RU2813279C1 - Method for image encoding based on internal prediction using mpm-list and equipment for it - Google Patents

Abstract

FIELD: image encoding.

SUBSTANCE: MPM flag information, planar flag information and MPM index information are generated. MPM flag information is related to whether to derive the intra prediction mode for the current unit on the most likely mode (MPM) candidates for the current unit. Planar flag information is related to whether to determine the intra prediction mode for the current unit as the planar mode. The MPM index information is associated with one of 5 possible non-planar MPM options from the possible MPM options for the current block. Image information containing MPM flag information, planar flag information and MPM index information are encoded. The MPM flag information is configured in the coding unit syntax for the current block. Based on the value of the MPM flag information representing that the intra prediction mode for the current block is retrieved based on the MPM candidates, the planar flag information is configured in the coding unit syntax.

EFFECT: improved efficiency of image encoding.

21 cl, 16 dwg

Description

State of the art

Field of technology to which the invention relates

[1] The present disclosure relates to image encoding technology, and more specifically, to a method and equipment for encoding images based on intra prediction using a list of most likely modes (MPM) in an image encoding system.

Description of the prior art

[2] Recently, the demand for high-quality high-definition images/videos, for example, 4K, 8K or even higher ultra-high definition (UHD) images/videos, has been growing in various fields of technology. As the resolution or quality of images/videos becomes higher, a relatively larger amount of information or number of bits is transmitted than for traditional image/video data. Therefore, if image/video data is transmitted over a medium such as an existing wired/wireless broadband line or stored on a legacy storage medium, transmission and storage costs increase significantly.

[3] In addition, there is growing interest and demand for virtual reality (VR) and artificial reality (AR) content and immersive multimedia, such as holograms; and there is also an increase in broadcasting of images/videos exhibiting characteristics of the images/videos that differ from those of the actual image/video, for example, game images/videos.

[4] Therefore, a highly efficient image/video compression technology is required in order to efficiently compress and transmit, store or play back high-quality, high-resolution images/videos exhibiting various characteristics as described above.

The essence of the invention

[5] The purpose of the present disclosure is to provide a method and equipment for improving the efficiency of image encoding.

[6] Another object of the present disclosure is to provide a method and equipment for improving the efficiency of internal forecasting.

[7] It is yet another object of the present disclosure to provide a method and equipment for performing intra prediction coding of images using an MPM list for a current block.

[8] Yet another object of the present disclosure is to provide a method and equipment for performing intra prediction based on an MPM list based on planar flag information representing whether or not to determine the intra prediction mode for a current block as planar mode.

[9] It is yet another object of the present disclosure to provide a method and equipment for configuring an MPM list for a current block.

[10] A further objective of the present disclosure is to provide a method and equipment for encoding an MPM index.

[11] An exemplary embodiment of the present disclosure provides a method for decoding images performed by decoding equipment. An image decoding method includes receiving intra prediction information including at least one of most likely mode (MPM) flag information representing whether or not to extract an intra prediction mode for the current block based on possible MPM options for of the current block, or planar flag information representing whether or not to determine the intra prediction mode for the current block as a planar mode, extracting the intra prediction mode for the current block based on the MPM flag information and the planar flag information, extracting the predicted block for the current block based on the intra prediction mode for the current block and generating a reconstructed frame based on the predicted block, and based on the MPM flag information representing that the intra prediction mode for the current block is retrieved based on the MPM candidates, the planar flag information is included in the intra prediction mode forecasting.

[12] In an exemplary embodiment, retrieving the intra-prediction mode for the current block may include retrieving the intra-prediction mode for the current block as a planar mode, based on planar flag information representing that the intra-prediction mode for the current block is extracted as planar mode.

[13] In an exemplary embodiment, the intra prediction information may further include MPM index information associated with one of the possible MPM options other than planar mode from the possible MPM options for the current block. Based on the planar flag information representing that the intra prediction mode for the current block is not extracted as a planar mode, MPM index information may be included in the intra prediction information. The intra prediction mode for the current block may be retrieved based on the MPM index information.

[14] In an exemplary embodiment, the total number of possible non-planar mode MPM options among the possible MPM options for the current block may be 5.

[15] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are identical, and the intra-prediction mode of the left neighboring block exceeds the intra-DC mode, the intra-prediction mode for zero of the MPM candidate may be the intra prediction mode of the left neighbor block with respect to the current block, the intra prediction mode for the first MPM candidate may be 2+((intra prediction mode of the left neighbor block with respect to the current block+61)% 64), and the intra-prediction mode for the second possible MPM option may be 2+((intra-prediction mode of the left adjacent block relative to the current block - 1)%64).

[16] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are not identical, the intra-prediction mode of the left neighboring block is less than or equal to the intra-DC mode, and the intra-prediction mode the upper neighbor block prediction is less than or equal to the inner DC mode, the intraprediction mode for the zero MPM opportunity may be the inner DC mode, the intraprediction mode for the first MPM opportunity may be the 50th intraprediction mode, the inner the prediction mode for the second MPM opportunity may be an 18th intra-prediction mode, the intra-prediction mode for the third MPM opportunity may be a 46th intra-prediction mode, and the intra-prediction mode for the fourth MPM opportunity may be 54 -th mode of internal forecasting.

[17] In an exemplary embodiment, the MPM index information may be based on a Truncated Rice (TR) binarization process.

[18] In an exemplary embodiment, cMax representing the maximum value of the MPM index information may be 4.

[19] Another exemplary embodiment of the present disclosure provides decoding equipment that performs image decoding. The decoding equipment includes an entropy decoder that receives intra prediction information including at least one of most likely mode (MPM) flag information representing whether or not to extract an intra prediction mode for the current block based on the possibilities. most probable modes (MPM) for the current block, or planar flag information representing whether or not the intra-prediction mode for the current block should be determined as a planar mode, a prediction module that extracts the intra-prediction mode for the current block based on the MPM flag information and planar flag information and retrieves a predicted block for the current block based on the intra-prediction mode for the current block, and an adder that generates a reconstructed frame based on the predicted block, and based on the MPM flag information representing what the intra-prediction mode is for the current block is extracted based on the MPM candidates, the planar flag information is included in the intra prediction information.

[20] In an exemplary embodiment, the prediction module may retrieve the intra prediction mode for the current block as a planar mode based on the planar flag information representing that the intra prediction mode for the current block is retrieved as the planar mode.

[21] In an exemplary embodiment, the intra prediction information may further include MPM index information associated with one of the possible MPM options other than planar mode from the possible MPM options for the current block. Based on the planar flag information representing that the intra prediction mode for the current block is not extracted as a planar mode, MPM index information may be included in the intra prediction information, and the intra prediction mode for the current block may be extracted based on the MPM index information.

[22] In an exemplary embodiment, the total number of possible MPM options other than planar mode among the possible MPM options for the current block may be 5.

[23] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are identical, and the intra-prediction mode of the left neighboring block exceeds the intra-DC mode, the intra-prediction mode for zero of the MPM candidate may be the intra prediction mode of the left neighbor block with respect to the current block, the intra prediction mode for the first MPM candidate may be 2+((intra prediction mode of the left neighbor block with respect to the current block+61)% 64), and the intra-prediction mode for the second possible MPM option may be 2+((intra-prediction mode of the left adjacent block relative to the current block - 1)%64).

[24] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are not identical, the intra-prediction mode of the left neighboring block is less than or equal to the intra-DC mode, and the intra-prediction mode the upper neighbor block prediction is less than or equal to the inner DC mode, the intra prediction mode for the zero MPM opportunity may be the inner DC mode, the intra prediction mode for the first MPM opportunity may be the 50th MPM opportunity, the mode The intra prediction mode for the second MPM opportunity may be the 18th intra prediction mode, the intra prediction mode for the third MPM opportunity may be the 46th intra prediction mode, and the intra prediction mode for the fourth MPM opportunity may be 54th internal forecasting mode.

[25] In an exemplary embodiment, the MPM index information may be based on a Truncated Rice (TR) binarization process.

[26] In an exemplary embodiment, cMax representing the maximum value of the MPM index information may be 4.

[27] Yet another exemplary embodiment of the present disclosure provides an encoding method performed by encoding equipment. An image encoding method includes extracting an intra prediction mode for a current block, generating most probable mode (MPM) flag information representing whether or not to extract an intra prediction mode for the current block based on candidate most likely modes (MPM) for the current block. generating planar flag information based on the MPM representing that the MPM flag information is associated with planar flag information representing whether or not the intra prediction mode for the current block should be determined as a planar mode, and encoding image information including at least one of MPM flag information or planar flag information.

[28] In an exemplary embodiment, based on the case in which the intra prediction mode for the current block is retrieved as a planar mode, the planar flag information may represent that the intra prediction mode for the current block is retrieved as a planar mode.

[29] In an exemplary embodiment, the intra prediction information may further include MPM index information associated with one of the possible MPM options other than planar mode from the possible MPM options for the current block. The image encoding method may further include generating MPM index information based on a case in which the intra prediction mode for the current block is not extracted as a planar mode.

[30] In an exemplary embodiment, the total number of possible MPM options other than planar mode among the possible MPM options for the current block may be 5.

[31] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are identical, and the intra-prediction mode of the left neighboring block exceeds the intra-DC mode, the intra-prediction mode for zero of the MPM candidate may be the intra prediction mode of the left neighbor block with respect to the current block, the intra prediction mode for the first MPM candidate may be 2+((intra prediction mode of the left neighbor block with respect to the current block+61)% 64), and the intra-prediction mode for the second possible MPM option may be 2+((intra-prediction mode of the left adjacent block relative to the current block - 1)%64).

[32] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are not identical, the intra-prediction mode of the left neighboring block is less than or equal to the intra-DC mode, and the intra-prediction mode upper neighbor block prediction is less than or equal to the inner DC mode, the intraprediction mode for the zero MPM opportunity may be the inner DC mode, the intraprediction mode for the first MPM opportunity may be the 50th intraprediction mode, the inner the prediction mode for the second MPM opportunity may be an 18th intra-prediction mode, the intra-prediction mode for the third MPM opportunity may be a 46th intra-prediction mode, and the intra-prediction mode for the fourth MPM opportunity may be 54 -th mode of internal forecasting.

[33] In an exemplary embodiment, the MPM index information may be based on a Truncated Rice (TR) binarization process.

[34] In an exemplary embodiment, cMax representing the maximum value of the MPM index information may be 4.

[35] Yet another exemplary embodiment of the present disclosure provides encoding equipment that performs image encoding. The encoding equipment includes a prediction module that extracts the intra-prediction mode for the current block, and an entropy encoder that generates most probable mode (MPM) flag information representing whether or not to extract the intra-prediction mode for the current block based on the most probable modes. probable modes (MPM) for the current block, generates planar flag information based on the MPM representing that the MPM flag information is associated with the planar flag information representing whether or not the intra prediction mode for the current block should be determined as a planar mode, and encodes MPM flag information including at least one of image information or planar flag information.

[36] In an exemplary embodiment, based on the case in which the intra prediction mode for the current block is retrieved as a planar mode, the planar flag information may represent that the intra prediction mode for the current block is retrieved as a planar mode.

[37] In an exemplary embodiment, the intra prediction information may further include MPM index information associated with one of the possible MPM options other than planar mode from the possible MPM options for the current block. The encoding equipment may generate MPM index information based on the case in which the intra prediction mode for the current block is not extracted as a planar mode.

[38] In an exemplary embodiment, the total number of possible MPM options other than planar mode among the possible MPM options for the current block may be 5.

[39] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are identical, and the intra-prediction mode of the left neighboring block exceeds the intra-DC mode, the intra-prediction mode for zero of the MPM candidate may be the intra prediction mode of the left neighbor block with respect to the current block, the intra prediction mode for the first MPM candidate may be 2+((intra prediction mode of the left neighbor block with respect to the current block+61)% 64), and the intra-prediction mode for the second possible MPM option may be 2+((intra-prediction mode of the left adjacent block relative to the current block - 1)%64).

[40] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are not identical, the intra-prediction mode of the left neighboring block is less than or equal to the intra-DC mode, and the intra-prediction mode upper neighbor block prediction is less than or equal to the inner DC mode, the intraprediction mode for the zero MPM opportunity may be the inner DC mode, the intraprediction mode for the first MPM opportunity may be the 50th intraprediction mode, the inner the prediction mode for the second MPM opportunity may be an 18th intra-prediction mode, the intra-prediction mode for the third MPM opportunity may be a 46th intra-prediction mode, and the intra-prediction mode for the fourth MPM opportunity may be 54 -th mode of internal forecasting.

[41] In an exemplary embodiment, the MPM index information may be based on a Truncated Rice (TR) code binarization process, and cMax representing the maximum value of the MPM index information may be 4.

[42] Yet another exemplary embodiment of the present disclosure provides a decoder-readable storage medium that stores information regarding instructions that instruct video decoding equipment to carry out decoding methods according to some exemplary embodiments.

[43] A further exemplary embodiment of the present disclosure provides a computer-readable storage medium including encoded information that instructs decoding equipment to perform an image decoding method. An image decoding method includes receiving intra prediction information including at least one of most likely mode (MPM) flag information representing whether or not to extract an intra prediction mode for a current block based on the most likely mode options. (MPM) for the current block, or planar flag information representing whether or not to determine the intra prediction mode for the current block as a planar mode, extracting the intra prediction mode for the current block based on the MPM flag information and planar flag information, extracting the predicted block for the current block based on the intra-prediction mode for the current block, and generating a reconstructed frame based on the predicted block, and based on the MPM flag information representing that the intra-prediction mode for the current block is retrieved based on the possible MPM options, the planar flag information included in internal forecasting information.

[44] In an exemplary embodiment, the intra prediction information may further include MPM index information associated with one of the possible MPM options other than planar mode from the possible MPM options for the current block. Based on the planar flag information representing that the intra prediction mode for the current block is not extracted as a planar mode, MPM index information may be included in the intra prediction information, and the intra prediction mode for the current block may be extracted based on the MPM index information.

[45] In an exemplary embodiment, the total number of possible MPM options other than planar mode among the possible MPM options for the current block may be 5.

[46] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are identical, and the intra-prediction mode of the left neighboring block exceeds the intra-DC mode, the intra-prediction mode for zero of the MPM candidate may be the intra prediction mode of the left neighbor block with respect to the current block, the intra prediction mode for the first MPM candidate may be 2+((intra prediction mode of the left neighbor block with respect to the current block+61)% 64), and the intra-prediction mode for the second possible MPM option may be 2+((intra-prediction mode of the left adjacent block relative to the current block - 1)%64).

[47] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are not identical, the intra-prediction mode of the left neighboring block is less than or equal to the intra-DC mode, and the intra-prediction mode the upper neighbor block prediction is less than or equal to the inner DC mode, the intraprediction mode for the zero MPM opportunity may be the inner DC mode, the intraprediction mode for the first MPM opportunity may be the 50th intraprediction mode, the inner the prediction mode for the second MPM opportunity may be an 18th intra-prediction mode, the intra-prediction mode for the third MPM opportunity may be a 46th intra-prediction mode, and the intra-prediction mode for the fourth MPM opportunity may be 54 -th mode of internal forecasting.

[48] In an exemplary embodiment, the MPM index information may be based on a Truncated Rice (TR) binarization process.

[49] In an exemplary embodiment, cMax representing the maximum value of the MPM index information may be 4.

[50] According to the present disclosure, it is possible to improve overall image/video compression efficiency.

[51] According to the present disclosure, it is possible to improve the efficiency of internal forecasting.

[52] According to the present disclosure, it is possible to efficiently perform intraprediction based on an MPM list.

[53] According to the present disclosure, it is possible to improve the coding efficiency of images based on intra prediction using an MPM list for a current block.

[54] According to the present disclosure, it is possible to improve the performance of intra prediction based on an MPM list based on planar flag information representing whether or not to determine the intra prediction mode for the current block as a planar mode.

[55] According to the present disclosure, the MPM list for the current block can be efficiently configured.

[56] According to the present disclosure, the MPM index can be efficiently encoded.

Brief description of drawings

[57] FIG. 1 schematically represents an example of a video/image coding system to which the present disclosure may apply.

[58] FIG. 2 is a diagram schematically illustrating the configuration of video/image encoding equipment to which the present disclosure may be applied.

[59] FIG. 3 is a diagram schematically illustrating the configuration of video/image decoding equipment to which the present disclosure may be applied.

[60] FIG. 4A and 4B are diagrams illustrating an example of an image encoding method carried out by the encoding equipment according to the exemplary embodiment and an example of the image decoding method carried out by the decoding equipment according to the exemplary embodiment.

[61] FIG. 5 is a flowchart illustrating an intra prediction method according to an exemplary embodiment.

[62] FIG. 6 is a diagram illustrating an example of directed intra prediction modes.

[63] FIG. 7 is a diagram for explaining the configuration of an MPM list according to an exemplary embodiment.

[64] FIG. 8 is a diagram for explaining the configuration of an MPM list according to another exemplary embodiment.

[65] FIG. 9 is a flowchart illustrating an MPM prediction method according to an exemplary embodiment.

[66] FIG. 10 is a flowchart illustrating an MPM prediction method according to another exemplary embodiment.

[67] FIG. 11 is a flowchart illustrating operation of encoding equipment according to an exemplary embodiment.

[68] FIG. 12 is a block diagram illustrating a configuration of encoding equipment according to an exemplary embodiment.

[69] FIG. 13 is a flowchart illustrating operation of decoding equipment according to an exemplary embodiment.

[70] FIG. 14 is a block diagram illustrating a configuration of decoding equipment according to an exemplary embodiment.

[71] FIG. 15 is a diagram illustrating an example of a content streaming system to which the disclosure of this document may be applied.

Detailed Description of Exemplary Embodiments

[72] Although the present disclosure is subject to various modifications and includes various embodiments, specific embodiments thereof are shown in the drawings by way of example and are described in detail below. However, it is not intended to limit the present disclosure to the specific embodiments disclosed herein. The terms used herein are for the purpose of describing specific embodiments only and are not used with the intent to limit the technical intent of the present disclosure. Singular forms may include plural forms unless the context clearly indicates otherwise. Terms such as “comprise,” “include,” and the like are intended to indicate that the features, numbers, steps, operations, elements, components, or combinations thereof set forth in the following description exist, and as such, it should not be understood that the possibility of the presence or addition of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing is precluded.

[73] Meanwhile, the respective configurations in the drawings described in the present disclosure are independently described for convenience of description with respect to characteristic functions different from each other, but do not mean that the configurations are implemented by separate hardware or software. For example, two or more configurations may be combined to form one configuration, and one configuration may be divided into multiple configurations. An embodiment having each component formed through integration and/or separation would fall within the scope of the patent rights of the present disclosure, provided that it does not depart from the spirit of the present disclosure.

[74] Hereinafter, preferred embodiments of the present disclosure are explained in more detail with reference to the accompanying drawings. Hereinafter in this document, identical reference numbers are used for identical components in the drawings, and repeated descriptions for identical components may be omitted.

[75] FIG. 1 illustrates an example of a video/image coding system to which the present disclosure may apply.

[76] Referring to FIG. 1, a video/image encoding system may include a first equipment (source device) and a second equipment (receiver device). A source device may transmit encoded information or video/image data to a receiving device via a digital storage medium or network in the form of a file or stream.

[77] The source device may include a video source, encoding equipment, and a transmitter. The receiving device may include a receiver, decoding equipment, and a rendering module. The encoding equipment may be referred to as "video/image encoding equipment" and the decoding equipment may be referred to as "video/image decoding equipment". The transmitter may be included in the encoding equipment. The receiver may be included in the decoding equipment. The rendering module may include a display, and the display may be configured as a separate device or an external component.

[78] The video source may obtain the video/image through a process for capturing, synthesizing, or shaping the video/image. The video source may include a video/image capture device and/or a video/image generation device. The video/image capturing device may include, for example, one or more cameras, video/image archives including previously captured video/images, and the like. The video/image generating apparatus may include, for example, computers, tablet computers and smartphones and may (electronically) generate video/images. For example, a virtual video/image may be generated via a computer or the like. In this case, the video/image capturing process may be replaced by a process for generating associated data.

[79] Encoding equipment can encode the input video/image. Encoding hardware may perform a sequence of procedures, such as prediction, transform, and quantization, for compression and encoding efficiency. Encoded data (encoded video/image information) may be output in the form of a bitstream.

[80] A transmitter may transmit information or encoded image/image data output in the form of a bitstream to a receiver of a receiving device via a digital storage medium or network in the form of a file or streaming. The digital storage medium may include various storage media such as USB, SD, CD, DVD, Blu-Ray, HDD, SSD, and the like. The transmitter may include an element for generating a multimedia file through a predefined file format and may include an element for transmission through a broadcast/communication network. The receiver may receive/extract the bit stream and transmit the received bit stream to decoding equipment.

[81] The decoding equipment may decode the video/image by performing a sequence of procedures such as dequantization, deconversion, and prediction corresponding to the operation of the encoding equipment.

[82] The renderer can render the decoded video/image. The video/image prepared by rendering can be displayed through the display.

[83] FIG. 2 illustrates the structure of video/image encoding equipment to which the present disclosure may be applied. Further, the video encoding equipment may include image encoding equipment.

[84] Referring to FIG. 2, the encoding equipment 200 includes an image segmentation module 210, a prediction module 220, a residual processor 230 and an entropy encoder 240, an adder 250, a filter 260, and a memory 270. The prediction module 220 may include an inter-prediction module 221 and an internal prediction module 222. forecasting. Residual processor 230 may include a transformer 232, a quantizer 233, a dequantizer 234, and an inverse transformer 235. Residual processor 230 may further include a subtractor 231. The adder 250 may be referred to as a “reconfiguration module” or a “reconstructed block generator.” The image segmentation module 210, prediction module 220, residual processor 230, entropy encoder 240, adder 250, and filter 260 may be configured by at least one hardware component (eg, a chipset or encoder processor) according to an exemplary embodiment. In addition, storage device 270 may include a decoded frame buffer (DPB) or may be configured with a digital storage medium. The hardware component may further include a storage device 270 as an internal/external component.

[85] The image segmentation module 210 may segment an input image (either a frame or a movie frame) input to the encoding equipment 200 into one more processing units. For example, a processing unit may be called a "coding unit (CU)". In this case, the coding unit may be recursively segmented according to a quadtree, binary tree, and ternary tree (QTBTTT) structure from a coding tree unit (CTU) or largest coding unit (LCU). For example, one coding unit may be segmented into multiple coding units of greater depth based on a quadtree structure, a binary tree structure, and/or a ternary structure. In this case, for example, a quadtree structure may be applied first, and a binary tree structure and a ternary structure may be subsequently applied. Alternatively, a binary tree structure may be used first. The encoding procedure of the present disclosure may be performed based on a final encoding unit that is no longer segmented. In this case, the largest coding unit can be used as the final coding unit based on the coding efficiency according to the characteristics of the images, or if necessary, the coding unit can be recursively segmented into coding units of greater depth, and the coding unit having the optimal size can be used as the final coding units. Here, the encoding procedure may include a prediction, transformation and reconstruction procedure, which is described below. As another example, the processing unit may further include a predictor (PU) or transformation unit (TU). In this case, the predictor and transformation unit may be split or segmented from the above final encoding unit. The predictor may be a sample prediction unit, and the transform unit may be a unit for extracting a transform coefficient and/or a unit for extracting a residual signal from the transform coefficient.

[86] Unit may be used interchangeably with terms such as block or zone in some cases. In general, an MxN block can represent a set of samples or transform coefficients consisting of M columns and N rows. A sample may generally represent a pixel or a pixel value, may represent only a pixel/pixel value of a luma component, or may represent only a pixel/pixel value of a chrominance signal component. Sampling can be used as a term corresponding to one frame (or image) for a pixel or pel.

[87] In the encoding equipment 200, the prediction signal (predicted block, prediction sample array) output from the inter-prediction module 221 or intra-prediction module 222 is subtracted from the input image signal (original block, source sample array) to generate a residual signal ( residual block, residual sample array), and the generated residual signal is transmitted to converter 232. In this case, as shown, a module for subtracting the prediction signal (predicted block, prediction sample array) from the input image signal (source block, source sample array) into encoder 200 may be referred to as "subtractor 231". The prediction module may perform prediction on a block to be processed (hereinafter referred to as a "current block") and generate a prediction block including prediction samples for the current block. The prediction module may determine whether intra prediction or inter prediction is applied based on the current block or CU. As described below in the description of each prediction mode, the prediction module may generate various prediction-related information, such as prediction mode information, and transmit the generated information to the entropy encoder 240. Information regarding the prediction may be encoded in the entropy encoder 240 and output in the form of a stream bits

[88] Intra prediction module 222 may predict the current block by reference to samples in the current frame. Samples for reference may be located in the surroundings of the current block or may be located independently according to the prediction mode. In intraprediction, prediction modes may include a plurality of non-directional modes and a plurality of directed modes. The omnidirectional mode may include, for example, DC mode and planar mode. The directional mode may include, for example, 33 directional prediction modes or 65 directional prediction modes according to the granularity of the prediction direction. However, this is merely an example; more or less directional prediction modes may be used depending on the setting. The intra prediction module 222 may determine the prediction mode applied to the current block by using the prediction mode applied to the adjacent block.

[89] The inter-prediction unit 221 may extract a predicted block for the current block based on a reference block (an array of reference samples) indicated by a motion vector for the reference frame. Here, in order to reduce the amount of motion information transmitted in the inter-prediction mode, motion information may be predicted in units of blocks, sub-blocks, or samples based on the correlation of motion information between a neighboring block and the current block. The motion information may include a motion vector and a reference frame index. The motion information may further include inter-prediction direction information (L0-prediction, L1-prediction, bi-prediction, etc.). In the case of mutual prediction, the neighbor block may include a spatial neighbor block present in the current image and a temporal neighbor block present in the reference image. The reference frame including the reference block and the reference frame including the temporary adjacent block may be identical or different. A temporary neighbor block may be called a “co-located reference block”, a “col-located CU (colCU)”, etc., and a reference frame including a temporary neighboring block may be called a “col-located frame (colPic)”. For example, the inter-prediction module 221 may configure a list of motion information candidates based on neighboring blocks and generate information indicating which candidate is used to retrieve the motion vector and/or reference frame index of the current block. Mutual prediction can be performed based on different prediction modes. For example, in the case of the skip mode and the merge mode, the inter-prediction unit 221 may use the motion information of the adjacent block as the motion information of the current block. In skip mode, unlike combine mode, the residual signal may not be transmitted. In the case of a motion vector prediction (MVP) mode, the motion vector of an adjacent block may be used as a motion vector predictor, and the motion vector of the current block may be indicated by signaling a motion vector difference.

[90] The prediction module 220 may generate a prediction signal based on various prediction methods described below. For example, the prediction module may not only apply intra-prediction or inter-prediction to predict one block, but also simultaneously apply both intra-prediction and inter-prediction. This may be referred to as "combined inter-intraprediction (CIIP)". In addition, the prediction module can be based on intra-block copy (IBC) prediction mode or palette mode for block prediction. The IBC prediction mode or palette mode can be used for encoding image/video content of a game and the like, for example, screen content encoding (SCC). IBC essentially performs prediction in the current frame, but can be performed similarly to inter-prediction in which the reference block is retrieved in the current frame. Thus, the IBC may use at least one of the inter-prediction technologies described in this document. Palette mode can be considered an example of intra-coding or intra-prediction. When palette mode is applied, a sampled value in a frame may be signaled based on information regarding the palette table and palette index.

[91] The prediction signal generated by the prediction module (including inter prediction module 221 and/or intra prediction module 222) can be used to generate a reconstructed signal or generate a residual signal. Converter 232 may generate conversion coefficients by applying conversion technology to the residual signal. For example, the transform technology may include at least one of a discrete cosine transform (DCT), a discrete sine transform (DST), a Karhunen-Loeve transform (KLT), a graph-based transform (GBT), or a conditionally nonlinear transform (CNT). ). Here, GBT means a graph-derived transformation when the relationship information between pixels is represented by the graph. CNT means a transform generated based on a prediction signal generated using all previously reconstructed pixels. In addition, the conversion process may be applied to square pixel blocks that are identical in size, or may be applied to blocks that are of variable size rather than square.

[92] Quantizer 233 may quantize the transform coefficients and transmit them to entropy encoder 240, and entropy encoder 240 may encode the quantized signal (information regarding the quantized transform coefficients) and output a bit stream. Information regarding the quantized transform coefficients may be referred to as "residual information". Quantizer 233 may re-arrange the block quantized transform coefficients into one-dimensional vector form based on the scanning order of the coefficients, and generate information regarding the quantized transform coefficients based on the quantized transform coefficients in one-dimensional vector form. Information regarding conversion factors can be generated. The entropy encoder 240 may implement various encoding techniques, such as, for example, exponential Golomb coding, context adaptive variable length coding (CAVLC), context adaptive binary arithmetic coding (CABAC), and the like. Entropy encoder 240 may encode information needed for video/image reconstruction other than quantized transform coefficients (eg, syntax element values, etc.) together or separately. Encoded information (eg, encoded video/image information) may be transmitted or stored in NAL (Network Abstraction Layer) units in the form of a bitstream. The video/image information may further include information regarding various parameter sets, such as an adaptation parameter set (APS), a frame parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS). In addition, the video/image information may further include general restriction information. In this document, information and/or syntax elements transmitted/signaled from encoding equipment to decoding equipment may be included in video/frame information. The video/image information may be encoded through the encoding procedure described above and included in the bitstream. The bit stream may be transmitted over a network or may be stored on a digital storage medium. The network may include a broadcast network and/or a communications network, and the digital storage medium may include various storage media such as USB, SD, CD, DVD, Blu-Ray, HDD, SSD, and the like. A transmitter (not shown) transmitting the signal output from the entropy encoder 240 and/or a storage module (not shown) storing the signal may be included as an internal/external element of the encoding equipment 200, and alternatively, the transmitter may be included in the entropy encoder 240 .

[93] The quantized transform coefficients output from quantizer 233 can be used to generate a predictive signal. For example, a residual signal (residual block or residual samples) may be reconstructed by applying dequantization and inverse transform to the quantized transform coefficients through dequantizer 234 and inverse transformer 235. Adder 250 adds the reconstructed residual signal with the prediction signal output from interprediction module 221 or module 222 internal prediction to generate a reconstructed signal (reconstructed frame, reconstructed block, array of reconstructed samples). If there is no remainder for a block to be processed, for example in a case in which the skip mode is applied, the predicted block can be used as a reconstructed block. The adder 250 may be referred to as a "reconfiguration module" or a "recovered block generator." The generated reconstructed signal can be used to internally predict the next block to be processed in the current frame, and can be used to inter-predict the next frame through filtering, as described below.

[94] Meanwhile, luma conversion with chrominance scaling (LMCS) can be applied during encoding and/or reconstruction of frames.

[95] Filter 260 may enhance the subjective/objective quality of images by applying filtering to the reconstructed signal. For example, filter 260 may generate a modified reconstructed frame by applying various filtering techniques to the reconstructed frame and store the modified reconstructed frame in storage device 270, namely, a DPB of storage device 270. Various filtering techniques may include, for example, deblocking filtering. , sampled adaptive bias, adaptive loop filter, bilateral filter, etc. The filter 260 may generate various filtering-related information and transmit the generated information to the entropy encoder 240, as described below in the description of each filtering method. Information associated with filtering may be encoded by entropy encoder 240 and output in the form of a bit stream.

[96] The modified reconstructed frame transferred to the storage device 270 can be used as a reference frame in the inter-prediction unit 221. When inter-prediction is applied by the encoding equipment, prediction mismatch between the encoding equipment 200 and the decoding equipment can be eliminated, and encoding efficiency can be improved.

[97] The DPB of the storage device 270 may store the modified reconstructed frame for use as a reference frame in the inter-prediction module 221. Memory 270 may store block motion information from which motion information in the current frame is retrieved (or encoded) and/or motion information of blocks in a frame that have already been reconstructed. The stored motion information may be transmitted to the inter-prediction unit 221 and used as spatial neighbor block motion information or temporal neighbor block motion information. Memory 270 may store reconstructed samples of reconstructed blocks in the current frame and may transmit reconstructed samples to intra prediction module 222.

[98] FIG. 3 illustrates the structure of video/image decoding equipment to which the present disclosure may be applied.

[99] Referring to FIG. 3, the decoding equipment 300 may include an entropy decoder 310, a residual processor 320, a prediction module 330, an adder 340, a filter 350, a memory 360. The prediction module 330 may include an inter-prediction module 331 and an intra-prediction module 332. Residual processor 320 may include a dequantizer 321 and an inverse converter 321. Entropy decoder 310, residual processor 320, prediction module 330, adder 340, and filter 350 may be configured by a hardware component (e.g., a chipset or decoder processor) according to an exemplary embodiment. . In addition, storage device 360 may include a decoded frame buffer (DPB) or may be configured with a digital storage medium. The hardware component may further include storage device 360 as an internal/external component.

[100] When a bit stream including video/image information is input, the decoding equipment 300 can reconfigure an image corresponding to the process in which the video/image information is processed in the encoding equipment of FIG. 2. For example, decoding equipment 300 may extract units/blocks based on block segmentation-related information obtained from the bit stream. The decoding equipment 300 may perform decoding using a processing unit used in the encoding equipment. That is, the decoding processing unit, for example, may be an encoding unit, and the encoding unit may be segmented according to a quadtree structure, a binary tree structure, and/or a ternary tree structure from an encoding tree unit or a largest encoding unit. One or more transformation units may be derived from a coding unit. The reconstructed image signal decoded and output by the decoding equipment 300 can be reproduced by the playback equipment.

[101] The decoding equipment 300 may receive a signal output from the encoding equipment of FIG. 2 in the form of a bit stream, and the received signal may be decoded through entropy decoder 310. For example, entropy decoder 310 may parse the bit stream to extract information (eg, video/image information) needed for image reconstruction (or frame reconstruction). The video/image information may further include information regarding various parameter sets, such as an adaptation parameter set (APS), a frame parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS). In addition, the video/image information may further include general restriction information. The decoding equipment may further decode the frame based on information regarding the parameter set and/or general constraint information. The signaling/receiving information and/or syntax elements described later in this document may be decoded, may be decoded by a decoding procedure, and obtained from the bit stream. For example, entropy decoder 310 decodes information in a bitstream based on an encoding method, such as exponential Golomb, CAVLC, or CABAC encoding, and the output syntax elements required for image reconstruction and the quantized values of the transform coefficients for the remainder. More specifically, the entropy CABAC decoding method may receive a resolution element corresponding to each syntax element in the bitstream, determine a context model using information of a target decoding syntax element, decoding information of a target decoding block, or information of a symbol/resolution element decoded in a previous stage, and perform arithmetic decoding for the permission element by predicting the probability of occurrence of the permission element according to the determined context model and generating a symbol corresponding to the meaning of each syntactic element. In this case, the entropy CABAC decoding method can update the context model by using the decoded symbol/grant element information for the context model of the next symbol/grant element after determining the context model. The prediction-related information from the information decoded by the entropy decoder 310 may be provided to the prediction module (inter-prediction module 332 and intra-prediction module 331), and the residual value for which entropy decoding is performed in the entropy decoder 310, i.e. the quantized transform coefficients and associated parameter information may be input to residual processor 320. Residual processor 320 may extract a residual signal (residual block, residual samples, array of residual samples). In addition, information regarding filtering from information decoded by the entropy decoder 310 may be provided to the filter 350. Meanwhile, a receiver (not shown) for receiving a signal output from the encoding equipment may be further configured as an internal/external element of the equipment 300 decoding, or the receiver may be a component of the entropy decoder 310. Meanwhile, the decoding equipment according to this document may be called "video/image/frame decoding equipment", and the decoding equipment may be classified into information decoder (video/image/frame information decoder) and selective decoder (video/image/frame sampling decoder). The information decoder may include an entropy decoder 310, and the sample decoder may include at least one of a dequantizer 321, an inverter 322, an adder 340, a filter 350, a memory 360, an inter-prediction module 332, and an intra-prediction module 331 .

[102] The dequantizer 321 may dequantize the quantized transform coefficients and output the transform coefficients. The dequantizer 321 may re-arrange the quantized transform coefficients into a two-dimensional block form. In this case, re-arrangement may be performed based on the order of coefficient scanning performed in the encoding equipment. The dequantizer 321 may perform dequantization on the quantized transform coefficients by using a quantization parameter (eg, quantization step size information) and obtain the transform coefficients.

[103] The inverse converter 322 inversely converts the transform coefficients to obtain a residual signal (residual block, residual sample array).

[104] Prediction module 230 may perform prediction for the current block and may generate a predicted block including prediction samples for the current block. The prediction module may determine whether intra prediction or inter prediction is applied to the current block based on the prediction information output from the entropy decoder 310, and may determine a particular intra/inter prediction mode.

[105] The prediction module 320 may generate a prediction signal based on various prediction methods described below. For example, the prediction module may not only apply intra-prediction or inter-prediction to predict one block, but also simultaneously apply intra-prediction and inter-prediction. This may be referred to as "combined inter-intraprediction (CIIP)". In addition, the prediction module can be based on intra-block copy (IBC) prediction mode or palette mode for block prediction. The IBC prediction mode or palette mode can be used for encoding image/video content of a game and the like, for example, screen content encoding (SCC). IBC essentially performs prediction in the current frame, but can be performed similarly to inter-prediction in which the reference block is retrieved in the current frame. Thus, the IBC may use at least one of the inter-prediction technologies described in this document. Palette mode can be considered an example of intra-coding or intra-prediction. When palette mode is applied, a sampled value in a frame may be signaled based on information regarding the palette table and palette index.

[106] The intra prediction module 331 may predict the current block by reference to the samples in the current frame. Samples for reference may be located in the surroundings of the current block or may be located independently according to the prediction mode. In intraprediction, prediction modes may include a plurality of non-directional modes and a plurality of directed modes. The intra prediction unit 331 may determine the prediction mode applied to the current block by using the prediction mode applied to the adjacent block.

[107] The inter-prediction unit 332 may extract a predicted block for the current block based on a reference block (an array of reference samples) indicated by a motion vector for the reference frame. In this case, in order to reduce the amount of motion information transmitted in the inter-prediction mode, the motion information may be predicted in units of blocks, sub-blocks, or samples based on the correlation of the motion information between a neighboring block and the current block. The motion information may include a motion vector and a reference frame index. The motion information may further include inter-prediction direction information (L0-prediction, L1-prediction, bi-prediction, etc.). In the case of mutual prediction, the neighbor block may include a spatial neighbor block present in the current image and a temporal neighbor block present in the reference image. For example, the inter-prediction module 332 may configure a motion information candidate list based on neighboring blocks and extract the current block's motion vector and/or reference frame index based on the received candidate selection information. The inter-prediction may be performed based on various prediction modes, and the information regarding the prediction may include information indicating the inter-prediction mode for the current block.

[108] The adder 340 may generate a reconstructed signal (recovered frame, reconstructed block, reconstructed sample array) by adding the resulting residual signal with a prediction signal (predicted block, predicted sample array) output from a prediction module (including inter-prediction module 332 and /or internal prediction module 331). If there is no remainder for a block to be processed, for example when a skip mode is applied, the predicted block can be used as the reconstructed block.

[109] The adder 340 may be referred to as a “reconfiguration module” or a “recovered block generator.” The generated reconstructed signal may be used to internally predict the next block to be processed in the current frame, may be output by filtering as described below, or may be used to inter-predict the next frame.

[110] Meanwhile, luma conversion with chrominance scaling (LMCS) can be applied in the frame decoding process.

[111] Filter 350 may enhance the subjective/objective quality of images by applying filtering to the reconstructed signal. For example, filter 350 may generate a modified reconstructed frame by applying various filtering techniques to the reconstructed frame and store the modified reconstructed frame in storage device 360, namely, a DPB of storage device 360. Various filtering techniques may include, for example, deblocking filtering. , sampled adaptive bias, adaptive contour filter, bilateral filter, etc.

[112] The (modified) reconstructed frame stored in the DPB of the storage device 360 can be used as a reference frame in the inter-prediction unit 332. Storage device 360 may store block motion information from which motion information in the current frame is retrieved (or decoded) and/or motion information of blocks in a frame that have already been reconstructed. The stored motion information may be transmitted to the inter-prediction unit 260 so that it is used as spatial neighbor block motion information or temporal neighbor block motion information. Storage device 360 may store reconstructed samples of reconstructed blocks in the current frame and transmit the reconstructed samples to intra prediction module 331.

[113] In the present disclosure, the embodiments described in the filter 260, the inter-prediction module 221, and the intra-prediction module 222 of the encoding equipment 200 may be identical or appropriately applied so that they correspond to the filter 350, the inter-prediction module 332, and the 331 internal prediction equipment 300 decoding. The same may also apply to module 332 and internal prediction module 331.

[114] As described above, when performing video encoding, prediction is performed in order to improve compression efficiency. Accordingly, a predicted block may be generated including predictive samples for a current block, which is a block to be encoded. Here, the predicted block includes predictive samples in a spatial domain (or pixel domain). The predicted block is extracted equally from the encoding equipment and the decoding equipment, and the encoding equipment can signal the residual information (residual information) between the original block and the predicted block rather than the original sample value of the original block itself to the decoding equipment, thereby improving efficiency image coding. The decoding equipment may extract a residual block including residual samples based on the residual information, generate a reconstructed block including the reconstructed samples by combining the residual block with a predicted block, and generate a reconstructed frame including the reconstructed blocks.

[115] Residual information can be generated through a transformation and quantization procedure. For example, the encoding equipment may signal associated residual information (via a bitstream) to the decoding equipment by extracting a residual block between an original block and a predicted block, extracting transform coefficients by performing a transform procedure on the residual samples (an array of residual samples) included in the residual block, and extracting the quantized transform coefficients by performing a quantization procedure on the transform coefficients. Here, the residual information may include information such as value information, location information, transformation technology, transformation kernel, and quantization parameters for the quantized transformation coefficients. The decoding equipment may perform a dequantization/deconversion procedure based on the residual information and extract the residual samples (or residual blocks). The decoding equipment can generate a reconstructed image based on the predicted block and the residual block. The encoding equipment may also extract the residual block by dequantizing/deconverting the quantized transform coefficients for the next frame inter-prediction reference and generate a reconstructed frame based on the extracted residual block.

[116] FIG. 4A and 4B are diagrams illustrating an example of an image encoding method carried out by the encoding equipment according to the exemplary embodiment and an example of the image decoding method carried out by the decoding equipment according to the exemplary embodiment.

[117] FIG. 4A illustrates an example of an image encoding method carried out by video encoding equipment. Referring to FIG. 4A, the image encoding method may include block segmentation, intra/inter-prediction, transform, quantization, and entropy encoding processes. For example, a current frame may be divided into multiple blocks, a predicted block with respect to the current block may be generated through intra/inter prediction, and a residual block with respect to the current block may be formed by subtracting a predicted block from an input block with respect to the current block. After this, the block of coefficients of the current block, i.e. transformation coefficients can be generated through a transformation for the residual block. The transform coefficients can be quantized and entropy encoded and stored in the bit stream.

[118] FIG. 4B illustrates an example of an image decoding method performed by decoding equipment. Referring to FIG. 4B, the image decoding method may include entropy decoding, dequantization, inverse transform, and intra/inter-prediction processes. For example, the decoding equipment may perform the reverse process for the encoding method. In particular, the quantized transform coefficients can be obtained by entropy decoding for the bit stream, and the block coefficients of the current block, i.e. transform coefficients can be obtained through a dequantization process for the quantized transform coefficients. The residual block with respect to the current block can be retrieved through an inverse transform for the transform coefficients, and the reconstructed block with respect to the current block can be retrieved by summing the predicted block with respect to the current block retrieved via intra/cross prediction and the residual block.

[119] FIG. 5 is a flowchart illustrating an intra prediction method according to an exemplary embodiment.

[120] As illustrated in FIG. 5, the intra prediction method according to the exemplary embodiment may include the following three steps. Thus, the intra prediction method according to an exemplary embodiment may include configuring a reference sample, predicting the sample, and performing post-filtering. When predicting a sample, the intra prediction method according to an exemplary embodiment may use known neighboring reference samples and an intra prediction mode to perform prediction for unknown samples.

[121] FIG. 6 is a diagram illustrating an example of directed intra prediction modes.

[122] When intra prediction is applied to the current block, the encoding equipment and/or decoding equipment according to the exemplary embodiment may extract the intra prediction mode for the current block and extract prediction samples for the current block based on the intra prediction mode. That is, the encoding equipment and/or decoding equipment can extract prediction samples for the current block by applying a directed intra prediction mode or an undirected intra prediction mode based on adjacent reference samples of the current block.

[123] In an example, the intra-prediction modes may include two non-directional (or non-angular) intra-prediction modes and 65 directional (or angular) intra-prediction modes. The non-directional intra-prediction modes may include a zero planar intra-prediction mode and a first DC intra-prediction mode, and the directed intra-prediction modes may include 65 intra-prediction modes including the second to 66th intra-prediction modes. Intra prediction based on 65 directed intra prediction modes can be applied to blocks of all sizes and can be applied to all of the luma signal component and the chrominance signal component. However, this is only illustrative and the configurations of the internal prediction modes may vary.

[124] Alternatively, the intra prediction mode may include two non-directed intra prediction modes and 129 directed intra prediction modes. The non-directional intra-prediction modes may include a planar intra-prediction mode and a DC intra-prediction mode, and the directed intra-prediction modes may include the second to 130th intra-prediction modes.

[125] Meanwhile, the intra prediction mode may further include a cross component linear model (CCLM) based mode for sampling the chrominance signal in addition to the above intra prediction modes. The CCLM mode can be classified into LT_CCLM, L_CCLM and T_CCLM depending on whether the left samples should be considered, the top samples considered or both considered to extract LM parameters, and can only be applied to the chrominance signal component.

[126] The intra prediction mode may be indexed, for example, as expressed in Table 1 below.

[127]

Table 1 Internal prediction mode Associated title 0 INTRA_PLANAR 1 INTRA_DC 2...66 INTRA_ANGULAR2...INTRA_ANGULAR66 81...83 INTRA_LT_CCLM, INTRA_L_CCLM, INTRA_T_CCLM

[128] Meanwhile, the intra prediction type (or additional intra prediction mode and the like) may include at least one of the above LIP, PDPC, MRL and ISP. The intra prediction type may be indicated based on the intra prediction type information, and the intra prediction type information may be implemented in various forms. In an example, the intra-prediction type information may include intra-prediction type index information indicating one of the intra-prediction types. In another example, the intra prediction type information may include at least one of reference sample line information (eg, intra_luma_ref_idx) representing whether or not the MRL is applied to the current block, and if so, which reference sample line used, ISP flag information (eg, intra_subpartitions_mode_flag) representing whether or not ISP is applied to the current block, ISP type information (eg, intra_subpartitions_split_flag) indicating that the subsegments indicate the split type if ISP is applied, flag information representing whether PDPC is applied or not, and flag information representing whether LIP is applied or not.

[129] Referring to FIG. 6, an intra prediction mode that has a horizontal direction and an intra prediction mode that has a vertical direction may be different from each other based on the 34th intra prediction mode that has a left-up diagonal prediction direction. H and V in Fig. The 6s represent horizontal directivity and vertical directivity, respectively, and the numbers -32 to 32 represent offsets in units of 1/32 for the sample grid position. The second - 33rd internal forecasting modes have a horizontal orientation, and the 34th - 66th internal forecasting modes have a vertical orientation. The 18th intra-prediction mode and the 50th intra-prediction mode represent the horizontal intra-prediction mode and the vertical intra-prediction mode, respectively, and the second intra-prediction mode may be called "left-down diagonal intra-prediction mode", the 34th intra-prediction mode can be called a “left-up diagonal intra-prediction mode”, and the 66th intra-prediction mode may be called a “right-up-diagonal intra-prediction mode”.

[130] Typically, when a block for an image is split, the current block to be encoded and neighboring blocks have similar image characteristics. Accordingly, there is a high probability that the current block and neighboring blocks have identical or similar intra prediction modes. Accordingly, the encoder may use the intra-prediction mode of an adjacent block to encode the intra-prediction mode of the current block.

[131] In a more specific example, the decoding equipment may derive a list of most likely modes (MPM) based on the intra-prediction mode and additional candidate modes of an adjacent block (e.g., a left adjacent block and/or an upper adjacent block) relative to the current block, select one of the MPM candidates in the retrieved MPM list based on the received MPM index, or select one of the remaining intra prediction modes not included in the MPM candidates based on the remaining intra prediction mode information. The MPM list can also be represented as a list of possible internal prediction mode options and can also be represented as candModeList.

[132] The encoding hardware (or encoder) may confirm or extract the prediction mode of an adjacent block if the adjacent block is internally encoded. For example, the prediction mode of the current block may be determined based on the prediction mode of the left neighbor block and the prediction mode of the upper neighbor block, and at this time, the prediction mode of the corresponding neighbor block may be determined as the most likely mode (MPM). The definition of MPM can also be expressed as a list of possible most probable modes (MPM) (or MPM list).

[133] The encoding equipment can confirm whether the left neighbor block prediction mode and the top neighbor block prediction mode are identical. The initial MPM list may be generated by performing a pruning process for the intra prediction modes of two adjacent blocks.

[134] If the left neighbor block prediction mode and the top neighbor block prediction mode are not identical, the first MPM may be set as the left neighbor block prediction mode, the second MPM may be set as the top neighbor block prediction mode, and the third MPM may be set as the any of the internal planar mode, internal DC mode or internal vertical mode (50th internal prediction mode). Specifically, when the intra prediction modes of two adjacent blocks are different from each other, the two intra prediction modes may be set as MPMs, and after checking the pruning by the MPM, one of the default intra prediction modes may be added to the MPM list. Here, the default internal modes may include an internal planar mode, an internal DC mode, and/or an internal vertical mode (50th intra prediction mode).

[135] In an example, the MPM list may include 3 possible MPM options, 5 possible options, or 6 possible MPM options. For example, the MPM list may include candidates that are retrieved based on the intra-prediction mode of an adjacent block, the retrieved intra-prediction mode, and/or the default intra-prediction mode. The encoding equipment/decoding equipment may search for neighboring blocks of the current block according to a specific order, and extract the intra-prediction mode of the neighboring blocks as MPM candidates in the retrieved order. For example, adjacent blocks may include a left adjacent block, an upper adjacent block, a lower left adjacent block, an upper right adjacent block, and an upper left adjacent block.

[136] In an example, an MPM list including three possible MPM options can be configured, and three possible MPM options can be retrieved based on the intra-prediction modes of the neighbor block (F) and the neighbor block (G). A neighbor block-based MPM prediction method for a current block including a neighbor block (F) and a neighbor block (G), for example, can be illustrated in FIG. 7.

[137] FIG. 7 is a diagram for explaining the configuration of an MPM list according to an exemplary embodiment.

[138] Referring to FIG. 7, neighboring blocks with respect to the current block may include neighboring block (A), neighboring block (B), neighboring block (C), neighboring block (D), neighboring block (E), neighboring block (F) and/or adjacent block (G).

[139] Here, an adjacent block (A) may represent an adjacent block that is positioned at the upper left relative to the current block's upper left sample position, an adjacent block (B) may represent an adjacent block that is positioned at the upper left relative to the current block's upper right sample position, the adjacent block (C) may represent an adjacent block that is positioned at the top right relative to the top right sample position of the current block, an adjacent block (D) may represent an adjacent block that is positioned at the left end relative to the bottom left sample position of the current block, an adjacent block (E) may represent a neighbor block that is positioned below the left bottom sample position of the current block, a neighbor block (G) may represent a neighbor block that is positioned above the top left sample position of the current block, and a neighbor block (F) may represent a neighbor block that is positioned at left end relative to the top left sample position of the current block.

[140] Additionally, for example, if the size of the current block is WxH, the X-axis component of the left upper sample position of the current block is 0, and its Y-axis component is 0, the adjacent block (A) may be a block including coordinate sample (-1,-1), adjacent block (B) may be a block including coordinate sample (W-1,-1), adjacent block (C) may be a block including coordinate sample ( W,-1), an adjacent block (D) may be a block including a coordinate sample (-1, H-1), an adjacent block (E) may be a block including a coordinate sample (-1, H ), an adjacent block (F) may be a block including a coordinate sample (-1, 0), and an adjacent block (G) may be a block including a coordinate sample (0, -1).

[141] In an exemplary embodiment, three possible MPM options can be extracted based on an intra-neighbor prediction mode (F) and an intra-neighbor prediction mode (G). For example, an intra-neighbor block prediction mode (F) and an intra-neighbor block prediction mode (G) may be extracted. Meanwhile, in the following three cases, the intra-neighbor block prediction mode (F) or the intra-neighbor block prediction mode (G) may be extracted as the intra-DC prediction mode. Thus, if an adjacent block (F) or an adjacent block (G) is not available, if an adjacent block (F) or an adjacent block (G) is not encoded in intra prediction mode (if an adjacent block (F) or an adjacent block (G) is not represent an intra-coded block), or if the neighbor block (F) or neighbor block (G) is outside the current coding tree unit, the neighbor block intra prediction mode (F) or neighbor block intra prediction mode (G) may be extracted as the mode internal DC forecasting.

[142] If the intra-neighbor block prediction mode (F) or the intra-neighbor block prediction mode (G) is determined, three possible MPM options can be retrieved, for example, based on Table 2 below.

[143] Tab. 2

if(internal mode F and G are equal)

{

if(internal mode F<internal mode 2)

{MPM-list 1}

else

{MPM-list 2}

}

else

{

if(neither F nor G internal mode is a planar internal mode),

{MPM-list 3}

else if(internal mode (F+G)<internal mode 2)

{MPM list 4}

else

{MPM list 5}

}

[144] Table 2 may roughly represent the pseudo codes configuring the MPM list.

[145] Referring to Table 2, it can be determined whether or not the intra-neighbor block prediction mode (F) and the intra-neighbor block prediction mode (G) are identical.

[146] If the intra-neighbor block prediction mode (F) and the intra-neighbor block prediction mode (G) are identical, and the mode number for the intra-neighbor block prediction mode (F) is less than 2, the MPM list of the current block may be retrieved as the MPM-list. list 1 (MPM-list 1). That is, if the intra-prediction mode of the neighbor block (F) and the intra-prediction mode of the neighbor block (G) are identical, and the intra-prediction mode of the neighbor block (F) is the zero intra-prediction mode or the first intra-prediction mode, the MPM list of the current block may be retrieved as MPM-List 1. Here, MPM-List 1 may represent an MPM-List consisting of possible MPM-variants {F, F-1, F+1}. F may represent an intra-prediction mode of an adjacent block (F), F-1 may represent an intra-prediction mode, wherein the value obtained by subtracting 1 from the mode number for the intra-prediction mode of an adjacent block (F) represents the mode number, and F+ 1 may represent an intra prediction mode, wherein the value obtained by adding 1 with the mode number for the inter prediction mode of an adjacent block (F) represents the mode number. For example, if the intra prediction mode of the neighboring block (F) is the Nth intra prediction mode, MPM list 1 may be configured as an MPM list including the Nth intra prediction mode, the (N-1)th mode internal forecasting and (N+1)th internal forecasting mode as possible MPM options.

[147] Additionally, if the intra-neighbor block prediction mode (F) and the intra-neighbor block prediction mode (G) are identical, and the mode number for the intra-neighbor block prediction mode (F) is not less than 2, the MPM list of the current block can be retrieved into as MPM list 2.

[148] Additionally, if the intra-neighbor block prediction mode (F) and the intra-neighbor block prediction mode (G) are not identical, and the intra-neighbor block prediction mode (F) and the intra-neighbor block prediction mode (G) are not planar modes. internal prediction, the MPM list of the current block can be retrieved as MPM list 3.

[149] Additionally, if the neighbor block intra prediction mode (F) and the neighbor block intra prediction mode (G) are not identical, and the sum of the mode number for the neighbor block intra prediction mode (F) and the mode number for the neighbor block intra prediction mode ( G) less than 2, the MPM list of the current block can be retrieved as MPM list 4.

[150] Additionally, if the intra-neighbor block prediction mode (F) and the intra-neighbor block prediction mode (G) are not identical, at least one of the intra-neighbor block prediction mode (F) and the intra-neighbor block prediction mode (G) is a planar intra-prediction mode, and the sum of the mode number for the intra-prediction mode of the neighboring block (F) and the mode number for the intra-prediction mode of the neighboring block (G) is not less than 2, the MPM list of the current block can be retrieved as the MPM list 5.

[151] Meanwhile, as the number of intra-prediction modes increases, the number of possible MPM options should increase. Accordingly, the number of possible MPM options may vary according to the number of internal prediction modes. Typically, as the number of intraprediction modes increases, the number of possible MPM options can increase. However, the number of possible MPM options does not always increase when the number of intraprediction modes increases. For example, if there are 35 intra-prediction modes or 67 intra-prediction modes, different possible MPM options, eg 3, 4, 5 and 6, may be provided according to the design.

[152] For example, the encoder/decoder may also configure an MPM list including 6 MPMs. Default internal modes, adjacent internal modes, and extractable internal modes may be considered in order to configure the MPM list.

[153] In the example, for adjacent internal modes, two adjacent blocks, i.e. left adjacent block (A) and top adjacent block (B). To generate an MPM list including 6 MPMs, a default initialized MPM list based on Table 3 below can be considered.

[154] Tab. 3

6 Default MPM Modes = {A, Planar (0) or DC (1), Vertical (50), HOR (18), VER-4 (46), VER+4 (54)}

After this, the 6 MPM modes are updated by performing a pruning process for the two adjacent internal modes. If two adjacent modes are identical to each other, and the adjacent mode exceeds the DC-(1)-mode, the 6 MPM modes shall include the three default modes (A, planar, DC-) and the three extracted modes that are obtained by summing preset offset values with adjacent mode and perform modular operation. Otherwise, if two neighboring modes are different, the two neighboring modes are assigned to the first two MPM modes, and the remaining four MPM modes are extracted from the default modes and neighboring modes. During the 6 MPM list generation process, pruning is used to remove duplicate modes so that only unique modes can be included in the MPM list. To entropy encode the 61 non-MPM modes, truncated binary code (TBC) is used.

[155] In another example, the configuration order of the 6 possible MPM options may be an order of neighbor (D), neighbor (B), planar intra prediction mode, intra DC prediction mode, neighbor (E), neighbor block (C) and the adjacent block (A). Thus, the intra prediction mode can be extracted, as MPM candidates, in the order of neighbor block (D) intra prediction mode, neighbor block (B) intra prediction mode, planar intra prediction mode, DC intra prediction mode, intra-neighbor prediction mode (E), intra-neighbor prediction mode (C), and intra-neighbor prediction mode (A) and may not be extracted as MPM candidates if the 6 MPM candidates are identical to the already extracted intra-prediction mode.

[156] Additionally, if the MPM list does not include the maximum number of possible MPM options, i.e. if the number of extracted MPM candidates is less than the maximum number of candidates, the directed intra prediction mode adjacent to the extracted MPM candidate and the preset default intra prediction mode may be considered as MPM candidates, and the pruning checking process may be performed together. Here, the directed intra prediction mode adjacent to the MPM candidate may represent an intra prediction mode having a mode number adjacent to the mode number of the MPM candidate. The above neighbor search and continuous pruning check provide the benefit of reducing the bit rate, but may increase the number of hardware duty cycles for configuring each block's MPM list. As a worst-case scenario, a 3840x2160 4K image could be split into 4x4 blocks for intra-prediction, and the increased number of hardware duty cycles for each 4x4 block could be considered important for throughput. Meanwhile, if a neighboring block encoded by inter-prediction of the current block knows the intra-prediction mode of the neighboring block, the intra-prediction mode of the neighboring block can be used to configure the MPM list.

[157] As described above, the current block to be encoded and the neighboring block may generally have similar image characteristics, and therefore there is a high probability that the current block and the neighboring block have identical or similar intra prediction modes. so that the MPM list of the current block can be determined to retrieve the intra prediction mode applied to the current block. However, when 67 intra prediction modes are used for intra prediction, an MPM list including 3 possible MPM options may not be sufficient to represent the diversity of multiple intra prediction modes. Additionally, a method for configuring a list of 6 MPMs including a neighbor search process and a pruning check process may be disadvantageous in complexity and throughput. In the present disclosure, various methods are described below that extract the intra prediction mode for the current block based on the MPM prediction.

[158] FIG. 8 is a diagram for explaining the configuration of an MPM list according to another exemplary embodiment.

[159] Referring to FIG. 8, in an exemplary embodiment, the left adjacent block A (which may be represented as LEFT) and the upper adjacent block B (which may be represented as ABOVE) may be used as expressed in Table 4 below to generate an MPM -list. The algorithm is as follows. Non-MPM encoding may be based on truncated binary code.

[160] Tab. 4

Defining internal LEFT and ABOVE modes

Setting MPM as MPM_ordering_0

If (LEFT==ABOVE)

If(LEFT>=DC_idx), then set MPM as MPM_ordering_1

Else if (LEFT>DC_idx and ABOVE>DC_idx), then specify MPM as MPM_ordering_2

Else if (LEFT+ABOVE>DC_idx), then specify MPM as MPM_ordering_3

[161] FIG. 9 is a flowchart illustrating an MPM prediction method according to an exemplary embodiment.

[162] The present disclosure uses specific terms or sentences to specify specific information or concept. For example, a particular intra-prediction mode that may be determined as the intra-prediction mode for the current block without MPM index information in the luminance intra-coding process is called a “significant mode,” an index indicating one of the possible MPM options included in the MPM. a list called the "MPM index", a flag indicating whether or not internal luminance coding should be applied is called the "integrated MPM flag", and the remaining internal prediction modes other than the possible MPM options when MPM prediction is not applied , are called "non-MPM modes". However, "significant mode" can be replaced by various terms such as significant_mode, default mode and possible mode variant, "MPM index" can be replaced by probable_mode_index, mpm_idx, intra_luma_mpm_idx, etc., "integrated MPM flag" can be replaced by unified_probable_mode_flag, MPM flag, intra_luma_mpm_flag, etc., and "non-MPM modes" may be replaced by various terms such as non-MPM modes, non_probable_modes, remaining intraprediction modes, and remaining MPM prediction modes, so that in In the interpretation of specific terms or sentences used to define specific information or concept in the present description of the invention through the specification, the construction should not be limited by the title, and it is necessary to interpret the specific terms and sentences with attention to the various operations, functions and advantages according to the content of the term .

[163] In an example, the significant mode may be an internal planar mode.

[164] In an exemplary embodiment, unified intra-luminance coding and signaling may be performed. When internally encoding luminance signals, at least one significant internal mode for the luminance signal may be signaled first, and then the MPM list may be configured based on the remaining internal modes to select the optimal mode from the possible MPM options included in MPM list.

[165] First, it can be determined whether or not an MRL or ISP is used. When MRL or ISP is used, the value of unified_probable_mode_flag may be specified as 1. If MRL or ISP is not used, unified_probable_mode_flag may be parsed.

[166] If unified_probable_mode_flag is 0, non_probable_mode_index can be parsed. If the value of unified_probable_mode_flag is 1, significant_mode_flag can be parsed. When the value of significant_mode_flag is 1, the internal prediction mode for the current block can be determined to be a significant mode (eg, internal planar mode), and when the value of significant_mode_flag is 0, probable_mode_index can be parsed.

[167] FIG. 10 is a flowchart illustrating an MPM prediction method according to another exemplary embodiment.

[168] In FIG. 10, intra prediction performed based on one integrated method (or algorithm) regardless of whether intra prediction based on multiple reference line (MRL) or intra sub segment prediction (ISP) is applied or not is called “unified intra mode coding for brightness signal". However, "integrated intra-mode luminance encoding" may be replaced by various terms such as integrated inter-mode luminance, integrated inter-prediction, integrated MPM, integrated MPM-prediction, unified_probable_mode, integrated inter-mode, and integrated inter-mode luminance. brightness

[169] A specific method for extracting an integrated internal mode for a luminance signal according to an exemplary embodiment is as follows.

[170] First, unified_probable_mode_flag can be parsed. When the value of unified_probable_mode_flag is 0, non_probable_mode_index can be parsed, and when the value of unified_probable_mode_flag is 1, significant_mode_flag can be parsed. When the value of significant_mode_flag is 1, the internal prediction mode for the current block can be determined to be a significant mode (eg, internal planar mode), and when the value of significant_mode_flag is 0, probable_mode_index can be parsed.

[171] Alternatively, a specific method for extracting an integrated internal mode for a luminance signal according to an exemplary embodiment may be expressed in Table 5 below.

[172] Tab. 5

Step 1: Parse unified_probable_mode_flag, or unified_probable_mode_flag is pre-assigned to a specific value.

If unified_probable_mode_flag is equal to 1, it indicates that the unified probable internal mode is used for the current internal coding unit (CU). Additionally, step 1.1 is then executed.

Otherwise, unified_probable_mode_flag is 0, indicating that the unified probable internal mode is not used. Instead, non_probable_mode is used for the current internal CU. Additionally, step 1.2 is then executed.

Stage 1.1. Parsing significant_mode_flag.

If significant_mode_flag is 1, it indicates that one significant internal mode is in use for the current internal coding unit (CU). Additionally, step 1.1.1 is then executed.

Otherwise, significant_mode_flag is 0, indicating that the significant internal mode is not used. Instead, one of the candidate modes in the candidate list is used for the current internal CU. Additionally, step 1.1.2 is then executed

Stage 1.1.1. A predefined one significant mode is assigned to predModeIntra, indicating that one specific significant mode is used for the current internal CU.

Stage 1.1.2. Parsing probable_mode_index.

probable_mode_index is parsed to indicate that one of the list of probable modes is in use for the current internal CU. The detailed construction of the list of likely modes is described in the following Table 6.

Stage 1.2. Parsing non_probable_mode_idx

non_probable_mode_idx is parsed to indicate that one of the list of nonprobable modes is in use for the current internal CU

[173] A method is provided for configuring an MPM list according to an exemplary embodiment. A list of MPM modes having length k can be configured. In the example, k is 5, and 5 conditions can be used when 5 different MPM lists are configured. Block (B) of FIG. 7 may be represented by A, and block (D) may be represented by L. For example, a method for configuring an MPM list according to the present exemplary embodiment may be expressed in Table 6 below.

[174] Tab. 6

1. Checking such condition 1, whether L and A are identical. If condition 1 is satisfied, then go to stage 2.1, otherwise go to stage 2.2.

L==A (condition 1)

2.

2.1 In this case, L and A are identical. The test for such condition 2 is whether L is greater than DC_idx, which implies that L and A represent angular modes. If condition 2 is satisfied, then go to stage 5.1, otherwise go to stage 5.2.

L>DC_idx (condition 2)

2.2. In this case, L and A are different. Testing such condition 3, greater than L or A or not DC_idx, implies that at least one of L and A represents an angular mode. If condition 3 is satisfied, then proceed to stage 3.

L>DC_idx or A>DC_idx (condition 3)

3. The following applies:

maxAB=max(L, A), whichever takes the greater value between L and A.

minAB=min(L, A), whichever takes the smaller value between L and A

The test for such a condition is 4, L and A are greater than or DC_idx is not present, which implies that L and A represent angular modes. If condition 4 is satisfied, then go to stage 4.1, otherwise go to stage 4.2.

L>DC_idx and A>DC_idx (condition 4)

4.

4.1 In this case, L and A represent angular modes. Checking such condition 5, the difference between L and A is equal to or less than 62, and equal to or more than or not 2. If condition 5 is satisfied, then go to step 5.3, otherwise go to step 5.4.

Variable diff=maxAB-minAB

diff <=62 AND diff >=2 (condition 5)

4.2. In this case, only one of L and A represents the angular mode. Go to stage 5.5

5. Construction of a general list of probable modes

5.1. List construction 1

mpm[0]=L

mpm[1]=L-1

mpm[2]=L+1

mpm[3]=DC_idx

mpm[4]=L-2

5.2. List construction 2

mpm[1]=DC_idx

mpm[2]=Vertical_idx

mpm[3]=Horizontal_idx

mpm[4]=Vertical_idx-4

mpm[5]=Vertical_idx+4

5.3. List construction 3

mpm[0]=L

mpm[1]=A

mpm[2]=DC_idx

mpm[3]=maxAB-1

mpm[4]=maxAB+1

5.4. List construction 4

mpm[0]=L

mpm[1]=A

mpm[2]=DC_idx

mpm[3]=maxAB-2

mpm[4]=maxAB+2

5.5. List construction 5

mpm[0]=maxAB

mpm[1]=DC_idx

mpm[2]=maxAB-1

mpm[3]=maxAB+1

mpm[4]=maxAB-2

In step 5, inner angular mode+1, inner angular mode - 1, and inner angular mode - 2 do not represent simple mathematical addition or subtraction of values. In some cases, through subtraction and summation of corner modes, one may become a non-corner mode that breaks the consistency of an adjacent internal mode, or one may exceed the maximum available internal mode index. For example, an internal angular mode minus 1 should result in an internal mode of 1, which is the DC index. Plus one to an internal angular mode of 66 must result in 67, which is greater than the maximum available internal mode of 66. Therefore, addition and subtraction are limited to the use of modular arithmetic (denoted by %) as explained below.

- Internal mode - 1 is:

(Internal mode+61)%64+2

- Internal mode+1 is:

(Internal mode - 1)%64+2

- Internal mode - 2 is:

(Internal mode+60)%64+2

- Internal mode+2 is:

(Internal mode)%64+2

[175] Meanwhile, the exemplary embodiment is not limited to performing integrated intra-luminance encoding only when the integrated MPM flag is transmitted in the signaling and the value of the signaling MPM flag is 1. For example, not even without transmission in the signaling signals of the integrated MPM flag, the decoding equipment according to the exemplary embodiment may perform integrated internal encoding of the luminance signals.

[176] In an exemplary embodiment, integrated intra-prediction signaling and intra-mode signaling can be combined with MPM list configuration, and a non-MPM list can be configured. The present exemplary embodiment may be based on the encoding unit syntax of Table 7 below.

[177]

Table 7 coding_unit(x0, y0, cbWidth, cbHeight, treeType) { Descriptor ... if(treeType==SINGLE_TREE | | treeType==DUAL_TREE_LUMA) { if((y0% CtbSizeY)>0) intra_luma_ref_idx[x0][y0] ae(v) if (intra_luma_ref_idx[x0][y0]==0 andand
(cbWidth<=MaxTbSizeY | | cbHeight<=MaxTbSizeY) andand
(cbWidth*cbHeight>MinTbSizeY*MinTbSizeY)) intra_subpartitions_mode_flag[x0][y0] ae(v) if(intra_subpartitions_mode_flag[x0][y0]==1 andand
cbWidth<=MaxTbSizeY andand cbHeight<=MaxTbSizeY) intra_subpartitions_split_flag[x0][y0] ae(v) if(intra_luma_ref_idx[x0][y0]==0 andand
intra_subpartitions_mode_flag[x0][y0]==0) intra_luma_mpm_flag[x0][y0] ae(v) if(intra_luma_mpm_flag[x0][y0]) intra_planar_flag[x0][y0] ae(v) if(intra_planar_flag==0) intra_luma_mpm_idx[x0][y0] ae(v) else intra_luma_mpm_remainder[x0][y0] ae(v) } ... }

[178] The encoding unit syntax of Table 7 may be based, for example, on the semantics of Table 8 below.

[179] Tab. 8

- intra_luma_mpm_flag[x0][y0], intra_planar_flag[x0][y0], intra_luma_mpm_idx[x0][y0] and intra_luma_mpm_remainder[x0][y0] indicate the intra-prediction mode for luma samples. The array indices x0, y0 indicate the location (x0, y0) of the upper left luminance signal sample of the encoding block in question relative to the upper left luminance signal sample of the movie frame. When intra_luma_mpm_flag[x0][y0] is 1, intra_planar_flag is parsed. When intra_planar_flag is 1, it indicates that the variable IntraPredModeY[xCb][yCb] is equal to INTRA_PLANAR. When intra_planar_flag is 0, the intra-prediction mode is inferred from the adjacent intra-planar encoding unit according to section 8.4.2.

When bcw_idx[x0][y0] is not present, it may be logically inferred to be 1.

[180] In an example, the decoding process for a coding unit that is encoded in the intra prediction mode may be based on the algorithm (or specification) of Table 9 below.

[181] Tab. 9

8.4.1. General decoding process for coding units encoded in intra prediction mode

- If pcm_flag[xCb][yCb] is 0, the following applies:

1. If intra_planar_flag[x0][y0] is equal to 1, IntraPredModeY[xCb][yCb] is equal to INTRA_PLANAR.

2. Otherwise, the extraction process for the intra-prediction mode of luminance signals, as specified in section 8.4.2, is activated with the location (xCb, yCb) of the luminance signal, the width cbWidth of the current encoding block in the luminance signal samples, and the height cbHeight of the current encoding block in samples the luminance signal as input. The output is IntraPredModeY[xCb][yCb], indicating the internal prediction mode of luminance signals.

With the extraction of IntraPredModeY[xCb][yCb] in the previous steps, the general decoding process for internal blocks, as specified in section 8.4.4.1, is activated with the location (xCb, yCb) of the luma signal, the treeType of the tree, the variable nTbW set to cbWidth, the variable nTbH set to cbHeight, the variable predModeIntra set to IntraPredModeY[xCb][yCb], and the variable cIdx set to 0 as inputs, and the output is the modified reconstructed frame before in-loop filtering.

Syntactic elements and associated binary conversions

Syntactic structure Syntactic element Conversion to binary form Process Input parameters coding_unit() intra_planar_flag[][] FL cMax=1

Assigning ctxInc to syntax elements with context-encoded permission elements

Case I

Syntactic element binIdx 0 1 2 3 4 >=5 intra_planar_flag[][] 0 n/a n/a n/a n/a n/a

Case II

The purpose of ctxInc is specified as follows using condL and condA specified for the syntax element intra_planar_flag [x0][y0]

- ctxInc=(condL andand availableL) || (conA andand availableA) or ctxInc=(condL andand availableL) andand (conA andand availableA)

- condL==PLANAR ? 10

- condA==PLANAR ? 10

-availableL, indicating the availability of the block located immediately to the left of the current block.

-availableA, indicating the availability of the block immediately to the left of the current block.

-

Syntactic element binIdx 0 1 2 3 4 >=5 intra_planar_flag[][] 0, 1 n/a n/a n/a n/a n/a

Case III

The purpose of ctxInc is specified as follows using condL and condA specified for the syntax element intra_planar_flag [x0][y0]

- ctxInc=(condL andand availableL)+(conA andand availableA)

- condL==PLANAR? 10

- condA==PLANAR? 10

-availableL, indicating the availability of the block located immediately to the left of the current block.

-availableA, indicating the availability of the block immediately to the left of the current block.

Syntactic element binIdx 0 1 2 3 4 >=5 intra_planar_flag[][] 0, 1, 2 n/a n/a n/a n/a n/a

The above embodiment (Case I, Case II and Case III) is only one practical example, the number of context models can be arbitrarily determined.

[182] In an example, the process for extracting the intra-prediction mode of luminance signals may be based on the algorithm (or specification) of Table 10 below.

[183] Tab. 10

8.4.2. Extraction process for intraprediction mode of luminance signals

Extraction process for intraprediction mode of luminance signals

The inputs to this process are as follows:

- luminance signal location (xCb, yCb) indicating the upper left sample of the current luminance encoding block relative to the upper left luminance signal sample of the current frame,

- cbWidth variable indicating the width of the current encoding block in luminance signal samples,

- cbHeight variable indicating the height of the current encoding block in luma samples.

In this process, the internal prediction mode of luminance signals IntraPredModeY[xCb][yCb] is extracted.

Table 8-1 indicates the value for the internal prediction mode IntraPredModeY[xCb][yCb] and associated names.

Table 8. Specification of internal forecasting mode and associated names

Internal prediction mode Associated title 0 INTRA_PLANAR 1 INTRA_DC 2...66 INTRA_ANGULAR2...INTRA_ANGULAR66 81...83 INTRA_LT_CCLM, INTRA_L_CCLM, INTRA_T_CCLM

Note: The INTRA_LT_CCLM, INTRA_L_CCLM and INTRA_T_CCLM intra prediction modes are only applicable to chrominance signal components.

IntraPredModeY[xCb][yCb] is retrieved through the following ordered steps:

1. Neighboring locations (xNbA, yNbA) and (xNbB, yNbB) are set to (xCb-1, yCb+cbHeight-1) and (xCb+cbWidth-1, yCb-1), respectively.

2. To replace X by A or by B, the candIntraPredModeX variables are retrieved as follows:

- The process of retrieving availability for a block, as specified in section 6.4. X [Ed. (BB): Neighbor Block Availability Process, TBD] is activated with location (xCurr, yCurr) set to (xCb, yCb) and neighbor location (xNbY, yNbY) set to (xNbX, yNbX) as inputs, and the output is assigned, for example, availabl,

- A possible variant of the internal prediction mode candIntraPredModeX is retrieved as follows:

- If one or more of the following conditions are true, candIntraPredModeX is set to INTRA_PLANAR.

- The availableX variable is false.

- CuPredMode[xNbX][yNbX] is not equal to MODE_INTRA

- pcm_flag[xNbX][yNbX] is equal to 1.

- X is equal to B, and yCb-1 is less than ((yCb>>CtbLog2SizeY)<<CtbLog2SizeY).

- Otherwise, candIntraPredModeX is set to IntraPredModeY[xNbX][yNbX].

3. candModeList[x] with x=0...4 is retrieved as follows:

- If candIntraPredModeB is equal to candIntraPredModeA, and candIntraPredModeA is greater than INTRA_DC, candModeList[x] with x=0...4 is retrieved as follows:

candModeList[0]=candIntraPredModeA (8-10)

candModeList[1]=2+((candIntraPredModeA+61)%64) (8-12)

candModeList[2]=2+((candIntraPredModeA-1)%64) (8-13)

candModeList[3]=INTRA_DC (8-11)

candModeList[4]=2+((candIntraPredModeA+60)%64) (8-14)

- Otherwise, if candIntraPredModeB is not equal to candIntraPredModeA, and candIntraPredModeA or candIntraPredModeB exceeds INTRA_DC, the following applies:

- Variables minAB and maxAB are retrieved as follows:

minAB=Min(candIntraPredModeA, candIntraPredModeB) (8-24)

maxAB=Max(candIntraPredModeA, candIntraPredModeB) (8-25)

- If candIntraPredModeA and candIntraPredModeB are greater than INTRA_DC, candModeList[x] with x=0...4 is retrieved as follows:

candModeList[0]=candIntraPredModeA (8-27)

candModeList[1]=candIntraPredModeB

candModeList[2]=INTRA_DC (8-29)

- If maxAB minAB is in the range 2-62, inclusive, the following applies:

candModeList[3]=2+((maxAB+61)%64) (8-30)

candModeList[4]=2+((maxAB-1)%64) (8-31)

- Otherwise, the following applies:

candModeList[3]=2+((maxAB+60)%64) (8-32)

candModeList[4]=2+((maxAB)%64) (8-33)

- Otherwise (candIntraPredModeA or candIntraPredModeB exceeds INTRA_DC), candModeList[x] with x=0...4 is retrieved as follows:

candModeList[0]=maxAB (8-65)

candModeList[1]=INTRA_DC (8-66)

candModeList[2]=2+((maxAB+61)%64) (8-66)

candModeList[3]=2+((maxAB-1)%64) (8-67)

candModeList[4]=2+((maxAB+60)%64) (8-68)

- Otherwise, the following applies:

candModeList[0]=INTRA_DC (8-71)

candModeList[1]=INTRA_ANGULAR50 (8-72)

candModeList[2]=INTRA_ANGULAR18 (8-73)

candModeList[3]=INTRA_ANGULAR46 (8-74)

candModeList[4]=INTRA_ANGULAR54 (8-75)

(8-81)

-

4. IntraPredModeY[xCb][yCb] is retrieved by applying the following procedure:

- If intra_luma_mpm_flag[xCb][yCb] is equal to 1, IntraPredModeY[xCb][yCb] is set to candModeList [intra_luma_mpm_idx[xCb][yCb]].

- Otherwise, IntraPredModeY[xCb][yCb] is retrieved by applying the following ordered steps:

1. When candModeList[i] exceeds candModeList[j] for i=0...4 and for each i, j=(i+1)...5, both values are rearranged as follows:

(candModeList[i], candModeList[j]) = Swap(candModeList[i], candModeList[j]) (8-94)

2. IntraPredModeY[xCb][yCb] is retrieved through the following ordered steps:

i. IntraPredModeY[xCb][yCb] is set to intra_luma_mpm_remainder[xCb][yCb].

ii. For i equal to 0-5, inclusive, when IntraPredModeY[xCb][yCb] is greater than or equal to candModeList[i], the value of IntraPredModeY[xCb][yCb] is incremented by one.

The variable IntraPredModeY[x][y] with x=xCb...xCb+cbWidth-1 and y=yCb...yCb+cbHeight-1 is set to IntraPredModeY[xCb][yCb].

[184] In an example, the decoding process for internal blocks may be based on the algorithm (or specification) of Table 11 below.

[185] Tab. eleven

8.4.4.17. General decoding process for indoor units

...

- For xPartIdx=0...numPartsX-1 and yPartIdx=0...numPartsY-1, the following applies:

The general intra sample prediction process as specified in section 8.4.4.2.1 is activated with location (xTbCmp, yTbCmp) set to (xTb0+nW*xPartIdx, yTb0+nH*yPartIdx), intra prediction mode predModeIntra, width nTbW and height nTbH of the transform block set to nW and nH, the width nCbW and height nCbH of the encoding block set to nTbW and nTbH, and the variable cIdx as inputs, and the output is an array predSamples (nTbW)x(nTbH).

[186] In an example, internal sample prediction may be based on the algorithm (or specification) of Table 12 below.

[187] Tab. 12

8.4.4.2.1. General internal sample forecasting

The internal sample forecasting process according to predModeIntra is applied as follows:

- If predModeIntra is INTRA_PLANAR, the corresponding intra prediction mode-based process specified in section 8.4.4.2.5 is activated with transform block width nTbW and transform block height nTbH, intra prediction reference line index refIdx and reference sample array p as inputs, and the output is an array of predSamples of predicted samples.

- Otherwise, if predModeIntra is equal to INTRA_DC, the corresponding intra prediction mode-based process specified in section 8.4.4.2.6 is activated with transform block width nTbW, transform block height nTbH, intra prediction reference line index refIdx and reference sample array p as inputs, and the output is an array of predSamples of predicted samples.

- Otherwise, if predModeIntra is equal to INTRA_LT_CCLM, INTRA_L_CCLM or INTRA_T_CCLM, the corresponding intra prediction mode-based process specified in section 8.4.4.2.8 is activated with predModeIntra intra prediction mode, sample location (xTbC, yTbC) set to (xTbCmp , yTbCmp), width nTbW and height nTbH of the transform block and an array of p reference samples as inputs, and the output is an array of predSamples of predicted samples.

- Otherwise, the corresponding intra prediction mode-based process specified in section 8.4.4.2.7 is activated with intra prediction mode predModeIntra, intra prediction reference line index refIdx, transform block width nTbW, transform block height nTbH, reference sample width refW , reference sample height refH, encoding block width nCbW and height nCbH, color component index cIdx and reference sample array p as inputs, and the modified intra prediction mode predModeIntra and predicted sample array predSamples as outputs.

[188] In the example, internal planar mode, internal DC mode, etc. may be based on the algorithm (or specification) in Table 13 below.

[189] Tab. 13

8.4.4.2.5. Specification of INTRA_PLANAR internal forecasting mode

Specification of INTRA_PLANAR internal forecasting mode

The inputs to this process are as follows:

- nTbW variable indicating the width of the conversion block,

- nTbH variable indicating the height of the transformation block,

- refIdx variable indicating the index of the internal forecasting reference line,

- adjacent samples p[x][y], with x=-1-refIdx, y=-1-refIdx...nTbH and x=-refIdx...nTbW, y=-1-refIdx.

The outputs of this process are the predicted samples predSamples[x][y], with x=0...nTbW-1, y=0...nTbH-1.

The variables nW and nH are retrieved as follows:

nW=Max(nTbW, 2) (8-116)

nH=Max(nTbH, 2) (8-117)

The values of the predictive samples predSamples[x][y], with x=0...nTbW-1 and y=0...nTbH-1, are extracted as follows: predV[x][y]=((nH-1- y)*p[x][-1-refIdx]+(y+1)*p[-1-refIdx][nTbH])<<Log2(nW) (8-118)

predH[x][y]=((nW-1-x)*p[-1-refIdx][y]+(x+1)*p[nTbW][-1-refIdx])<<Log2(nH ) (8-119)

predSamples[x][y]=(predV[x][y]+predH[x][y]+nW*nH)>>(Log2(nW)+Log2(nH)+1) (8-120)

8.4.4.2.6. INTRA_DC Intra Prediction Mode Specification

The inputs to this process are as follows:

- nTbW variable indicating the width of the conversion block,

- nTbH variable indicating the height of the transformation block,

- refIdx variable indicating the index of the internal forecasting reference line,

- adjacent samples p[x][y], with x=-1-refIdx, y=-1-refIdx...nTbH-1 and x=-refIdx...nTbW-1, y=-1-refIdx.

The outputs of this process are the predicted samples predSamples[x][y], with x=0...nTbW-1, y=0...nTbH-1.

The values of the predictive samples predSamples[x][y], with x=0...nTbW-1, y=0...nTbH-1, are extracted through the following ordered steps:

1. The dcVal variable is retrieved as follows:

- When nTbW is equal to nTbH:

- dcVal (8-121)

- When nTbW is greater than nTbH:

- dcVal (8-122)

- When nTbW is less than nTbH:

- dcVal (8-123)

2. Predictive samples predSamples[x][y] are retrieved as follows:

predSamples[x][y]=dcVal, with x=0...nTbW-1, y=0...nTbH-1 (8-124)

[190] In the example, a process for converting scaled transform coefficients and the like. may be based on the algorithm (or specification) in Table 14 below.

[191] Tab. 14

8.7.4.1. Conversion Process for Scaled Conversion Factors

Table 8-15. Specification of trTypeHor and trTypeVer depending on predModeIntra predModeIntra trTypeHor trTypeVer INTRA_PLANAR,
INTRA_ANGULAR31,
INTRA_ANGULAR32,
INTRA_ANGULAR34,
INTRA_ANGULAR36,
INTRA_ANGULAR37 (nTbW>=4 andand
- nTbW<=16)? 10 (nTbH>=4 andand
- nTbH<=16)? 10 INTRA_DC,
INTRA_ANGULAR33,
INTRA_ANGULAR35 0 0 INTRA_ANGULAR2,
INTRA_ANGULAR4, ..., INTRA_ANGULAR28,
INTRA_ANGULAR30,
INTRA_ANGULAR39,
INTRA_ANGULAR41, ..., INTRA_ANGULAR63,
INTRA_ANGULAR65 (nTbW>=4 andand
- nTbW<=16)? 10 0 INTRA_ANGULAR3,
INTRA_ANGULAR5, ..., INTRA_ANGULAR27,
INTRA_ANGULAR29,
INTRA_ANGULAR38,
INTRA_ANGULAR40, ..., INTRA_ANGULAR64,
INTRA_ANGULAR66 0 (nTbH>=4 andand
- nTbH<=16)? 10

Table 9-5. Associating ctxIdxOffset and syntax elements for each initializationType during initialization Syntactic structure Syntactic element ctxTable initType 0 1 2 coding_tree_unit() alf_ctb_flag[][][] Table 9-6 0 9 18

...

coding_unit cu_skip_flag[][] 0 3 pred_mode_ibc_flag pred_mode_flag intra_luma_ref_idx[][] intra_subpartitions_mode_flag intra_subpartition_split_flag intra_luma_mpm_flag[][] intra_planar_flag[][] intra_chroma_pred_mode[][] merge_flag[][] inter_pred_idc[x0][y0] inter_affine_flag[][] cu_affine_type_flag[][] ref_idx_l0[][] mvp_l0_flag[][] ref_idx_l1[][] mvp_l1_flag[][] avmr_flag[][] amvr_precision_flag[][] gbi_idx[][] cu_cbf cu_sbt_flag cu_sbt_quad_flag cu_sbt_horizontal_flag cu_sbt_pos_flag

Table 9.9. Syntactic elements and associated binary conversions Syntactic structure Syntactic element Conversion to binary form Process Input parameters coding_unit() cu_skip_flag[][] FL cMax=1 pred_mode_ibc_flag FL cMax=1 pred_mode_flag FL cMax=1 pcm_flag[][] FL cMax=1 intra_luma_ref_idx[][] TR cMax=2, cRiceParam=0 intra_subpartitions_mode_flag FL cMax=1 intra_subpartition_split_flag FL cMax=1 intra_luma_mpm_flag[][] FL cMax=1 intra_planar_flag[][] FL cMax=1 intra_luma_mpm_idx[][] TR cMax=4, cRiceParam=0 intra_luma_mpm_remainder[][] TB cMax=60 intra_chroma_pred_mode[][] 9.5.3.8 - merge_flag[][] FL cMax=1 inter_pred_idc[x0][y0] 9.5.3.9 cbWidth, cbHeight inter_affine_flag[][] FL cMax=1 cu_affine_type_flag[][] FL cMax=1 ref_idx_l0[][] TR cMax=NumRefIdxActive[0]-1, cRiceParam=0 mvp_l0_flag[][] FL cMax=1 ref_idx_l1[][] TR cMax=NumRefIdxActive[1]-1, cRiceParam=0 mvp_l1_flag[][] FL cMax=1 avmr_flag[][] FL cMax=1 amvr_precision_flag[][] FL cMax=1 gbi_idx[][] TR cMax=NoBackwardPredFlag? 4:2 cu_cbf FL cMax=1 cu_sbt_flag FL cMax=1 cu_sbt_quad_flag FL cMax=1 cu_sbt_horizontal_flag FL cMax=1 cu_sbt_pos_flag FL cMax=1

[192] In an example, an example of assigning ctxInc for syntax elements including context-encoded permission elements may be based on Table 15 below.

[193]

Table 15 Syntactic element binIdx 0 1 2 3 4 >=5 intra_luma_ref_idx[][] 0 1 n/a n/a n/a n/a intra_subpartitions_mode_flag 0 n/a n/a n/a n/a n/a intra_subpartition_split_flag 0 n/a n/a n/a n/a n/a intra_luma_mpm_flag[][] 0 n/a n/a n/a n/a n/a intra_planar_flag[][] intra_luma_ref_idx!=0? 2:
(intra_subpartitions_mode_flag? 0:1) n/a n/a n/a n/a n/a intra_luma_mpm_idx[][] bypass bypass bypass bypass bypass n/a intra_luma_mpm_remainder[][] bypass bypass bypass bypass bypass bypass intra_chroma_pred_mode[][]
- sps_cclm_enabled_flag==0 0 bypass bypass n/a n/a n/a

[194] Referring to Table 7, it can be confirmed that intra_planar_flag is decoded based on the decoding result that the value of intra_luma_mpm_flag is 1; intra_luma_mpm_flag may represent an example of an MPM flag, and intra_planar_flag may represent an example of a planar flag.

[195] Referring to (8-10), (8-12) and (8-13) from Table 10, it can be confirmed that of the possible MPM options included in the MPM list, candModeList[0] is defined as candIntraPredModeA representing the internal prediction mode for the left neighboring block with respect to the current block, candModeList[1] is defined as 2+((candIntraPredModeA+61)%64), and candModeList[2] is defined as 2+(candIntraPredModeA-1) %64).

[196] Referring to Table 14, it can be confirmed that cMax representing the maximum value of intra_luma_mpm_idx is determined to be 4.

[197] An exemplary embodiment provides a method for performing integrated MPM prediction and a method for encoding and/or signaling information regarding associated intra prediction modes. Additionally, an exemplary embodiment provides a method for extracting a transformation kernel. According to an exemplary embodiment, the coding unit syntax expressed in Tables 16 to 24 below can be configured/encoded and signaled to decoding equipment, and the decoding equipment can extract an intra prediction mode for the current block (CU) based on the coding unit syntax and MPM list.

[198] For example, according to the present exemplary embodiment, the planar mode may be included in the MPM list as a possible mode option, and when the value of the MPM flag is 1, the planar flag (intra_planar_flag) may be first signaled to indicate that Whether or not planar mode is used as the intra-prediction mode of the current block. If the value of the planar flag is 0, the MPM index (intra_luma_mpm_idx) may be signaled to indicate one of the remaining possible MPM options other than planar mode. At this time, in the example, the MPM list including the remaining options other than the planar mode may be called a "modified MPM list".

[199] If the total number of possible MPM options that include planar mode is 6, the total number of possible options in the modified MPM list other than planar mode may be 5, in which case, the MPM index values may be equal to 0-4. Thus, the maximum MPM index value may be set to 4. At this time, the maximum MPM index value may be represented as cMax MPM index. The planar flag resolution element may be regularly encoded based on the context model, as described below in Tables 16-24, and as described below in Tables 16-24, ctxInc to indicate the context model i) may use only one specific value (e.g., 0), ii) may be variably retrieved based on whether the left neighbor block is available or not, and/or whether the top neighbor block is available or not, and the value of the planar flag (if available), or iii) may also have a value variably determined depending on whether or not MRLs or ISPs apply. Additionally, the present exemplary embodiment may extract a transform kernel (vertical transform kernel/horizontal transform kernel) for the current block based on the size and/or intra prediction type/mode of the current block. For example, as described below in Tables 16-24, if the ISP is not applied to the current block or is not available, a transformation core (vertical transformation core/horizontal transformation core) may be retrieved as a value of 1 or 0 further with reference to the size of the current block.

[200] According to the present exemplary embodiment, if internal MRL prediction is applied (ie, if the MRL index is greater than 0), planar mode or DC mode may be applied to the current block, and if internal ISP prediction is also applied, planar mode or DC mode can be applied to the current block. Accordingly, the MPM list can be configured based on the integrated MPM prediction whether or not MRL, ISP, etc. are applied. Tables 16-24 are provided below, and the details of Tables 16-24 should be easily understood by those skilled in the art.

[201] Table 16 below expresses an example of the syntax of a coding unit.

[202]

Table 16 coding_unit(x0, y0, cbWidth, cbHeight, treeType) { Descriptor ... if(treeType==SINGLE_TREE | | treeType==DUAL_TREE_LUMA) { if((y0% CtbSizeY)>0) intra_luma_ref_idx[x0][y0] ae(v) if (intra_luma_ref_idx[x0][y0]==0 andand
(cbWidth<=MaxTbSizeY | | cbHeight<=MaxTbSizeY) andand
(cbWidth*cbHeight>MinTbSizeY*MinTbSizeY)) intra_subpartitions_mode_flag[x0][y0] ae(v) if(intra_subpartitions_mode_flag[x0][y0]==1 andand
cbWidth<=MaxTbSizeY andand cbHeight<=MaxTbSizeY) intra_subpartitions_split_flag[x0][y0] ae(v) if(intra_luma_ref_idx[x0][y0]==0 andand
intra_subpartitions_mode_flag[x0][y0]==0) intra_luma_mpm_flag[x0][y0] ae(v) if(intra_luma_mpm_flag[x0][y0]) intra_planar_flag[x0][y0] ae(v) if(intra_planar_flag==0) intra_luma_mpm_idx[x0][y0] ae(v) Else intra_luma_mpm_remainder[x0][y0] ae(v) } ... }

[203] The syntax of the encoding unit of table 16 may be based, for example, on the semantics of table 17 below.

[204] Tab. 17

- intra_luma_mpm_flag[x0][y0], intra_planar_flag[x0][y0], intra_luma_mpm_idx[x0][y0] and intra_luma_mpm_remainder[x0][y0] indicate the intra-prediction mode for luma samples. The array indices x0, y0 indicate the location (x0, y0) of the upper left luminance signal sample of the encoding block in question relative to the upper left luminance signal sample of the movie frame. When intra_luma_mpm_flag[x0][y0] is 1, intra_planar_flag is parsed. When intra_planar_flag is 1, it indicates that the variable IntraPredModeY[xCb][yCb] is equal to INTRA_PLANAR. When intra_planar_flag is 0, the intra-prediction mode is inferred from the adjacent intra-planar encoding unit according to section 8.4.2.

When bcw_idx[x0][y0] is not present, it may be logically inferred to be 1.

[205] In an example, the decoding process for coding units that are encoded in the intra prediction mode may be based on the algorithm (or specification) of Table 18 below.

[206] Tab. 18

8.4.1. General decoding process for coding units encoded in intra prediction mode

- If pcm_flag[xCb][yCb] is 0, the following applies:

1. If intra_planar_flag[x0][y0] is equal to 1, IntraPredModeY[xCb][yCb] is equal to INTRA_PLANAR.

2. Otherwise, the extraction process for the intra-prediction mode of luminance signals, as specified in section 8.4.2, is activated with the location (xCb, yCb) of the luminance signal, the width cbWidth of the current encoding block in the luminance signal samples, and the height cbHeight of the current encoding block in samples the luminance signal as input. The output is IntraPredModeY[xCb][yCb], indicating the internal prediction mode of luminance signals.

With the extraction of IntraPredModeY[xCb][yCb] in the previous steps, the general decoding process for internal blocks, as specified in section 8.4.4.1, is activated with the location (xCb, yCb) of the luma signal, the treeType of the tree, the variable nTbW set to cbWidth, the variable nTbH set to cbHeight, the variable predModeIntra set to IntraPredModeY[xCb][yCb], and the variable cIdx set to 0 as inputs, and the output is the modified reconstructed frame before in-loop filtering.

Syntactic elements and associated binary conversions

Syntactic structure Syntactic element Conversion to binary form Process Input parameters coding_unit() intra_planar_flag[][] FL cMax=1

Assigning ctxInc to syntax elements with context-encoded permission elements

Case I

Syntactic element binIdx 0 1 2 3 4 >=5 intra_planar_flag[][] 0 n/a n/a n/a n/a n/a

Case II

The purpose of ctxInc is specified as follows using condL and condA specified for the syntax element intra_planar_flag [x0][y0]

- ctxInc=(condL andand availableL) || (conA andand availableA) or ctxInc=(condL andand availableL) andand (conA andand availableA)

- condL==PLANAR? 10

- condA==PLANAR? 10

-availableL, indicating the availability of the block located immediately to the left of the current block.

-availableA, indicating the availability of the block immediately to the left of the current block.

-

Syntactic element binIdx 0 1 2 3 4 >=5 intra_planar_flag[][] 0, 1 n/a n/a n/a n/a n/a

Case III

The purpose of ctxInc is specified as follows using condL and condA specified for the syntax element intra_planar_flag [x0][y0]

- ctxInc=(condL andand availableL)+(conA andand availableA)

- condL==PLANAR? 10

- condA==PLANAR? 10

-availableL, indicating the availability of the block located immediately to the left of the current block.

-availableA, indicating the availability of the block immediately to the left of the current block.

Syntactic element binIdx 0 1 2 3 4 >=5 intra_planar_flag[][] 0, 1, 2 n/a n/a n/a n/a n/a

The above embodiment (Case I, Case II and Case III) is only one practical example, the number of context models can be arbitrarily determined.

[207] In an example, the extraction process for the intra-prediction mode of luminance signals may be based on the algorithm (or specification) of Table 19 below.

[208] Tab. 19

8.4.2. Extraction process for intraprediction mode of luminance signals

Extraction process for intraprediction mode of luminance signals

The inputs to this process are as follows:

- luminance signal location (xCb, yCb) indicating the upper left sample of the current luminance encoding block relative to the upper left luminance signal sample of the current frame,

- cbWidth variable indicating the width of the current encoding block in luminance signal samples,

- cbHeight variable indicating the height of the current encoding block in luma samples.

In this process, the internal prediction mode of luminance signals IntraPredModeY[xCb][yCb] is extracted.

Table 8-1 indicates the value for the internal prediction mode IntraPredModeY[xCb][yCb] and associated names.

Table 8. Specification of internal forecasting mode and associated names Internal prediction mode Associated title 0 INTRA_PLANAR 1 INTRA_DC 2...66 INTRA_ANGULAR2...INTRA_ANGULAR66 81...83 INTRA_LT_CCLM, INTRA_L_CCLM, INTRA_T_CCLM

Note: The INTRA_LT_CCLM, INTRA_L_CCLM and INTRA_T_CCLM intra prediction modes are only applicable to chrominance signal components.

IntraPredModeY[xCb][yCb] is retrieved through the following ordered steps:

1. Neighboring locations (xNbA, yNbA) and (xNbB, yNbB) are set to (xCb-1, yCb+cbHeight-1) and (xCb+cbWidth-1, yCb-1), respectively.

2. To replace X by A or by B, the candIntraPredModeX variables are retrieved as follows:

- The process of retrieving availability for a block, as specified in section 6.4. X [Ed. (BB): Neighbor Block Availability Process, TBD] is activated with location (xCurr, yCurr) set to (xCb, yCb) and neighbor location (xNbY, yNbY) set to (xNbX, yNbX) as inputs, and the output is assigned, for example, availabl,

- A possible variant of the internal prediction mode candIntraPredModeX is retrieved as follows:

- If one or more of the following conditions are true, candIntraPredModeX is set to INTRA_PLANAR.

- The availableX variable is false.

- CuPredMode[xNbX][yNbX] is not equal to MODE_INTRA

- pcm_flag[xNbX][yNbX] is equal to 1.

- X is equal to B, and yCb-1 is less than ((yCb>>CtbLog2SizeY)<<CtbLog2SizeY).

- Otherwise, candIntraPredModeX is set to IntraPredModeY[xNbX][yNbX].

3. candModeList[x] with x=0...4 is retrieved as follows:

- If candIntraPredModeB is equal to candIntraPredModeA, and candIntraPredModeA is greater than INTRA_DC, candModeList[x] with x=0...4 is retrieved as follows:

candModeList[0]=candIntraPredModeA (8-10)

candModeList[1]=2+((candIntraPredModeA+61)%64) (8-12)

candModeList[2]=2+((candIntraPredModeA-1)%64) (8-13)

candModeList[3]=INTRA_DC (8-11)

candModeList[4]=2+((candIntraPredModeA+60)%64) (8-14)

- Otherwise, if candIntraPredModeB is not equal to candIntraPredModeA, and candIntraPredModeA or candIntraPredModeB exceeds INTRA_DC, the following applies:

- Variables minAB and maxAB are retrieved as follows:

minAB=Min(candIntraPredModeA, candIntraPredModeB) (8-24)

maxAB=Max(candIntraPredModeA, candIntraPredModeB) (8-25)

- If candIntraPredModeA and candIntraPredModeB are greater than INTRA_DC, candModeList[x] with x=0...4 is retrieved as follows:

candModeList[0]=candIntraPredModeA (8-27)

candModeList[1]=candIntraPredModeB

candModeList[2]=INTRA_DC (8-29)

- If maxAB minAB is in the range 2-62, inclusive, the following applies:

candModeList[3]=2+((maxAB+61)%64) (8-30)

candModeList[4]=2+((maxAB-1)%64) (8-31)

- Otherwise, the following applies:

candModeList[3]=2+((maxAB+60)%64) (8-32)

candModeList[4]=2+((maxAB)%64) (8-33)

- Otherwise (candIntraPredModeA or candIntraPredModeB exceeds INTRA_DC), candModeList[x] with x=0...4 is retrieved as follows:

candModeList[0]=maxAB (8-65)

candModeList[1]=INTRA_DC (8-66)

candModeList[2]=2+((maxAB+61)%64) (8-66)

candModeList[3]=2+((maxAB-1)%64) (8-67)

candModeList[4]=2+((maxAB+60)%64) (8-68)

- Otherwise, the following applies:

candModeList[0]=INTRA_DC (8-71)

candModeList[1]=INTRA_ANGULAR50 (8-72)

candModeList[2]=INTRA_ANGULAR18 (8-73)

candModeList[3]=INTRA_ANGULAR46 (8-74)

candModeList[4]=INTRA_ANGULAR54 (8-75)

(8-81)

-

4. IntraPredModeY[xCb][yCb] is retrieved by applying the following procedure:

- If intra_luma_mpm_flag[xCb][yCb] is equal to 1, IntraPredModeY[xCb][yCb] is set to candModeList [intra_luma_mpm_idx[xCb][yCb]].

- Otherwise, IntraPredModeY[xCb][yCb] is retrieved by applying the following ordered steps:

1. When candModeList[i] exceeds candModeList[j] for i=0...4 and for each i, j=(i+1)...5, both values are rearranged as follows:

(candModeList[i], candModeList[j]) = Swap(candModeList[i], candModeList[j]) (8-94)

2. IntraPredModeY[xCb][yCb] is retrieved through the following ordered steps:

i. IntraPredModeY[xCb][yCb] is set to intra_luma_mpm_remainder[xCb][yCb].

ii. For i equal to 0-5, inclusive, when IntraPredModeY[xCb][yCb] is greater than or equal to candModeList[i], the value of IntraPredModeY[xCb][yCb] is incremented by one.

The variable IntraPredModeY[x][y] with x=xCb...xCb+cbWidth-1 and y=yCb...yCb+cbHeight-1 is set to IntraPredModeY[xCb][yCb].

[209] In an example, the process for decoding internal blocks may be based on the algorithm (or specification) of Table 20 below.

[210] Tab. 20

8.4.4.1. General decoding process for indoor units

...

- For xPartIdx=0...numPartsX-1 and yPartIdx=0...numPartsY-1, the following applies:

The general intra sample prediction process as specified in section 8.4.4.2.1 is activated with location (xTbCmp, yTbCmp) set to (xTb0+nW*xPartIdx, yTb0+nH*yPartIdx), intra prediction mode predModeIntra, width nTbW and height nTbH of the transform block set to nW and nH, the width nCbW and height nCbH of the encoding block set to nTbW and nTbH, and the variable cIdx as inputs, and the output is an array predSamples (nTbW)x(nTbH).

[211] In an example, the internal sample prediction may be based on the algorithm (or specification) of Table 21 below.

[212] Tab. 21

8.4.4.2.1. General internal sample forecasting

The internal sample forecasting process according to predModeIntra is applied as follows:

- If predModeIntra is INTRA_PLANAR, the corresponding intra prediction mode-based process specified in section 8.4.4.2.5 is activated with transform block width nTbW and transform block height nTbH, intra prediction reference line index refIdx and reference sample array p as inputs, and the output is an array of predSamples of predicted samples.

- Otherwise, if predModeIntra is equal to INTRA_DC, the corresponding intra prediction mode-based process specified in section 8.4.4.2.6 is activated with transform block width nTbW, transform block height nTbH, intra prediction reference line index refIdx and reference sample array p as inputs, and the output is an array of predSamples of predicted samples.

- Otherwise, if predModeIntra is equal to INTRA_LT_CCLM, INTRA_L_CCLM or INTRA_T_CCLM, the corresponding intra prediction mode-based process specified in section 8.4.4.2.8 is activated with predModeIntra intra prediction mode, sample location (xTbC, yTbC) set to (xTbCmp , yTbCmp), width nTbW and height nTbH of the transform block and an array of p reference samples as inputs, and the output is an array of predSamples of predicted samples.

- Otherwise, the corresponding intra prediction mode-based process specified in section 8.4.4.2.7 is activated with intra prediction mode predModeIntra, intra prediction reference line index refIdx, transform block width nTbW, transform block height nTbH, reference sample width refW , reference sample height refH, encoding block width nCbW and height nCbH, color component index cIdx and reference sample array p as inputs, and the modified intra prediction mode predModeIntra and predicted sample array predSamples as outputs.

[213] In the example, internal planar mode, internal DC mode, etc. may be based on the algorithm (or specification) of Table 22 below.

[214] Tab. 22

8.4.4.2.5. Specification of INTRA_PLANAR internal forecasting mode

Specification of INTRA_PLANAR internal forecasting mode

The inputs to this process are as follows:

- nTbW variable indicating the width of the conversion block,

- nTbH variable indicating the height of the transformation block,

- refIdx variable indicating the index of the internal forecasting reference line,

- neighboring samples p[x][y], with x=-1-refIdx, y=-1-refIdx...nTbH and x=-refIdx...nTbW, y=-1-refIdx.

The outputs of this process are the predicted samples predSamples[x][y], with x=0...nTbW-1, y=0...nTbH-1.

The variables nW and nH are retrieved as follows:

nW=Max(nTbW, 2) (8-116)

nH=Max(nTbH, 2) (8-117)

The values of the predictive samples predSamples[x][y], with x=0...nTbW-1 and y=0...nTbH-1, are extracted as follows: predV[x][y]=((nH-1- y)*p[x][-1-refIdx]+(y+1)*p[-1-refIdx][nTbH])<<Log2(nW) (8-118)

predH[x][y]=((nW-1-x)*p[-1-refIdx][y]+(x+1)*p[nTbW][-1-refIdx])<<Log2(nH ) (8-119)

predSamples[x][y]=(predV[x][y]+predH[x][y]+nW*nH)>>(Log2(nW)+Log2(nH)+1) (8-120)

8.4.4.2.6. INTRA_DC Intra Prediction Mode Specification

The inputs to this process are as follows:

- nTbW variable indicating the width of the conversion block,

- nTbH variable indicating the height of the transformation block,

- refIdx variable indicating the index of the internal forecasting reference line,

- neighboring samples p[x][y], with x=-1-refIdx, y=-1-refIdx...nTbH-1 and x=-refIdx...nTbW-1, y=-1-refIdx.

The outputs of this process are the predicted samples predSamples[x][y], with x=0...nTbW-1, y=0...nTbH-1.

The values of the predictive samples predSamples[x][y], with x=0...nTbW-1, y=0...nTbH-1, are extracted through the following ordered steps:

1. The dcVal variable is retrieved as follows:

- When nTbW is equal to nTbH:

- dcVal (8-121)

- When nTbW is greater than nTbH:

- dcVal (8-122)

- When nTbW is less than nTbH:

- dcVal (8-123)

2. Predictive samples predSamples[x][y] are retrieved as follows:

predSamples[x][y]=dcVal, with x=0...nTbW-1, y=0...nTbH-1 (8-124)

[215] In the example, a process for converting scaled transform coefficients and the like. may be based on the algorithm (or specification) in Table 23 below.

[216] Tab. 23

8.7.4.1. Conversion Process for Scaled Conversion Factors

The inputs to this process are as follows:

- luminance signal location (xTbY, yTbY) indicating the top left sample of the current luminance transform block relative to the top left sample of the luminance signal of the current frame,

- nTbW variable indicating the width of the current transformation block,

- nTbH variable indicating the height of the current transformation block,

- cIdx variable indicating the color component of the current block,

- array d[x][y] (nTbW)x(nTbH) of scaled transformation coefficients with x=0...nTbW-1, y=0...nTbH-1.

The output of this process is an array r[x][y] (nTbW)x(nTbH) of residual samples with x=0...nTbW-1, y=0...nTbH-1.

The implicitMtsEnabled variable is retrieved as follows:

- If sps_mts_enabled_flag is 1 and one of the following conditions is true, implicitMtsEnabled is set to 1:

- IntraSubPartitionsSplitType is not equal to ISP_NO_SPLIT

- cu_sbt_flag is 1, and Max(nTbW, nTbH) is less than or equal to 32

- sps_explicit_mts_intra_enabled_flag and sps_explicit_mts_inter_enabled_flag are equal to 0, and CuPredMode[xTbY][yTbY] is equal to MODE_INTRA

- Otherwise, implicitMtsEnabled is set to 0.

The trTypeHor variable indicating the horizontal transformation kernel and the trTypeVer variable indicating the vertical transformation kernel are retrieved as follows:

- If cIdx is greater than 0, trTypeHor and trTypeVer are set to 0.

- Otherwise, if implicitMtsEnabled is 1, the following applies:

- If IntraSubPartitionsSplitType is not equal to ISP_NO_SPLIT or (sps_explicit_mts_intra_enabled_flag, and sps_explicit_mts_inter_enabled_flag are 0), trTypeHor and trTypeVer are retrieved as follows

- trTypeHor=(nTbW>=4 andand nTbW<=16)? 1 : 0 (8-1028)

- trTypeVer=(nTbH>=4 andand nTbH<=16)? 1 : 0 (8-1029)

Otherwise, if cu_sbt_flag is 1, trTypeHor and trTypeVer are specified in Table 8-14 depending on cu_sbt_horizontal_flag and cu_sbt_pos_flag.

Table 9-5. Associating ctxIdxOffset and syntax elements for each initializationType during initialization Syntactic structure Syntactic element ctxTable initType 0 1 2 coding_tree_unit() alf_ctb_flag[][][] Table 9-6 0 9 18

...

coding_unit() cu_skip_flag[][] 0 3 pred_mode_ibc_flag pred_mode_flag intra_luma_ref_idx[][] intra_subpartitions_mode_flag intra_subpartition_split_flag intra_luma_mpm_flag[][] intra_planar_flag[][] intra_chroma_pred_mode[][] merge_flag[][] inter_pred_idc[x0][y0] inter_affine_flag[][] cu_affine_type_flag[][] ref_idx_l0[][] mvp_l0_flag[][] ref_idx_l1[][] mvp_l1_flag[][] avmr_flag[][] amvr_precision_flag[][] gbi_idx[][] cu_cbf cu_sbt_flag cu_sbt_quad_flag cu_sbt_horizontal_flag cu_sbt_pos_flag

Table 9.9. Syntactic elements and associated binary conversions Syntactic structure Syntactic element Conversion to binary form Process Input parameters coding_unit() cu_skip_flag[][] FL cMax=1 pred_mode_ibc_flag FL cMax=1 pred_mode_flag FL cMax=1 pcm_flag[][] FL cMax=1 intra_luma_ref_idx[][] TR cMax=2, cRiceParam=0 intra_subpartitions_mode_flag FL cMax=1 intra_subpartition_split_flag FL cMax=1 intra_luma_mpm_flag[][] FL cMax=1 intra_planar_flag[][] FL cMax=1 intra_luma_mpm_idx[][] TR cMax=4, cRiceParam=0 intra_luma_mpm_remainder[][] TB cMax=60 intra_chroma_pred_mode[][] 9.5.3.8 - merge_flag[][] FL cMax=1 inter_pred_idc[x0][y0] 9.5.3.9 cbWidth, cbHeight inter_affine_flag[][] FL cMax=1 cu_affine_type_flag[][] FL cMax=1 ref_idx_l0[][] TR cMax=NumRefIdxActive[0]-1, cRiceParam=0 mvp_l0_flag[][] FL cMax=1 ref_idx_l1[][] TR cMax=NumRefIdxActive[1]-1, cRiceParam=0 mvp_l1_flag[][] FL cMax=1 avmr_flag[][] FL cMax=1 amvr_precision_flag[][] FL cMax=1 gbi_idx[][] TR cMax=NoBackwardPredFlag? 4:2 cu_cbf FL cMax=1 cu_sbt_flag FL cMax=1 cu_sbt_quad_flag FL cMax=1 cu_sbt_horizontal_flag FL cMax=1 cu_sbt_pos_flag FL cMax=1

[217] In an example, an example of assigning ctxInc for syntax elements including context-encoded permission elements may be based on Table 24 below.

[218]

Table 24 Syntactic element binIdx 0 1 2 3 4 >=5 intra_luma_ref_idx[][] 0 1 n/a n/a n/a n/a intra_subpartitions_mode_flag 0 n/a n/a n/a n/a n/a intra_subpartition_split_flag 0 n/a n/a n/a n/a n/a intra_luma_mpm_flag[][] 0 n/a n/a n/a n/a n/a intra_planar_flag[][] intra_luma_ref_idx!=0? 2:
(intra_subpartitions_mode_flag? 0:1) n/a n/a n/a n/a n/a intra_luma_mpm_idx[][] bypass bypass bypass bypass bypass n/a intra_luma_mpm_remainder[][] bypass bypass bypass bypass bypass bypass intra_chroma_pred_mode[][]
- sps_cclm_enabled_flag==0 0 bypass bypass n/a n/a n/a

[219] An exemplary embodiment provides a method for performing integrated MPM prediction and a method for encoding and/or signaling information regarding associated intra prediction modes. Additionally, an exemplary embodiment provides a method for extracting a transformation kernel. According to an exemplary embodiment, the coding unit syntax expressed in Tables 16 to 24 can be configured/encoded and signaled to the decoding equipment, and the decoding equipment can extract the intra prediction mode for the current block (CU) based on the coding unit syntax and MPM -list.

[220] For example, according to the present exemplary embodiment, the MPM list may include planar mode as a possible mode option, and if the value of the MPM flag is 1, the planar flag (intra_planar_flag) may first be signaled to indicate that , whether or not planar mode is used as the intra-prediction mode of the current block. If the value of the planar flag is 0, the MPM index (intra_luma_mpm_idx) may be signaled to indicate one of the remaining possible MPM options other than planar mode. At this time, in one example, the MPM list including the remaining options other than the planar mode may be referred to as a "modified MPM list."

[221] If the total number of possible MPM options that include planar mode is 6, the total number of possible options in the modified MPM list other than planar mode may be 5, in which case, the MPM index values may be equal to 0-4. Thus, the maximum MPM index value may be set to 4. At this time, the maximum MPM index value may be represented as cMAX MPM index. The planar flag resolution element may be regularly encoded based on the context model, as described below in Tables 25-33, and as described below in Tables 25-33, ctxInc to indicate the context model i) may use only one specific value (e.g., 0), ii) may be variably retrieved based on whether or not the left neighbor block and/or top neighbor block and the value of the planar flag (if available) are available, or iii) may also have a value variably determined depending on whether MRLs are applied or not or ISP. Additionally, according to the present exemplary embodiment, a transform kernel (vertical transform kernel/horizontal transform kernel) for the current block can be extracted based on the size and/or intra prediction type/mode of the current block. For example, as described below in Tables 25-33 below, if the ISP is not applied to the current block or is not available, a transformation core (vertical transformation core/horizontal transformation core) may be retrieved as a value of 1 or 0 additionally with reference to the size of the current block.

[222] According to the present exemplary embodiment, the MPM list can be configured based on the integrated MPM prediction regardless of whether MRL, ISP, or the like is applied. Tables 25-33 are provided below, and the details of Tables 25-33 should be easily understood by those skilled in the art.

[223] Table 25 below expresses an example of the syntax of a coding unit.

[224]

Table 25 coding_unit(x0, y0, cbWidth, cbHeight, treeType) { Descriptor ... if(treeType==SINGLE_TREE | | treeType==DUAL_TREE_LUMA) { if((y0% CtbSizeY)>0) intra_luma_ref_idx[x0][y0] ae(v) if (intra_luma_ref_idx[x0][y0]==0 andand
(cbWidth<=MaxTbSizeY | | cbHeight<=MaxTbSizeY) andand
(cbWidth*cbHeight>MinTbSizeY*MinTbSizeY)) intra_subpartitions_mode_flag[x0][y0] ae(v) if(intra_subpartitions_mode_flag[x0][y0]==1 andand
cbWidth<=MaxTbSizeY andand cbHeight<=MaxTbSizeY) intra_subpartitions_split_flag[x0][y0] ae(v) if(intra_luma_ref_idx[x0][y0]==0 andand
intra_subpartitions_mode_flag[x0][y0]==0) intra_luma_mpm_flag[x0][y0] ae(v) if(intra_luma_mpm_flag[x0][y0]) { if (intra_luma_ref_idx[x0][y0]==0) intra_planar_flag[x0][y0] ae(v) if(intra_planar_flag==0) intra_luma_mpm_idx[x0][y0] ae(v) } Else intra_luma_mpm_remainder[x0][y0] ae(v) } ... }

[225] The syntax of the encoding unit of table 25 may be based, for example, on the semantics of table 26 below.

[226] Tab. 26

- intra_luma_mpm_flag[x0][y0], intra_planar_flag[x0][y0], intra_luma_mpm_idx[x0][y0] and intra_luma_mpm_remainder[x0][y0] indicate the intra-prediction mode for luma samples. The array indices x0, y0 indicate the location (x0, y0) of the upper left luminance signal sample of the encoding block in question relative to the upper left luminance signal sample of the movie frame. When intra_luma_mpm_flag[x0][y0] is 1, intra_planar_flag is parsed. When intra_planar_flag is 1, it indicates that the variable IntraPredModeY[xCb][yCb] is equal to INTRA_PLANAR. When intra_planar_flag is 0, the intra-prediction mode is inferred from the adjacent intra-planar encoding unit according to section 8.4.2.

When bcw_idx[x0][y0] is not present, it may be logically inferred to be 1.

[227] In an example, a process for decoding a coding unit that is encoded in an intra prediction mode may be based on the algorithm (or specification) of Table 27 below.

[228] Tab. 27

8.4.1. General decoding process for coding units encoded in intra prediction mode

- If pcm_flag[xCb][yCb] is 0, the following applies:

1. If intra_planar_flag[x0][y0] is equal to 1, IntraPredModeY[xCb][yCb] is equal to INTRA_PLANAR.

2. Otherwise, the extraction process for the intra-prediction mode of luminance signals, as specified in section 8.4.2, is activated with the location (xCb, yCb) of the luminance signal, the width cbWidth of the current encoding block in the luminance signal samples, and the height cbHeight of the current encoding block in samples the luminance signal as input. The output is IntraPredModeY[xCb][yCb], indicating the internal prediction mode of luminance signals.

With the extraction of IntraPredModeY[xCb][yCb] in the previous steps, the general decoding process for internal blocks, as specified in section 8.4.4.1, is activated with the location (xCb, yCb) of the luma signal, the treeType of the tree, the variable nTbW set to cbWidth, the variable nTbH set to cbHeight, the variable predModeIntra set to IntraPredModeY[xCb][yCb], and the variable cIdx set to 0 as inputs, and the output is the modified reconstructed frame before in-loop filtering.

Syntactic elements and associated binary conversions

Syntactic structure Syntactic element Conversion to binary form Process Input parameters coding_unit() intra_planar_flag[][] FL cMax=1

Assigning ctxInc to syntax elements with context-encoded permission elements

Case I

Syntactic element binIdx 0 1 2 3 4 >=5 intra_planar_flag[][] 0 n/a n/a n/a n/a n/a

Case II

The purpose of ctxInc is specified as follows using condL and condA specified for the syntax element intra_planar_flag [x0][y0]

- ctxInc=(condL andand availableL) || (conA andand availableA) or ctxInc=(condL andand availableL) andand (conA andand availableA)

- condL==PLANAR? 10

- condA==PLANAR? 10

-availableL, indicating the availability of the block located immediately to the left of the current block.

-availableA, indicating the availability of the block immediately to the left of the current block.

-

Syntactic element binIdx 0 1 2 3 4 >=5 intra_planar_flag[][] 0, 1 n/a n/a n/a n/a n/a

Case III

The purpose of ctxInc is specified as follows using condL and condA specified for the syntax element intra_planar_flag [x0][y0]

- ctxInc=(condL andand availableL)+(conA andand availableA)

- condL==PLANAR? 10

- condA==PLANAR? 10

-availableL, indicating the availability of the block located immediately to the left of the current block.

-availableA, indicating the availability of the block immediately to the left of the current block.

Syntactic element binIdx 0 1 2 3 4 >=5 intra_planar_flag[][] 0, 1, 2 n/a n/a n/a n/a n/a

The above embodiment (Case I, Case II and Case III) is only one practical example, the number of context models can be arbitrarily determined.

[229] In an example, the process for decoding the intra-luminance prediction mode may be based on the algorithm (or specification) of Table 28 below.

[230] Tab. 28

8.4.2. Extraction process for intraprediction mode of luminance signals

Extraction process for intraprediction mode of luminance signals

The inputs to this process are as follows:

- luminance signal location (xCb, yCb) indicating the upper left sample of the current luminance encoding block relative to the upper left luminance signal sample of the current frame,

- cbWidth variable indicating the width of the current encoding block in luminance signal samples,

- cbHeight variable indicating the height of the current encoding block in luma samples.

In this process, the internal prediction mode of luminance signals IntraPredModeY[xCb][yCb] is extracted.

Table 8-1 indicates the value for the internal prediction mode IntraPredModeY[xCb][yCb] and associated names.

Table 8. Specification of internal forecasting mode and associated names

Internal prediction mode Associated title 0 INTRA_PLANAR 1 INTRA_DC 2...66 INTRA_ANGULAR2...INTRA_ANGULAR66 81...83 INTRA_LT_CCLM, INTRA_L_CCLM, INTRA_T_CCLM

Note: The INTRA_LT_CCLM, INTRA_L_CCLM and INTRA_T_CCLM intra prediction modes are only applicable to chrominance signal components.

IntraPredModeY[xCb][yCb] is retrieved through the following ordered steps:

1. Neighboring locations (xNbA, yNbA) and (xNbB, yNbB) are set to (xCb-1, yCb+cbHeight-1) and (xCb+cbWidth-1, yCb-1), respectively.

2. To replace X by A or by B, the candIntraPredModeX variables are retrieved as follows:

- The process of retrieving availability for a block, as specified in section 6.4. X [Ed. (BB): Neighbor Block Availability Process, TBD] is activated with location (xCurr, yCurr) set to (xCb, yCb) and neighbor location (xNbY, yNbY) set to (xNbX, yNbX) as inputs, and the output is assigned, for example, availabl,

- A possible variant of the internal prediction mode candIntraPredModeX is retrieved as follows:

- If one or more of the following conditions are true, candIntraPredModeX is set to INTRA_PLANAR.

- The availableX variable is false.

- CuPredMode[xNbX][yNbX] is not equal to MODE_INTRA

- pcm_flag[xNbX][yNbX] is equal to 1.

- X is equal to B, and yCb-1 is less than ((yCb>>CtbLog2SizeY)<<CtbLog2SizeY).

- Otherwise, candIntraPredModeX is set to IntraPredModeY[xNbX][yNbX].

3. candModeList[x] with x=0...4 is retrieved as follows:

- If candIntraPredModeB is equal to candIntraPredModeA, and candIntraPredModeA is greater than INTRA_DC, candModeList[x] with x=0...4 is retrieved as follows:

candModeList[0]=candIntraPredModeA (8-10)

candModeList[1]=2+((candIntraPredModeA+61)%64) (8-12)

candModeList[2]=2+((candIntraPredModeA-1)%64) (8-13)

candModeList[3]=INTRA_DC (8-11)

candModeList[4]=2+((candIntraPredModeA+60)%64) (8-14)

- Otherwise, if candIntraPredModeB is not equal to candIntraPredModeA, and candIntraPredModeA or candIntraPredModeB exceeds INTRA_DC, the following applies:

- Variables minAB and maxAB are retrieved as follows:

minAB=Min(candIntraPredModeA, candIntraPredModeB) (8-24)

maxAB=Max(candIntraPredModeA, candIntraPredModeB) (8-25)

- If candIntraPredModeA and candIntraPredModeB are greater than INTRA_DC, candModeList[x] with x=0...4 is retrieved as follows:

candModeList[0]=candIntraPredModeA (8-27)

candModeList[1]=candIntraPredModeB

candModeList[2]=INTRA_DC (8-29)

- If maxAB minAB is in the range 2-62, inclusive, the following applies:

candModeList[3]=2+((maxAB+61)%64) (8-30)

candModeList[4]=2+((maxAB-1)%64) (8-31)

- Otherwise, the following applies:

candModeList[3]=2+((maxAB+60)%64) (8-32)

candModeList[4]=2+((maxAB)%64) (8-33)

- Otherwise (candIntraPredModeA or candIntraPredModeB exceeds INTRA_DC), candModeList[x] with x=0...4 is retrieved as follows:

candModeList[0]=maxAB (8-65)

candModeList[1]=INTRA_DC (8-66)

candModeList[2]=2+((maxAB+61)%64) (8-66)

candModeList[3]=2+((maxAB-1)%64) (8-67)

candModeList[4]=2+((maxAB+60)%64) (8-68)

- Otherwise, the following applies:

candModeList[0]=INTRA_DC (8-71)

candModeList[1]=INTRA_ANGULAR50 (8-72)

candModeList[2]=INTRA_ANGULAR18 (8-73)

candModeList[3]=INTRA_ANGULAR46 (8-74)

candModeList[4]=INTRA_ANGULAR54 (8-75)

(8-81)

-

4. IntraPredModeY[xCb][yCb] is retrieved by applying the following procedure:

- If intra_luma_mpm_flag[xCb][yCb] is equal to 1, IntraPredModeY[xCb][yCb] is set to candModeList [intra_luma_mpm_idx[xCb][yCb]].

- Otherwise, IntraPredModeY[xCb][yCb] is retrieved by applying the following ordered steps:

1. When candModeList[i] exceeds candModeList[j] for i=0...4 and for each i, j=(i+1)...5, both values are rearranged as follows:

(candModeList[i], candModeList[j]) = Swap(candModeList[i], candModeList[j]) (8-94)

2. IntraPredModeY[xCb][yCb] is retrieved through the following ordered steps:

i. IntraPredModeY[xCb][yCb] is set to intra_luma_mpm_remainder[xCb][yCb].

ii. For i equal to 0-5, inclusive, when IntraPredModeY[xCb][yCb] is greater than or equal to candModeList[i], the value of IntraPredModeY[xCb][yCb] is incremented by one.

The variable IntraPredModeY[x][y] with x=xCb...xCb+cbWidth-1 and y=yCb...yCb+cbHeight-1 is set to IntraPredModeY[xCb][yCb].

[231] In an example, the process for decoding internal blocks may be based on the algorithm (or specification) of Table 29 below.

[232] Tab. 29

8.4.4.1. General decoding process for indoor units

...

- For xPartIdx=0...numPartsX-1 and yPartIdx=0...numPartsY-1, the following applies:

The general intra sample prediction process as specified in section 8.4.4.2.1 is activated with location (xTbCmp, yTbCmp) set to (xTb0+nW*xPartIdx, yTb0+nH*yPartIdx), intra prediction mode predModeIntra, width nTbW and height nTbH of the transform block set to nW and nH, the width nCbW and height nCbH of the encoding block set to nTbW and nTbH, and the variable cIdx as inputs, and the output is an array predSamples (nTbW)x(nTbH).

[233] In an example, the internal sample prediction may be based on the algorithm (or specification) of Table 30 below.

[234] Tab. thirty

8.4.4.2.1. General internal sample forecasting

The internal sample forecasting process according to predModeIntra is applied as follows:

- If predModeIntra is INTRA_PLANAR, the corresponding intra prediction mode-based process specified in section 8.4.4.2.5 is activated with transform block width nTbW and transform block height nTbH, intra prediction reference line index refIdx and reference sample array p as inputs, and the output is an array of predSamples of predicted samples.

- Otherwise, if predModeIntra is equal to INTRA_DC, the corresponding intra prediction mode-based process specified in section 8.4.4.2.6 is activated with transform block width nTbW, transform block height nTbH, intra prediction reference line index refIdx and reference sample array p as inputs, and the output is an array of predSamples of predicted samples.

- Otherwise, if predModeIntra is equal to INTRA_LT_CCLM, INTRA_L_CCLM or INTRA_T_CCLM, the corresponding intra prediction mode-based process specified in section 8.4.4.2.8 is activated with predModeIntra intra prediction mode, sample location (xTbC, yTbC) set to (xTbCmp , yTbCmp), width nTbW and height nTbH of the transform block and an array of p reference samples as inputs, and the output is an array of predSamples of predicted samples.

- Otherwise, the corresponding intra prediction mode-based process specified in section 8.4.4.2.7 is activated with intra prediction mode predModeIntra, intra prediction reference line index refIdx, transform block width nTbW, transform block height nTbH, reference sample width refW , reference sample height refH, encoding block width nCbW and height nCbH, color component index cIdx and reference sample array p as inputs, and the modified intra prediction mode predModeIntra and predicted sample array predSamples as outputs.

[235] In the example, internal planar mode, internal DC mode, etc. may be based on the algorithm (or specification) of Table 31 below.

[236] Tab. 31

8.4.4.2.5. Specification of INTRA_PLANAR internal forecasting mode

Specification of INTRA_PLANAR internal forecasting mode

The inputs to this process are as follows:

- nTbW variable indicating the width of the conversion block,

- nTbH variable indicating the height of the transformation block,

- refIdx variable indicating the index of the internal forecasting reference line,

- adjacent samples p[x][y], with x=-1-refIdx, y=-1-refIdx...nTbH and x=-refIdx...nTbW, y=-1-refIdx.

The outputs of this process are the predicted samples predSamples[x][y], with x=0...nTbW-1, y=0...nTbH-1.

The variables nW and nH are retrieved as follows:

nW=Max(nTbW, 2) (8-116)

nH=Max(nTbH, 2) (8-117)

The values of the predictive samples predSamples[x][y], with x=0...nTbW-1 and y=0...nTbH-1, are extracted as follows: predV[x][y]=((nH-1- y)*p[x][-1-refIdx]+(y+1)*p[-1-refIdx][nTbH])<<Log2(nW) (8-118)

predH[x][y]=((nW-1-x)*p[-1-refIdx][y]+(x+1)*p[nTbW][-1-refIdx])<<Log2(nH ) (8-119)

predSamples[x][y]=(predV[x][y]+predH[x][y]+nW*nH)>>(Log2(nW)+Log2(nH)+1) (8-120)

8.4.4.2.6. INTRA_DC Intra Prediction Mode Specification

The inputs to this process are as follows:

- nTbW variable indicating the width of the conversion block,

- nTbH variable indicating the height of the transformation block,

- refIdx variable indicating the index of the internal forecasting reference line,

- adjacent samples p[x][y], with x=-1-refIdx, y=-1-refIdx...nTbH-1 and x=-refIdx...nTbW-1, y=-1-refIdx.

The outputs of this process are the predicted samples predSamples[x][y], with x=0...nTbW-1, y=0...nTbH-1.

The values of the predictive samples predSamples[x][y], with x=0...nTbW-1, y=0...nTbH-1, are extracted through the following ordered steps:

1. The dcVal variable is retrieved as follows:

- When nTbW is equal to nTbH:

- dcVal (8-121)

- When nTbW is greater than nTbH:

- dcVal (8-122)

- When nTbW is less than nTbH:

- dcVal (8-123)

2. Predictive samples predSamples[x][y] are retrieved as follows:

predSamples[x][y]=dcVal, with x=0...nTbW-1, y=0...nTbH-1 (8-124)

[237] In the example, a process for converting scaled transform coefficients and the like. may be based on the algorithm (or specification) of Table 32 below.

[238] Tab. 32

8.7.4.1. Conversion Process for Scaled Conversion Factors

The inputs to this process are as follows:

- luminance signal location (xTbY, yTbY) indicating the top left sample of the current luminance transform block relative to the top left sample of the luminance signal of the current frame,

- nTbW variable indicating the width of the current transformation block,

- nTbH variable indicating the height of the current transformation block,

- cIdx variable indicating the color component of the current block,

- array d[x][y] (nTbW)x(nTbH) of scaled transformation coefficients with x=0...nTbW-1, y=0...nTbH-1.

The output of this process is an array r[x][y] (nTbW)x(nTbH) of residual samples with x=0...nTbW-1, y=0...nTbH-1.

The implicitMtsEnabled variable is retrieved as follows:

- If sps_mts_enabled_flag is 1 and one of the following conditions is true, implicitMtsEnabled is set to 1:

- IntraSubPartitionsSplitType is not equal to ISP_NO_SPLIT

- cu_sbt_flag is 1, and Max(nTbW, nTbH) is less than or equal to 32

- sps_explicit_mts_intra_enabled_flag and sps_explicit_mts_inter_enabled_flag are equal to 0, and CuPredMode[xTbY][yTbY] is equal to MODE_INTRA

- Otherwise, implicitMtsEnabled is set to 0.

The trTypeHor variable indicating the horizontal transformation kernel and the trTypeVer variable indicating the vertical transformation kernel are retrieved as follows:

- If cIdx is greater than 0, trTypeHor and trTypeVer are set to 0.

- Otherwise, if implicitMtsEnabled is 1, the following applies:

- If IntraSubPartitionsSplitType is not equal to ISP_NO_SPLIT or (sps_explicit_mts_intra_enabled_flag, and sps_explicit_mts_inter_enabled_flag are 0), trTypeHor and trTypeVer are retrieved as follows

- trTypeHor=(nTbW>=4 andand nTbW<=16)? 1 : 0 (8-1028)

- trTypeVer=(nTbH>=4 andand nTbH<=16)? 1 : 0 (8-1029)

Otherwise, if cu_sbt_flag is 1, trTypeHor and trTypeVer are specified in Table 8-14 depending on cu_sbt_horizontal_flag and cu_sbt_pos_flag.

Table 9-5. Associating ctxIdxOffset and syntax elements for each initializationType during initialization Syntactic structure Syntactic element ctxTable initType 0 1 2 coding_tree_unit() alf_ctb_flag[][][] Table 9-6 0 9 18

...

coding_unit() cu_skip_flag[][] 0 3 pred_mode_ibc_flag pred_mode_flag intra_luma_ref_idx[][] intra_subpartitions_mode_flag intra_subpartition_split_flag intra_luma_mpm_flag[][] intra_planar_flag[][] intra_chroma_pred_mode[][] merge_flag[][] inter_pred_idc[x0][y0] inter_affine_flag[][] cu_affine_type_flag[][] ref_idx_l0[][] mvp_l0_flag[][] ref_idx_l1[][] mvp_l1_flag[][] avmr_flag[][] amvr_precision_flag[][] gbi_idx[][] cu_cbf cu_sbt_flag cu_sbt_quad_flag cu_sbt_horizontal_flag cu_sbt_pos_flag

Table 9.9. Syntactic elements and associated binary conversions Syntactic structure Syntactic element Conversion to binary form Process Input parameters coding_unit() cu_skip_flag[][] FL cMax=1 pred_mode_ibc_flag FL cMax=1 pred_mode_flag FL cMax=1 pcm_flag[][] FL cMax=1 intra_luma_ref_idx[][] TR cMax=2, cRiceParam=0 intra_subpartitions_mode_flag FL cMax=1 intra_subpartition_split_flag FL cMax=1 intra_luma_mpm_flag[][] FL cMax=1 intra_planar_flag[][] FL cMax=1 intra_luma_mpm_idx[][] TR cMax=4, cRiceParam=0 intra_luma_mpm_remainder[][] TB cMax=60 intra_chroma_pred_mode[][] 9.5.3.8 - merge_flag[][] FL cMax=1 inter_pred_idc[x0][y0] 9.5.3.9 cbWidth, cbHeight inter_affine_flag[][] FL cMax=1 cu_affine_type_flag[][] FL cMax=1 ref_idx_l0[][] TR cMax=NumRefIdxActive[0]-1, cRiceParam=0 mvp_l0_flag[][] FL cMax=1 ref_idx_l1[][] TR cMax=NumRefIdxActive[1]-1, cRiceParam=0 mvp_l1_flag[][] FL cMax=1 avmr_flag[][] FL cMax=1 amvr_precision_flag[][] FL cMax=1 gbi_idx[][] TR cMax=NoBackwardPredFlag? 4:2 cu_cbf FL cMax=1 cu_sbt_flag FL cMax=1 cu_sbt_quad_flag FL cMax=1 cu_sbt_horizontal_flag FL cMax=1 cu_sbt_pos_flag FL cMax=1

[239] In an example, an example of ctxInc assignment for syntax elements including context-encoded permission elements may be based on Table 33 below.

[240] Tab. 33

9.5.4.2.1 from the VVC specification

Table 9-15. Assigning ctxInc to syntax elements with context-encoded permission elements Syntactic element binIdx 0 1 2 3 4 >=5 intra_luma_ref_idx[][] 0 1 n/a n/a n/a n/a intra_subpartitions_mode_flag 0 n/a n/a n/a n/a n/a intra_subpartition_split_flag 0 n/a n/a n/a n/a n/a intra_luma_mpm_flag[][] 0 n/a n/a n/a n/a n/a intra_planar_flag[][] intra_luma_ref_idx!=0? 2:
(intra_subpartitions_mode_flag? 0:1) n/a n/a n/a n/a n/a intra_luma_mpm_idx[][] bypass bypass bypass bypass bypass n/a intra_luma_mpm_remainder[][] bypass bypass bypass bypass bypass bypass intra_chroma_pred_mode[][] sps_cclm_enabled_flag==0 0 bypass bypass n/a n/a n/a

[241] Referring to Table 25, it may be confirmed that the intra_planar_flag is checked based on the check result that the intra_luma_ref_idx value is 0; intra_luma_ref_idx may represent an example of a multiple reference line (MRL) index, and intra_planar_flag may represent an example of a planar flag.

[242] Referring to Table 27, it can be confirmed that the context index value (ctxInc or ctxIdx) for the permission element associated with intra_planar_flag is 0 or 1. Thus, it can be confirmed that the context index value for the permission element associated with intra_planar_flag, can be one of two different integers.

[243] Referring to Table 33, it can be confirmed that the context index for the permission element associated with intra_planar_flag is based on the value of intra_subpartitions_mode_flag. intra_subpartitions_mode_flag may represent an example of an ISP flag indicating whether or not intra-subpartitions (ISP) mode is applied to the current block.

[244] FIG. 11 is a flowchart illustrating operation of encoding equipment according to an exemplary embodiment, and FIG. 12 is a block diagram illustrating a configuration of encoding equipment according to an exemplary embodiment.

[245] The encoding equipment of FIG. 11 and 12 can perform operations corresponding to the decoding equipment of FIG. 13 and 14. Accordingly, operations of the decoding equipment which is described below with reference to FIGS. 13 and 14 can also be applied to the encoding equipment of FIGS. 11 and 12.

[246] Each step illustrated in FIG. 11 may be performed by the encoding equipment 200 illustrated in FIG. 2. Additionally, the operations according to S1100 and S1110 are based on the content portion described with reference to FIG. 4-10. Accordingly, detailed descriptions that overlap with the descriptions given above with reference to FIGS. 2 and 4-10 are omitted or simplified.

[247] As illustrated in FIG. 12, the encoding equipment according to the exemplary embodiment may include a prediction module 220 and an entropy encoder 240. However, in some cases, not all components illustrated in FIG. 12 may not represent essential components of the encoding equipment, and the encoding equipment may be implemented by more or less components than those illustrated in FIG. 12.

[248] In the encoding equipment according to an exemplary embodiment, the prediction module 220 and the entropy encoder 240 may be implemented as separate chips, or at least two components may also be implemented through a single chip.

[249] The encoding equipment according to an exemplary embodiment may generate at least one of MPM flag information representing whether or not to encode an intra prediction mode based on the MPM options for the current block, or planar flag information representing whether whether or not the intra-prediction mode for the current block should be determined as a planar mode based on the intra-prediction mode for the current block (S1100).

[250] For example, the encoding equipment may extract the intra prediction mode for the current block, generate MPM flag information representing whether or not to encode the intra prediction mode based on the MPM candidates for the current block6, and generate planar flag information based on the MPM. representing that the MPM flag information is associated with the planar flag information representing whether or not the intra prediction mode for the current block should be determined as a planar mode.

[251] The encoding equipment according to the exemplary embodiment can encode image information including at least one of MPM flag information or planar flag information (S1110). More specifically, the entropy encoder 240 of the encoding equipment can encode MPM flag information including at least one of image information or planar flag information.

[252] In an exemplary embodiment, based on the case in which the intra prediction mode for the current block is retrieved as a planar mode, the planar flag information may represent that the intra prediction mode for the current block is retrieved as a planar mode.

[253] In an exemplary embodiment, the intra prediction information may further include MPM index information associated with one of the possible MPM options other than planar mode from the possible MPM options for the current block. The image encoding method may further include generating MPM index information based on a case in which the intra prediction mode for the current block is not extracted as a planar mode.

[254] In an exemplary embodiment, the total number of possible non-planar mode MPM options among the possible MPM options for the current block may be 5.

[255] In an exemplary embodiment, the MPM index information includes a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. -options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are identical, and the intra-prediction mode of the left neighboring block exceeds the intra-DC mode, the intra-prediction mode for zero of the MPM candidate may be the intra prediction mode of the left neighbor block with respect to the current block, the intra prediction mode for the first MPM candidate may be 2+((intra prediction mode of the left neighbor block with respect to the current block+61)% 64), and the intra-prediction mode for the second possible MPM option may be 2+((intra-prediction mode of the left adjacent block relative to the current block - 1)%64).

[256] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. Based on the case in which the intra prediction mode of the left neighboring block with respect to the current block and the intra prediction mode of the upper neighboring block with respect to the current block are not identical, and the intra prediction mode of the left neighboring block is less than or equal to the internal DC mode, and the mode the inner prediction mode of the upper adjacent block is less than or equal to the inner DC mode, the intraprediction mode for the zero MPM opportunity may be the inner DC mode, the intraprediction mode for the first MPM opportunity may be the 50th intraprediction mode, the mode The intra prediction mode for the second MPM opportunity may be the 18th intra prediction mode, the intra prediction mode for the third MPM opportunity may be the 46th intra prediction mode, and the intra prediction mode for the fourth MPM opportunity may be 54th internal forecasting mode.

[257] In an exemplary embodiment, the MPM index information may be based on a Truncated Rice (TR) binarization process.

[258] In an exemplary embodiment, cMax representing the maximum value of the MPM index information may be 4.

[259] According to the encoding equipment and the method for operating the encoding equipment illustrated in FIG. 11 and 12, the encoding equipment may generate at least one of MPM flag information representing whether or not the intra prediction mode should be encoded based on the MPM options for the current block, or planar flag information representing whether or not no determine the intra prediction mode for the current block as a planar mode based on the intra prediction mode for the current block (S1100), and encode MPM flag information including at least one of image information or planar flag information (S1110) .

[260] Thus, the present disclosure can improve the efficiency of coding images based on intra prediction using the MPM list for the current block. Alternatively, the present disclosure may improve the efficiency of intra prediction based on the MPM list based on planar flag information representing whether or not to determine the intra prediction mode for the current block as a planar mode. Alternatively, the present disclosure may effectively configure an MPM list for the current block. Alternatively, the present entity disclosure may effectively encode an MPM index.

[261] FIG. 13 is a flowchart illustrating operation of decoding equipment according to an exemplary embodiment, and FIG. 14 is a block diagram illustrating a configuration of decoding equipment according to an exemplary embodiment.

[262] Each step illustrated in FIG. 13 may be performed by the decoding equipment 300 illustrated in FIG. 3. Accordingly, detailed descriptions that overlap with the above content are omitted or simplified.

[263] As illustrated in FIG. 14, the decoding equipment according to the exemplary embodiment may include an entropy decoder 310, a prediction module 330, and an adder 340. However, in some cases, all of the components illustrated in FIG. 14 may not represent essential components of the decoding equipment, and the decoding equipment may be implemented by more or less components than the components illustrated in FIG. 14.

[264] In the decoding equipment according to the exemplary embodiment, the entropy decoder 310, the prediction module 330, and the adder 340 may be implemented as separate chips, respectively, or at least two or more components may also be implemented through a single chip.

[265] The decoding equipment according to an exemplary embodiment may receive intra prediction information including at least one of MPM flag information representing whether or not to extract an intra prediction mode for the current block based on the candidate most likely modes. (MPM) for the current block, or planar flag information representing whether or not the intra prediction mode for the current block should be determined as the most likely planar mode mode (S1300).

[266] In an example, intra prediction information may be included in the syntax of a coding unit.

[267] In an example, MPM flag information may be represented as intra_luma_mpm_flag, and planar flag information may be represented as intra_luma_not_planar_flag. If the intra_luma_not_planar_flag value is 1, it may be determined that the intra prediction mode for the current block is not a planar mode, and if the intra_luma_not_planar_flag value is 0, it may be determined that the intra prediction mode for the current block is a planar mode.

[268] In another example, planar flag information may also be represented as intra_luma_planar_flag or intra_planar_flag. If the intra_luma_planar_flag value is 1, it may be determined that the intra prediction mode for the current block is a planar mode, and if the intra_luma_planar_flag value is 0, it may be determined that the intra prediction mode for the current block is not a planar mode.

[269] In an example, the decoding equipment may determine that the value of the MPM flag information is associated with decoding the planar flag information based on determining that the value of the MPM flag information is 1. Thus, the decoding equipment may decode the planar flag information at basis for determining that the value of the MPM flag information is 1.

[270] The decoding equipment according to the exemplary embodiment can extract the intra prediction mode for the current block based on the MPM flag information and the planar flag information (S1310).

[271] The decoding equipment according to the exemplary embodiment may extract a predicted block for the current block based on the intra prediction mode for the current block (S1320).

[272] The decoding equipment according to the exemplary embodiment can generate a reconstructed frame based on the predicted block (S1330).

[273] In an exemplary embodiment, planar flag information may be included in the intra prediction information based on the case in which the MPM flag information represents that the intra prediction mode for the current block is retrieved based on the MPM candidates.

[274] In an exemplary embodiment, retrieving the intra-prediction mode for the current block may include retrieving the intra-prediction mode for the current block as a planar mode, based on the case in which the planar flag information represents that the intra-prediction mode for the current block is extracted as planar mode.

[275] In an exemplary embodiment, the intra prediction information may further include MPM index information associated with one of the non-planar mode MPM candidates of the MPM candidates for the current block. The MPM index information may be included in the intra prediction information based on the case in which the planar flag information represents that the intra prediction mode for the current block is not extracted as a planar mode. The image decoding method is different in that the intra prediction mode for the current block is extracted based on the MPM index information. In an example, the decoding equipment may check the MPM index information based on a check result such that the value of intra_luma_not_planar_flag is 1.

[276] In an exemplary embodiment, the number of possible MPM options other than planar mode among the possible MPM options for the current block may be 5. In an example, the possible MPM options may include 1st through 5th possible MPM options. The first MPM candidate can be associated with MPM index 0, the second MPM candidate can be associated with MPM index 1, the third MPM candidate can be associated with MPM index 2, the fourth MPM candidate can be associated with with MPM index 3, and the fifth possible MPM option can be associated with MPM index 4.

[277] In an exemplary embodiment, the MPM index information may represent a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is included in the MPM candidates. options other than planar mode from the possible MPM options for the current block. In an example, based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block is identical to the intra-prediction mode of the upper neighboring block with respect to the current block, and the intra-prediction mode of the left neighboring block exceeds the intra-DC mode, the intra-prediction mode for the zero MPM opportunity may be the intra-prediction mode of the left neighbor block with respect to the current block, the intra-prediction mode for the first MPM opportunity may be 2+((intra-prediction of the left neighbor block with respect to the current block+61) %64), and the internal prediction mode for the second possible MPM option may be 2+((internal prediction mode of the left adjacent block with respect to the current block - 1)%64).

[278] In an example, the MPM index information may be represented as intra_luma_mpm_idx, and the zero MPM candidate to the fourth MPM candidate corresponding to MPM index 0 to MPM index 4 may be represented as candModeList[0], candModeList[1 ], candModeList[2], candModeList[3] and candModeList[4], respectively.

[279] In an example, if the intra prediction mode for the left neighbor block with respect to the current block is candIntraPredModeA, the intra prediction mode for the top neighbor block with respect to the current block is candIntraPredModeB, candIntraPredModeA and candIntraPredModeB are identical, and candIntraPredModeA exceeds INTRA_DC. the zero MPM candidate, the first MPM candidate, and the second MPM candidate of the MPM candidates configuring the MPM list may be determined as follows.

[280] equation 1

[281] candModeList[0]=candIntraPredModeA

[282] candModeList[1]=2+((candIntraPredModeA+61)%64)

[283] candModeList[2]=2+((candIntraPredModeA-1)%64)

[284] In another example, based on the case in which the intra prediction mode of the left neighboring block with respect to the current block and the intra prediction mode of the upper neighboring block with respect to the current block are not identical, the intra prediction mode of the left neighboring block is less than or equal to the internal DC mode, and the inner prediction mode of the upper adjacent block is less than or equal to the inner DC mode, the intra prediction mode for the zero MPM opportunity may be the inner DC mode, the intra prediction mode for the first MPM opportunity may be 50. 1st intra-prediction mode, the intra-prediction mode for the second MPM candidate may be the 18th intra-prediction mode, the intra-prediction mode for the third MPM candidate may be the 46th intra-prediction mode, and the intra-prediction mode for the fourth candidate The MPM variant may be a 54th internal prediction mode.

[285] In an exemplary embodiment, the MPM index information may be based on a Truncated Rice (TR) binarization process.

[286] In an exemplary embodiment, cMax indicating the maximum value of the MPM index information may be 4.

[287] According to the decoding equipment and the method for operating the decoding equipment illustrated in FIG. 13 and 14, the decoding equipment may receive intra prediction information including at least one of MPM flag information representing whether or not to extract an intra prediction mode for the current block based on the most probable mode (MPM) options. for the current block, or planar flag information representing whether or not to determine the intra prediction mode for the current block as a planar mode (S1300), extract the intra prediction mode for the current block based on the MPM flag information and the planar flag information (S1310) , extract a predicted block for the current block based on the intra prediction mode for the current block (S1320), and generate a reconstructed frame based on the predicted block (S1330). At this time, based on the case in which the MPM flag information represents that the intra prediction mode for the current block is retrieved based on the MPM candidates, the planar flag information may be included in the intra prediction information.

[288] Thus, the present disclosure can improve the efficiency of intra prediction based on an MPM list based on planar flag information representing whether or not to determine the intra prediction mode for the current block as a planar mode. Alternatively, the present disclosure can improve the efficiency of image coding by determining whether or not planar flag information should be signaled based on the MRL index information. Alternatively, the present disclosure may effectively configure an MPM list for the current block. Alternatively, the present disclosure may determine the context index value for the permission element associated with the planar flag information based on whether or not the ISP mode is applied to the current block.

[289] In the above embodiments, although the methods are described based on method flow diagrams shown as a sequence of steps or blocks, the present disclosure is not limited to the order of the steps, and a particular step may occur in a different order or simultaneously with a step different from stage described above. Additionally, those skilled in the art will understand that the steps shown in the flowchart are not exhaustive and other steps may be included or one or more steps in the flowchart may be deleted without affecting the scope true revelation of the essence.

[290] The above method according to the present disclosure may be implemented in the form of encoding software and hardware, and/or decoding equipment according to the present disclosure may be included in equipment for performing image processing, such as a television, computer, smartphone, set-top box, display device and so on.

[291] When the embodiments in the present disclosure are implemented in software, the above method may be implemented as a module (process, function, etc.) to perform the above function. The module may be stored in a storage device and executed by a processor. The storage device may be located inside or outside the processor and may be coupled to the processor through various known means. The processor may include application specific integrated circuits (ASICs), other chipsets, logic circuits, and/or data processing devices. The storage device may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium, and/or other storage devices. Thus, the embodiments described in the present disclosure may be performed through implementation on a processor, microprocessor, controller, or chip. For example, the functional modules illustrated in each drawing may be implemented by implementation on a computer, processor, microprocessor, controller, or chip. In this case, implementation information (eg, information regarding instructions) or algorithm may be stored on a digital storage medium.

[292] Additionally, the decoding equipment and encoding equipment to which the present disclosure applies may be included in a broadcast multimedia transceiver device, a mobile communication terminal, a home theater system video device, a digital cinema system video device, a surveillance camera, a video communication device, a communication device real-time video, mobile streaming device, storage medium, video recording camera, video-on-demand (VoD) service provider, over-the-top video (OTT video), internet streaming service provider , three-dimensional video device, virtual reality (VR) style device, augmented reality (AR) style device, video telephony system video device, transportation terminal (for example, a terminal in a vehicle (including an autonomous vehicle), a terminal in an aircraft, marine terminal, etc.) and medical video device, etc. and can be used to process video or data signals. For example, an OTT video device may include a gaming console, Blu-ray player, Internet-enabled television, home theater system, smartphone, tablet PC, digital video recorder (DVR), and the like.

[293] Additionally, the processing method to which the present disclosure applies may be formed in the form of a program executed by a computer and may be stored on a computer-readable recording medium. Multimedia data having a data structure according to the present disclosure may also be stored on a computer-readable recording medium. The computer-readable recording medium includes all kinds of storage devices and distributed storage devices on which computer-readable data is stored. The computer-readable recording medium may include, for example, a Blu-ray disc (BD), a universal serial bus (USB), a ROM, a PROM, an EPROM, an EEPROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, and an optical storage device. . Additionally, the computer-readable recording medium also includes media implemented in the form of a carrier wave (eg, Internet transmissions). Additionally, the bitstream generated by the encoding method may be stored in a computer-readable recording medium or transmitted through wired/wireless communication networks.

[294] Additionally, embodiments of the present disclosure may be implemented as a computer program product through program code, and the program code may be executed on a computer according to embodiments of the present disclosure. The program code may be stored on a machine-readable medium.

[295] This document relates to video/image coding. For example, the method/embodiment disclosed in this document may be applied to the method disclosed in the Versatile Video Coding (VVC) standard, the Fundamental Video Coding (EVC) standard, the AOMedia Video 1 (AV1) standard, the second generation audio/video coding standard (AVS2) or next generation video/image coding standard (for example, H.267, H.268, etc.).

[296] Herein, a variety of embodiments related to video/image coding may be provided, and unless otherwise noted, embodiments may be combined and executed.

[297] As used herein, video may refer to a sequence of images over time. A frame generally means a unit representing one image in a particular time frame, and a slice/tile means a unit constituting a frame from an encoding point of view. A slice/tile may include one or more coding tree units (CTUs). One frame can consist of one or more slices/tiles. One frame can consist of one or more groups of tiles. One tile group may include one or more tiles. A brick can represent a rectangular area of CTU rows in a tile in a frame. A tile can be segmented into multiple bricks, each of which consists of one or more CTU rows in the tile. A tile that is not segmented into multiple bricks may also be called a "brick". A brick scan is a specific sequential ordering of CTUs segmenting a frame, where CTUs are ordered sequentially in a raster CTU scan within a brick, bricks within a tile are ordered sequentially in a raster scan of tile bricks, and tiles within a frame are ordered sequentially in a raster scan of frame tiles. A tile is a rectangular CTU area in a particular column of tiles and a particular row of tiles in a frame. A column of tiles is a rectangular area of CTUs having a height equal to the height of the frame and a width specified by syntax elements in the frame parameter set. A row of tiles is a rectangular area of CTUs having a height specified by syntax elements in the frame parameter set and a width equal to the width of the frame. A tile scan is a specified sequential ordering of the CTUs segmenting a frame, where the CTUs are ordered sequentially in a raster scan of the CTUs in a tile, while the tiles in a frame are ordered sequentially in a raster tile scan of the frame. A slice includes an integer number of frame bricks that can be contained exclusively in a single NAL unit. A slice can consist of either a specific number of full tiles, or only a rigid sequence of full bricks of a single tile. In this document, tile group and slice can be used interchangeably. For example, in this document, a tile group/tile group header may also be referred to as a "slice/slice header".

[298] Pixel or pel can mean the smallest unit that makes up one frame (or image). Additionally, "sample" can be used as a term corresponding to a pixel. A sample may generally represent a pixel or a pixel value, and may represent only a pixel/pixel value of a luma component or only a pixel/pixel value of a chroma component.

[299] The unit may represent a basic image processing unit. The unit may include at least one of a specific frame area and information associated with the area. One unit may include one block of luma signals and two blocks of chrominance signals (eg, cb, cr). Unit may be used interchangeably with terms such as block or zone in some cases. In general, an MxN block may include samples (or arrays of samples) or a set (or array) of transform coefficients of M columns and N rows.

[300] In this document, the terms "/" and "" are to be interpreted to indicate "and/or". For example, the expression "A/B" could mean "A and/or B". Additionally, "A, B" may mean "A and/or B". Additionally, "A/B/C" may mean "at least one of A, B and/or C". In addition, "A/B/C" may mean "at least one of A, B and/or C".

[301] Additionally, as used herein, the term “or” should be interpreted to indicate “and/or.” For example, the expression "A or B" may contain 1) only A, 2) only B, and/or 3) both A and B. In other words, the term "or" in this document should be interpreted to indicate "in addition or alternatively" .

[302] FIG. 15 represents an example of a content streaming system to which the disclosure of this document may apply.

[303] Referring to FIG. 15, the content streaming system to which the present disclosure applies may mainly include an encoding server, a streaming server, a web server, a media storage, a user device, and a media input device.

[304] The encoding server functions to digitally compress content input from media input devices such as a smartphone, camera, video recorder, etc. to form a bit stream and transmit it to the streaming server. As another example, if a smartphone, camera, video recorder, etc. directly generates the bit stream, the encoding server can be omitted.

[305] The bitstream may be generated by an encoding method or a bitstream generation method to which the present disclosure applies. In addition, the streaming server may temporarily store the bitstream in the process for transmitting or receiving the bitstream.

[306] The streaming server transmits multimedia data to the subscriber device based on the user's request through a web server, which functions as a tool that informs the user as to what service is provided. When a user requests a service that he wants, the web server transmits it to the streaming server and the streaming server streams the media data to the user. In this regard, the content streaming system may include a separate control server, in which case, the control server functions to manage commands/responses between associated equipment in the content streaming system.

[307] The streaming server may receive content from a media storage and/or encoding server. For example, in case the content is received from an encoding server, the content may be received in real time. In this case, the streaming server can store the bit stream for a predetermined period of time to smoothly provide the streaming service.

[308] For example, a subscriber device may include a mobile phone, a smartphone, a laptop computer, a digital broadcast terminal, a personal digital assistant (PDA), a portable media player (PMP), a navigation device, a tablet PC, a tablet PC, an ultrabook, a wearable device (for example, a watch terminal (smart watch), a glasses terminal (smart glasses), a head-mounted display (HMD)), a digital TV, a desktop computer, a digital signage system, etc.

[309] Each of the servers in the content streaming system may operate as a distributed server, in which case, data received through each server may be distributedly processed.

Claims (66)

1. Decoding equipment for decoding images, containing: Memory device; And at least one processor coupled to the storage device, wherein the at least one processor is configured to: receiving intra prediction information comprising most likely mode (MPM) flag information associated with whether or not to extract an intra prediction mode for the current block based on possible MPM options for the current block, planar flag information associated with whether or not determine the intra prediction mode for the current block as a planar mode, and MPM index information associated with one of the 5 possible MPM options other than the planar mode from the possible MPM options for the current block; retrieving an intra prediction mode for the current block based on at least one of an MPM flag information value, a planar flag information value, or an MPM index information value; retrieving a predicted block for the current block based on an intra prediction mode for the current block; And forming a reconstructed frame based on the predicted block, wherein the MPM flag information is configured in the coding unit syntax for the current block, wherein, based on the value of the MPM flag information representing that the intra prediction mode for the current block is retrieved based on the MPM candidates, the planar flag information is configured in the coding unit syntax, and wherein, based on the value of the planar flag information representing that the intra prediction mode for the current block is not extracted as a planar mode, the MPM index information is configured in the coding unit syntax. 2. The image decoding equipment of claim 1, wherein the intra prediction mode for the current block is extracted as a planar mode based on the planar flag information representing that the intra prediction mode for the current block is extracted as a planar mode, and wherein the planar flag information is transmitted in signaling between the MPM flag information and the MPM index information. 3. The image decoding equipment of claim 1, wherein the MPM index information represents a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is contained in possible MPM options other than planar mode, from the possible MPM options for the current block, and wherein based on the case in which the intra prediction mode of the left neighboring block with respect to the current block and the intra prediction mode of the upper neighboring block with respect to the current block are identical and the intra prediction mode of the left neighboring block exceeds the intra DC mode, the intra prediction mode for the zero MPM candidate is the intra-prediction mode of the left neighbor block relative to the current block, the intra-prediction mode for the first MPM candidate is 2+((internal prediction mode of the left neighbor block relative to the current block + 61)%64 ) and the internal prediction mode for the second possible MPM option is 2+((internal prediction mode of the left neighboring block with respect to the current block - 1)%64). 4. The image decoding equipment of claim 1, wherein the MPM index information represents a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is contained in possible MPM options other than planar mode, from the possible MPM options for the current block, and wherein, based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are not identical, the intra-prediction mode of the left neighboring block is less than or equal to the inner DC mode and the mode The inner prediction mode of the upper adjacent block is less than or equal to the inner DC mode, the inner prediction mode for the zero MPM opportunity is the inner DC mode, the inner prediction mode for the first MPM opportunity is the 50th inner prediction mode, the inner prediction mode for the second MPM opportunity is the 18th intra-prediction mode, the intra-prediction mode for the third MPM opportunity is the 46th intra-prediction mode, and the intra-prediction mode for the fourth MPM opportunity is the 54th intra-prediction mode . 5. The image decoding equipment of claim 1, wherein the MPM index information is based on a Truncated Rice (TR) binarization process, and cMax, which represents the maximum value of the MPM index information, is 4. 6. The image decoding equipment of claim 1, wherein the encoding unit syntax includes internal sub-segment mode flag information related to whether or not the current block is divided into sub-segments, wherein the value of the planar flag information is retrieved based on the contextual increase for the resolution element of the planar flag information, and wherein the context increase for the planar flag information enable element is determined based on the value of the mode flag information of the inner subsegments. 7. The image decoding equipment of claim 6, wherein based on the internal subsegment mode flag information value of 1, the context magnification for the planar flag information resolution element is determined to be 0, and wherein, based on the internal subsegment mode flag information value of 0, the context increase for the planar flag information resolution element is determined to be 1. 8. Encoding equipment for encoding images, containing: Memory device; And at least one processor coupled to the storage device, wherein the at least one processor is configured to: retrieving an intra prediction mode for the current block; generating MPM flag information, planar flag information and MPM index information based on the extracted intra prediction mode, wherein the MPM flag information is associated with whether or not to extract the intra prediction mode for the current block based on the most likely mode (MPM) options ) for the current block, wherein the planar flag information is associated with whether or not the intra prediction mode for the current block should be determined as a planar mode, and the MPM index information is associated with one of 5 possible MPM options other than planar mode among the possible MPM options for current block, encoding image information containing MPM flag information, planar flag information and MPM index information, wherein the MPM flag information is configured in the coding unit syntax for the current block, wherein, based on the value of the MPM flag information representing that the intra prediction mode for the current block is retrieved based on the MPM candidates, the planar flag information is configured in the coding unit syntax, and wherein, based on the value of the planar flag information representing that the intra prediction mode for the current block is not extracted as a planar mode, the MPM index information is configured in the coding unit syntax. 9. The encoding equipment of claim 8, wherein based on the case in which the intra prediction mode for the current block is extracted as a planar mode, the planar flag information represents that the intra prediction mode for the current block is extracted as a planar mode, wherein the planar flag information is transmitted in signaling between the MPM flag information and the MPM index information. 10. The image encoding equipment of claim 8, wherein the MPM index information represents a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is contained in possible MPM options other than planar mode, from the possible MPM options for the current block, and wherein based on the case in which the intra prediction mode of the left neighboring block with respect to the current block and the intra prediction mode of the upper neighboring block with respect to the current block are identical and the intra prediction mode of the left neighboring block exceeds the intra DC mode, the intra prediction mode for the zero MPM candidate is the intra-prediction mode of the left neighbor block relative to the current block, the intra-prediction mode for the first MPM candidate is 2+((internal prediction mode of the left neighbor block relative to the current block + 61)%64 ) and the internal prediction mode for the second possible MPM option is 2+((internal prediction mode of the left neighboring block with respect to the current block - 1)%64). 11. The image encoding equipment of claim 8, wherein the MPM index information represents a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is contained in possible MPM options other than planar mode, from the possible MPM options for the current block, and wherein, based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are not identical, the intra-prediction mode of the left neighboring block is less than or equal to the inner DC mode and the mode The inner prediction mode of the upper adjacent block is less than or equal to the inner DC mode, the inner prediction mode for the zero MPM opportunity is the inner DC mode, the inner prediction mode for the first MPM opportunity is the 50th inner prediction mode, the inner prediction mode for the second MPM opportunity is the 18th intra-prediction mode, the intra-prediction mode for the third MPM opportunity is the 46th intra-prediction mode, and the intra-prediction mode for the fourth MPM opportunity is the 54th intra-prediction mode . 12. The image encoding equipment of claim 8, wherein the MPM index information is based on a Truncated Rice (TR) binarization process, and cMax, which represents the maximum value of MPM index information, is 4. 13. The image encoding equipment of claim 8, wherein the encoding unit syntax includes internal sub-segment mode flag information related to whether or not the current block is divided into sub-segments, wherein the value of the planar flag information is retrieved based on the contextual increase for the resolution element of the planar flag information, and wherein the context increase for the planar flag information enable element is determined based on the value of the mode flag information of the inner subsegments. 14. The image encoding equipment of claim 13, wherein based on the internal sub-segment mode flag information value of 1, the context magnification for the planar flag information resolution element is determined to be 0, and wherein, based on the internal subsegment mode flag information value of 0, the context increase for the planar flag information resolution element is determined to be 1. 15. Data transmission equipment for image information, comprising: at least one processor configured to receive a bitstream of image information including most likely mode (MPM) flag information, planar flag information, and MPM index information, wherein the MPM flag information is associated with whether or not the intra prediction mode for the current block should be retrieved based on the possible MPM options for the current block, the planar flag information is associated with whether or not the intra prediction mode for the current block should be determined as a planar mode , and the MPM index information is associated with one of 5 possible MPM options other than planar mode from the possible MPM options for the current block; And a transmitter configured for data including a bit stream of image information, wherein the MPM flag information is configured in the coding unit syntax for the current block, wherein, based on the value of the MPM flag information representing that the intra prediction mode for the current block is retrieved based on the MPM candidates, the planar flag information is configured in the coding unit syntax, and wherein, based on the value of the planar flag information representing that the intra prediction mode for the current block is not extracted as a planar mode, the MPM index information is configured in the coding unit syntax. 16. The transmission equipment of claim 15, wherein based on the case in which the intra prediction mode for the current block is extracted as a planar mode, the planar flag information represents that the intra prediction mode for the current block is extracted as a planar mode, wherein the planar flag information is transmitted in signaling between the MPM flag information and the MPM index information. 17. The transmission equipment of claim 15, wherein the MPM index information is a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is contained in possible MPM options other than planar mode from the possible MPM options for the current block, and wherein based on the case in which the intra prediction mode of the left neighboring block with respect to the current block and the intra prediction mode of the upper neighboring block with respect to the current block are identical and the intra prediction mode of the left neighboring block exceeds the intra DC mode, the intra prediction mode for of the zero MPM opportunity is the intra-prediction mode of the left neighbor block with respect to the current block, the intra-prediction mode for the first MPM opportunity is 2+((intra-prediction mode of the left neighbor of the current block + 61)%64 ) and the internal prediction mode for the second possible MPM option is 2+((internal prediction mode of the left neighboring block with respect to the current block - 1)%64). 18. The transmission equipment of claim 15, wherein the MPM index information is a zero MPM candidate, a first MPM candidate, a second MPM candidate, a third MPM candidate, or a fourth MPM candidate that is contained in possible MPM options other than planar mode from the possible MPM options for the current block, and wherein, based on the case in which the intra-prediction mode of the left neighboring block with respect to the current block and the intra-prediction mode of the upper neighboring block with respect to the current block are not identical, the intra-prediction mode of the left neighboring block is less than or equal to the inner DC mode and the mode The inner prediction mode of the upper adjacent block is less than or equal to the inner DC mode, the inner prediction mode for the zero MPM opportunity is the inner DC mode, the inner prediction mode for the first MPM opportunity is the 50th inner prediction mode, the inner prediction mode for the second MPM opportunity is the 18th intra-prediction mode, the intra-prediction mode for the third MPM opportunity is the 46th intra-prediction mode, and the intra-prediction mode for the fourth MPM opportunity is the 54th intra-prediction mode . 19. The transmission equipment of claim 15, wherein the MPM index information is based on a Truncated Rice (TR) binarization process, and cMax, which represents the maximum value of MPM index information, is 4. 20. The transmission equipment of claim 15, wherein the encoding unit syntax includes internal subsegment mode flag information related to whether or not the current block is subsegmented, wherein the value of the planar flag information is retrieved based on the contextual increase for the resolution element of the planar flag information, and wherein the context increase for the planar flag information enable element is determined based on the value of the mode flag information of the inner subsegments. 21. The transmission equipment of claim 20, wherein, based on the internal subsegment mode flag information value of 1, the context gain for the planar flag information resolution element is determined to be 0, and wherein, based on the internal subsegment mode flag information value of 0, the context increase for the planar flag information resolution element is determined to be 1.

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