Video signal decoding device

Abstract

The present invention relates to a video signal decoding device. The video signal decoding device of one embodiment of the present invention comprises: a transform region information acquisition unit, used to acquire transform region information indicating at least one or more of a plurality of transform regions included in a transform block, the transform block including a plurality of transform coefficient groups; and a transform coefficient group scanning unit, used to divide the transform block into at least one of the plurality of transform regions based on the transform region information, respectively acquire scanning methods of the transform regions, scan the plurality of transform coefficient groups included in the first transform region by using the scanning method of the first transform region, and scan the plurality of transform coefficient groups included in the second transform region by using the scanning method of the second transform region.

Description

[0001] This application is a divisional application of a patent application with application date of May 26, 2017, application number 201780033620.7, and title “Video Signal Encoding or Decoding Method and Device”. Technical Field

[0002] The present invention relates to a decoding device for a video signal. Background Art

[0003] Recently, the demand for high-resolution and high-quality images such as high-definition (HD) images and ultra-high-definition (UHD) images has increased in various application fields. In order to make image data high-resolution and high-quality, the amount of data has increased relatively compared with the previous image data. Therefore, when the image data is transmitted using a medium such as a conventional wired or wireless broadband circuit or stored using a conventional storage medium, the transmission cost and storage cost increase. In order to solve this problem that occurs as the image data becomes high-resolution and high-quality, a highly efficient image compression technology is used.

[0004] Video compression techniques include spatial prediction and / or temporal prediction in order to reduce or remove the inherent redundancy in video sequences. In a block-based video encoding process, a video frame or slice can be divided into blocks. Individual blocks can be additionally segmented. Blocks in an intra-frame coded I frame or slice are coded using spatial prediction of reference samples in adjacent blocks in the same frame or slice. Blocks in a slice of an inter-frame coded P or B frame can use spatial prediction of reference samples in adjacent blocks in the same frame or slice or temporal prediction of reference samples in other reference frames. Spatial or temporal prediction can occur with a predicted block related to the coded block. The remaining data represents the pixel difference between the coded original block and the predicted block.

[0005] Typically, the current block encodes an image using a square coding block (CU) and a transform block (TU) of the same size, and multiple transform blocks are applied to the coding block through a quadtree partitioning structure based on the size of each coding block or prediction block. However, when using such a square coding block, it is necessary to transmit the prediction mode and prediction information of each coding block. Therefore, unnecessary information is transmitted depending on the type of image, resulting in reduced coding efficiency. In addition, there is a problem that the characteristics of the residual block signal generated according to the characteristics of the image corresponding to the coding block and the prediction mode have not been considered.

[0006] Furthermore, in the video decoder, various sizes of coding units are used, so that the spatial resolution and characteristics of the image can be effectively considered for encoding. Generally, when the resolution of the image is small or the pixel value is locally increased, it is more effective to use a small-sized coding unit to perform intra-screen and inter-screen prediction. As described above, when a small-sized coding unit is used, the amount of header bits used for encoding increases, but, relatively speaking, the prediction can be made accurately, so that the amount of bits used for encoding quantization errors and change coefficients is reduced.

[0007] On the contrary, in areas where the spatial resolution of the image is large or the change in pixel value is small, the use of large coding units can improve the coding efficiency. In this case, compared with the case of using small coding units, the use of large coding units does not significantly increase the prediction error, so when encoding such blocks, the use of large coding units effectively reduces the amount of transmission bits. However, even with the use of various coding units in the past, it is difficult to effectively encode various images with high resolution.

[0008] In video compression technology for improving coding efficiency, motion prediction is used to remove temporal repetitiveness between multiple consecutive pictures. In order to detect temporal repetitiveness, multiple reference pictures are used to predict the motion of the current block, and motion compensation is performed to generate a predicted block. Motion information includes at least one reference picture index and at least one motion vector.

[0009] Furthermore, in order to obtain motion information, the current block performs bidirectional prediction to form a predicted motion vector list of the current block, which is used to transmit a differential motion vector as a differential value with the motion vector of the current block to the decoder. In this case, the predicted motion vector lists including predicted motion vectors for each direction are independent of each other. However, multiple sizes are used for inter-picture prediction and increase the correlation between the motion information of the current block and the motion information of one or more adjacent blocks. Therefore, according to the previous compression method, the size of the picture is larger than that of the high-quality picture, and when multiple sizes are used for motion prediction and motion compensation, the compression efficiency of the motion information is reduced. Summary of the invention

[0010] Technical issues

[0011] The technical problem to be solved by the present invention is to provide a video signal encoding and decoding device, that is, to improve the encoding efficiency by utilizing encoding blocks and transform blocks of various shapes according to the image.

[0012] Furthermore, another problem to be solved by the present invention is to provide a method and apparatus for encoding and decoding a video signal, that is, to determine the encoding order of transform blocks that can improve encoding efficiency according to the intra-frame prediction mode of the current block.

[0013] The technical problem to be solved by the present invention is to provide a method and device for decoding a video signal, that is, to improve the coding efficiency of intra-picture prediction by using transform blocks of various shapes.

[0014] Furthermore, the technical problem to be solved by the present invention is to provide a method and device for decoding a video signal, that is, firstly encoding the transform coefficient group of the low frequency region compared with the high frequency region, thereby improving the encoding efficiency.

[0015] The technical problem to be solved by the present invention is to provide a method and device for constructing a prediction motion vector list, which utilizes highly correlated information during bidirectional prediction of a current block, thereby improving the coding efficiency of inter-picture prediction.

[0016] Furthermore, the technical problem to be solved by the present invention is to provide a method and device for constructing a prediction motion vector list that improves coding efficiency according to whether reference pictures used for bidirectional prediction of a current block are the same.

[0017] Technical Solution

[0018] A video signal decoding device according to an embodiment of the present invention for solving the above-mentioned problem comprises: a transform region information acquisition unit, configured to acquire transform region information indicating at least one or more of a plurality of transform regions included in a transform block, wherein the transform block comprises a plurality of transform coefficient groups; and a transform coefficient group scanning unit, configured to divide the transform block into at least one of the plurality of transform regions based on the transform region information, respectively acquire scanning methods of the transform regions, scan the plurality of transform coefficient groups included in the first transform region by using the scanning method of the first transform region, and scan the plurality of transform coefficient groups included in the second transform region by using the scanning method of the second transform region.

[0019] A video signal decoding method according to an embodiment of the present invention for solving the above-mentioned problem comprises: a step of setting a structure of a coding block constituting a current image; a step of setting a structure of a plurality of transform blocks corresponding to the coding block; and a step of generating a prediction signal using the plurality of transform blocks, wherein the coding block comprises one or more of a square block and a non-square block.

[0020] The transform blocks include one or more of square transform blocks and non-square transform blocks of the same size and smaller size as the coding blocks.

[0021] In one embodiment, the square transform block is a transform block having a quadtree structure, and the non-square transform block is a transform block having a non-square binary tree structure or a non-square quadtree structure. In addition, the decoding method of the video signal may further include a step of receiving transform block partition information indicating the shape and size of the transform block.

[0022] In one embodiment, the transform block is divided into one or more of a non-square transform sub-block and a square transform sub-block, and the transform block is further divided into a plurality of sub-transform blocks, and when the transform block is divided into the plurality of sub-transform blocks, the prediction signal is generated corresponding to each of the sub-transform blocks. Furthermore, the plurality of sub-transform blocks include one or more of a non-square transform sub-block and a square transform sub-block.

[0023] In one embodiment, the decoding method of the above-mentioned video signal may also include: when the above-mentioned current block performs intra-picture prediction, a step of judging to which mode area the direction of the intra-picture prediction mode of the above-mentioned current block belongs, among a first mode area with an angle greater than 90 degrees and less than 180 degrees, a second mode area with an angle greater than 180 degrees and less than 225 degrees, and a third area with an angle greater than 45 degrees and less than 90 degrees; and a step of determining the encoding order of the above-mentioned transform block in a variably manner based on the mode area to which the above-mentioned intra-picture prediction mode belongs.

[0024] When the direction of the intra-picture prediction mode is the second mode area, the transform block is encoded in a sequence from the lower left end to the upper right end. If the transform block is a square transform block, it is encoded in the sequence of the lower left end, the lower right end, the upper left end and the upper right end. If the transform block is a square transform block, it is encoded in the sequence of the lower left end, the upper left end, the lower right end and the upper right end.

[0025] Furthermore, if the transform block is a non-square transform block divided vertically, it is encoded in order from left to right; if the transform block is a non-square transform block divided horizontally, it is encoded in order from bottom to top.

[0026] When the direction of the intra-picture prediction mode is the third area mode, the transform block is encoded in an order from the upper right end to the lower left end. If the transform block is a square transform block, it is encoded in an order of the upper right end, the upper left end, the lower right end and the lower left end. If the transform block is a square transform block, it is encoded in an order of the upper right end, the lower right end, the upper left end and the lower left end.

[0027] Furthermore, if the above-mentioned transform block is a non-square transform block divided vertically, it is encoded in order from the right to the left, and if the above-mentioned transform block is a non-square transform block divided horizontally, it is encoded in order from the top to the bottom.

[0028] A video signal decoding device according to another embodiment of the present invention for solving the above-mentioned problem comprises: a block setting unit, which sets the structure of a coding block constituting a current image, and sets the structure of a plurality of transform blocks corresponding to the coding block; and a prediction signal generating unit, which generates a prediction signal using the plurality of transform blocks, wherein the coding block and the transform block include one or more of a square block and a non-square block, and the prediction signal generating unit encodes the plurality of transform blocks in a variable coding order according to which mode area the intra-frame prediction mode of the coding block belongs to among a plurality of mode areas distinguished according to prediction directions.

[0029] A video signal decoding method of an embodiment of the present invention for solving the above-mentioned problem scans a transform block including multiple transform coefficient groups. The method includes: a step of acquiring transform region information representing one or more transform regions included in the transform block; a step of scanning multiple transform coefficient groups included in a first transform region based on the transform region information; and a step of scanning multiple transform coefficient groups included in a second transform region in the transform block.

[0030] Among the plurality of transform coefficient groups, the transform coefficient group in the low frequency region is scanned preferentially compared to the transform coefficient group in the high frequency region.

[0031] In one embodiment, the transform region information is received from an encoder or obtained from one or more of a sequence parameter set and a slice header. Furthermore, the transform region information is obtained in a decoder by a preset method.

[0032] Before the step of obtaining the transformation area information, the method further includes a step of determining whether the transformation block is a non-square block. The determination step is performed based on the horizontal length and the vertical length of the transformation block.

[0033] A video signal decoding device according to an embodiment of the present invention for solving the above-mentioned other problem comprises: a transform region information acquisition unit, for acquiring transform region information representing one or more transform regions contained in a transform block; and a transform coefficient group scanning unit, for sequentially scanning a plurality of transform coefficient groups contained in the transform region corresponding to each of the above-mentioned one or more transform regions based on the above-mentioned transform region information.

[0034] A method for constructing a predicted motion vector list according to an embodiment of the present invention for solving the above-mentioned problem comprises: a step of acquiring a motion vector related to a first direction of a current block; and a step of using the motion vector related to the above-mentioned first direction to set one or more candidate predicted motion vectors of the second direction constituting a predicted motion vector list of the above-mentioned second direction.

[0035] The one or more candidate prediction motion vectors of the second direction are set by copying the motion vector related to the first direction, and the reference picture related to the first direction and the reference picture related to the second direction have the same picture information. And the candidate prediction motion vectors of the second direction are assigned to the index in the order of having the smallest codeword.

[0036] In one embodiment, the candidate predicted motion vectors in the second direction are set by scaling the motion vectors related to the first direction based on picture information, and the picture information of the reference picture related to the first direction and the reference picture related to the second direction are different. The candidate predicted motion vectors in the second direction are assigned to the indexes in the order of having the smallest codeword.

[0037] Before the step of setting at least one candidate predicted motion vector for the second direction, the method further includes a step of determining whether picture information of a reference picture related to the first square and a reference picture related to the second direction are the same.

[0038] Another embodiment of the present invention for solving the above-mentioned problem comprises a device for constructing a prediction motion vector list, comprising: a motion vector acquisition unit, for acquiring a motion vector related to a first direction of a current block; and a second direction prediction motion vector list setting unit, for setting one or more candidate prediction motion vectors for the second direction constituting the prediction motion vector list for the second direction using the motion vector related to the above-mentioned first direction.

[0039] The second direction prediction motion vector list setting unit includes: a first candidate prediction motion vector setting unit, which uses the motion vector related to the first direction to set one or more candidate prediction motion vectors for the second direction; and a second candidate prediction motion vector setting unit, which uses the spatially and temporally adjacent blocks of the current block to set one or more candidate prediction motion vectors for the second direction.

[0040] The candidate prediction motion vector for the second direction obtained from the first candidate prediction motion vector setting unit is set by copying the motion vector related to the first direction, and the picture information of the reference picture related to the first direction and the reference picture related to the second direction are the same.

[0041] The candidate motion vector predictor for the second direction obtained from the first candidate motion vector predictor setting unit is set by scaling the motion vector related to the first direction based on picture information, and the picture information of the reference picture related to the first direction and the reference picture related to the second direction are different. Furthermore, the candidate motion vector predictor for the second direction obtained from the first candidate motion vector predictor setting unit is assigned to the index in the order of having the smallest codeword.

[0042] Beneficial Effects

[0043] According to an embodiment of the present invention, the present invention provides an encoding and decoding apparatus for a video signal, that is, using a non-square coding block and a non-square transform block according to an image, thereby improving encoding efficiency.

[0044] Furthermore, according to another embodiment of the present invention, the present invention provides a video signal encoding and decoding device, that is, the encoding order of the transform block is changed according to the direction of the intra-frame prediction mode of the current block, thereby encoding and decoding high-resolution images, and determining the encoding order of the transform block that increases the encoding efficiency.

[0045] According to an embodiment of the present invention, the present invention provides an encoding and decoding device for a video signal, that is, when a transform block is a non-square block, the transform block is divided into one or more transform regions including a part of a plurality of transform coefficient groups, so as to sequentially scan the transform coefficient groups contained in the transform region, thereby improving the coding efficiency of intra-picture prediction.

[0046] Furthermore, according to another embodiment of the present invention, the present invention provides a video signal encoding and decoding device, that is, the transform block is divided into one or more transform regions, and the transform coefficient groups contained in the above-mentioned divided transform regions are scanned sequentially, thereby preferentially encoding the transform coefficient groups in the low-frequency region compared to the high-frequency region, thereby improving the encoding efficiency.

[0047] According to an embodiment of the present invention, the present invention provides a video signal encoding and decoding device, that is, when constructing a predicted motion vector list for the second direction, the motion vector of the first direction of the current block performing bidirectional prediction is used for more than one candidate predicted motion vector setting, thereby, when inter-picture prediction is performed, highly correlated information is used to improve the encoding efficiency of inter-picture prediction.

[0048] Furthermore, according to another embodiment of the present invention, the present invention provides an encoding and decoding device for a video signal, that is, determining whether the reference pictures used for bidirectional prediction of a current block are the same or not, and based on whether they are the same or not, using a motion vector for a first direction as one or more candidate prediction motion vectors when a prediction motion vector list for a second direction is constructed through a plurality of methods, thereby improving encoding efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The block diagram briefly shows a video encoding apparatus according to an embodiment of the present invention.

[0050] Figure 2 The block diagram briefly shows a video decoding device according to an embodiment of the present invention.

[0051] Figure 3The coded block of the current block is used to illustrate the general method.

[0052] Figures 4a to 4c An example of a non-square coding block of a current block according to an embodiment of the present invention is shown.

[0053] Figures 5a to 6d An example of multiple transform blocks for a current coding block according to an embodiment of the present invention is shown.

[0054] Figures 7a to 10 An example of multiple sub-transform blocks according to an embodiment of the present invention is shown.

[0055] Fig.11 The encoding order and method of transform blocks used to illustrate the general method.

[0056] Figures 12a to 12c An example of multiple transform blocks according to an embodiment of the present invention is shown.

[0057] Fig.13 FIG. 2 shows a mode area to which the intra-frame prediction modes belong according to an embodiment of the present invention.

[0058] Fig.14a and Fig.14b The following is a diagram showing the encoding order of multiple transform blocks when the intra prediction mode of the current block belongs to the first mode area according to an embodiment of the present invention.

[0059] Figures 15a to 15c The following is a diagram showing the encoding order of multiple transform blocks when the intra prediction mode of the current block belongs to the second mode area according to an embodiment of the present invention.

[0060] Figures 16a to 16c The coding order of multiple transform blocks when the intra-picture prediction mode of the current block belongs to the third mode area according to an embodiment of the present invention is shown.

[0061] Figures 17a to 19c Various examples of the order of encoding square and non-square transform blocks are shown using the order of encoding transform blocks taking into account the intra prediction mode according to an embodiment of the present invention.

[0062] Fig. 20 Used to illustrate the structure of a general transform block.

[0063] Fig.21 Used to illustrate the transform coefficient groups that constitute a general 16x16 transform block.

[0064] Fig. 22 A transform coefficient group used to illustrate a general method and a transform scanning method for the transform coefficient group.

[0065] Figures 23a to 23d A transformation coefficient group used to explain a general method and types of scanning methods of the above-mentioned transformation coefficient group.

[0066] Fig.24a and Figure 24b An example used to illustrate a scanning method applied to a transform block in one embodiment of the present invention.

[0067] Fig.25 This is an example used to illustrate the application of a general scanning method to the transformation of a 16x8 transformation block.

[0068] Fig.26 The flowchart is a method for scanning a transform coefficient group according to an embodiment of the present invention.

[0069] Fig. 27 A device for scanning a transform coefficient group according to an embodiment of the present invention is shown.

[0070] Fig.28a and Fig.28b The method for scanning a transform coefficient group of a non-square transform block used in one embodiment of the present invention is described.

[0071] Figures 29a to 30d It is used to illustrate various methods of scanning non-square transform blocks used in one embodiment of the present invention.

[0072] Fig.31 Used to illustrate the general method of obtaining the candidate prediction motion vector (MVP candidate) position of the current block.

[0073] Figure 32 to Figure 33b A method for explaining a general method of constructing a prediction motion vector list for a current block.

[0074] Fig.34 FIG. 4 is a flowchart for explaining a method for constructing a predicted motion vector list according to an embodiment of the present invention.

[0075] Fig.35 FIG. 4 is a flowchart for explaining an apparatus for constructing a predicted motion vector list according to an embodiment of the present invention.

[0076] Fig.36 and Fig.37 A flowchart and a constituting device of a method for constituting a predicted motion vector list according to another embodiment of the present invention are shown.

[0077] Fig.38a and Figure 38b The method for constructing a prediction motion vector list according to an embodiment of the present invention is described.

[0078] Fig.39 The flowchart is a method for constructing a predicted motion vector list according to another embodiment of the present invention. DETAILED DESCRIPTION

[0079] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0080] The embodiments of the present invention are provided to provide the present invention more fully to those skilled in the art to which the present invention belongs. The following embodiments can be transformed into various other forms, and the scope of the present invention is not limited to the following embodiments. On the contrary, these embodiments make the present disclosure more substantial and complete, and fully provide the concept of the present invention to those skilled in the art of the present invention.

[0081] In addition, in the figures, the thickness or size of each unit is exaggerated for the convenience and clarity of description, and the same reference numerals in the figures represent the same structural elements. As used in this specification, the term "and / or" includes all combinations of one or more of the corresponding listed items.

[0082] The terms used in this specification are used to describe specific embodiments and are not intended to limit the present invention. As used in this specification, the singular form does not specify other situations in the context, but may include the plural form. Moreover, in the case of use in this specification, "comprise" and / or "comprising" specifically mention the existence of shapes, numbers, steps, actions, parts, elements and / or these groups, does not exclude the existence or addition of more than one other shape, number, action, part, element and / or group.

[0083] In this specification, the terms first, second, etc. are used to describe a variety of structural elements, components, parts, regions and / or parts, and these structural elements, components, parts, regions and / or parts are not limited to these terms. These terms are used to distinguish one structural element, component, part area or part from other areas or parts. Therefore, hereinafter, the above-mentioned first structural element, component, part, area or part may be referred to as the second structural element, component, part, area or part without exceeding the subject matter of the present invention. Furthermore, the term and / or includes a combination of multiple related recorded items or one item in multiple related recorded items.

[0084] When a structural element is “connected” or “coupled” to other structural elements, it includes the case where it is directly connected or coupled to the other structural elements and the case where the other structural elements exist between the one structural element and the other structural elements. However, when a structural element is “directly connected” or “directly coupled” to other structural elements, there is no other structural element in between, but the one structural element is directly connected or coupled to the other structural elements.

[0085] Embodiments of the present invention are described below with reference to the accompanying drawings that briefly illustrate embodiments of the present invention. In the drawings, for example, the size and shape of components are exaggerated for the convenience and clarity of the description, and when actually embodied, deformation of the shapes shown can be expected. Therefore, embodiments of the present invention are not limited to the specific shapes of the regions shown in this specification.

[0086] Figure 1 The block diagram briefly shows a video encoding device according to an embodiment of the present invention.

[0087] Reference Figure 1 The image encoding device 1000 includes a picture segmentation unit 1050, an inter-frame prediction unit 1100, an intra-frame inter-frame prediction unit 1150, a transformation unit 1200, a quantization unit 1250, a re-arrangement unit 1300, an entropy coding unit 1350, an inverse quantization unit 1400, an inverse transformation unit 1450, a filtering unit 1500 and a memory 1550.

[0088] Figure 1 The various structural elements shown are shown independently in order to present different specific functions in the image encoding device, and each structural element is not formed by a separate hardware or a software constituent unit. That is, each structural element is listed as an individual structural element for the convenience of explanation, and among each structural element, at least two structural elements are combined into other structural elements, or one structural element is divided into multiple structural elements. Such embodiments of the combination of various structural elements or separated embodiments also fall within the scope of protection of the present invention as long as they do not exceed the essential implementation method of the present invention.

[0089] The picture segmentation unit 1050 can segment the input picture into at least one picture processing unit. The above processing unit can be a prediction block (Prediction Unit, hereinafter referred to as "PU"), a transform block (Transform Unit, hereinafter referred to as "TU"), or a coding block (Coding Unit, hereinafter referred to as "CU"). However, in this specification, for the convenience of explanation, the prediction block is represented as a prediction unit, the transform block is represented as a transform unit, and the coding or decoding block is represented as a coding unit or a decoding unit.

[0090] In one embodiment, the picture partitioning unit 1050 partitions a picture into a plurality of coding blocks, prediction blocks, and transform blocks, and selects a coding block, prediction block, and transform block combination based on a predetermined criterion (eg, a cost function) to encode the picture.

[0091] For example, a picture can be divided into multiple coding blocks. In one embodiment, a picture uses a recursive tree structure such as a quadtree or binary tree structure to divide the above coding blocks, and an image or a largest coding unit is used as a tree root to divide the coding blocks of other coding blocks into nodes with the number of codes. Through this process, coding blocks that can no longer be divided can become leaf nodes. For example, for a coding block, when only square cutting can be performed, it can be divided into one coding block, for example, 4 coding blocks.

[0092] However, in the present invention, the above coding blocks, prediction blocks and / or transform blocks are not limited to symmetrical partitioning when partitioning, but can also be asymmetrical partitioning (Asymmetric Partition), not only 4 partitions, but also 2 partitions. However, this number of partitions is only an example, and the present invention is not limited to this. As mentioned above, referring to Figures 3 to 19c A method and apparatus for encoding and decoding a video signal using non-square blocks symmetrically divided into coding blocks and transform blocks are described.

[0093] The prediction block is also divided into at least one square or non-square shape with the same size in a coding block. Among the prediction blocks divided in a coding block, the shape and size of one prediction block are different from those of other prediction blocks. In one embodiment, the coding block and the prediction block may be the same. That is, the coding block and the prediction block are not distinguished, and prediction is performed based on the divided coding block.

[0094] The inter-picture prediction unit may include an inter-picture prediction unit 1100 for performing inter-picture prediction and an intra-picture prediction unit 1150 for performing intra-picture prediction. In order to improve the coding efficiency, instead of performing coding of the image signal, a specific area inside a picture that has been previously coded and decoded is used to predict the image, and the residual interpolation between the original image and the predicted image is encoded. In addition, the prediction mode information, motion vector information, etc. used for prediction are encoded together with the residual interpolation in the entropy coding unit 1350 and transmitted to the decoding unit. When a specific coding mode is used, the prediction block is not generated by the inter-picture prediction units 1100 and 1150, but the original block is directly encoded and transmitted to the decoding unit.

[0095] In one embodiment, the inter-picture prediction unit 1100, 1150 determines whether to perform inter-picture prediction or intra-picture prediction on the prediction block, and can determine specific information of the above prediction method based on the inter-picture prediction mode, motion vector and reference picture. In this case, the processing unit and prediction method for performing the prediction are different from the processing unit. For example, the prediction mode and prediction method can be determined according to the prediction block, and the execution of the prediction can be changed according to the transform block.

[0096] The inter-picture prediction units 1100 and 1150 perform prediction on the processing units of the picture divided in the picture dividing unit 1050 to generate prediction blocks composed of predicted samples. The picture processing units in the inter-picture prediction units 1100 and 1150 may be coding block units, transform block units, or prediction block units.

[0097] The inter-picture prediction unit 1100 predicts a prediction block based on information of one or more pictures in the previous picture or the next picture of the current picture, and predicts the prediction block based on information of a part of the region in which the encoding in the current picture is completed. The inter-picture prediction unit 1100 may include a reference picture interpolation unit, a motion inter-picture prediction unit, and a motion compensation unit.

[0098] In one embodiment, the information of the one or more pictures used for prediction in the inter-picture prediction unit 1100 may be information of pre-encoded and decoded pictures, or information of pictures deformed and stored in any direction. For example, the pictures deformed and stored by any of the above methods may be pictures that are enlarged or reduced in encoding and decoding, or pictures that are formed in a color format by changing the brightness of all pixel values ​​in the pictures.

[0099] The reference picture interpolation unit receives the reference picture information from the storage unit 1550 to generate pixel information below the positive number pixel in the reference picture. In the case of brightness pixels, an 8-point interpolation filter based on discrete cosine transform (DCT-based Interpolation Filter) that changes the filter coefficients is used to generate pixel information below the positive number in units of 1 / 4 pixel. In the case of color difference information, a 4-point interpolation filter based on discrete cosine transform that changes the filter coefficients is used to generate pixel information below the positive number in units of 1 / 8 pixel. However, the type of filter and the unit for generating pixel information below the positive number are not limited to this, and the unit for generating pixel information below the positive number using multiple interpolation filters can be determined.

[0100] The inter-motion picture prediction unit performs motion prediction based on the reference picture interpolated by the above-mentioned picture interpolation unit. A variety of methods are used to calculate the motion vector. The motion vector has a motion vector value of a speed-up pixel unit or a 1 / 4 or 1 / 8 pixel unit based on the interpolated pixel. In one embodiment, in the inter-motion picture prediction unit, the motion prediction method is changed to predict the prediction unit of the current block. The above-mentioned motion prediction method can use a variety of methods including a hybrid method, an advanced motion vector prediction method and a jump method. As described above, the information including the index of the reference picture selected in the inter-picture prediction unit 1100, the candidate prediction motion vector, and the residual signal is entropy encoded and transmitted to the decoder.

[0101] Unlike inter-picture prediction, the intra-picture inter-picture prediction unit 1150 generates a prediction block based on reference pixel information surrounding a current block, which is pixel information in a current picture. When a neighboring block of the prediction block is a block for which inter-picture prediction is performed, reference pixels included in the block are replaced with reference pixel information of the neighboring blocks for which intra-picture prediction is performed.

[0102] In the case where the reference pixel cannot be used, it is necessary to set the reference pixel to be usable. Usually, in the above case, the available reference pixel is replaced by at least one reference pixel among the available surrounding pixels or a preset sample value is assigned.

[0103] However, the method of using the unusable reference pixels by copying the available reference pixels has the problem of reducing the efficiency of intra-picture prediction coding when decoding the current image. According to various embodiments of the present invention, in order to solve this problem, when encoding the transform block, the encoding order of multiple transform blocks is changed by various methods along the direction of the intra-picture prediction mode by using the available reference pixel area to perform intra-picture prediction compared to the unusable reference pixel area. The detailed description of this will be described later.

[0104] Furthermore, the intra prediction unit 1150 may use the most likely intra prediction mode obtained from the neighboring blocks to encode the intra prediction mode. According to various embodiments of the present invention, the most likely intra prediction mode list composed of the most likely intra prediction modes is constructed by various methods.

[0105] In the case where the intra-picture and inter-picture prediction unit 1150 performs intra-picture prediction, the processing unit that performs the prediction is different from the processing unit that determines the prediction method and specific content. For example, the prediction mode is determined as a prediction unit to perform the prediction through the above prediction unit, and the prediction mode is determined as a prediction unit and is performed through the transform unit that performs the prediction. In one embodiment, the prediction mode is determined as a coding block, and the above coding block unit and the prediction unit are the same, so that the prediction is performed through the above coding block unit.

[0106] The prediction mode of intra-picture prediction may include 65 directional prediction modes and at least 2 non-directional modes. The non-directional modes may include a DC prediction mode and a planar mode. The number of the above 67 inter-picture prediction modes is only an example, and the present invention is not limited thereto. In order to perform prediction by multiple methods, intra-picture prediction may be performed by more directional or non-directional modes.

[0107] In one embodiment, intra prediction may be applied to reference pixels to generate a prediction block. In this case, whether the reference pixels are applicable may be determined according to the intra prediction mode and / or size of the current block.

[0108] The prediction unit can determine a variety of sizes and shapes from the coding unit that cannot be further divided. For example, in the case of inter-picture prediction, the prediction unit can have a size such as 2Nx2N, 2NxN, Nx2N or NxN (N is a positive number). In the case of intra-picture prediction, the prediction unit can have a size such as 2Nx2N or NxN (N is a positive number), and intra-picture prediction can be performed with the above-mentioned square size and non-positive size shape. In this case, the prediction unit of NxN size is only applicable in specific cases. In addition, in addition to the prediction units of the above-mentioned sizes, intra-picture prediction units with sizes such as NxmN, mNxN, 2NxmN or mNx2N can also be used.

[0109] The residual block value (residual block or residual block signal) between the prediction block and the original block generated in the intra-frame and inter-frame prediction unit 1150 can be input to the transformation unit 1200. In addition, the prediction mode information, interpolation filter information, etc. used for prediction are encoded together with the residual block value in the entropy coding unit 1350 and transmitted to the decoder.

[0110] The transformation unit 1200 transforms the residual block including residual block value information of the prediction unit generated by the inter-picture prediction unit 1150 with the original unit and the original block 1100 by using a transformation method such as discrete cosine transform (DCT), discrete sine transform (DST), and feature selection and extraction (KLT). In order to transform the residual block, discrete cosine transform, discrete sine transform, and feature selection and extraction are determined based on intra-picture prediction mode information of the prediction unit used to generate the residual block.

[0111] The transform block in the transform unit 1200 is a transform block TU, which may be in a square structure, a non-square structure, a square quadtree structure, a non-square quadtree structure, or a binary tree structure. In one embodiment, the size of the transform unit may be determined within a specified maximum and minimum size range. In addition, a sub-transform block of a transform block may be further divided, and the above-mentioned multiple sub-transform blocks may be in a square structure, a non-square structure, a square quadtree structure, a non-square quadtree structure, or a binary tree structure.

[0112] The quantization unit 1250 performs a quantization on the residual interpolation value transformed in the transformation unit 1200 to generate a quantization coefficient. In one embodiment, the residual interpolation value of the transformation may be a value transformed into a frequency domain. The quantization coefficient is changed according to the importance of the transformation unit or the image, and the value calculated in the quantization unit 125 is provided to the inverse quantization unit 1400 and the re-arrangement unit 1300 again.

[0113] The re-arrangement unit 1300 may re-arrange the quantized coefficients provided from the quantization unit 1250. The re-arrangement unit 1300 re-arranges the quantized coefficients, thereby improving the encoding efficiency in the entropy coding unit 1350. The re-arrangement unit 1300 re-arranges the quantized coefficients in the two-dimensional block form into a one-dimensional vector form by a coefficient scanning method. The coefficient scanning method determines which scanning method to use according to the size of the transform unit and the intra-picture prediction mode. The coefficient scanning method may include zigzag scanning, vertical scanning of scanning the coefficients in the two-dimensional block form along the column direction, and horizontal scanning of scanning the coefficients in the two-dimensional block form along the row direction. In one embodiment, the re-arrangement unit 1300 changes the order of coefficient scanning based on the probability statistics of the coefficients transmitted in the quantization unit, thereby improving the entropy coding efficiency in the entropy coding unit 1350.

[0114] The entropy coding unit 1350 performs entropy coding on the quantized coefficients in the reordering unit 1300. For example, the entropy coding may use a variety of coding methods such as Exponential Golomb, Context-Adaptive Variable Length Coding (CAVLC), and Content-Adaptive Binary Arithmetic Coding (CABAC).

[0115] The entropy coding unit 1350 can read and encode various information such as quantization coefficient information and block type information, prediction mode information, partition unit information, prediction unit information, transmission unit information, motion vector information, reference picture information, block interpolation information, and filter information of the coding unit received from the reordering unit 1300 and the inter-picture prediction units 1100 and 1150. In addition, in one embodiment, the entropy coding unit 1350 adds a predetermined change to the transmitted parameter group or syntax when necessary.

[0116] The inverse quantization unit 1400 inversely quantizes the value quantized in the quantization unit 1250, and the inverse transformation unit 145 inversely transforms the value inversely quantized in the inverse quantization unit 1400. The residual block values ​​generated in the inverse quantization unit 1400 and the inverse transformation unit 1450 are merged with the prediction blocks predicted in the inter-picture prediction units 1100 and 1150 to generate a reconstructed block. The image composed of the reconstructed blocks generated above can be a motion compensated image or a motion compensated image (Motion Compensated Picture).

[0117] The motion compensated image may be input to the filter unit 1500. The filter unit 1500 may include a deblocking filter unit, an offset modification unit (Sample Adaptive Offset, SAO), and an adaptive loop filter (ALF, Adaptive Loop Filter). Simply put, after the motion compensated image is subjected to a deblocking filter in the deblocking filter unit to remove or reduce blocking artifacts, the offset input to the offset modification unit may be modified. The image output in the offset modification unit passes through an adaptive loop filter to the adaptive loop filter unit, and the image that passes through the filter is transmitted to the memory 1550.

[0118] Specifically, the filter unit 1500 is described. The deblocking filter unit removes the distortion within the block generated by the boundary between the blocks in the restored picture. In order to determine whether to perform deblocking, it is determined whether to apply the deblocking filter to the current block based on the pixels in several columns or rows in the block. In the case where the deblocking filter is applied to the block, a strong filter or a weak filter can be applied according to the required deblocking filter strength. In addition, in the process of applying the deblocking filter, when the vertical filter and the horizontal filter are executed, the horizontal direction filtering and the vertical direction filtering are processed in parallel.

[0119] The offset modification unit modifies the offset of the residual block to which the deblocking filter is applied with respect to the original image in pixel units. In order to modify the offset for a specific picture, the pixels in the image are divided into a predetermined number of regions, and then the region to be modified is determined. A method of applying a modified offset to the corresponding region (Band Offset) or a method of applying an offset in consideration of edge information of each pixel (Edge Offset) may be applied. However, in one embodiment, no filter is used in the filter unit 1500 for the restored block used for inter-picture prediction.

[0120] Adaptive loop filtering (ALF) is based on comparing the values ​​of the filtered restored image with the original image, and is only performed when it is most efficient. After the pixels in the image are divided into specified groups, a filter applicable to the corresponding group is determined to perform different filtering on each group. Among the information related to whether the above-mentioned adaptive loop filter is applicable, brightness information can be transmitted corresponding to each coding unit (CU), and the shape and filter coefficients of the adaptive loop filter applied are different for each block, and the same form (fixed form) of the adaptive loop filter can be applied regardless of the characteristics of the applicable object block.

[0121] The memory 1550 may store the restored block or picture calculated by the filtering unit 1500. The restored block or picture stored in the memory 1550 may be provided to the inter-picture prediction unit 1100 or the intra-picture inter-picture prediction unit 1150 that performs inter-picture prediction. The pixel value of the restored block used in the intra-picture inter-picture prediction unit 1150 is data that does not use the deblocking filtering unit, the offset modification unit, and the adaptive loop filtering.

[0122] Figure 2 FIG. 1 is a block diagram briefly showing a video decoding device according to an embodiment of the present invention. Figure 2 The image decoding device 2000 includes an entropy decoding unit 2100, a re-arrangement unit 2150, an inverse quantization unit 2200, an inverse transformation unit 2250, an inter-picture prediction unit 2300, an intra-picture inter-picture prediction unit 2350, a filtering unit 2400, and a memory 2450.

[0123] When an image bitstream is input from an image encoding device, the input bitstream is decoded by the inverse process of the step in which the image information is processed in the encoding device. For example, in order to perform entropy coding in the image encoding device, when variable length coding (VLC, hereinafter referred to as VLC) such as CAVLC is used, the entropy decoding unit 2100 also performs entropy decoding using a variable length coding table that is the same as the variable length coding table used in the encoding device. Furthermore, in order to perform entropy coding in the encoding device, when CABAC is used, entropy decoding using CABAC is performed in the entropy decoding unit 2100 accordingly.

[0124] Among the information decoded by the entropy decoding unit 2100 , information for generating a prediction block is provided to the inter prediction unit 2300 and the intra inter prediction unit 2350 , and the residual interpolation value entropy-decoded by the entropy decoding unit is input to the re-arranging unit 2150 .

[0125] The reordering unit 2150 reorders the bit stream entropy decoded in the entropy decoding unit 2100 based on the method of reordering in the video encoder. The reordering unit 2150 receives information related to coefficient scanning performed in the encoding device, and reorders the bit stream by the reverse scanning method based on the scanning order of the encoding device.

[0126] The inverse quantization unit 2200 performs inverse quantization based on the quantization parameter provided in the encoding device and the coefficient value of the rearranged block. The inverse transform unit 2250 performs inverse DCT, inverse DST or inverse KLT on the DCT, DST or KLT performed by the transform unit of the encoding device for the quantization result performed in the image encoding device. The inverse transform is performed based on the transmission unit or the image segmentation unit determined in the encoding device. In the transform unit of the encoding device, DCT, DST or KLT is selectively performed according to information such as the prediction method, the size of the current block and the prediction direction, and the inverse transform unit 2250 of the decoding device determines the inverse transform method based on the transform information performed in the transform unit of the encoding device to perform the inverse transform.

[0127] The inter-picture prediction units 2300 and 2305 generate a prediction block based on information related to prediction block generation provided in the entropy decoding unit 2100 and previously decoded block and / or picture information provided in the memory 2450. The restored block can be generated using the prediction block generated in the inter-picture prediction units 2300 and 2350 and the residual block provided in the inverse transform unit 2250. The specific prediction method performed by the inter-picture prediction units 2300 and 2350 is the same as the prediction method performed by the inter-picture prediction units 1100 and 1150 of the encoding device.

[0128] The inter-picture prediction unit 2300, 2350 may include a prediction unit determination unit (not shown), the inter-picture prediction unit 2300, and an intra-picture inter-picture prediction unit 2350. The prediction unit determination unit receives various information such as prediction unit information input from the entropy decoding unit 2100, prediction mode information of the intra-picture prediction method, and motion prediction related information of the inter-picture prediction method to distinguish the prediction block in the current coding block, and determines whether the prediction block performs inter-picture prediction or intra-picture prediction.

[0129] The inter-picture prediction unit 2300 uses the information required for inter-picture prediction of the current prediction block provided by the video encoder to perform inter-picture prediction with the current prediction block based on information in at least one picture before or after the current picture in the current prediction block.

[0130] Specifically, in inter-picture prediction, a reference picture is selected for the current block, and a reference block of the same size as the current block is selected to generate a prediction block related to the current block. At this time, in order to use the information of the reference picture, the information of the surrounding blocks of the current picture can be used. For example, a method such as skip mode, merge mode and advanced motion vector prediction is used to generate a prediction block related to the current block based on the information of the surrounding blocks.

[0131] The prediction block can be generated in sample units of positive numbers such as 1 / 2 pixel sample units and 1 / 4 pixel sample units. In this case, the motion vector is also expressed in units of positive pixels. For example, the brightness pixel is expressed in 1 / 4 pixel units, and the color difference pixel is expressed in 1 / 8 pixel units.

[0132] The motion information including the motion vector and reference picture index required for inter-picture prediction of the current block confirms the skip flag, mix flag, etc. received from the encoding device and is guided accordingly.

[0133] The intra-frame and inter-frame prediction unit 2350 generates a prediction block based on pixel information in the current picture. In the case of a prediction unit that performs intra-frame prediction, intra-frame prediction is performed based on intra-frame prediction mode information of the prediction unit provided by the image encoder. In the case of a block that performs inter-frame prediction in a neighboring block of the prediction unit, that is, in the case of a pixel that performs inter-frame prediction in a reference pixel, the reference pixel in the block that performs inter-frame prediction is replaced by the reference pixel information of the neighboring block that performs intra-frame prediction.

[0134] In the case where the reference pixel is unavailable, it is set to be available. Typically, in the above case, the unavailable reference pixel is replaced by at least one reference pixel in the available surrounding pixel values ​​or is assigned a preset quality.

[0135] However, in this method of using unusable reference pixels by copying available reference pixels, when decoding the current image, the intra-picture prediction coding efficiency is reduced. According to various embodiments of the present invention, in order to solve this problem, when encoding a transform block, the encoding order of multiple transform blocks is changed along the direction of the intra-picture prediction mode by using an available reference pixel area compared to an unusable reference pixel area to perform intra-picture prediction. A detailed description of this will be described later.

[0136] Furthermore, the intra-frame inter-frame prediction unit 2350 uses the most probable intra-frame prediction mode (MPM: Most Probable Mode) obtained from the neighboring blocks to encode the intra-frame prediction mode. In one embodiment, the most probable intra-frame prediction mode may use the intra-frame prediction mode of the spatial neighboring blocks of the current block.

[0137] In one embodiment, the processing unit that performs prediction in the intra-frame and inter-frame prediction unit 2350 is different from the processing unit that determines the prediction method and specific content. For example, the prediction mode is determined by the prediction unit to perform prediction by the prediction unit, and the prediction mode is determined by the prediction unit to perform intra-frame prediction by the transform unit.

[0138] In this case, the prediction block determines various sizes and shapes from the coding block that cannot be further divided. For example, in the case of intra-picture prediction, the prediction block can have a size such as 2Nx2N or NxN (N is a positive number), not only the above square size, but also NxmN, mNxN, 2NxmN or mNx2N (m is a fraction or a positive number) with non-square size shapes to perform intra-picture prediction. In this case, the prediction unit of NxN size is only applicable in specific cases.

[0139] Furthermore, the transform block may be determined to be of various sizes and forms. For example, the transform block may have a size such as 2Nx2N or NxN (N is a positive number), not only the above-mentioned square size, but also NxmN, mNxN, 2NxmN or mNx2N (m is a fraction or a positive number) as a non-square size to perform intra-picture prediction. In this case, the prediction unit of NxN size is applicable only in specific cases. In one embodiment, the transform block may be one of blocks having a square structure, a non-square structure, a square quadtree structure, a non-square quadtree structure or a binary tree structure. In one embodiment, the size of the transform block may be determined within the range of a specified maximum and minimum size. Furthermore, a transform block may be divided into sub-transform blocks, in which case it may be divided into a square structure, a non-square structure, a square quadtree structure, a non-square quadtree structure or a binary tree structure.

[0140] The intra-frame and inter-frame prediction unit 235 may include an adaptive intra-frame smoothing (AIS) filter unit, a reference pixel interpolation unit, and a DC filter unit. The adaptive intra-frame smoothing filter unit is a part that performs filtering on the reference pixels of the current block, and determines whether to apply the filter according to the prediction mode of the current prediction unit. The adaptive intra-frame smoothing filter information of the prediction mode of the prediction unit provided in the image encoder is used to perform adaptive intra-frame smoothing filtering on the reference pixels of the current block. When the prediction mode of the current block does not perform adaptive intra-frame smoothing filtering, the adaptive intra-frame smoothing filter unit is not applicable to the current block.

[0141] The reference pixel interpolation unit interpolates reference pixels to generate reference pixels of pixel units with positive values ​​or less, when the prediction mode of the prediction unit performs intra-screen prediction based on sample values ​​of interpolated reference pixels. The prediction mode of the current prediction unit does not interpolate reference pixels, but in the case of a prediction mode for generating a prediction block, the reference pixels are not interpolated. The DC filter unit generates a prediction block by filtering, when the prediction mode of the current block is the DC mode.

[0142] The restored block and / or picture may be provided to the filter unit 2400. The filter unit 2400 may include a deblocking filter unit, an offset modification unit, and / or an adaptive loop filter unit in the restored block and / or picture. The deblocking filter unit may receive information indicating whether a strong filter or a weak filter is applicable when the information indicating whether a deblocking filter and a deblocking filter are applicable to the object block or picture from the image encoder. The deblocking filter unit receives the deblocking filter related information provided in the image encoder, and performs deblocking filtering of the corresponding block in the image decoder.

[0143] The offset modification unit performs offset modification on the restored image based on the type of offset information and offset value information applied to the image when encoding. The adaptive loop filter unit applies the adaptive loop filter in coding units based on information on whether the adaptive loop filter is applied or not and information on coefficient information of the adaptive loop filter provided from the encoder. The information related to the adaptive loop filter is provided in a specific parameter set.

[0144] The memory 2450 stores the restored picture or block and uses it as a reference picture or reference block later, and provides the restored picture to the input unit.

[0145] In this specification, although it is omitted for convenience of explanation, the bit stream input to the decoding device is input to the entropy decoding unit through a parsing step. And, the entropy decoding unit performs the parsing process.

[0146] In this specification, encoding can be interpreted as coding or decoding according to the situation, and information includes values, parameters, coefficients, elements, flags, etc. "Screen" or "picture" is a unit of an image generally represented in a specific time, and "slice", "frame", etc. are units that constitute a part of a picture in the actual video signal encoding process, and are mixed with pictures as needed.

[0147] "Pixel", "pixel" or "primitive" means the smallest unit constituting an image. Also, "sample" can be used as a term to indicate a specific pixel value. Samples can be divided into luminance (Luma) and chromaticity (Chroma) components, and usually, a term that includes both of them is used. The chromaticity component indicates the difference between certain colors and is generally composed of Cb and Cr.

[0148] "Unit" is a basic unit of image processing or a specific position of an image, such as a coding unit, a prediction unit, or a transform unit, and is used in combination with terms such as "block" or "region" depending on the situation. In addition, a block represents a set of samples or transform coefficients consisting of M columns and N rows.

[0149] Figure 3 A coded block of a current block used to illustrate the prior art.

[0150] Reference Figure 3, the image corresponding to the current block can be encoded or decoded using square coding blocks 11, 12, 13, and 14 of the same size. For example, the current block 10 is tilted to one side within the current block, so that in the square coding block, only when coding block 112 and coding block 314 are located, it is divided into 4 square coding blocks, so that coding block 011 and coding block 213, which are coding blocks that do not actually exist, are encoded or decoded. Therefore, it is necessary to transmit the prediction mode and prediction information for the above-mentioned coding block 011 and coding block 213. The above method has nothing to do with the characteristics of the image of the corresponding block, and a lot of information needs to be transmitted, thereby reducing the coding efficiency. In order to solve this problem, the coding blocks of an embodiment of the present invention may include square coding blocks and non-square coding blocks.

[0151] Figures 4a to 4c An example of a non-square coding block of a current block according to an embodiment of the present invention is shown.

[0152] like Figures 4a to 4c As shown, the coding block may include a non-square coding block. Moreover, each coding block may independently determine a prediction mode and prediction information for transmission. In one embodiment, the non-square coding block may include a non-square coding block in the longitudinal direction whose lateral length is greater than the longitudinal length and a non-square coding block in the transverse direction whose longitudinal length is less than the lateral length.

[0153] First, refer to Figure 4a , the coding blocks 21 to 27 for encoding the current block include coding blocks 21, 24, 25 of a non-square shape in the longitudinal direction. For example, the non-square coding block in the longitudinal direction has a size 21 of 16x32 or may have a size 24, 25 of 8x32. In the present invention, the horizontal and vertical size ratios of the coding blocks are not limited thereto. In one embodiment, the non-square coding block in the longitudinal direction is used when the longitudinal change of the image corresponding to the current block is greater than the lateral change.

[0154] And, refer to Figure 4b , the coding blocks 31 to 37 for encoding the current block include coding blocks 31, 34, and 35 of a horizontal non-square shape. For example, the horizontal non-square coding block has a size 31 of 32x16 or has a size 34 and 35 of 32x8. In the present invention, the horizontal and vertical sizes of the coding blocks are not limited to this. In one embodiment, the horizontal non-square shaped coding block is used when the vertical change of the image corresponding to the current block is less than the horizontal change. However, this is only an example. For the current block, the method for determining which direction of the non-square coding block to use is not limited to this, and the maximum and minimum sizes of the non-square coding blocks are not limited to this. In addition, the number of non-square coding blocks and the ratio of the horizontal length to the vertical length are not limited to this. The current block can be divided into 1:N.

[0155] In one embodiment, the prediction block corresponding to the current coding block is not set, and the current coding block can directly use the prediction block. In this case, as in the general method, the coding block is square and non-square, and the current block including the above coding block has a 1:N split structure. In addition, in another embodiment, the current coding block is used as a prediction block and a transform block. In this case, as described above, the current block including the current coding block is divided into a square block structure, a non-square block structure, and a 1:N structure.

[0156] Reference Figure 4c , the Coding Tree Unit (CTU) may include square coding blocks of various sizes CB0 to CB4, CB8, CB9, CB11, CB12, CB15 and non-square coding blocks of various sizes CB5 to CB7, CB10, CB13, CB14, CB17 to CB19.

[0157] In the previous video signal encoding process, only square blocks were used as coding blocks, and only square transform blocks were used as transform blocks. Multiple transform blocks based on the size of each coding block or prediction block are further divided into a quadtree division structure. For example, when a transform block is divided into a quadtree structure, the transform block can be divided into 4 square sub-transform blocks. It is difficult for the previous encoding method that only uses such square multiple transform blocks to consider the characteristics of the residual block signal generated according to the characteristics of the image corresponding to the coding block and the prediction mode. Therefore, the video signal encoding method of an embodiment of the present invention can use non-square coding blocks and non-square transform blocks and non-square sub-transform blocks as transform blocks.

[0158] Figures 5a to 6c An example of multiple transform blocks for a current coding block according to an embodiment of the present invention is shown. Figure 5a and Figure 5b is an example of the construction of an initial transform block for a current square coding block (not shown) of size NxN. Figures 6a to 6c The structure of the early transform block for a non-square current coding block is shown.

[0159] In the case where one or more transform blocks are used for a square current coding block, the transform blocks constituting the current coding block may include a square transform block and a non-square transform block. The transform block may transform the residual block signal into a frequency region using a transform matrix.

[0160] Reference Figure 5a The square coding block is the composition of the initial transform block, which can be composed of one square transform block 41 or four square transform blocks 42 to 45. Figure 5bIn the case of using a square coding block, the initial transform block may be composed of two non-square transform blocks 46 to 48 or four non-square transform blocks 51 to 58. The second non-square transform block may be a non-square transform block 46, 47 in the vertical direction of N / 2xN size or a non-square transform block 48, 49 in the horizontal direction of NxN / 2 size, and the four non-square transform blocks may be a non-square transform block 51 to 54 in the vertical direction of N / 4xN size or a non-square transform block 55 to 58 in the horizontal direction of NxN / 4 size.

[0161] As described above, in the case of forming a transform block for a square coding block, an initial transform block can be formed by a square transform block and a non-square transform block. Two or four non-square transform blocks are shown previously, and in the present invention, the size and number of non-square transform blocks are not limited to this. In addition, in the case where the current coding block performs intra-screen prediction, the transform block composition of the current coding block is different according to the directionality of the intra-screen prediction mode. For example, in the case where the current coding block uses the intra-screen prediction mode in the vertical direction, a horizontally divided non-square transform block is used as the transform block for the current coding block, thereby generating a prediction signal for the current transform block using the reference sample encoded at the upper end.

[0162] According to reference Figures 6a to 6d In an embodiment of the present invention, when one or more transform blocks are used for a non-square current coding block (not shown), the transform blocks constituting the current coding block may include a square transform block and a non-square transform block.

[0163] Reference Figure 6a In the present invention, the coding block may be a non-square coding block 60a, 60b having a different horizontal length A from a vertical length B. In this case, when the current non-square coding block is initially formed by one or more transform blocks, a square transform block or a non-square transform block is used to equally divide the coding block.

[0164] Reference Figure 6b As the initial transform block structure for the non-square coding blocks 60a and 60b, N square transform blocks 61 of size axa may be used. In this case, the horizontal and vertical lengths a of the square transform block 61 are the same as the smaller length of the horizontal and vertical lengths of the non-square coding block. In one embodiment, the horizontal and vertical lengths of the square transform block 61 are calculated from the upper parameters or obtained by a preset method.

[0165] Reference Figure 6cAs the composition of the initial transform blocks for the non-square coding blocks 60a and 60b, M (where M is a positive number) non-square transform blocks 62 to 65 can be used. The size of the non-square transform blocks 62 and 63 is the same as that of the non-square coding block 60a, or they can be non-square transform blocks 64 and 65 that are smaller than the size of the non-square coding blocks 60a and 60b. In one embodiment, the horizontal length a and the vertical length b of the non-square transform blocks 62 and 63 are the same as the horizontal and vertical lengths of the coding blocks 60a and 60b. In another embodiment, the horizontal and vertical lengths of the non-square transform blocks 64 and 65 are calculated by the upper parameters or obtained by a preset method.

[0166] And, refer to Figure 6d As the initial transform blocks for the non-square coding blocks 60a and 60b, M non-square or square transform blocks 66 and 67 of a quadtree structure can be used. The size of the non-square or square transform blocks 66 and 67 is smaller than that of the non-square coding blocks, and can be used when the size of the non-square coding blocks is large and does not correspond to one transform block. In the present invention, only a plurality of transform blocks of a quadtree structure are described, but the number of the non-square or square transform blocks 66 and 67 is not limited thereto.

[0167] The transform block constituting the current coding block may be divided into a plurality of sub-transform blocks of smaller size. The plurality of sub-transform blocks independently perform a transform process to generate transform coefficients, and may have a variety of shapes and sizes. Furthermore, the division method is determined differently based on the size and shape of the upper transform block before being divided into the plurality of sub-transform blocks, and has an independent shape different from the shape of the upper transform block.

[0168] Figures 7a to 10 An example of a sub-transform block according to an embodiment of the present invention is shown. Figures 7a to 7d An example of a plurality of sub-transform blocks of the above transform block when the transform block is a square transform block, Figures 8a to 8d An example of a plurality of sub-transform blocks in the case of a horizontal non-square transform block is shown, Figures 9a to 9d An example of a plurality of sub-transform blocks of a horizontal non-square transform block is shown. Fig.10 A transform block composed of a plurality of sub-transform blocks is shown.

[0169] Reference Figures 7a to 7d In the case where the current transform block is a square transform block 70 of NxN size, the square transform block 70 is divided and generates sub-transform blocks 71a to 74d by a plurality of methods. The square transform block 70 is divided into four square sub-transform blocks 71a to 71d ( Figure 7b), using a binary tree partitioning method to partition into horizontal or vertical non-square 2 or more sub-transformation blocks 72a to 72d ( Figure 7c In one embodiment, a non-square quadtree partitioning method is used to partition the block into four non-square sub-transform blocks 73a to 73h ( Figure 7d ). The number and size of the above-mentioned multiple sub-transform blocks that are divided are only an example, and the present invention is not limited thereto.

[0170] Reference Figures 8a to 8d ,like Figure 8a As shown in FIG. 1 , when the current transform block is a non-square transform block 80 of size A (horizontal length) x B (vertical length), the non-square transform block 80 is divided by a plurality of methods to generate sub-transform blocks 81a to 84d. The non-square transform block 80 is divided into four square sub-transform blocks 81a to 81d ( Figure 8b ), divided into four or more sub-transform blocks (not shown). In this case, the horizontal and vertical lengths of the square sub-transform blocks can be the same as the shorter length ( Figure 8a In the case where the longitudinal length B of the non-square transform block 80 is a positive multiple of the lateral length A, the non-square transform block 80 is as follows: Figure 8b The square partitioning method shown is partitioned into transform blocks.

[0171] Reference Figure 8c The non-square transform block 80 can be divided into two or more non-square sub-transform blocks 82a to 82d in the vertical or horizontal direction using a binary tree partitioning method. Figure 8d , the non-square transform block 80 is divided into four non-square sub-transform blocks 83a to 83d using a non-square quadtree partitioning method. The number and size of the above-mentioned multiple sub-transform blocks are only an example, and the present invention is not limited thereto.

[0172] Reference Figures 9a to 9d ,like Figure 9a As shown in FIG. 1 , when the current transform block is a non-square transform block 90 of size A (horizontal length) x B (vertical length), the non-square transform block 90 is divided by a plurality of methods to generate sub-transform blocks 91a to 94d. The non-square transform block 90 is divided into four square sub-transform blocks 91a to 91d ( Figure 9b ), is divided into four or more sub-transform blocks (not shown). In this case, the horizontal and vertical lengths of the square sub-transform blocks can be the same as the shorter length ( Figure 9aIn the case where the horizontal length A of the non-square transform block 90 is a positive multiple of the vertical length B, the non-square transform block 90 may be configured as follows: Figure 9b The square partitioning method shown is partitioned into sub-transform blocks.

[0173] Reference Fig.9c The non-square transform block 90 is divided into two or more non-square sub-transform blocks 92a to 92d in the vertical or horizontal directions by using a binary tree partitioning method. Figure 9d , using the non-square quadtree partitioning method, the non-square transform block 90 can be partitioned into four non-square sub-transform blocks 93a to 93d. The number and size of the above-mentioned multiple sub-transform blocks are only an example, and the present invention is not limited thereto.

[0174] Fig.10 Show the use of Figures 7a to 9d The segmentation method shown is an example of transforming the current coding block. Fig.10 , the current coding block is not only a square transform block, but also a non-square transform block. The square or non-square transform block is not only a square sub-transform block, but also a non-square sub-transform block. This transform block is applicable to the sub-transform block segmentation combination Figures 7a to 9d Furthermore, the shape and number of transform blocks or the shape and number of sub-transform blocks are not limited to the examples of the present invention.

[0175] Generally, when intra-picture prediction is performed on the current block, a raster scan method is used to decode the transform block, and reference samples used to generate a prediction signal in the direction of the intra-picture prediction mode are determined.

[0176] Fig.11 The encoding order and method of transform blocks used to illustrate the general method. Fig.11 , when the direction of the intra-picture prediction mode of the current block is 2 to 10, multiple transform blocks TU0 to TU3 always use the reference samples located on the left side of the above transform blocks to generate prediction signals. In this case, among the multiple transform blocks, the first transform block TU0 that generates the prediction signal first uses the first reference sample area 111 located in the transform block to generate the prediction signal, and the first reference sample area 111 may be composed of available reference samples and / or unavailable reference samples. Afterwards, the second transform block TU1 also consists of a part of the pixels of the first transform block TU0 to form a second reference sample area 112 for the second transform block TU1, and therefore, the second reference sample area 112 consists of a part of the pixels of the first transform block TU0 as the sample to be encoded, that is, the available reference samples.

[0177] Afterwards, the third transform block TU2 for generating the prediction signal uses the pixels located on the left side of the third transform block TU2 as reference samples, and does not use the pixels of the encoded first transform block TU0 and the second transform block TU1, so the third reference sample area 113 for prediction can be composed of unusable reference samples. The fourth transform block TU3 is composed of a portion of pixels of the third transform block TU2 to form a fourth reference sample area 114 for the fourth transform block TU3, so the fourth reference sample area 114 can be composed of a portion of pixels of the third transform block TU2 as encoded samples, that is, usable reference samples.

[0178] As described above, according to the conventional encoding order, when generating a prediction signal from a transform block, a prediction signal may be generated using a reference sample that cannot be used along the direction of the intra-picture prediction mode. Therefore, a method for encoding a video signal according to an embodiment of the present invention can determine the encoding order of a plurality of transform blocks in a variable manner along the direction of the intra-picture prediction mode of the current encoding block, thereby improving encoding efficiency.

[0179] Figures 12a to 12c An example of multiple transform blocks according to an embodiment of the present invention is shown.

[0180] Reference Figures 12a to 12c In one embodiment of the present invention, the plurality of transform blocks may be in a structure where four transform blocks of the same size are formed in two lines ( Fig.12a ), which can be a structure in which multiple transform blocks of the same size are arranged horizontally or vertically ( Figure 12b and Fig.12c ). The above-mentioned multiple transform blocks can be further divided into multiple sub-transform blocks of smaller size. When further divided, the structure of the multiple sub-transform blocks is also as follows: Figures 12a to 12c The structure shown.

[0181] If a plurality of transform blocks are encoded without considering the intra-frame prediction mode of the current block, unencoded surrounding blocks may be used when generating prediction signals for each transform block. In this case, the reference sample used to generate the prediction signal may be an unavailable sample, and therefore, the unavailable sample is used by copying the available samples of the surroundings, so that the coding efficiency is not excellent. Therefore, in the present invention, a method for determining the coding order of transform blocks in a variable manner is proposed, taking into account which mode area the intra-frame prediction mode of the current block corresponding to the plurality of transform blocks belongs to.

[0182] In order to determine the encoding order of a plurality of transform blocks in a variably manner according to the intra-screen prediction mode, first, the intra-screen prediction mode is divided again according to the prediction direction. Fig.13 FIG. 2 shows a mode area to which the intra-frame prediction modes belong according to an embodiment of the present invention.

[0183] Reference Fig.13 , the directional intra-frame prediction mode can be divided into a first mode area to a third mode area 131 to 133 along the prediction direction). Fig.13 Among the intra-picture prediction modes shown, the intra-picture prediction mode having an angle of 90 to 180 degrees other than the horizontal and vertical intra-picture prediction modes may be the intra-picture prediction mode constituting the first mode area 131. The second mode area may be the intra-picture prediction mode having a horizontal prediction mode and an angle of 180 to 225 degrees, and the third mode area may be the intra-picture prediction mode having a vertical prediction mode and an angle of 45 to 90 degrees. Based on the mode areas distinguished as above, the encoding order of the plurality of transform blocks is determined in a variable manner according to the mode areas to which the plurality of transform blocks belong.

[0184] Fig.14a and Fig.14b The coding order of multiple transform blocks when the intra prediction mode of the current block belongs to the first mode area according to an embodiment of the present invention is shown. The coding order of multiple transform blocks when belonging to the first mode area is the same as the coding order of multiple transform blocks in the past. Fig.14a Indicates the coding order when multiple transform blocks have an NxN structure, and can be coded in the order of TB0, TB1, TB2, and TB3. Fig.14b Indicates the coding order when multiple transform blocks are non-square transform blocks in the horizontal and vertical directions, and are coded from left to right and from top to bottom. For example, TB4, TB5, TB6, TB7, TB8, TB9, and TB10 are coded in this order.

[0185] Figures 15a to 15c FIG. 2 shows the coding order of multiple transform blocks belonging to the second mode area in the intra-picture prediction mode according to an embodiment of the present invention. The multiple transform blocks are coded sequentially from the lower left end to the upper right end. The multiple transform blocks with an NxN structure can be coded as follows: Fig.15a and Fig.15b Encoding shown. Fig.15a , from TB2 at the lower left end to TB3, B0 and TB1, refer to Fig.15b , encoded sequentially from TB2 located at the lower left end to TB0, TB3 and TB1.

[0186] Furthermore, the non-square transform blocks in the horizontal and vertical directions are encoded in order from the left to the right and from the bottom to the top. Fig.15c , encoding is performed from TB4 on the left to TB5 and TB6, and encoding is performed from TB10 on the lower right to TB9, TB8 and TB7 in sequence.

[0187] Figures 16a to 16cFIG. 2 shows the coding order of multiple transform blocks belonging to the third mode area in the intra-picture prediction mode according to an embodiment of the present invention. The multiple transform blocks can be coded sequentially from the upper right end to the lower left end. The multiple transform blocks with NxN structure are as follows: Fig.16a and Fig.16b Encoding. Fig.16a , from TB1 located at the upper right end to TB0, TB3 and TB2 in sequence, refer to Fig.16b , encoded in sequence from the upper right end to TB3, TB0 and TB2.

[0188] Furthermore, a plurality of non-square transform blocks in the horizontal and vertical directions may be encoded in the order from the right to the left and from the top to the bottom. Fig.16c , TB7 located at the upper right end is encoded downward in sequence to TB8, TB9 and TB10, and among the multiple vertical non-square transform blocks on the left, TB6, TB5 and TB4 located on the right are encoded in sequence.

[0189] As described above, the coding order of the transform blocks is determined in a variable manner taking into account the mode area distinguished by the direction of the intra-frame prediction mode of the current block and the shape of the transform block, and the prediction signal is generated using the available reference samples of the surrounding blocks decoded by each transform block, thereby improving the coding efficiency.

[0190] In one embodiment, in a plurality of transform blocks having the above-described Figures 12a to 12c In the case of a structure of the type, the encoding order of multiple transform blocks determined according to the mode area to which the intra-screen prediction mode of the current coding block corresponding to the above-mentioned multiple transform blocks belongs is as shown in the following Table 1.

[0191] Table 1

[0192]

[0193] Figures 17a to 17c The coding order of the transform blocks recorded in Table 1 is used to construct the coding order of square and non-square transform blocks of the current block. Fig.17a shows the coding order of multiple transform blocks of the current block when the intra-picture prediction mode of the current block belongs to the first mode area, Fig.17b shows the coding order of multiple transform blocks of the current block when the intra-picture prediction mode of the current block belongs to the second mode area, Fig.17c The coding order of multiple transform blocks of the current block is shown when the intra-picture prediction mode of the current block belongs to the third mode area.

[0194] Reference Fig.17aIn the case where the intra-picture prediction mode of the current block belongs to the first mode area, regardless of the shape of the transform block, multiple transform blocks are encoded in the same order as the general encoding order, from the upper left end to the lower right end. In addition, in the case where the intra-picture prediction mode of the current block belongs to the second mode area, when the transform block generates a prediction signal, a reference sample belonging to the lower left end block can be used. Therefore, the transform block is encoded in the order from the lower left end to the upper right end to improve the encoding efficiency. Fig.17b In the process of sequentially encoding the current block from the lower left end to the upper right end, a method of sequentially encoding the lower left end, the lower right end, the upper left end, and the upper right end is selected.

[0195] When the intra-picture prediction mode of the current block belongs to the third mode area, when the transform block generates a prediction signal, the reference sample belonging to the upper left end is used, so the transform block is encoded in order from the upper right end to the lower left end to improve the encoding efficiency. Fig.17c , among which, a method of sequential encoding of the upper right end, the upper left end, the lower right end and the lower left end can be selected.

[0196] In another embodiment, the coding order of the transform blocks considering the intra-picture prediction mode is determined as shown in Table 2 below.

[0197] Table 2

[0198]

[0199]

[0200] Figures 18a to 18c The coding order of the transform blocks recorded in Table 2 is used to construct the coding order of square and non-square transform blocks of the current block. Fig.18a shows the coding order of multiple transform blocks of the current block when the intra-picture prediction mode of the current block belongs to the first mode area, Fig.18b shows the coding order of multiple transform blocks of the current block when the intra-picture prediction mode of the current block is the second mode area, Fig.18c The coding order of multiple transform blocks of the current block is shown when the intra-picture prediction mode of the current block is the third mode area.

[0201] Reference Fig.18a Regardless of the shape of the transform block in the first mode region in the intra-picture prediction mode of the current block, the plurality of transform blocks are encoded in the same order from the upper left end to the lower right end as in the general encoding order. Furthermore, when the intra-picture prediction mode of the current block belongs to the second mode region, when generating the prediction signal, the reference sample belonging to the lower left end block is used, and therefore, the transform blocks are encoded in the order from the lower left end to the upper right end to improve the encoding efficiency. Fig.18bIn the process of sequentially encoding the current block from the lower left end to the lower right end, a method of sequentially encoding from the lower left end, the upper left end, the lower right end and the upper right end is selected.

[0202] When the intra-picture prediction mode of the current block belongs to the third mode area, when the transform block generates a prediction signal, the reference sample belonging to the upper right end is used, so the transform block is encoded in order from the upper right end to the lower left end to improve the encoding efficiency. Fig.18c , wherein a method of encoding in the order of the upper right end, the lower right end, the upper left end, and the lower left end is selected.

[0203] The coding order of multiple transform blocks based on such a pattern region is not limited to the above examples, and can also be determined by a combination of the above examples.

[0204] Figures 19a to 19c Show references in cross selection Figures 17a to 18c The coding order of multiple transform blocks in the case of describing the coding order of multiple transform blocks in the mode region.

[0205] Fig.19a shows the coding order of multiple transform blocks of the current block when the intra-picture prediction mode of the current block belongs to the first mode area, Fig.19b shows the coding order of multiple transform blocks of the current block when the intra-picture prediction mode of the current block belongs to the second mode area, Fig.19c The coding order of multiple transform blocks of the current block is shown when the intra-picture prediction mode of the current block belongs to the third mode area.

[0206] In the case of the first mode region, as referenced Fig.17a and Fig.18a In the case of the second mode area, refer to Fig.19b , according to reference Fig.17b The coding order is determined, and multiple transform blocks are coded in the order of the lower left end, the lower right end, the upper left end, and the upper right end, referring to Fig.19c , when the intra-picture prediction mode of the current block is the third mode area, according to the reference Fig.18c In another embodiment, the encoding order of the second mode area and the third mode area can be based on the encoding order of the upper right end, the lower right end, the upper left end and the lower left end. Fig.18b and Fig.17c As described above, for a plurality of transform blocks of a current block, a combination of a plurality of encoding orders determined according to the intra-picture prediction mode of the current block is used to generate a prediction signal, thereby improving encoding efficiency.

[0207] Fig. 20 and Fig.21 It is used to explain the structure of the transform block and the transform coefficient group of the 16x16 transform block that constitute the general method.

[0208] Reference Fig. 20 , a coding block CB may include multiple transform blocks TB0, TB1...TB12. The multiple transform blocks may include multiple transform blocks with multiple shapes and / or sizes. The transform blocks may include square blocks and non-square blocks, and the transform blocks may be one of blocks in a square quad tree structure, a non-square quad tree structure, or a binary tree structure.

[0209] Reference Fig.21 , the transform block 210 may include more than one transform coefficient group CG0, CG1, ... CG15. For example, the transform block 210 is a 16x16 block, and the size of the transform coefficient group in the transform block may be 4x4. That is, the 16x16 transform block may include 16 4x4 transform coefficient groups, and the index of the transform coefficient group may be based on the following formula: Fig.21 The transform coefficient scanning order is shown.

[0210] Fig. 22 A transform coefficient group used to illustrate a general method and a transform scanning method for the transform coefficient group.

[0211] Reference Fig. 22 Generally, the scanning order of the transform coefficient groups of the transform block 220 is the same as the scanning order of the transform coefficients. For example, if the transform block 220 is 8x8 in size and the size of the transform coefficient groups is a 4x4 block, when the Up-right diagonal scanning method is used for the transform block 220, the transform coefficient groups are applied with the same scanning method as the transform coefficients. Fig. 22 As shown, the transform coefficients 15 to 0 of the transform coefficient group CG3 included in the lower right end of the transform block 220 are scanned by vertical diagonal lines, and then the transform coefficients of the transform coefficient group CG2 at the upper right end are scanned by the same method. Then, the transform coefficients contained in the above transform coefficient groups are scanned by the same method in the order of the transform coefficient group CG1 at the lower left end and the transform coefficient group CG0 at the upper left end.

[0212] Figures 23a to 23d Various examples of transform coefficient groups and scanning methods for the transform coefficient groups are used to illustrate a general method. Figures 23a to 23c represents the scanning method of the transform coefficient group in the intra-picture prediction mode, Fig.23dIndicates the scanning method of the transform coefficient group for the inter-picture prediction mode.

[0213] Reference Figures 23a to 23c In the case of intra-picture prediction, an up-right diagonal scan can be used, which scans sequentially from the lower right end to the upper left end. Fig.23a ), horizontal scan from the right to the left, from the upper end of the lower line Figure 23b ) and vertical scanning (Vertical scan, which scans from the bottom to the top and from the right to the left) Fig.23c ) method. Fig.23d , in the case of inter-picture prediction, only vertical diagonal scanning can be used.

[0214] In one embodiment, a scanning method of a transform coefficient group in intra-picture prediction may be determined according to an intra-picture prediction mode. For example, in the case of intra-picture prediction mode indexes 6 to 14 where the intra-picture prediction mode is horizontal prediction, a vertical scanning method is used to scan the transform coefficient group, and in the case of indexes 20 to 30 where the intra-picture prediction mode is horizontal prediction, a horizontal scanning method is used, and for the remaining intra-picture prediction modes, a vertical diagonal scanning method may be used.

[0215] In recent video coding, square transform blocks have been considered. Therefore, the transform coefficient group and the transform within the transform coefficient group described below are also suitable for square transform blocks. However, when a non-square transform block is used as a transform block, the encoding efficiency is reduced when the conventional transform coefficient group and transform coefficient scanning method are applied. Therefore, in the following, Figure 24a to Figure 3 0, a method for scanning a transform coefficient group that can improve the coding efficiency of an embodiment of the present invention is described.

[0216] Fig.24a and Figure 24b This is an example used to illustrate the application of a general scanning method to a transform block in an embodiment of the present invention.

[0217] Reference Fig.24a , the current transform block TB1 230a is a non-square block, and in the case of having a size of 8×16, if the conventional method is applied by the method of scanning the transform coefficient group and the transform coefficient, three scanning methods can be selected. For example, in the example where the current transform block 230a applies the conventional three scanning methods to scan the transform coefficient group, the vertical diagonal scanning method, the vertical scanning method, and the horizontal scanning method are applied from the left to scan the transform coefficient group.

[0218] Reference Figure 24bThe current transform block TB2 230b is a non-square block and has a size of 16x8. If the conventional method is applied as a method of scanning the transform coefficient group and the transform coefficient, three scanning methods can be selected. For example, when the current transform block 230b is applied with the three conventional scanning methods to scan the transform coefficient group, the vertical diagonal scanning method, the vertical scanning method, and the horizontal scanning method are applied from the left to scan the transform coefficient group.

[0219] Fig.25 This is an example used to illustrate the application of a general scanning method to the transform coefficients of a 16x8 transform block.

[0220] Reference Fig.25 In the case where the current transform block TB2 230b is applied to the horizontal scanning method, the transform coefficient and the transform coefficient group may be applied to the horizontal manner as the same scanning method. For example, a plurality of transform coefficient groups including a plurality of transform coefficients are scanned in units of each transform coefficient group. In the transform block, after the transform coefficients in the transform coefficient group at the rightmost lower end are scanned in the horizontal manner, the transform coefficients in the transform coefficient group located on the left side of the above-mentioned rightmost lower end transform coefficient group are scanned in the horizontal manner. Thereafter, scanning is performed in the above-mentioned transform coefficient group unit in the same manner.

[0221] Through this transformation process, most of the energy of the residual signal is concentrated in the DC region on the upper left side. Therefore, for the efficiency of entropy coding, it is more effective for the transform coefficients and / or transform coefficient groups in the low-frequency region to have indices representing the scanning order of small values. However, for non-square transform blocks, such as Figure 24a to Figure 25 As shown, when the scanning order of the general transform coefficient group is applied, the transform coefficient group in the high frequency area is encoded before the transform coefficient group in the low frequency area, so the encoding efficiency is reduced.

[0222] Therefore, a method for scanning transform scanning coefficients according to an embodiment of the present invention includes dividing a transform block into transform regions including a plurality of upper regions of transform scanning coefficients, and scanning the transform scanning coefficients corresponding to each of the divided transform regions.

[0223] Fig.26 and Fig. 27 A flow chart of a method and apparatus for scanning a transform coefficient group according to an embodiment of the present invention is shown.

[0224] Reference Fig.26 and Fig. 27 In order to scan the transform coefficient groups, the transform unit obtains transform region information indicating that the plurality of transform coefficient groups in the transform block are divided into one or more transform regions in the transform region information acquisition unit 240 (step S10). The transform block may have a variety of sizes and / or shapes. In one embodiment, the transform block may be a transform block of a non-square shape.

[0225] The transform region information may divide the transform block into more than one region, and each transform region may include a plurality of transform coefficient groups. The transform coefficient group includes a plurality of transform coefficients. Furthermore, the transform region information may be information received from an encoder. For example, the transform region information may be obtained from one or more of a sequence parameter set (SPS) and a slice header, and the present invention is not limited thereto, and is not limited to whether the sentence has any level in any form, as long as it is information received from an encoder.

[0226] In one embodiment, the above-mentioned transformation region information can be obtained by a method preset in the decoding device. For example, the above-mentioned transformation region information calculates the horizontal length and vertical length of the transformation region based on the horizontal length and vertical length of the transformation block to determine the size and number of the transformation region and obtain it. Alternatively, the above-mentioned transformation region information divides the small length into the block size of the transformation coefficient group in the horizontal and vertical lengths of the transformation block, thereby determining the size and number of the transformation region. The horizontal and vertical lengths, shape and number of the transformation region represented by the above-mentioned transformation region information can be determined according to the method determined in the decoding device, and are not limited to the above-mentioned example.

[0227] Then, the transform coefficient group scanning unit 250 may scan a plurality of transform coefficient groups in one or more transform regions divided based on the transform region information. In order to scan the transform coefficient groups of the divided transform regions, the transform coefficient group scanning unit 250 may include a first transform region scanning unit 251 and a second transform region scanning unit 252. The transform region scanning unit is not limited to the first transform region scanning unit 251 and the second transform region scanning unit 252, and may correspond to the number of transform regions divided into the transform block.

[0228] First, the first transform region scanning unit 251 may scan a plurality of transform coefficient groups in the first transform region among the plurality of transform regions divided based on the transform region information (step S20). Then, the second transform region scanning unit 252 may scan a plurality of transform coefficient groups in the second transform region (step S30). When there are three or more transform region scanning units, the transform coefficient groups in the transform regions are scanned sequentially.

[0229] In one embodiment, the first transform area scanning unit 251 may include a transform coefficient group of a low frequency area, compared to the second transform area scanning unit 252. As described above, the transform coefficient group scanning method of the present invention determines scanning in such a manner that the transform coefficient group of the low frequency area is scanned before the transform coefficient group of the high frequency area, the transform coefficient group of the high frequency area is preferentially encoded and transmitted, and the transform coefficient group of the low frequency area has a large value of the scanning index, thereby solving the problem of reducing the encoding efficiency.

[0230] Furthermore, in one embodiment, before obtaining the transform region information, it may be determined whether the transform block is a non-square block. The transform coefficient group corresponding to the high frequency region is scanned preferentially over the transform coefficient group corresponding to the low frequency region, so that the coding efficiency is reduced frequently when the transform block is a non-square block. Therefore, before obtaining the transform region information, it is preferred to determine whether the current transform block is a non-square block.

[0231] In one embodiment, multiple methods are used to determine whether the transform block is a non-square block. For example, the horizontal length and the vertical length of the transform block are compared to determine whether the transform block is a non-square block. Alternatively, the determination is made based on information on the size and shape of the transform block received from the encoding device or one or more of the segmentation information, direction information, α, β, and pixel information of the transform block obtained in the decoding device.

[0232] Furthermore, the determination is made based on transform block type information indicating the type of the transform block. The transform block type information may be received from the encoding device, or may be calculated in the decoding device based on one or more of the segmentation information, direction information, pixel information, and horizontal length and vertical length information of the transform block. By the above method, when it is determined that the transform block is a non-square block, by referring to Fig.26 and Fig. 27 The above method scans the transform coefficient group contained in the transform area corresponding to each transform block.

[0233] Fig.28a and Fig.28b The method for scanning a transform coefficient group of a non-square transform block used in one embodiment of the present invention is described.

[0234] Reference Fig.28a , the non-square transform blocks 260a and 260b of the present invention may have a horizontal length A and a vertical length B. The non-square transform blocks 260a and 260b with a size of AxB include multiple transform coefficient groups, which are divided into transform block regions of a size of αxβ. The above α and β represent the number of transform coefficient groups in the transform block. That is, the region of the size of αxβ is a region of α transform coefficient groups in the horizontal direction and β transform coefficient groups in the vertical direction. In one embodiment, the transform region information may include information about the above α and β. Furthermore, the transform region information may include information indicating the horizontal and vertical sizes of the transform region. For example, in the case where the non-square transform block 260a has a size of 8x16, αxβ indicating the structure of the transform region is 2x2, and the size of the transform region of the partitioned transform block 260a is 8x8.

[0235] This transform region information is calculated in the upper parameter or in the previous decoding process, and is simply calculated from the number of sizes of blocks of transform coefficients with small lengths in the horizontal and vertical lengths of the non-square transform block. However, in the present invention, the method of obtaining the transform region information is not limited to this.

[0236] Reference Fig.28b , the transform blocks 260a and 260b divided into a plurality of transform regions apply a scanning method determined from a higher-level parameter or a higher-level process to scan the transform coefficient group in each transform region. For example, the transform block 260b having a size of 16x8 is divided into transform regions having a size of 8x8 (αxβ=2x2), and when the transform regions and the transform coefficient groups are scanned by the upright diagonal scanning method, the transform coefficient group in (CG Region1) is first scanned by the upright diagonal scanning method, and then the transform coefficient group in (CG Region0) is scanned by the upright diagonal scanning method.

[0237] Figures 29a to 30d It is used to illustrate various methods of scanning transform coefficient groups for non-square transform blocks used in one embodiment of the present invention.

[0238] Reference Figures 29a to 30d , a transform coefficient group in the case where the transform block 270 is partitioned into transform regions having a small side length of the transform block may be scanned by various methods. Fig.29a As shown, when the transform block 270 has a size of 16x32, each transform region (CG Region0) 271 and (CG Region1) 272 may have a size of 16x16. α and β representing the number of horizontal and vertical transform coefficient groups CG are α=β=4.

[0239] In one embodiment, the transform block 270 may sequentially scan the transform coefficient groups in each transform region corresponding to each transform region. Fig.29b As shown, when the transform block 270 is scanned by the vertical diagonal scanning method, the 32nd transform coefficient group CG 31 in the second transform region (CG Region1) at the lower end sequentially scans the 17th transform coefficient group CG 16, and then, the 16th transform coefficient group CG 15 in the first transform region (CG Region0) and the first transform coefficient group CG0 are sequentially scanned. In addition, the transform block is divided into two transform regions. When the vertical scanning method and the horizontal scanning method are applied to the transform block, as shown in FIG. Fig.29c and Fig.29d Same as shown.

[0240] Reference Figures 30a to 30dIn the case where the transform block 280 is divided into transform regions with a small side length of the transform block 280, the transform coefficient groups may be scanned by various methods. Fig.30a As shown, when the transform block 280 has a size of 32x16, each transform region (CG Region0) 281 and (CG Region1) 282 may have a size of 16x16. α and β indicating the number of horizontal and vertical transform coefficient groups CG may be α=β=4.

[0241] In one embodiment, the transform block 280 sequentially scans the transform coefficient groups in each transform region according to the transform region. Fig.30b As shown, in the case where the transform block 280 is scanned by the upright diagonal scanning method, from the 32nd transform coefficient group CG 31 in the second transform area 282 (CG area 1) on the right, the 17th transform coefficient group CG 16 is sequentially scanned according to the upright diagonal method, and then, the 16th transform coefficient group CG 15 in the first transform area 281 (CG area 0) is sequentially scanned to the first transform coefficient group CG 0. And, as Fig.30c As shown, in the case where the transform block 280 is scanned by the vertical scanning method, the 17th transform coefficient group CG 16 is sequentially scanned in a vertical manner from the 32nd transform coefficient group CG 31 in the second transform area 282 (CG area 1) on the right, and then the 1st transform coefficient group CG 0 is sequentially scanned from the 16th transform coefficient group CG 15 in the first transform area 281 (CG area 0). The transform block is divided into two transform areas. In the case where the horizontal scanning method is applied to the above transform block, as shown in Fig.30d Same as shown.

[0242] As described above, according to the method of dividing a transform block from one or more transform regions including a plurality of transform coefficient groups and scanning corresponding to each of the above transform regions, the transform coefficient group in a low-frequency region is scanned and transmitted preferentially compared to the transform coefficient group in a high-frequency region, thereby improving the coding efficiency.

[0243] Fig.31 It is used to illustrate the position of the candidate prediction motion vector (MVP candidate) of the current block in a general method of obtaining the position.

[0244] Reference Fig.31In order to form a prediction motion vector list (MVP list), the current block can use the motion information of spatial neighboring blocks A0, A1, B0, B1 and the motion information of temporal neighboring blocks T0, T1. The motion information of the spatial neighboring blocks is determined by one motion information in the surrounding blocks located on the left side of the current block and one motion information in the surrounding blocks located on the upper side of the current block. In addition, the motion information of the temporal neighboring blocks can be determined by the motion information of the surrounding blocks located on the lower right side of the current block or the motion information of the blocks located at the same position as the current block within the reference image referenced by the current block.

[0245] The motion information of the spatially adjacent blocks is scanned and searched for motion information in the order of A0≥A1≥scaled A0≥scaled A1 for the surrounding blocks located on the left side of the current block. Afterwards, the surrounding blocks located on the upper side of the current block are scanned in the order of B0≥B1≥B2. In the case where the reference image referenced by the current block and the reference image referenced by the motion information of the A0 and A1 blocks are different, the motion information of the A0 and A1 blocks scaled in a manner that matches the reference image referenced by the current block can be used.

[0246] The motion information of the temporal neighboring blocks is scanned in the order of T0 and T1. In this case, the motion vectors of the temporal neighboring blocks can be scaled to the image referenced by the current block and used.

[0247] In one embodiment, Advanced Motion Vector Prediction can use two predicted motion vectors. First, the motion information of spatial neighboring blocks is scanned to input into the predicted motion vector list. In this process, if the list is not filled, the motion information of temporal neighboring blocks is scanned to fill the list. When the motion information of the adjacent blocks is scanned, if the same motion information is input into the predicted motion vector list, the duplicated motion information is deleted. Through this process, even if the motion information scanning of temporal and spatial neighboring blocks is completed, if the predicted motion vector list is not filled, the unfilled list is filled with (0, 0) to complete the predicted motion vector list.

[0248] Figure 32 to Figure 33b A method for explaining a general method of constructing a prediction motion vector list for a current block.

[0249] Reference Fig.32 , when the current block CB performs bidirectional prediction, the motion vector may be obtained from the reference picture 301 for the first direction, and the motion vector may be obtained from the reference picture 302 for the second direction. Fig.32As shown at the bottom of , the prediction motion vector list (advanced motion vector prediction list) for inter-picture prediction of the current block includes more than one candidate prediction motion vector (MVP candidate) in each direction. Afterwards, the difference value between a prediction motion vector selected from the candidate prediction motion vectors in the above prediction motion vector list and the motion vector of the current block is calculated to obtain a differential motion vector and encode it.

[0250] In one embodiment, the selected predicted motion vector may be selected from the candidate predicted motion vectors included in the predicted motion vector list with the highest coding efficiency. The selected predicted motion vector is encoded in the form of index information indicating the same, and is transmitted together with the differential motion vector.

[0251] Fig.33a A method of constructing a prediction motion vector list of a current block according to a general method will be described when the bidirectional reference images 320a and 330a referenced by the current block 310 are the same. Figure 33b A method of constructing a predictive motion vector list for the current block according to a general method will be described when the bidirectional reference images 320 b and 330 b referenced by the current block 310 are different.

[0252] Reference Fig.33a , the reference image 320a and the reference image 330a referred to along the first direction for inter-picture prediction by the current block 310 are the same POC8. As described above, when the bidirectional reference images 320a and 330a referred to by the current block 310 are the same, the MV of the motion vector related to the first direction L0 of the current block 310 is L0 and MV as the motion vector associated with the second direction L1 L1 However, the prediction motion vector list of the current block in the general method does not reflect these, and for each direction, motion information is obtained from the neighboring blocks of the independent current block, as shown in the following Table 3, to form a prediction motion vector list.

[0253] Table 3

[0254]

[0255] When the reference picture 320a in the first direction and the reference picture 330a in the second direction for the current block 310 are the same, there is a high possibility that the motion vectors in the respective directions are similar. Fig.33a , it is possible to confirm the motion vector (MV L0 ) and the motion vector (MV L1) are similar to (2, 1) and (2, 2) respectively. However, as described above, according to the general prediction motion vector list construction method, the prediction motion vector list for each direction is independently constructed.

[0256] Therefore, in order to construct the prediction motion vector list of the second direction, the motion vector (MV L1 ) is a motion vector of a neighboring block of the current block 310 with a low correlation, so that the motion vector (MV L1 However, the prediction motion vector list of the general method is independently constructed for each direction, and a differential motion vector MVD representing the difference between the prediction motion vector selected in the above list and the motion vector in each direction is obtained. L0 =(2,0) and MVD L1 =(2, 1) to transmit to the decoding device.

[0257] Reference Figure 33b In the case where the reference picture 320b of the first direction referenced by the current block 310 is different from the reference picture 330b of the second direction, in the process of forming a prediction motion vector list according to a general method, a prediction motion vector list for each direction is independently formed. The formed prediction motion vector list is shown in the following Table 4.

[0258] Table 4

[0259]

[0260] Even if the reference picture 320b in the first direction and the reference picture 330b in the second direction for the current block 310 are different, they are pictures referenced by the current block 310. Therefore, the possibility that the motion vectors in each direction are similar based on the distance and correlation of the reference pictures cannot be ruled out. However, as described above, according to the general prediction motion vector list construction method, the prediction motion vector lists for the directions are independently constructed.

[0261] like Figure 33b As shown, the motion vector (MV L0 ) and the motion vector (MV L1 ) are (-5, -8) and (4, 10), respectively, as shown in Table 2, which can form a prediction motion vector list. In this case, if Advanced Motion Vector Prediction_L0_0 and Advanced Motion Vector Prediction_L1_1 are selected as the prediction motion vector, the differential motion vector (MVD L0 , MVD L1 ) are (-3, -5) and (6, -1) respectively.

[0262] As described above, when a prediction motion vector list is constructed by a general method, when constructing a prediction motion vector list for the second direction, motion information of adjacent blocks of the current block is used. Thus, when the reference picture in the second direction has a relatively high correlation with the reference picture in the first direction compared to the current picture, the encoding efficiency of the motion vector is reduced.

[0263] Therefore, in the method for constructing a prediction motion vector list according to an embodiment of the present invention, when bidirectional prediction is performed on the current block, the motion vector related to the first direction is used to construct a prediction motion vector list for the second direction.

[0264] Fig.34 and Fig.35 A flowchart and a device for explaining a predicted motion vector list according to an embodiment of the present invention are shown.

[0265] Reference Fig.34 and Fig.35 , the prediction motion vector list formation unit 700 may include a first direction prediction motion vector list setting unit 710, a motion vector acquisition unit 720, and a second direction prediction motion vector list setting unit 730. The first direction prediction motion vector list setting unit 710 may set a first direction prediction motion vector list. The first direction prediction motion vector list may be composed of first direction candidate prediction motion vectors (MVP Candidate) obtained from motion information of temporal and spatial neighboring blocks of the current block. The first direction prediction motion vector list may include more than two candidate prediction motion vectors, and an index representing each candidate prediction motion vector is assigned. The first direction prediction motion vector list may be selected based on a reference. Figure 3 The motion information acquisition unit 720 may acquire a motion vector (MV L0 ) (Step S40). When the motion vector is predicted between pictures in the conventional video codec, the current block can be obtained according to the method of obtaining the motion vector, but the present invention is not limited thereto.

[0266] Then, the second direction prediction motion vector list setting unit 730 may set a prediction motion vector list for the second direction (step S50). Among the candidate prediction motion vectors for the second direction constituting the prediction motion vector list for the second direction, at least one may use the motion vector (MV L0). In one embodiment, the candidate predicted motion vector of the second direction set by the motion vector related to the first direction is set by directly copying the motion vector related to the first direction, such as scaling the motion vector related to the first direction and modifying it. Furthermore, the candidate predicted motion vector of the second direction may be included in the predicted motion vector list of the second direction.

[0267] The reference picture used for the bidirectional prediction of the current block is likely to have a high correlation, so the motion vector associated with the first direction and the motion vector associated with the second direction obtained bidirectionally (MV L0 , MV L1 ) is likely to be similar. Therefore, when using the motion vector (MV L0 ) to obtain more than one candidate prediction motion vector for the second direction, compared with the previous method, the differential motion vector (MVD L1 ) to transmit.

[0268] Furthermore, the second direction prediction motion vector list setting unit 730 simultaneously uses the motion vectors of the temporal neighboring blocks and the spatial neighboring blocks of the above-mentioned current block to obtain one or more candidate prediction motion vectors in the second direction, thereby forming a prediction motion vector list for the second direction together with the candidate prediction motion vectors for the second direction obtained using the motion vectors related to the above-mentioned first direction. In the present invention, the number, acquisition order, and index allocation method of the candidate prediction motion vectors for the second direction set using the motion vectors related to the above-mentioned first direction and the candidate prediction motion vectors for the second direction set by the general method are not limited.

[0269] Fig.36 and Fig.37 A flowchart and a constituting device of a method for constituting a predicted motion vector list according to another embodiment of the present invention are shown.

[0270] Reference Fig.36 , first, as reference Fig.34 and Fig.35 First, a motion vector of the current block related to the first direction may be obtained (step S40). The acquisition of the motion vector related to the first direction is performed regardless of the order of the predicted motion vector list constituting the first direction. The motion vector related to the first direction is acquired after the predicted motion vector list constituting the first direction is acquired, and the acquisition is performed by information independently received from the predicted motion vector list constituting the first direction, but the present invention is not limited thereto.

[0271] Reference Fig.36 and Fig.37The second direction prediction motion vector list setting unit 730 includes a first candidate prediction motion vector setting unit 731 and a second candidate prediction motion vector setting unit 732. The first candidate prediction motion vector setting unit 731 sets a first candidate prediction motion vector, which is a motion vector (MV L0 ) to form a candidate prediction motion vector of the prediction motion vector list of the second direction, which can be a set candidate prediction motion vector (step S41). The above-mentioned first candidate prediction motion vector can be more than one candidate prediction motion vector.

[0272] The first candidate prediction motion vector has the highest correlation with the motion vector of the current block among the candidate prediction motion vectors. Therefore, when forming the first prediction motion vector list, the first candidate prediction motion vector is assigned to the index with the smallest codeword, thereby improving the coding efficiency. In one embodiment, if there are at least two first candidate prediction motion vectors, the first candidate prediction motion vectors are assigned indices in the order of having small codewords to improve the coding efficiency.

[0273] The second candidate prediction motion vector setting unit 732 is also independent of the first candidate prediction motion vector setting unit 731 and is not related to the order. It uses the spatial and temporal neighboring blocks of the current block to set one or more candidate prediction motion vectors (step S42). The one or more candidate prediction motion vectors may be the second candidate prediction motion vector. The second candidate prediction motion vector is obtained by referring to Figure 3 The method for obtaining the general predicted motion vector described in the description is obtained, and together with the first candidate predicted motion vector, a predicted motion vector list for the second direction is formed. In this case, when the predicted motion vector list for the second direction is formed, the number, acquisition order, and index allocation method of the first candidate predicted motion vector and the second candidate predicted motion vector are not limited, as long as they are methods that can be implemented by ordinary technicians in the technical field to which the present invention belongs.

[0274] As described above, in the method and device for constructing a prediction motion vector list of one embodiment of the present invention, when bidirectional inter-picture prediction is performed on the current block, the motion vector in the first direction is used to obtain one or more candidate prediction motion vectors in the second direction, thereby improving the coding efficiency.

[0275] Fig.38a and Figure 38b The method for constructing a prediction motion vector list according to an embodiment of the present invention is described.

[0276] Reference Fig.38a, the current block 310 performs bidirectional prediction, and when the pictures 340a and 350a referenced in the first direction and the second direction have the same POC=8, the motion vector (MV L0 ) is used to construct a list of predicted motion vectors for the second direction. For example, in the first direction of the current block, the motion vector (MV L0 ) is (2, 1), the first candidate prediction motion vector in the second direction can be set to MV L0 =(2, 1) In one embodiment, the first candidate predicted motion vector may have the shortest codeword in the index constituting the predicted motion vector list of the second direction, but the present invention is not limited thereto, and it is also possible to allocate an index in the predicted motion vector list of the second direction.

[0277] Reference Fig.38a and Fig.33a , when the current block 310 is predicted bidirectionally, under the condition that the images referenced in each direction are the same, the differential motion vector of the second direction transmitted when the motion information related to the first direction is independently obtained from the adjacent blocks of the current block to form the prediction motion vector list of the second direction is (2, 1). However, as the first candidate prediction motion vector of the second direction, when the motion vector related to the first direction is used, the differential motion vector of the second direction can be (0, 1). The composition of the advanced motion vector prediction list of one embodiment of the present invention is shown in the following Table 5.

[0278] Table 5

[0279]

[0280] As described above, the motion vector related to the first direction and the motion vector related to the second direction have a high correlation. Therefore, the method of using the motion vector related to the first direction to set the first predicted motion vector constituting the second direction of the present invention encodes and transmits a differential motion vector (MVD) that is smaller than the previous method.

[0281] Figure 38b It shows that the current block 310 performs bidirectional prediction. When the picture 340b referenced in the first direction is different from the picture 350b referenced in the second direction, the motion vector (MV L0) is used to set the first candidate prediction motion vector as the prediction motion vector list constituting the second direction. The first candidate prediction motion vector is also obtained by using reference picture information such as the POC of the reference picture for the first direction and the reference picture for the second direction. For example, the reference picture 340b for the first direction of the current block 310 is POC=8, and the reference picture 350b for the second direction is POC=12. The motion vector MV related to the first direction of the current block 310 is L0 When it is (5, 8), as shown in the following Table 6, the first predicted motion vector in the second direction can be (-5, 8) based on POC scaling.

[0282] Table 6

[0283]

[0284] Reference Figure 38b and Figure 33b When the current block 310 is bidirectionally predicted, under the condition that the images referenced in the two directions are different, in order to form a predicted motion vector list for the second direction (advanced motion vector prediction_L1), the motion information related to the first direction is independently obtained from the adjacent blocks of the current block to form the differential motion information (MVD) of the second direction transmitted. L1 ) can be (6, -1). However, as the first candidate prediction motion vector, in the case of using the scaled motion vector related to the first direction (Scaled_MV L0), the differential motion vector in the second direction (MVD L1 ) can be (-1, 2).

[0285] As mentioned above, the motion vector (MV L0 ) and a motion vector associated with the second direction (MV L1 ) has a high correlation. Therefore, based on the POC, the motion vector related to the first direction is scaled (Scaled_MV L0 ) to set the first predicted motion vector (MV L1 ) of the present invention is compared with the previous method of forming the prediction motion vector list of the relatively small differential motion vector (MVD L1 ) is encoded and transmitted, thereby improving the coding efficiency. In one embodiment, in order to improve the coding efficiency, the first candidate predicted motion vector has the shortest codeword in the index constituting the predicted motion vector list of the second direction, but the present invention is not limited to this. In the present invention, as the first candidate predicted motion vector of the second direction, a method for scaling the motion vector related to the first direction based on POC is disclosed, but the scaling method is not limited to this.

[0286] Fig.39 FIG. 1 is a flow chart showing a method for constructing a predicted motion vector list according to another embodiment of the present invention. Fig.39 In order to form an advanced motion vector prediction list for the current block, first, the motion vector (MV L0 )(Step S40). The motion vector related to the above-mentioned first direction is obtained in the decoder by using the candidate predicted motion vector and the differential motion vector in the predicted motion vector list of the first direction received from the encoder, and can also be received from the encoder. The method for obtaining the motion vector related to the above-mentioned first direction of the present invention is not limited to this.

[0287] Then, the picture information (POC) of the reference picture related to the first direction of the bidirectional prediction for the current block is determined. ref_L0 ) and picture information of the reference picture related to the second direction (POC ref_L1 ) are the same (step S60). For example, whether the first and second reference pictures are the same or not can be determined by picture information such as POC.

[0288] When the picture information of the reference picture for the first direction and the picture information of the reference picture for the second direction are the same (Yes in S60), the motion vector (MV L0 )(Step S70). The above-mentioned first candidate predicted motion vector may be more than one candidate predicted motion vector. Furthermore, the one or more remaining candidate predicted motion vectors (MVP_L1_N) constituting the predicted motion vector list of the above-mentioned second direction may be set according to a general method (Step S80). When the first candidate predicted motion vector of the above-mentioned second direction is set by copying the motion vector related to the above-mentioned first direction and the acquisition order of the remaining candidate predicted motion vectors of the above-mentioned second direction obtained by the general method and the predicted motion vector list of the second direction are constituted, the index allocation method is not restricted.

[0289] When the picture information of the reference picture in the first direction and the picture information of the reference picture in the second direction are different (No in S60), the scaled value (Scaled_MV L0)(Step S90). The above-mentioned first candidate predicted motion vector may be more than one candidate predicted motion vector. Furthermore, the one or more remaining candidate predicted motion vectors (MVP_L1_N) constituting the predicted motion vector list of the above-mentioned second direction may be set according to a general method (Step S95). The index allocation method is not limited when the first candidate predicted motion vector of the above-mentioned second direction is set by scaling the value of the motion vector related to the above-mentioned first direction and the remaining candidate predicted motion vectors of the above-mentioned second direction obtained by a general method are obtained in an acquisition order and constitute the predicted motion vector list of the second direction.

[0290] In the advanced motion vector prediction list constructed by the above method, the motion vector of the first direction with high correlation is used to construct the prediction motion vector list of the second direction when predicting between pictures, so that a method for constructing a prediction motion vector list with improved coding efficiency of inter-picture prediction can be provided. In addition, in bidirectional prediction, considering whether the picture information of the reference picture in the first direction and the reference picture in the second direction are the same and the distance between the reference picture and the current picture, one or more candidate prediction motion vectors constituting the prediction motion vector list of the second direction are set to improve coding efficiency.

[0291] The present invention described above is not limited to the above embodiments and the accompanying drawings. A person skilled in the art may make various substitutions, deformations and changes without departing from the technical concept of the present invention.

Claims

1. A video signal decoding device, comprising: a transform region information acquisition unit, configured to acquire transform region information indicating at least one or more of a plurality of transform regions included in a transform block, the transform block including a plurality of transform coefficient groups; as well as a transform coefficient group scanning unit, configured to divide the transform block into at least one transform region among the plurality of transform regions based on the transform region information, respectively acquire scanning methods for the transform regions, scan a plurality of transform coefficient groups included in the first transform region by using the scanning method for the first transform region, and scan a plurality of transform coefficient groups included in the second transform region by using the scanning method for the second transform region, The plurality of transform coefficient groups respectively include a plurality of transform coefficients.

2. The video signal decoding device according to claim 1, wherein: The transform region information is received from an encoder.

3. The video signal decoding device according to claim 1, wherein: The transform region information acquiring unit further determines a type of the transform block before acquiring the transform region information.

4. The video signal decoding device according to claim 2, wherein: The type of the transform block is determined based on a horizontal length and a vertical length of the transform block.

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