadtree partition syntactic structure, in the non-quadtree partition syntactic structure the sum of "cqtDepth" and "mttDepth", instead of "cqtDepth", is compared to "diff_cu_qp_delta_depth". In FIG. 19, the sum of "cqtDepth" and "mttDepth" is compared to "diff_cu_qp_delta_depth", but, according to one embodiment, the weighted sum of "cqtDepth" and "mttDepth" may be compared to "diff_cu_qp_delta_depth".

[00255] The table at the bottom of Fig. 19 depicts the syntax structure of a transform block. tu_cbf_luma[x0][y0] indicates whether the current luma block located at (x0, y0) has residual data. Then, tu_cbf_cb[x0][y0] and tu_cbf_cr[x0][y0] indicate whether the current block Cb and the current block Cr, respectively located at (x0, y0), have residual data. When the current luma block, the current block Cb and the current block Cr have no residual data, difference quantization parameter information is not obtained.

[00256] Conversely, when at least one of the current luminance block, the current block Cb and the current block Cr includes residual data, "cu_qp_delta_abs" indicating absolute value information of the difference quantization parameter, and "cu_qp_delta_sign_flag" indicating parameter sign information the difference quantizations are obtained from the bit stream. Then "CuQpDeltaVal" indicating the difference quantization parameter is determined from "cu_qp_delta_abs" and "cu_qp_delta_sign_flag". In addition, "IsCuQpDeltaCoded" indicating whether a difference quantization parameter exists is defined as 1.

[00257] When a block to be decoded after the current block is included in the same quantization group of the current block (i.e., when "cqtDepth" or the (weighted) sum of "cqtDepth" and "mttDepth" is greater than "diff_cu_qp_delta_depth"), "CuQpDeltaVal" and "IsCuQpDeltaCoded" are not triggered, and thus the block to be decoded after the current block is inversely quantized according to "CuQpDeltaVal" used in the decoding procedure for the current block.

[00258] In FIG. 19, the configuration for obtaining difference quantization parameter information is carried out in the syntax structure of the transform block, but according to one embodiment, the configuration may be carried out in another syntax.

[00259] FIG. 20 depicts a method for decoding images by determining a block quantization parameter according to a quantization group and decoding residual block data according to the determined quantization parameter.

[00260] In step 2010, a predicted quantization parameter of the current quantization group determined according to at least one of the block division information and the block size information is determined.

[00261] The current quantization group can be determined according to the number of times of partitioning with a quadtree and the number of times of partitioning without a quadtree. In detail, the current quantization group can be determined according to the weighted sum of the number of times of partitioning with a quadtree and the number of times of partitioning without a quadtree.

[00262] The current quantization group may be determined based on the sum of the block height and width or the average of the block height and width. Alternatively, the current quantization group may be determined based on the sum of the binary logarithm values of the block height and width, or the average of the binary logarithm values of the block height and width. Alternatively, the current quantization group can be determined based on the block area or the binary logarithm value of the area.

[00263] The predicted quantization parameter of the current block may be determined based on the quantization parameter of the top adjacent block of the current quantization group, the quantization parameter of the left adjacent block of the current quantization group, and the quantization parameter of the quantization group that was decoded immediately before the current quantization group.

[00264] In operation 2020, the difference quantization parameter of the current quantization group is determined. In detail, absolute value information of the difference quantization parameter and sign information of the difference quantization parameter can be obtained from the bit stream. Then, the difference quantization parameter of the current quantization group can be determined based on the absolute value information of the difference quantization parameter and the sign information of the difference quantization parameter.

[00265] According to one embodiment, when the flag provided by the difference quantization parameter indicates that it is possible to determine the quantization parameter according to the difference quantization parameter, the difference quantization parameter of the current block can be obtained.

[00266] In step 2030, the quantization parameter of the current quantization group is determined based on the predicted quantization parameter and the difference quantization parameter of the current quantization group. For example, the quantization parameter of the current quantization group can be determined based on the sum of the predicted quantization parameter and the difference quantization parameter.

[00267] At step 2040, the current block included in the current quantization group is reverse quantized according to the quantization parameter of the current quantization group.

[00268] The image decoding method of FIG. 20 may include various embodiments with respect to a method for determining a quantization parameter according to a quantization group of the image decoding apparatus of FIG. 16.

[00269] The image decoding apparatus 1600 may perform inverse quantization based on a quantization parameter element indicating an area where the same quantization parameter is used. Next, an inverse quantization method based on a quantization parameter element will be described.

[00270] FIG. 21 depicts an embodiment of a quantization parameter element structure and a tree structure of a coding block.

[00271] A frame or slice may vary in subjective image quality degradation in its parts. Thus, to optimize coding efficiency, it is necessary to set different quantization parameters according to the characteristics of the respective parts of the frame or slice. The distribution of quantization parameters is not equal to the tree structure of the encoding element, which is the basic encoding element. Thus, the quantization parameter element map is determined independently of the encoding element tree structure.

[00272] In FIG. 21, quantization parameter element 2110 may be a rectangle of size MxN. Here, a frame is represented as a quantization parameter map 2120 consisting of a plurality of quantization parameter elements. Each of the quantization parameter elements in the quantization parameter map 2120 has a quantization parameter. In FIG. 21, quantization parameter element 2110 is illustrated as a rectangle, but, according to one embodiment, quantization parameter element 2110 may be illustrated as an irregular shape rather than a rectangle.

[00273] The quantization parameter of the quantization parameter element 2110 may be determined according to a characteristic of a portion of the corresponding frame. The quantization parameter map 2120 and the quantization parameter of the quantization parameter element 2110 are encoded and decoded independently of the predictive encoding information according to the encoding block structure 2140 . When the residual data of the encoding block 2130 is encoded and decoded, a quantization parameter can be obtained from a quantization parameter element 2110 that corresponds to the position of the encoding element 2130.

[00274] The quantization parameter determiner 1610 may match the current block to the current quantization parameter element based on at least one of a position and a size of the current block.

[00275] For example, the quantization parameter determiner 1610 may determine, as the current quantization parameter element of the current block, a quantization parameter element including coordinate values of the top left sample of the current block.

[00276] As another example, when the current block includes a plurality of quantization parameter elements, the quantization parameter determiner 1610 may determine the plurality of quantization parameter elements as the current quantization parameter elements of the current block. In this regard, the quantization parameter determining means 1610 may determine, as the quantization parameter of the current block, the average value of a plurality of quantization parameters of the current quantization parameter elements.

[00277] FIGS. 22A and 22B depict a method for determining a quantization parameter element corresponding to a current block.

[00278] FIG. 22A depicts an embodiment in which a quantization parameter element 2200 corresponds to a plurality of encoding elements 2202-2224. Blocks 2202, 2204, 2206, 2210, 2212, and 2214, all of which are included in quantization parameter element 2200, are inversely quantized according to the quantization parameter corresponding to quantization parameter element 2200.

[00279] Blocks whose portions are included in the quantization parameter element 2200 can then be determined as to whether the quantization parameter of the quantization parameter element 2200 should be applied to it based on the upper left sample of the block. Thus, for blocks 2208, 2216, 2218, 2220, 2222 and 2224, the upper left samples of which are included in the quantization parameter element 2200, can be inversely quantized according to the quantization parameter corresponding to the quantization parameter element 2200.

[00280] In FIG. 22A, an embodiment in which a quantization parameter element is determined based on the top left sample of a block is described, but according to one embodiment, the block quantization parameter element may be determined based on a center sample, the top right sample , lower left sample, lower right sample, or the like for the block.

[00281] FIG. 22B depicts an embodiment in which a plurality of quantization parameter elements 2252-2274 correspond to block 2250.

[00282] Quantization parameter elements 2252, 2254, 2258, 2260, 2264, and 2266 are included entirely within block 2250. Thus, block 2250 may be inversely quantized according to at least one quantization parameter from elements 2252, 2254, 2258, 2260 , 2264 and 2266 quantization parameters. For example, the quantization parameter of block 2250 may be defined as the average of the quantization parameters of quantization parameter elements 2252, 2254, 2258, 2260, 2264, and 2266.

[00283] Alternatively, quantization parameter elements 2256, 2262, 2268, 2270, 2272, and 2274, which partially overlap block 2250, may be used to determine the quantization parameter of block 2250. Thus, the reverse may be true for block 2250. quantizing according to a quantization parameter determined according to at least one of the quantization parameter elements 2252-2274.

[00284] FIGS. 23A and 23B depict the correlation between a block and a quantization parameter element.

[00285] FIG. 23A depicts a block tree structure and a quantization parameter map according to one embodiment. According to one embodiment, the quantization parameter element corresponding to the upper left sample of the block corresponds to the block. That is, block 2308 corresponds to quantization parameter element 2300, block 2310 corresponds to quantization parameter element 2302, block 2312 corresponds to quantization parameter element 2304, and block 2314 corresponds to quantization parameter element 2306. When the block and quantization parameter element match references are different, other quantization parameter elements 2302, 2304, and 2306 may match block 2308.

[00286] FIG. 23B depicts a block tree structure and a quantization parameter map according to one embodiment. As in FIG. 23A, when the quantization parameter element corresponding to the upper left sample of a block corresponds to a block, all of the blocks 2328, 2330, 2332 and 2334 correspond to the quantization parameter element 2334. Because the quantization parameter of quantization parameter element 2334 applies to all of blocks 2328, 2330, 2332, and 2334, the quantization parameter is first calculated with respect to block 2328 having the earliest decoding order. The quantization parameter used for block 2328 can then be used unchanged for blocks 2330, 2332, and 2334.

[00287] The quantization parameter is not determined for a block that has no residual data. For example, when block 2328 has no residual data, inverse quantization is not necessary for block 2328, and thus the quantization parameter of block 2328 is not determined. When block 2330, which is to be decoded after block 2328, has residual data, the quantization parameter of block 2330 can be determined. The quantization parameter used for block 2330 can then be used unchanged for blocks 2332 and 2334.

[00288] The quantization parameter determiner 1610 may obtain a predicted quantization parameter with respect to the current quantization parameter element.

[00289] The quantization parameter determiner 1610 may obtain a predicted quantization parameter from at least one of a left quantization parameter element of the current quantization parameter element, a top quantization parameter element of the current quantization parameter element, and a block decoded immediately before the current block.

[00290] Alternatively, the quantization parameter determiner 1610 may determine, as a predicted quantization parameter with respect to the current quantization parameter element, a predicted quantization parameter with respect to a frame or slice including the current quantization parameter element.

[00291] The quantization parameter determiner 1610 may obtain a difference quantization parameter with respect to the current quantization parameter element.

[00292] The quantization parameter determiner 1610 may determine the quantization parameter of the current quantization parameter element based on the predicted quantization parameter and the difference quantization parameter.

[00293] The inverse quantizer 1620 may inversely quantize the current block according to the quantization parameter of the current quantization parameter element.

[00294] FIG. 24 depicts a method for decoding images by determining a block quantization parameter according to a quantization parameter element and decoding residual block data according to the determined quantization parameter.

[00295] At step 2410, the current block is matched to the current quantization parameter element based on at least one of the current block's position and size.

[00296] According to one embodiment, a quantization parameter element including coordinate values of the upper left sample of the current block may be defined as the current quantization parameter element of the current block.

[00297] According to one embodiment, when the current block includes a plurality of quantization parameter elements, the plurality of quantization parameter elements may be determined as the current quantization parameter element of the current block. In this regard, the current quantization parameter of the current block may be determined from at least one of a plurality of quantization parameter elements.

[00298] At step 2420, a predicted quantization parameter is obtained with respect to the current quantization parameter element.

[00299] According to one embodiment, the predicted quantization parameter can be obtained from at least one of the left quantization parameter element of the current quantization parameter element, the top quantization parameter element of the current quantization parameter element, and the block decoded immediately before the current block.

[00300] Alternatively, the predicted quantization parameter with respect to the frame or slice including the current quantization parameter element may be determined as the predicted quantization parameter with respect to the current quantization parameter element.

[00301] At operation 2430, a difference quantization parameter is obtained with respect to the current quantization parameter element.

[00302] At step 2440, the quantization parameter of the current quantization parameter element is determined based on the predicted quantization parameter and the difference quantization parameter.

[00303] At step 2450, the current block is inversely quantized according to the quantization parameter of the current quantization parameter element.

[00304] The image decoding method of FIG. 24 may include various embodiments with respect to a method for determining a quantization parameter according to a quantization group of the image decoding apparatus of FIG. 16.

[00305] The image spatial domain data may be encoded for each of the tree structure encoding elements by a tree encoding element-based image encoding technique, and can be recovered by decoding each of the largest encoding elements by a tree structure encoding element-based image decoding technique as described above with reference to FIGS. 1-24, so that a frame and an image, which is a sequence of frames, can be reconstructed. The recovered video can be played back by a playback device, can be stored in a storage medium, or can be transmitted over a network.

[00306] The above-described embodiments of the disclosure may be implemented in the form of a computer-executable program and executed through a computer-readable storage medium by a general purpose digital computer for program execution.

[00307] While the disclosure has been described above in connection with specific best embodiments, other disclosures by implementing alternatives, modifications and changes to the disclosure will be apparent to one of ordinary skill in the art in view of the foregoing description. That is, the appended claims are to be understood to cover all such alternatives, modifications and variations. Accordingly, all provisions described in this specification and illustrated in the drawings are to be interpreted in an illustrative and non-limiting sense.

Clause 1. A method for decoding images, comprising the steps of:

determining a predicted quantization parameter of the current quantization group determined according to at least one of the block division information and the block size information;

determining a difference quantization parameter of the current quantization group;

determining a quantization parameter of the current quantization group based on the predicted quantization parameter and a difference quantization parameter of the current quantization group; And

reverse quantization of the current block contained in the current quantization group according to the quantization parameter of the current quantization group.

Provision 2. The image decoding method according to Proposition 1, wherein in said determination of the predicted quantization parameter of the current quantization group, the predicted quantization parameter of the current block is determined based on the quantization parameter of the upper adjacent block of the current quantization group, the quantization parameter of the left adjacent block of the current quantization group, and the quantization parameter of the group quantization decoded immediately before the current quantization group.

Provision 3: A method for decoding images according to Proposition 1, in which the current quantization group contains one or more blocks containing the current block, and the blocks contained in the current quantization group are inversely quantized according to the same quantization parameter.

Regulation 4. The image decoding method according to Regulation 1, in which

block splitting information contains the number of times of splitting with a quadtree and the number of times of splitting without a quadtree,

the current quantization group is determined according to the number of times of partitioning with a quadtree and the number of times of partitioning without a quadtree, and

the number of times of quadtree partitioning indicates the number of times that a quadtree partition is performed to obtain the current quantization group from the largest encoding block, and the number of times of non-quadtree partitioning indicates the number of times that a partition that is not a quadtree partition is performed to obtain the current quantization group from the largest coding block.

Proposition 5: The image decoding method according to Proposition 4, in which the current quantization group is determined according to the weighted sum of the number of times of partitioning with a quadtree and the number of times of partitioning without a quadtree.

Provision 6: A method for decoding images according to Proposition 1, in which the block size information contains the block height and width, and the current quantization group is determined based on the sum of the block height and width or the average value of the block height and width.

Clause 7. A method for decoding pictures according to Clause 1, in which the block size information contains the binary logarithm (log) values of the block height and width, and the current quantization group is determined based on the sum of the binary logarithm values of the block height and width or the average of the binary logarithm values of the height and width. block width.

Provision 8: A method for decoding images according to Proposition 1, in which the block size information contains a block area or a binary logarithm of the area value, and the current quantization group is determined based on the block area or the binary logarithm of the area value.

Clause 9. A method for decoding images according to Clause 1, wherein said determining a difference quantization parameter of a current quantization group comprises the steps of:

obtaining absolute value information of the difference quantization parameter and sign information of the difference quantization parameter from the bit stream; And

determine the difference quantization parameter of the current quantization group according to the absolute value information of the difference quantization parameter and the sign information of the difference quantization parameter.

Statement 10. The image decoding method according to Statement 1, further comprising the step of obtaining a flag provided by a difference quantization parameter with respect to the top data element of the current quantization group, wherein said determining the difference quantization parameter of the current quantization group comprises the step of obtaining, when provided by the parameter The difference quantization flag indicates that it is possible to determine the quantization parameter according to the difference quantization parameter, obtaining the difference quantization parameter of the current block.

Clause 11: An image decoding apparatus comprising a processor configured to

determine a predicted quantization parameter of the current quantization group determined according to at least one of the block division information and the block size information,

determine the difference quantization parameter of the current quantization group,

determine a quantization parameter of the current quantization group based on the predicted quantization parameter and the difference quantization parameter of the current quantization group, and

reverse quantize the current block contained in the current quantization group according to the quantization parameter of the current quantization group.

Clause 12: A method for decoding images, comprising the steps of:

mapping the current block to the current quantization parameter element based on at least one of a position and a size of the current block;

obtaining a predicted quantization parameter with respect to the current quantization parameter element;

obtaining a difference quantization parameter with respect to the current quantization parameter element;

determining a quantization parameter of the current quantization parameter element based on the predicted quantization parameter and the difference quantization parameter; And

carry out reverse quantization of the current block according to the quantization parameter of the current element of the quantization parameter.

Statement 13: A method for decoding images according to Statement 12, in which all quantization parameter elements of the frame or slice containing the current quantization parameter element are rectangles, each of size M×N.

Statement 14: An image decoding method according to Statement 12, wherein obtaining a predicted quantization parameter with respect to a current quantization parameter element comprises obtaining a predicted quantization parameter from at least one of a left quantization parameter element of the current quantization parameter element, a top quantization parameter element the current quantization parameter element and the block decoded immediately before the current block.

Provision 15. A method for decoding images according to Proposition 12, wherein obtaining a predicted quantization parameter with respect to a current quantization parameter element comprises determining a predicted quantization parameter with respect to a frame or slice containing the current quantization parameter element as a predicted quantization parameter with respect to current quantization parameter element.

Statement 16. A method for decoding images according to Statement 12, wherein said matching a current block to a current quantization parameter element based on at least one of a position and a size of the current block comprises determining a quantization parameter element containing coordinate values of the upper left sample of the current block, as the current element of the current block's quantization parameter.

Regulation 17. The method of decoding images according to Regulation 12, in which

said matching of a current block to a current quantization parameter element based on at least one of a position and a size of the current block comprises: when the current block contains a plurality of quantization parameter elements, determining the plurality of quantization parameter elements as the current quantization parameter elements of the current block ,

the aforementioned obtaining a predicted quantization parameter with respect to the current quantization parameter element, obtaining a difference quantization parameter with respect to the current quantization parameter element, and determining a quantization parameter of the current quantization parameter element based on the predicted quantization parameter and the difference quantization parameter are performed with respect to each of the current quantization parameter elements, and

said inverse quantization of the current block according to the quantization parameter of the current quantization parameter element comprises a step of inversely quantizing the current block according to the average value of the quantization parameters of the current quantization parameter element.

Clause 18: An image decoding apparatus comprising a processor configured to:

associate the current block with the current quantization parameter element based on at least one of the position and size of the current block,

obtain the predicted quantization parameter with respect to the current quantization parameter element,

get the difference quantization parameter with respect to the current quantization parameter element,

determine the quantization parameter of the current quantization parameter element based on the predicted quantization parameter and the difference quantization parameter, and

carry out inverse quantization of the current block according to the quantization parameter of the current element of the quantization parameter.

Claims (24)

1. A method of image decoding performed by a device and containing the steps of: dividing the upper-level encoding block into a plurality of lower-level encoding blocks in accordance with the partitioning information; determining the current quantization group based on the partition amount of the current encoding block among the plurality of lower layer encoding blocks and the partition amount of the current quantization group; obtaining a quantization parameter of the current quantization group; perform inverse quantization of the transform coefficients in the current transform block in the current encoding block using this quantization parameter, wherein the splitting amount of the current encoding block is increased by 1 if the current encoding block is obtained by dividing the upper-level encoding block into two lower-level encoding blocks according to non-quadtree partitioning, the splitting amount of the current encoding block is increased by 2 if the current encoding block is obtained by dividing the upper-layer encoding block into four lower-layer encoding blocks according to quad-tree partitioning, and a non-quadtree partition includes a binary partition. 2. An image decoding device comprising at least one processor configured to: dividing the upper-level encoding block into a plurality of lower-level encoding blocks according to the partitioning information; determine the current quantization group based on the partition amount of the current encoding block among the plurality of lower layer encoding blocks and the partition amount of the current quantization group; get the quantization parameter of the current quantization group; And perform inverse quantization of the transform coefficients in the current transform block in the current encoding block using this quantization parameter, wherein the splitting amount of the current encoding block is increased by 1 if the current encoding block is obtained by splitting the upper-level encoding block into two lower-level encoding blocks according to the non-quadtree partition, the splitting amount of the current encoding block is increased by 2 if the current encoding block is obtained by dividing the upper-level encoding block into four lower-level encoding blocks according to quadtree partitioning, and a non-quadtree partition includes a binary partition. 3. An image encoding method performed by a device and comprising the steps of: dividing the upper-level encoding block into a plurality of lower-level encoding blocks; determining the current quantization group based on the partition amount of the current encoding block among the plurality of lower layer encoding blocks and the partition amount of the current quantization group; obtaining a quantization parameter of the current quantization group; And quantizing the transform coefficients in the current transform block in the current encoding block using this quantization parameter, wherein the splitting amount of the current encoding block is increased by 1 if the current encoding block is obtained by dividing the upper-level encoding block into two lower-level encoding blocks according to non-quadtree partitioning, the splitting amount of the current encoding block is increased by 2 if the current encoding block is obtained by dividing the upper-layer encoding block into four lower-layer encoding blocks according to quad-tree partitioning, and a non-quadtree partition includes a binary partition.