WO2020175908A1

WO2020175908A1 - Method and device for partitioning picture on basis of signaled information

Info

Publication number: WO2020175908A1
Application number: PCT/KR2020/002733
Authority: WO
Inventors: 파루리시탈; 김승환
Original assignee: 엘지전자 주식회사
Priority date: 2019-02-26
Filing date: 2020-02-26
Publication date: 2020-09-03

Abstract

A method for decoding an image by a decoding device according to the present disclosure comprises the steps of: obtaining image information including partition information of a current picture and prediction information of a current block included in the current picture from a bitstream; deriving a partitioning structure of the current picture, which is based on a plurality of tiles, on the basis of the partition information of the current picture; deriving prediction samples of the current block on the basis of the prediction information of the current block included in one tile among the plurality of tiles; and reconstructing the current picture on the basis of the prediction samples.

Description

Specification

Name of the invention: Picture partitioning method and apparatus based on signaled information

Technical field

[1] This disclosure is about video coding technology, and more specifically, video coding.

It relates to a picture partitioning method and apparatus based on information signaled by the system.

Background

四 The latest 4K or 8K or higher UHD (Ultra High Definition) video/video

The demand for high-resolution, high-quality video/video is increasing in various fields. The higher the resolution and quality of the video/video data, the higher the amount of information or bits to be transmitted compared to the existing video/video data.Therefore, the video data can be transmitted using a medium such as a wired/wireless broadband line or an existing storage medium When the video/video data is stored using the method, the transmission cost and storage cost increase.

[3] In addition, interest and demand for immersive media such as VR (Virtual Reality) and AR (Artificial Realtiy) contents and holograms are increasing recently. Broadcasting for video/video is increasing.

[4] Accordingly, in recent years, video/video applications with various characteristics

A flexible picture partitioning method that can be applied to efficiently compress and play back images/videos is required.

Detailed description of the invention

Technical task

[5] The technical task of this disclosure is to provide a method and apparatus to increase the image coding efficiency.

[6] Another technical task of this disclosure is to provide a method and apparatus for signaling partitioning information.

[7] Another technical task of this disclosure is to create pictures based on signaled information.

It is to provide a flexible partitioning method and device.

[8] Another technical task of this disclosure is to provide a method and apparatus for partitioning a current picture based on partition information for the current picture.

[9] Another technical task of this disclosure is flag information on whether the current picture is divided into motion constrained tile sets (MCTS), information on the number of MCTSs in the current picture, and upper left for each of the MCTSs. Position information of the tile located at the (top-left) or the position of the tile located at the bottom-right for each MCTS It is intended to provide a method and apparatus for partitioning the current picture based on at least one of the information.

Problem solving means

[1] According to an embodiment of the present disclosure, an image decoding method performed by a decoding apparatus is provided. The method includes partition information for a current picture and a current block included in the current picture. For example, acquiring image information including prediction information from a bitstream; Based on the partitioning information for the current picture, a partitioning structure of the current picture based on a plurality of tiles is also provided. A step of; Deriving prediction samples for the current block based on the prediction information for the current block included in one of the plurality of tiles; And the current picture based on the prediction samples Including a step of restoring, the division information on the current picture, flag information on whether the current picture is divided into motion constrained tile sets (MCTS), information on the number of MCTSs in the current picture, It includes at least one of the location information of a tile located at the top-left of each of the MCTSs or the location information of a tile located at the bottom-right of each of the MCTSs.

[11] According to another embodiment of the present disclosure, a decoding device for performing image decoding is provided. The decoding device includes partition information for a current picture and a current block included in the current picture. For example, obtaining image information including prediction information from a bitstream, and reducing the partitioning structure of the current picture based on a plurality of tiles, based on the partitioning information for the current picture. An entropy decoding unit; A prediction unit for deriving prediction samples for the current block based on the prediction information for the current block included in one of the plurality of tiles; And the current picture based on the prediction samples Including an adder for restoring the current picture, the division information on the current picture, flag information on whether the current picture is divided into motion constrained tile sets (MCTS), number information on the number of MCTSs in the current picture , At least one of the location information of a tile positioned at the top-left of each of the MCTSs or the location information of a tile positioned at the bottom-right of each of the MCTSs.

[12] According to another embodiment of the present disclosure, an image encoding method performed by an encoding device is provided. The method includes the steps of dividing a current picture into a plurality of tiles; based on the plurality of tiles. Generating segmentation information for the current picture; Deriving prediction samples for a current block included in one of the plurality of tiles; Generating prediction information for the current block based on the prediction samples And the division information for the current picture and the Including the step of encoding image information including prediction information on the current block, wherein the division information on the current picture is, Neulrag information on whether the current picture is divided into motion constrained tile sets (MCTS). ,Information on the number of MCTSs in the current picture, location information of a tile located on the top-left side of each of the MCTSs, or information on the bottom-right side of each of the MCTSs Includes at least one of the tile's location information.

According to another embodiment of the present disclosure, an encoding device for performing image encoding is provided. The encoding device divides a current picture into a plurality of tiles, and the current picture is divided based on the plurality of tiles. An image segmentation unit that generates segmentation information for a picture, extracts prediction samples for the current block included in one of the plurality of tiles, and generates prediction information for the current block based on the prediction samples. Entropy encoding image information including prediction unit and segmentation information for the current picture and prediction information for the current block

Including an encoding unit, the partition information on the current picture, Always lag information on whether the current picture is divided into motion constrained tile sets (MCTS), number information on the number of MCTSs in the current picture, the It includes at least one of the location information of a tile located at the top-left of each of the MCTSs or the location information of a tile located at the bottom-right of each of the MCTSs.

[14] According to another embodiment of the present disclosure, a storage medium readable by a decoder for storing image information encoded by the image encoding method is provided. The encoding method according to the above exemplary embodiment includes a plurality of current pictures. Dividing into tiles; Generating segmentation information for the current picture based on the plurality of tiles; deriving prediction samples for the current block included in one of the plurality of tiles; the current picture based on the predicted samples Generating prediction information for a block; And encoding image information including segmentation information for the current picture and prediction information for the current block, wherein the segmentation information for the current picture is, Always lag information on whether the current picture is divided into MCTS (motion constrained tile sets), information on the number of MCTSs in the current picture, and information on each of the MCTSs

It includes at least one of the location information of the tile located at the top-left or the location information of the tile located at the bottom-right of each of the MCTSs. Effects of the Invention

[15] According to this disclosure, the overall image/video compression efficiency can be improved.

[16] According to this disclosure, the efficiency of picture partitioning can be improved.

[17] According to this disclosure, it is possible to increase the flexibility of picture partitioning based on the division information for the current picture. 2020/175908 1»（：1/10公020/002733 According to this disclosure, flag information on whether the current picture is divided into motion constrained tile sets (MCTS)), information on the number of MCTSs in the current picture, MCTS By dividing the current picture based on at least one of the position information of the tile located at the top-left with respect to each of the lifts or the position information of the tile located at the bottom-right of each of the MCTSs, It can increase the efficiency of signaling for partitioning.

Brief description of the drawing

[19] Fig. 1 schematically shows an example of a video/video coding system to which this disclosure can be applied.

[2] Fig. 2 shows the configuration of a video/video encoding device to which this disclosure can be applied.

This is a schematic drawing.

[21] Figure 3 shows the configuration of a video/video decoding apparatus to which this disclosure can be applied.

This is a schematic drawing.

4 exemplarily shows a hierarchical structure for coded data.

5 is a diagram showing an example of partitioning a picture.

6 is a flowchart illustrating a procedure for encoding a picture based on a tile and/or a tile group according to an embodiment.

7 is a flowchart illustrating a tile and/or tile group-based picture decoding procedure according to an embodiment.

8 is a diagram showing an example of partitioning a picture into a plurality of tiles.

9 is a block diagram showing the configuration of an encoding device according to an embodiment.

W is a block diagram showing the configuration of a decoding apparatus according to an embodiment.

11 is a diagram showing an example of a tile and a tile group unit constituting the current picture

]]] This is a drawing.

243

[2223] Fig. 12 schematically shows an example of the signaling structure of tile group information

It is a drawing.

13 is a diagram showing an example of a picture in a video conference video program.

14 is a diagram showing an example of partitioning a picture into tiles or tile groups in a video conference video program.

15 is a diagram illustrating an example of partitioning a picture into tiles or tile groups based on MCTS (Motion Constrained Tile Set).

16 is a diagram illustrating an example of dividing a picture based on an ROI area.

17 is a diagram showing an example of partitioning a picture into a plurality of tiles.

18 is a flow chart showing the operation of the decoding apparatus according to an embodiment.

19 is a block diagram showing a configuration of a decoding apparatus according to an embodiment.

20 is a flow chart showing the operation of the encoding device according to an embodiment.

21 is a block diagram showing the configuration of an encoding apparatus according to an embodiment. 2020/175908 1»（：1^1{2020/002733

[4] Fig. 22 shows an example of a content streaming system to which the disclosure of this document can be applied.

Show.

Modes for the implementation of the invention

[41] Since this disclosure can make various changes and have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present disclosure to specific embodiments. The terms commonly used in the specification are only used to describe specific embodiments and are not intended to limit the technical idea of this disclosure. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "include" or "have" are intended to designate the existence of a feature, number, step, action, component, part, or combination of one or more other features listed in the specification. It is to be understood that figures, numbers, steps, actions, components, and parts diagrams do not preclude the existence or additional possibility of any combination of them.

[42] On the other hand, each of the configurations in the drawings described in this disclosure

As shown independently for the convenience of explanation of the functions, it does not mean that each configuration is implemented with separate hardware or separate software; for example, two or more of each configuration may be combined to form a single configuration. One configuration may be divided into a plurality of configurations. Embodiments in which each configuration is incorporated and/or separated are also included in the scope of the rights of this disclosure, as long as it does not depart from the essence of this disclosure.

[43] In this specification, 1 or show or p" may mean "only show," "only, or "show and ^ all." In other words, 1 or show 01 in this specification is 1 and/ Or it can be interpreted as show （1/（epidermis”. For example, in this specification, “6” or “：（人 3 or（：）” means “only show”, “only ，,” only 0 \ or “人：8 and （：any combination of arbitrary （

6 Can mean （1〔:）”.

[44] A forward slash (/) or comma (¥111111幻) is used in this specification.

For example, "show 思" could mean 1 and/or 6".

“Show 思” can mean “only show”, “only, or “show and ^ all”. For example, “人 3,（:” can mean “人 3 or (:”).

[45]

It can be interpreted in the same way.

[46] Also, in this specification, “at least one 6 and 01 6 mountain (I!)” means,

“Only show”, “only ，,” only 0 \ or “：8 and （：any combination of any （ combination of A, B and C)”. Also, “at least one of A, B or C” or “at least one A, B and/or C ( "at least one of A, B and/or C)" can mean "at least one of A, B and/or C".

[47] In addition, parentheses used in this specification may mean “for example.” Specifically, when indicated as “predictive (intra prediction)”, “intra prediction” as an example of “prediction” In other words, “predictions” in this specification are not limited to “intra predictions”, and “intra predictions” may be suggested as an example of “predictions”. That is, even if it is marked as “intra prediction)”, “intra prediction” may have been proposed as an example of “prediction”.

[48] In this specification, technical features that are described individually within a single drawing may be implemented individually or simultaneously.

[49] Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the present disclosure will be described in more detail. Hereinafter, the same reference numerals are used for the same components in the drawings, and duplicated descriptions for the same components will be described. Can be omitted.

[5] Fig. 1 schematically shows an example of a video/video coding system to which this disclosure can be applied.

Referring to FIG. 1, the video/video coding system may include a first device (source device) and a second device (receive device). The source device is encoded.

Video/image information or data can be transferred to a receiving device via a digital storage medium or network in the form of a file or streaming.

[52] The source device may include a video source, an encoding device, and a transmission unit. The receiving device may include a receiver, a decoding device, and a renderer. The encoding device may be referred to as a video/image encoding device, and the decoding device may be referred to as a video/image decoding device. The transmitter may be included in the encoding device. The receiver may be included in the decoding device. The renderer may include a display unit, and the display unit may be composed of separate devices or external components.

[53] Video sources are captured through video/video capture, synthesis, or generation

Video/image can be acquired Video sources can include video/image capture devices and/or video/image generation devices Video/image capture devices can be, for example, one or more cameras, previously captured video/image Video/image archives, etc. Video/image generation devices may include, for example, computers, tablets and smartphones, and may (electronically) generate video/images, e.g. computers A virtual video/video can be created through the like, and in this case, the video/video capture process can be replaced by the process of generating related data.

[54] The encoding device can encode the input video/video. The encoding device can compress and For coding efficiency, a series of procedures such as prediction, transformation, and quantization can be performed.

The encoded data (encoded video/video information) can be summarized in the form of a bitstream.

[55] The transmission unit is encoded video/video information output in the form of a bitstream or

Data can be transferred to the receiver of the receiving device via a digital storage medium or network in the form of a file or streaming. The digital storage medium can include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD, SSD, etc. The transmission unit may include an element for generating a media file through a predetermined file format and may include an element for transmission through a broadcasting/communication network. The receiving unit may receive/extract the bitstream and transmit it to the decoding device. have.

[56] The decoding device is inverse quantization, inverse transformation, prediction, etc. corresponding to the operation of the encoding device.

Video/video can be decoded by performing a series of procedures.

[57] The renderer can render decoded video/video. The rendered video/video can be displayed through the display unit.

[58] This document is about video/image coding. For example,

The method/embodiment includes a versatile video coding (VVC) standard, an essential video coding (EVC) standard, an AOMedia Video 1 (AVI) standard, a 2nd generation of audio video coding standard (AVS2), or a next-generation video/image coding standard (ex.H). .267 or H.268, etc.).

[59] In this document, various embodiments of video/image coding are presented, and the above embodiments may be implemented in combination with each other unless otherwise stated.

[6 In this document, a video is a series of images over time.

It can mean a set. A picture generally refers to a unit representing one image in a specific time period, and a slice/tile is a unit constituting a part of a picture in coding. A tile can contain more than one CTU (coding tree unit); a picture can consist of more than one slice/tile.

[61] A tile is a rectangular region of CTUs within a particular tile column and a particular tile row in a picture). The tile row is a rectangular region of CTUs. The tile column is a rectangular region of CTUs having a height equal to the height of the picture and width can be specified by syntax elements in the picture parameter set. a width specified by syntax elements in the picture parameter set).The tile row is a rectangular area of CTUs, the rectangular area has a width specified by syntax elements in the picture parameter set, and the height can be the same as the height of the picture. (The tile row is a rectangular region of CTUs having a height specified by syntax elements in the picture parameter set and a width equal to the width of the picture). 2020/175908 1»（：1/10公020/002733 Can represent sequential ordering, the CTUs can be sequentially sorted by CTU raster scan within a tile, and tiles within a picture are continuous by raster scan of the tiles of the picture. (A tile scan is a specific sequential ordering of CTUs partitioning a picture in which the CTUs are ordered consecutively in CTU raster scan in a tile whereas tiles in a picture are ordered consecutively in a raster scan of the tiles of the picture A slice can contain any number of complete tiles or multiple consecutive CTU rows within one tile of a picture that can be contained in a single NAL unit. Tile groups and slices can be mixed in this document, for example In a document, the tile group/tile group header can be called a slice/slice header.

[62] On the other hand, a picture can be divided into two or more subpictures. A subpicture can be a rectangular region of one or more slices within a picture (an mctangular mgion of one or more slices within a picture).

[63] A pixel or pel may mean the smallest unit constituting a picture (or image). In addition,'sample' may be used as a term corresponding to a pixel. Sample In general, can represent the pixel or pixel value, it can represent only the pixel/pixel value of the luma component, or it can represent only the pixel/pixel value of the chroma component.

[64] A unit can represent a basic unit of image processing. A unit can contain at least one of a specific area of a picture and information related to that area. A unit can contain one luma block and two chromas (one luma block and two chromas). ex. cb, cr) may contain a block A unit may be used interchangeably with terms such as _block or area in some cases. In general, the MxN block may include a set (or array) of samples (or sample array) or transform coefficients consisting of M columns and N rows.

[65] Figure 2 shows the configuration of a video/video encoding apparatus to which this disclosure can be applied.

This is a schematic diagram. Hereinafter, the video encoding device may include an image encoding device.

Referring to FIG. 2, the encoding device 200 includes an image partitioner 210,

Predictor (220), residual processor (230), entropy encoder (240), adder (250), filtering unit (filter, 260) and memory (memory, 270) It can be configured to include. For example, the part 220 is

It may include a prediction unit 221 and an intra prediction unit 222. The residual processing unit 230 includes a transform unit 232, a quantizer 233, an inverse quantizer 234, and an inverse transform unit ( An inverse transformer 235 may be included. The residual processing unit 230 may further include a subtractor 231. The addition unit 250 may include a reconstructor or a recontructged block generator. The image segmentation unit 210 described above, the prediction unit 220, the residual processing unit 230, the entropy encoding unit 240, The addition unit 250 and the filtering unit 260 are

The hardware component may be configured by a component (e.g., an encoder chipset or processor). Also, the memory 270 may include a decoded picture buffer (DPB), and may be configured by a digital storage medium. The hardware component is a memory 270. You can also include more as internal/external components.

[67] The image segmentation unit (2W) is an input image (or, picture, input) input to the encoding device 200

Frame) can be divided into one or more processing units. For example, the processing unit may be referred to as a coding unit (CU), in which case the coding unit is a coding tree unit (CTU). Alternatively, it can be divided recursively from the largest coding unit (LCU) according to the QTBTTT (Quad-tree binary-tree ternary-tree) structure. For example, one coding unit has a quad tree structure, Based on the binary tree structure and/or ternary structure, it can be divided into a plurality of coding units of deeper depth. In this case, for example, the quad tree structure is applied first, and the binary tree structure and/or ternary structure is It may be applied later. Or the binary retrieval structure may be applied first. The coding procedure according to this disclosure may be performed based on the final coding unit that is no longer divided. In this case, based on the coding efficiency according to the image characteristics, etc., the maximum possible The coding unit can be used directly as the final coding unit, or if necessary, the coding unit can be

It is recursively divided into coding units of a lower depth, so that the optimal size coding unit can be used as the final coding unit. Here, the coding procedure may include procedures such as prediction, conversion, and restoration described later. As another example, the processing unit may further include a unit (PU: Prediction Unit) or a transformation unit (TU: Transform Unit). In this case, the prediction unit and the transformation unit are each divided from the final coding unit described above. Alternatively, it may be partitioned. The prediction unit may be a unit of sample prediction, and the transform unit may be a unit for inducing a conversion factor and/or a unit for inducing a residual signal from the conversion factor.

[68] Units are sometimes used interchangeably with terms such as block or area.

In general, an MxN block can represent a set of samples or transform coefficients consisting of M columns and N rows. A sample can typically represent a pixel or pixel value, and the luminance ( It can represent only the pixel/pixel value of the luma component, or it can represent only the pixel/pixel value of the chroma component. A sample corresponds to one picture (or image) corresponding to a pixel or pel. Can be used as a term.

[69] The encoding device 200 subtracts the prediction signal (predicted block, prediction sample array) output from the inter prediction unit 221 or the intra prediction unit 222 from the input video signal (original block, original sample array). Thus, a residual signal (residual signal, residual block, residual sample array) can be generated, and the generated residual signal is transmitted to the conversion unit 232. In this case, the input image within the encoding device 200 as shown Signal (original block, original The unit that subtracts the prediction signal (prediction block, prediction sample array) from the sample array) may be referred to as a subtraction unit 231. The prediction unit performs prediction on a block to be processed (hereinafter referred to as a current block), and the above A predicted block including predicted samples for the current block can be generated. The prediction unit can determine whether intra prediction is applied or inter prediction is applied in units of the current block or CU. The prediction unit may generate various types of information related to prediction, such as prediction mode information, as described later in the description of each prediction mode, and transmit it to the entropy encoding unit 240. The information on prediction may be encoded in the entropy encoding unit 240 and summarized in the form of a bitstream.

The PI intra prediction unit 222 may predict the current block by referring to samples in the current picture. The referenced samples are of the current block according to the prediction mode.

It can be located in the neighborhood, or it can be located away from it. In intra prediction, the prediction modes can include a plurality of non-directional modes and a plurality of directional modes. Non-directional modes are, for example, DC mode and planner mode. Can include (Planar mode) Directional mode, for example, depending on the precision of the predicted direction.

It may include 33 directional prediction modes or 65 directional prediction modes. However, this is an example and more or less directional predictions depending on the setting.

Modes may be used. The intra prediction unit 222 may determine a prediction mode to be applied to the current block by using the prediction mode applied to the surrounding block.

P 1] The inter prediction unit 221 refers to a reference specified by a motion vector on the reference picture.

Based on the block (reference sample array), it is possible to induce the predicted block for the current block. In this case, based on the correlation of the motion information between the neighboring block and the current block to reduce the amount of motion information transmitted in the inter prediction mode. Motion information can be predicted in units of blocks, sub-blocks, or samples. The motion information may include a motion vector and a reference picture index. The motion information indicates inter prediction direction (L0 prediction, L1 prediction, Bi prediction, etc.) In the case of inter prediction, the peripheral block may include a spatial neighboring block existing in the current picture and a temporal neighboring block existing in the reference picture. The reference picture including the reference block and the reference picture including the temporal peripheral block may be the same or different. The temporal peripheral block may be a collocated reference block, a co-located CU (colCU), etc. It can be called by the name of, and the reference picture containing the temporal surrounding block is the same position.

It can also be called a picture (collocated picture, colPic), for example, inter

The prediction unit 221 may construct a motion information candidate list based on the neighboring blocks, and generate information indicating which candidate is used to derive the motion vector and/or reference picture index of the current block. Inter prediction may be performed based on the prediction mode. For example, in the case of the skip mode and the merge mode, the inter prediction unit 221 moves the motion information of the neighboring block to the current block. It can be used as information In the case of skip mode, unlike the merge mode, the residual signal may not be transmitted In the case of motion information e.g. (motion vector prediction, MVP) mode, the motion vector of the neighboring block is used as a motion vector, i.e. vector predictor), and by signaling the motion vector difference, the motion vector of the current block can be indicated.

2] The prediction unit 220 may generate a prediction signal based on various prediction methods to be described later. For example, the prediction unit may apply intra prediction or inter prediction to predict one block, as well as intra prediction. Prediction and inter prediction can be applied at the same time. This can be called combined inter and intra prediction ([can be referred to as). Also, for example, it may be based on an intra block copy (IBC) prediction mode for example. Or it may be based on a palette mode. The IBC prediction mode or palette mode can be used for content video/video coding such as games, for example SCC (screen content coding), etc. IBC is basically This can be done similarly to inter prediction in that it performs prediction within the current picture but derives a reference block within the current picture, i.e. IBC can use at least one of the inter prediction techniques described in this document. The mode can be seen as an example of intracoding or intra prediction. When the palette mode is applied, the sample value in the picture can be signaled based on the information about the palette table and palette index.

3] The prediction signal generated through the prediction unit (including the inter prediction unit 221 and/or the intra prediction unit 222) may be used to generate a restoration signal or may be used to generate a residual signal. The transform unit 232 may generate transform coefficients by applying a transform method to the residual signal. For example, the transform method is DCT (Discrete Cosine Transform), DST (Discrete Sine Transform),

KLT (Karhunen-Loeve Transform), GBT (Graph-Based Transform), or

It may include at least one of CNT (Conditionally Non-linear Transform).

Here, when it is said that GBT expresses relationship information between pixels in a graph,

It means the transformation obtained from the graph. CNT refers to a transformation that is obtained based on, e.g., generating a signal using all previously reconstructed pixels. Also, the transformation process can be applied to a block of pixels of the same size of a square, and It can also be applied to blocks of variable size that are not square.

4] The quantization unit 233 quantizes the transform coefficients to the entropy encoding unit 240

After being transmitted, the entropy encoding unit 240 encodes the quantized signal (information on quantized transformation coefficients) and outputs it as a bitstream. The information on the quantized transformation coefficients may be referred to as residual information. The quantization unit 233 can rearrange the quantized transformation coefficients of the block form into a one-dimensional vector form based on the coefficient scan order, and the quantized transformation coefficients of the one-dimensional vector form Based on the quantized transformation coefficients, information on the quantized transformation coefficients may be generated. The entropy encoding unit 240 includes, for example, exponential Golomb,

Various encoding methods such as CAVLC (context-adaptive variable length coding) and CABAC (context-adaptive binary arithmetic coding) can be performed. The entropy encoding unit 240 includes quantized conversion factors and information necessary for video/image restoration. (E.g., values of syntax elements) can be encoded together or separately Encoded information (ex.encoded video/video information) is transmitted in the form of a bitstream in units of network abstraction layer (NAL) units or The video/video information may further include information about various parameter sets, such as an appointment parameter set (APS), a picture parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS). In addition, the video/video information may further include general constraint information. In this document, information transmitted/signaled from the encoding device to the decoding device and/or syntax elements may be included in the video/video information. The video/video information may be encoded through the above-described encoding procedure and included in the bitstream. The bitstream may be transmitted through a network or may be stored in a digital storage medium. Here, the network is a broadcasting network and/or The digital storage medium may include a variety of storage media such as USB, SD, CD, DVD, Blu-ray, HDD, SSD, etc. The signal output from the entropy encoding unit 240 is transmitted by a transmission unit ( (Not shown) and/or a storage unit (not shown) for storing may be configured as an internal/external element of the encoding apparatus 200, or a transmission unit may be included in the entropy encoding unit 240.

5] The quantized transformation coefficients output from the quantization unit 233 can be used to generate the predicted signal. For example, the quantization unit 234 and the inverse transformation unit 235 are applied to the quantized transformation coefficients. Residual by applying quantization and inverse transformation

A signal (residual block or residual samples) can be restored. The addition unit 155 restores the restored residual signal by adding the restored residual signal to the prediction signal output from the inter prediction unit 221 or the intra prediction unit 222. A (reconstructed) signal (restored picture, reconstructed block, reconstructed sample array) can be generated If there is no residual for the block to be processed, such as when the skip mode is applied, the predicted block can be used as a reconstructed block. The unit 250 may be referred to as a restoration unit or a restoration block generation unit. The generated restoration signal may be used for intra prediction of the next processing target block in the current picture, and inter prediction of the next picture through filtering as described below. It can also be used for

R6] Meanwhile, LMCS (luma mapping with chroma scaling) may be applied during picture encoding and/or restoration.

7] The filtering unit 260 applies filtering to the restored signal to improve subjective/objective image quality.

For example, the filtering unit 260 applies various filtering methods to the restored picture. By applying the modified (modified) restored picture can be generated, the modified restored picture can be stored in the memory 270, specifically the DPB of the memory 270. The various filtering methods include, for example, deblocking filtering. , A sample adaptive offset, an adaptive loop filter, a bilateral filter, etc. The filtering unit 260 performs filtering as described later in the description of each filtering method. A variety of information related to may be generated and transmitted to the entropy encoding unit 240. The filtering information may be encoded by the entropy encoding unit 240 and output in the form of a bitstream.

8] The modified reconstructed picture transmitted to the memory 270 can be used as a reference picture in the inter prediction unit 221. When the inter prediction is applied through this, the encoding device is predicted by the encoding device (W0) and the decoding device. Mismatch can be avoided and coding efficiency can be improved.

9] Memory 270 The DPB can store the modified restored picture for use as a reference picture in the inter prediction unit 221. The memory 270 is a block of the block from which motion information in the current picture is derived (or encoded). It is possible to store motion information and/or motion information of blocks in a picture that has already been restored. The stored motion information can be transmitted to the inter prediction unit 221 for use as motion information of spatial neighboring blocks or motion information of temporal neighboring blocks. The memory 270 may store restoration samples of the restored blocks in the current picture, and may transmit the restoration samples to the intra prediction unit 222.

[8] Fig. 3 shows the configuration of a video/video decoding apparatus to which this disclosure can be applied.

This is a schematic drawing.

[81] Referring to FIG. 3, the decoding apparatus 300 includes an entropy decoder 310, a residual processor 320, a predictor 330, and an adder 340. , Can be configured including a filtering unit (filter, 350) and memory (memory, 360). The prediction unit 330 may include an intra prediction unit 331 and an inter prediction unit 332.

The residual processing unit 320 may include a dequantizer 321 and an inverse transformer 321. The above-described entropy decoding unit 310, a residual processing unit 320, a prediction unit 330, The addition unit 340 and the filtering unit 350 may be configured by one hardware component (for example, a decoder chipset or processor) according to an embodiment. Further, the memory 360 may include a decoded picture buffer (DPB). In addition, it may be configured by a digital storage medium. The hardware component may include a memory 360 as an internal/external component loader.

When a bitstream including video/image information is input, the decoding device 300 can restore the image in response to a process in which the video/image information is processed in the encoding device of FIG. 3. For example, decoding The device 300 may derive units/blocks based on the block division related information acquired from the bitstream. The decoding device 300 may perform decoding using a processing unit applied in the encoding device. Therefore, decoding The processing unit of may be, for example, a coding unit, and the coding unit is From the coding tree unit or the maximum coding unit, it can be divided according to the quad tree structure, the binary tree structure, and/or the turner tree structure. One or more conversion units can be derived from the coding unit. And, decoding through the decoding device 300, And the output restored image signal can be reproduced through the reproduction device.

[83] The decoding device 300 converts the signal output from the encoding device of FIG. 3 into a bitstream.

It can be received in a form, and the received signal can be decoded through the entropy decoding unit 310. For example, the entropy decoding unit 3W parses the bitstream and is required for image restoration (or picture restoration). Information (ex. video/video information) can be derived. The video/video information may further include information on various parameter sets, such as an appointment parameter set (APS), a picture parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS). /Video information may further include general constraint information. The decoding device may further decode the picture based on the information on the parameter set and/or the general limit information. The signaling/received information and/or syntax elements described later in this document are decoded through the decoding procedure, It can be obtained from the bitstream. For example, the entropy decoding unit (3W) decodes the information in the bitstream based on a coding method such as exponential Golomb coding, CAVLC or CABAC, In more detail, the CABAC entropy decoding method receives the bin corresponding to each syntax element in the bitstream, and receives the decoding target syntax element information and the surrounding and decoding information of the decoding target block. Alternatively, the context model is determined using the symbol/bin information decoded in the previous step, and the probability of occurrence of bins is predicted according to the determined context model, and arithmetic decoding of bins is performed. A symbol corresponding to the value of the syntax element can be generated. In this case, the CABAC entropy decoding method can update the context model using information of the decoded symbol/bin for the context model of the next symbol/bin after determining the context model. Among the information decoded by the entropy decoding unit (3W), information about prediction is provided to the prediction unit (inter prediction unit 332 and intra prediction unit 331), and entropy decoding is performed by the entropy decoding unit 3W. The residual value, that is, quantized transform coefficients and related parameter information may be input to the residual processing unit 320.

The residual processing unit 320 may derive a residual signal (residual block, residual samples, and residual sample array). In addition, information about filtering among information decoded by the entropy decoding unit 310 is a filtering unit. Can be provided as 350. On the other hand, a receiving unit (not shown) that receives the signal output from the encoding device may be further configured as an internal/external element of the decoding device 300, or the receiving unit may be a component of the entropy decoding unit 3W. ,The decoding device according to this document may be called a video/image/picture decoding device, and the decoding device is an information decoder (video/image/picture information decoder) and a sample decoder (video/image/picture sample). Decoder), the information decoder is the entropy

A decoding unit (3W) may be included, and the sample decoder includes the inverse quantization unit 321, an inverse transform unit 322, an addition unit 340, a filtering unit 350, a memory 360, an inter prediction unit ( 332) and an intra prediction unit 331.

[84] The inverse quantization unit 321 may inverse quantize the quantized transformation coefficients and output the transformation coefficients. The inverse quantization unit 321 may rearrange the quantized transformation coefficients in a two-dimensional block form. In this case, the above reordering The inverse quantization unit 321 performs inverse quantization on the quantized transform coefficients using a quantization parameter (for example, quantization step size information) based on the coefficient scan order performed by the silver encoding device. And, you can obtain transform coefficients.

In the inverse transform unit 322, a residual signal (residual block, residual sample array) is obtained by inverse transforming the transform coefficients.

[86] The prediction unit performs prediction on the current block, and predicts the current block

A predicted block including samples may be generated. The prediction unit determines whether intra prediction or inter prediction is applied to the current block based on the information about the prediction output from the entropy decoding unit 310. Can be determined and specific intra/inter prediction modes can be determined.

[87] The prediction unit 330 may generate a prediction signal based on various prediction methods to be described later. For example, the prediction unit may not only apply intra prediction or inter prediction to predict a single block, but also apply it. Intra prediction and inter prediction can be applied at the same time. This can be called combined inter and intra prediction ([can be referred to as). In addition, for example, the example is based on the intra block copy (IBC) prediction mode for block prediction. It may or may be based on a palette mode. The IBC prediction mode or palette mode can be used for content video/video coding such as games, for example, SCC (screen content coding), etc. IBC is Basically, the prediction is performed within the current picture, but it can be performed similarly to inter prediction in that it derives a reference block within the current picture, i.e., IBC can use at least one of the inter prediction techniques described in this document. Palette mode can be seen as an example of intra coding or intra prediction. When the palette mode is applied, information about the palette table and palette index may be included in the video/video information and signaled.

[88] The intra prediction unit 331 may predict the current block by referring to samples in the current picture. The referenced samples are of the current block according to the prediction mode.

The prediction modes may include a plurality of non-directional modes and a plurality of directional modes in intra prediction. The intra prediction unit 331 is a prediction applied to a peripheral block. Using the mode, you can also determine the prediction mode that applies to the current block. [89] The inter prediction unit 332 may induce a predicted block for the current block based on a reference block (reference sample array) specified by a motion vector on the reference picture. At this time, transmitted in the inter prediction mode. In order to reduce the amount of motion information, motion information can be predicted in units of blocks, sub-blocks, or samples based on the correlation of motion information between the neighboring block and the current block. The motion information may include a motion vector and a reference picture index. The motion information may further include information on the inter prediction direction (L0 prediction, L1 prediction, Bi prediction, etc.) In the case of inter prediction, the neighboring block is a spatial neighboring block existing in the current picture and a reference picture. It can include a temporal neighboring block that exists in. For example, the inter prediction unit 332 may construct a motion information candidate list based on the neighboring blocks, and derive a motion vector and/or a reference picture index of the current block based on the received candidate selection information. Inter prediction may be performed based on the prediction mode, and the information on the prediction may include information indicating a mode of inter prediction for the current block.

[9 This addition unit 340 is a prediction unit (inter prediction unit 332) and/or the obtained residual signal

In addition to the prediction signals (predicted blocks, prediction sample arrays) output from the intra prediction unit 331), a restoration signal (restored picture, restoration block, restoration sample array) can be generated. Processing as in the case where skip mode is applied. If there is no residual for the target block, the predicted block can be used as a restore block.

[91] The addition unit 340 may be referred to as a restoration unit or a restoration block generation unit. The generated restoration signal may be used for intra prediction of the next processing target block in the current picture, and output after filtering as described later. It may be used or it may be used for inter prediction of the next picture.

[92] Meanwhile, luma mapping with chroma scaling (LMCS) may be applied in the picture decoding process.

[93] The filtering unit 350 applies filtering to the restored signal to improve subjective/objective image quality.

For example, the filtering unit 350 may apply various filtering methods to the restored picture to generate a modified restored picture, and store the modified restored picture in a memory 360, specifically a memory 360. The various filtering methods include, for example, deblocking filtering, sample adaptive offset, adaptive loop filter, bilateral filter, etc. can do.

[94] The (modified) reconstructed picture stored in the DPB of the memory 360 may be used as a reference picture in the inter prediction unit 332. The memory 360 is the one from which motion information in the current picture is derived (or decoded). The motion information of the block and/or the motion information of the blocks in the picture that has already been restored can be stored. The stored motion information is interpolated to be used as the motion information of the spatial surrounding block or the motion information of the temporal surrounding block.

It can be transmitted to the prediction unit 332. The memory 360 is a block of the restored blocks in the current picture. Restore samples can be stored, and can be delivered to the intra prediction unit 331.

[95] In the present specification, the embodiments described in the filtering unit 260, the inter prediction unit 221, and the intra prediction unit 222 of the encoding apparatus 100 are respectively described in the filtering unit 350 of the decoding apparatus 300 , The inter prediction unit 332 and the intra prediction unit 331 may be applied to be the same or corresponding to each other.

[96] As described above, prediction is performed to increase compression efficiency in performing video coding. Through this, a predicted block including predicted samples for the current block, which is a block to be coded, can be generated. The block includes prediction samples in the spatial domain (or pixel domain). The predicted block is derived identically in the encoding device and the decoding device, and the encoding device is the original block and the original block, not the original sample value itself. The video coding efficiency can be increased by signaling the predicted residual information (residual information) between the predicted blocks with a decoding device. The decoding device derives a residual block including residual samples based on the residual information, and , The residual block and the predicted block may be summed to generate a restoration block including restoration samples, and a restoration picture including restoration blocks may be generated.

[97] The residual information may be generated through transformation and quantization procedures. For example, the encoding device derives a residual block between the original block and the predicted block, and the residual information is included in the residual block. Transformation coefficients are derived by performing a transformation procedure on samples (residual sample array), quantized transformation coefficients are derived by performing a quantization procedure on the transformation coefficients, and related residual information (via bitstream) Here, the residual information may include information such as value information of the quantized conversion coefficients, location information, conversion technique, conversion kernel, and quantization parameters. The decoding apparatus is inverse based on the residual information. The quantization/inverse transform procedure can be performed and residual samples (or residual blocks) can be derived. The decoding device can generate a reconstructed picture based on the predicted block and the residual block. The encoding device can also generate a later picture. For reference for inter prediction, a residual block is derived by inverse quantization/inverse transformation of the quantized transformation coefficients, and a reconstructed picture can be generated based on this.

4 exemplarily shows a hierarchical structure for coded data.

[99] Referring to FIG. 4, the coded data is between a video coding layer (VCL) that deals with the video/image coding process and itself, and a sub-system that stores and transmits the coded video/image data. It can be classified as a network abstraction layer (NAL).

[10 This VCL is a set of parameters corresponding to headers such as sequences and pictures (picture parameter set (PPS), sequence parameter set (SPS), video parameter set (VPS), etc.)) and in addition to the video/image coding process. Required Supplemental Enhancement (SEI) information) message can be created. The SEI message is separated from the video/image information (slice data). The VCL containing the video/image information consists of the slice data and the slice header. On the other hand, the slice header is a tile group header. It may be referred to as, and the slice data may be referred to as tile group data.

[101] In NAL, header to RBSP (Raw Byte Sequence Payload) generated from VCL

NAL unit can be created by adding information (NAL unit header). At this time, RBSP refers to slice data, parameter set, SEI message, etc. generated from VCL. The NAL unit header may include NAL unit type information specified according to RBSP data included in the corresponding NAL unit.

[102] The NAL unit, which is the basic unit of NAL, plays a role of mapping the coded image to the bit stream of sub-systems such as file format, RTP (Real-time Transport Protocol), TS (Transport Strea), etc. according to a predetermined standard.

[103] As shown, the NAL unit is the NAL unit according to the RBSP generated from the VCL.

It can be divided into a VCL NAL unit and a Non-VCL NAL unit. The VCL NAL unit can mean a NAL unit that contains information about the video (slice data), and the Non-VCL NAL unit is a NAL unit that contains the information (parameter set or SEI message) necessary for decoding the video. Can mean

[104] The above-described VCL NAL unit and Non-VCL NAL unit can be transmitted through a network by attaching header information according to the data standard of the sub-system. For example, the NAL unit is in H.266/VVC file format, RTP (Real- time Transport Protocol), TS (Transport Stream), etc.

[105] As described above, the NAL unit is RBSP data included in the NAL unit.

The NAL unit type may be specified according to the structure, and information on the NAL unit type may be stored in the NAL unit header and signaled.

[106] For example, whether the NAL unit contains information about the image (slice data)

Depending on whether or not, it can be largely classified into VCL NAL unit type and Non-VCL NAL unit type. The VCL NAL unit type can be classified according to the properties and types of pictures included in the VCL NAL unit, and the non-VCL NAL unit type can be classified according to the type of parameter set.

[107] The following is an example of the NAL unit type specified according to the type of parameter set included in the Non-VCL NAL unit type. The NAL unit type can be specified according to the type of parameter set, etc. For example, the NAL unit type is an APS (Adaptation Parameter Set) NAL unit, which is a type for NAL units including APS, and a type for NAL units including DPS. In DPS (Decoding Parameter Set) NAL unit, VPS (Video Parameter Set) NAL unit, which is a type for NAL unit including VPS, SPS (Sequence Parameter Set) NAL unit, which is a type for NAL unit including SPS, and It can be specified as any one of the PPS (Picture Parameter Set) NAL units, which are types for NAL units including PPS.

[108] The above-described NAL unit types have syntax information for the NAL unit type, and the syntax information may be stored in the NAL unit header and signaled. For example, the syntax information may be nal_unit_type, and the NAL unit types are nal_unit_type values. Can be specified.

[109] On the other hand, as described above, one picture can contain a plurality of slices, and one slice can contain a slice header and slice data. In this case, multiple slices (slice header and slice data) within one picture. For a set), one picture header can be added. The picture header (picture header syntax) can include information/parameters commonly applicable to the picture. The slice header (slice header syntax) can be added to the slice. Commonly applicable information/parameters may be included. The above APS (APS syntax) or PPS (PPS syntax) may contain information/parameters commonly applicable to one or more slices or pictures. SPS (SPS syntax) above. May contain information/parameters that are commonly applicable to more than one sequence. The VPS (VPS syntax) may contain information/parameters that are commonly applicable to multiple layers. The DPS (DPS syntax) is common throughout the video. The DPS may include information/parameters applicable to the CVS (coded video sequence) concatenation. The high level syntax (HLS) in this document refers to the APS. At least one of syntax, PPS syntax, SPS syntax, VPS syntax, DPS syntax, a picture header syntax, and slice header syntax can be included.

[110] In this document, the image/video information encoded from the encoding device to the decoding device and signaled in the form of a bitstream only includes intra-picture partitioning information, intra/inter prediction information, residual information, and in-loop filtering information. Rather, information included in the slice header, information included in the picture header, information included in the APS, information included in the PPS, information included in the SPS, information included in the VPS, and/or the information included in the DPS. Information may be included. In addition, the image/video information may further include information of the NAL unit header.

5 is a diagram showing an example of partitioning a picture.

[112] Pictures can be divided into coding tree units (CTUs), and CTU is a coding tree unit.

Block (CTB) can be responded. The CTU can contain a coding tree block of luma samples and two coding tree blocks of chroma samples corresponding thereto. On the other hand, the maximum allowable size of CTU for coding and prediction is the CTU for conversion. It may be different from the maximum allowable size.

[113] A tile can correspond to a series of CTUs covering a rectangular area of a picture, and a picture can be divided into one or more tile rows and one or more tile columns. 2020/175908 1»（：1^1{2020/002733

[114] On the other hand, a slice can consist of an integer number of complete tiles or an integer number of consecutive complete 0X1 rows. In this case, two slice modes including raster scan (-) slice mode and rectangular slice mode can be supported.

[115] In raster scan slice mode, the slice is in the tile raster scan of the picture.

It can contain a series of complete tiles. In square slice mode, a slice is a number of complete tiles that collectively form a rectangular area of the picture, or a number of consecutive tiles in a single tile that collectively form a rectangular area of the picture. (：1!1 rows can be included. Tiles within a square slice can be scanned in tile raster scan order within the square area corresponding to the slice.

[116] In Fig. 5, an example of dividing a picture into tiles and raster scan slices is shown.

This is a diagram showing, for example, a picture can be divided into 12 tiles and 3 raster scan slices.

[117] Also, Figure 5 shows an example of dividing a picture into tiles and square slices.

This is the drawing shown, for example, a picture can be divided into 24 tiles (6 tile columns and 4 tile rows) and 9 square slices.

[118] Further, the figure in Fig. 5 shows an example of dividing the picture into tiles and square slices.

This is the drawing shown, for example, a picture can be divided into 24 tiles (2 tile columns and 2 tile rows) and 4 square slices.

6 is a flowchart illustrating a tile and/or tile group-based picture encoding procedure according to an embodiment.

[12 in this embodiment, picture partitioning 600] and information on tiles/tile groups

Generation 610) can be performed by the video segmentation unit 210 of the encoding device, and for video/video information including information about tiles/tile groups.

The encoding 620) can be performed by the entropy encoding unit 240 of the encoding device.

[121] The encoding apparatus according to an embodiment may perform picture partitioning to encode an input picture 600). The picture may include one or more tiles/tile groups. The encoding apparatus is an image of the picture. Considering the characteristics and coding efficiency, the picture can be partitioned into various types, and information indicating the partitioning type with the optimum coding efficiency can be generated and signaled to the decoding device.

[122] An encoding apparatus according to an embodiment includes a tile/tile applied to the picture

Determine the group and create information about the tile/tile group 610). The information on the tile/tile group may include information indicating the structure of the tile/tile group for the picture. The information on the tile/tile group includes various parameter sets and/or tile group headers as described later. It can be signaled through. A specific example is described below.

[123] The encoding apparatus according to an embodiment may encode video/image information including information on the tile/tile group and output it in a bitstream format 620). The bitstream may be transmitted to a decoding device through a digital storage medium or a network. The video/image information may include the HLS and/or tile group header syntax described in this document. In addition, the video/image information is The above-described prediction information, residual information, (in-loop) filtering information, etc. may be further included. For example, the encoding device restores the current picture, applies in-loop filtering, and encodes the parameters related to the in-loop filtering. It can be output in bitstream format.

7 is a flow diagram illustrating a tile and/or tile group-based picture decoding procedure according to an embodiment.

[125] In one embodiment, the step of acquiring information on a tile/tile group from a bitstream (S700) and deriving a tile/tile group within a picture (Stage 0), and decoding a picture based on a tile/tile group Step (S720) of performing is the entropy of the decoding device

It may be performed by the decoding unit 310, and the step (S620) of encoding video/image information including information on a tile/tile group may be performed by a sample decoder of the decoding apparatus.

[126] A decoding apparatus according to an embodiment includes tiles/tiles from a received bitstream.

Information on the group can be obtained (S700). The information on the tile/tile group can be obtained through various parameter sets and/or tile group headers as described later. A specific example will be described later.

The decoding apparatus according to an embodiment may derive a tile/tile group in a current picture based on the information on the tile/tile group (S phase 0).

[128] The decoding apparatus according to an embodiment may decode the current picture based on the tile/tile group (S720). For example, the decoding apparatus derives a CTU/CU located in the tile, and performs it. Based on inter/intra prediction, residual processing, restoration block (picture) generation, and/or in-loop filtering procedures can be performed. In this case, for example, the decoding device can perform context model/information in tile/tile group units. In addition, if the surrounding block or the surrounding sample referenced during inter/intra prediction is located on a tile different from the current tile where the current block is located, the decoding device may treat the surrounding block or the surrounding sample as not available. .

In one embodiment, tiles may refer to areas within a picture defined by a set of vertical and/or horizontal boundaries that divide the picture into a plurality of rectangles. FIG. 8 shows one picture 700 Figure 8 shows an example of splitting into multiple tiles based on a plurality of column boundaries (810) and row boundaries (820) within the first 32 maximum coding units (or 820). Coding Tree Units (CTUs) are numbered and shown.

[131] In one embodiment, each tile may include an integer number of CTUs processed in a raster scan order within each tile. In this case, a plurality of tiles within a picture, including each tile, may also include the picture. It can be processed as a raster scan order within. The tiles can be grouped to form tile groups, and tiles within a single tile group can be raster scanned. Splitting a picture into tiles is

It can be defined based on the syntax and semantics of the Picture Parameter Set (PPS).

[132] In one embodiment, the information derived from the PPS about tiles may be used to check (or read) the following items. First, check whether a tile exists in the picture or whether more than one tile exists. If more than one tile is present, it can be checked whether the above one or more tiles are uniformly distributed, the dimension of the tiles can be checked, and whether the loop filter is enabled can be checked. have.

In one embodiment, the PPS may signal the syntax element single_tile_in_pic_flag first. The single_tile_in_pic_flag may indicate whether only one tile in a picture exists or whether a plurality of tiles in a picture exist. A plurality of tiles in a picture When they are present, the decoding device can parse information about the number of tile rows and tile columns using the syntax elements num_tile_columns_minus 1 and num_tile_rows_minusl. The syntax element num_tile_columns_minus 1 and

num_tile_rows_minusl can specify the process of dividing a picture into tile rows and columns. The heights of tile rows and widths of tile columns are from the perspective of CTBs (i.e.

CTB in units).

[134] In one embodiment, whether or not tiles in a picture are uniformly spaced

Additional flags can be parsed to check if the tiles in the picture are not uniformly spaced, the number of CTBs per tile can be explicitly signaled for each tile row and column boundaries (i.e. CTB within each tile row). The number of and the number of CTBs in each tile row can be signaled) If the tiles are spaced uniformly, the tiles can have the same width and height.

[135] In one embodiment, a loop filter is enabled for tile boundaries.

Another flag (e.g. the syntax element loop_filter_across_tiles_enabled_flag) can be parsed to determine if it has been enabled.

[136] Table 1 below summarizes examples of main information about tiles that can be derived by parsing the PPS. Table 1 can represent the PPS RBSP syntax. 2020/175908 1»(：1/10公020/002733

[137] [Table 1]

Table 2 below shows an example of semantics for the syntax elements described in Table 1 above.

[139] [S.2]

2020/175908 1»（：1/10公020/002733

[14 this

9 is a block diagram showing a configuration of an encoding apparatus according to an embodiment, and FIG. 9 is a block diagram showing a configuration of a decoding apparatus according to an embodiment.

9 shows an example of a block diagram of an encoding apparatus. The encoding apparatus 900 shown in FIG. 9 includes a partitioning module 910 and an encoding module 920. The partitioning module (0) and the image division unit (0) of the encoding device shown in FIG. The same and/or similar operations may be performed, and the encoding module 920 may perform the same and/or similar operations as the entropy encoding unit 240 of the encoding apparatus shown in FIG. 2. The input video is a partitioning module 9 After being divided in W), it can be encoded in the encoding module 920. After being encoded, the encoded video can be output from the encoding device 900.

An example of a block diagram of a decoding apparatus is shown in FIG. W. The decoding apparatus 1000 shown in FIG. W includes a decoding module 1010 and a deblocking filter 1020. The decoding module ( 1010) can perform the same and/or similar operations as the entropy decoding unit 3W of the decoding apparatus shown in FIG. 3, and the deblocking filter 1020 is a filtering unit 350 of the decoding apparatus shown in FIG. The same and/or similar operations can be performed. The decoding module 1010 decodes the input received from the encoding device 900 to derive information about tiles. A processing unit based on the decoded information The deblocking filter 1020 may apply an in-loop deblocking filter to process the processing unit. In-loop filtering may be applied to remove coding artifacts generated during the partitioning process. The in-loop filtering The operation may include an adaptive loop filter (ALF), a deblocking filter (DF), a sample adaptive operation set (SAO), etc. After that, the decoded picture can be output.

[144] Examples of descriptors that specify the parsing process of each syntax element are shown in Table 3 below.

[145] [S3]

]

11 is a diagram illustrating an example of a tile and tile group unit constituting a current picture.

[148] As mentioned above, tiles can be grouped to form tile groups. 11 shows an example in which one picture is divided into tiles and tile groups. In FIG. 11, the picture includes 9 tiles and 3 tile groups. Each tile group can be independently coded.

12 schematically shows an example of the signaling structure of tile group information

It is a drawing.

[150] In CVS (Coded Video Sequence), each tile group has a tile group header.

Tile groups can have a similar meaning to a slice group. Each tile group can be independently coded. A tile group can contain one or more tiles. A tile group header can refer to a PPS, and a PPS can sequentially refer to a SPS (Sequence Parameter Set). .

12, a tile group header is a PPS of a PPS referenced by the tile group header.

It can have an index. The PPS can refer to the SPS in sequence.

[152] In addition to the PPS index, the tile group header according to one embodiment can be determined for the following information. First, if more than one tile exists per picture, the tile group address and the number of tiles in the tile group are determined. Next, you can determine the tile group type, such as intra/predictive/bi-directional. Next, you can determine the picture order count (POC) of the Lease Significant Bits (LSB). Next, if there is more than one tile in a picture, you can determine the offset length and entry point to the tile.

[153] Table 4 below shows an example of the syntax of the tile group header. In Table 4, the tile group header (tile_group_header) can be replaced with a slice header.

2020/175908 1»(：1^1{2020/002733

[154] [Table 4]

Table 5 below shows an example of English semantics for the syntax of the tile group header.

[156] [S.5]

When present, the value of the tile group header syntax element, group_pic_parameter_set_id and ti le_group_pic_order_cnt_l sb shall be ame in all tile group headers of a coded picture. _*' ti le_group_pic_para eter_set_id specifies the value of

pps_pic_parameter_set_id for the PPS in use. The value of ti 1 e_group_pic_para eter_set_id shall be in the range of 0 to 63, inclusive. _* · _'

It is a requirement of bitstream conformance that the value of Temporal Id of the current picture shall be greater than or equal to the value of Temporal Id of the PPS that has pps_pic_parameter_set_id equal to ti 1 e_group_p i c_parameter _set_id. _*' ti le_group_address specifies the tile address of the first tile in the tile group, where tile address is the tile ID as specified by Equation c-7. The length of ti le_group_address is Cei 1 (Log2 (NumTi lesInPic)) bits. The value of ti le_group_address shall be in the range of 0 to

NumTi lesInPic-1, inclusive, and the value of ti le_group_address shall not be equal to the value of ti le_group_address of any other coded tile group ML unit of the same coded picture. When ti le_group_address is not present it is inferred to be equal to 0..： num_tiies_in_ti le_group_minusl plus 1 specifies the number of tiles [157] in the tile group. The value of num_ti les_in_ti le_group_minusl shall be in the range of 0 to Nu Ti lesInPic-1, inclusive. When not present, the value of num_t i 1 es_ i n_t i le_group_minusl is inferred to be equal to 0.-' ti le_group_type specifies the coding type of the tile group according to table 6.-· _'

When nal_unit_type is equal to IRAP_NUT, i.e., the picture is an

I RAP picture, ti le_group_type shall be equal to 2.*· ti le_group_pic_order_cnt_lsb specifies the picture order count modulo MaxPicOrderCntLsb for the current picture. The length of the ti le_group_pic_order_cnt_lsb syntax element is log2_max_pic_order_cnt_lsb_minus4 + 4 bits. The value of the ti le_group_pic_order_cnt_lsb shall be in the range of 0 to

MaxPicOrderCntLsb-1, inclusive.- _' of fset_len_ inusl plus 1 specifies the length, in bits, of the entry_point_offset_ inusl [i] syntax elements. The value of offset_len_minusl shall be in the range of 0 to 31, inclusive.-· _' entry_point_of fset_minusl[ i] plus 1 specifies the i-th entry point offset in bytes, and is represented by offset_len_minusl plus 1 bits. The tile group data that follow the tile group header consists of nu _ti les_in_ti le_group_ inusl +1 subsets, with subset index values 2020/175908 1»(：1/10公020/002733

[158]

[159] [Table 6]

[16 In this embodiment, the tile group may include a tile group header and tile group data. When the tile group address is known, each 0X1 in the tile group is 2020/175908 PCT/KR2020/002733 Locations can be mapped and decoded. Table 7 below shows an example of the syntax of tile group data. In Table 7, tile group data can be replaced with slice data.

[161] [Table 刀

[162] Table 8 below shows an example of English semantics for the syntax of the tile group data.

WO 2020/175908 PCT/KR2020/002733

[163] [S.8]

[164] = 0; j <= num_t i le_rows_minusl; j++ )·,·

RowHeight[ j] = ((j + l) PicHeight InCtbsY) / ows_minusl + 1)-(j * PicHeight InCtbsY) / ws_minusl + 1) ght [num_t i le_rows_aiinusl] = PicHeight InCtbsY

= 0： j <nu _t i le_rows_minusl： j++) i,·

RowHeight [j] = t i 1 e_row_he ight_mi nus 1 [j] + !-

RowHeight [num_t i le_rows_mimisl] -= RowHeight [j] _* '

st ColBd[ i] for i ranging from 0 to nuin_t i le_columns_minusl e, specifying the location of the i-th tile column boundary TBs, is derived as follows—

olBd[ 0] = 0, i = 0: i <= num_tile_coluinns_mInusl： i++ )· ColBd[ i + 1] = ColBd[ i] + Colfidtht i]

st RowBd[ j] for j ranging from 0 to num_t i le_rows_jninusl + specifying the location of the j-th tile row boundary in, is derived as follows—·

owBd[ 0] = 0, j = 0: j <= num_t i le_rows_minusl: j++ )· [165] Ro Bd [j + 1] = RowBd [j] + RowHeight[ j]

The list CtbAddrRsToTs[ ctbAddrRs] for ctbAddrRs ranging from 0 to PicSizelnCtbsY-1, inclusive, specifying the conversion from a CTB address in CTB raster scan of a picture to a CTB address in tile scan, is derived as follows: *

fori ctbAddrRs = Q; ctbAddrRs <PicSizelnCtbsY: ctbAddrRs++)-tbX = ctbAddrRs% ricWidthlnCtbsY,

tbY = ctbAddrRs / PicfidthlnCtbsY

fori i = 0： i <= num_ti ]e_coluiiins_minusl： i++ )<·

if (tbX >= ColBd[ i] ).

ti leX = i _' fori j = 0： j <= num_t ile_rows_minusl; j++)

iff tbY >= Ro«-Bd[ j])

tileY-j ·

CrbAddrRsToTsf ctbAddrRs] = 0

for( i = 0: i <ci leX ^' iH-)

CrbAddrRsToTs[ ctbAddrRs] += RowHeighi [tileY] *

Colffidtht i )·

fori j ~ 0: j <tileY; j++ ).·

CtbAddrRsToTs[ ctbAddrRs] += Gί cWidthlnCtbsY * [166] RowHei ht [j]-

CtbAddrRsToTst ctbAddrRs] += (tbY-RowBd[ tileY]) *

Coiffidth[ tileS] + tbX-ColBd[ tiieX ].·

The list CtbAddrTsToRs[ ctbAddrTs] for ctbAddrTs ranging from 0 to

FicSizelnCtbsY-1, inclusive, specifying the conversion from a CTB address in tile scan to a CTB address in CTB raster scan of a picture, is derived as follows:- for( ctbAddrRs = 0： ctbAddrRs <FicSizelnCtbsY: ctbAddrRs++) CtbAddrTsToRs[ CtbAddrRsTo ]] = ctbAddrRs-·

The list Tileld[ ctbAddrTs] for ctbAddrTs ranging from 0 to ricSizelnCtbsY-1, inclusive, specifying the conversion from a CTB address in tile scan to a tile ID, is derived as follows:- for( j = 0. tileldx = 0: j <= num_t i le_rows_minusl: j++) _*· for( i = 0: i <= num_t i le_columns_niinusl; i++, tileldx++ )«· for( y = RowBd [j ]; y <RowBd[ j + 1 ]; y++). ··

for( x = ColBd[ i ]： x <CoIBd[ i + 1 ]： X-H- )-

Tileidt CtbAddrRsToTst y * PicWidthInCtbsY+ x 3 J = tileldx-

The list NumCtusInTi ie[ tileldx] for tileldx ranging from 0 to [167] PicSizelnCtbsY-1, inclusive, specifying the conversion from a tile index to the number of CTUs in the tile, is derived as follows·· _*·

for( j = 0, tileldx = 0; j <= num_tile_rows_minusl; j++) _* for( i = 0: i <= nuin_t ile_columns_minusl; i++, tileldx++)

NumCtusInTi le[ tileldx] = Colfidth[ i] * RowHeight[ j] _' The list FirstCtbAddrTs[ tileldx] for tileldx ranging from 0 to NumTilesInPic-1. inclusive, specifying the conversion from a tile ID to the CTB address in tile scan of the first CTB in the tile are derived as fol lows：-for( ctbAddrTs = 0, tileldx = 0, tileStartFIag = 1： ctbAddrTs <

PicSizeln CtbsY;

if( tileStartFIag

FirstCtbAddrTsf t i ieldx] = ctbAddrTs

tileStartFIag = 0

}*>

tiieEndFlag = ctbAddrTs = = PicSizelnCtbsY-1

Ti 1 e Id [ctbAddrTs + 1] != Tiieldt ctbAddrTs] _*

if( tiieEndFlag) 1

ti leldx+A

tileStartFIag = 1 2020/175908 1»（：1/10公020/002733

[168]

[169] There may be various application examples that require picture division based on tiles.

And, the present embodiments may be related to the above application examples.

[17 In this example, we review parallel processing. Multicore

Some implementations running on CPUs require dividing the source picture into tiles and tile groups, where each tile group can be processed in parallel on a separate core. The parallel processing is a high-resolution real-time encoding of videos. In addition, the above parallel processing can reduce the sharing of information between groups of tiles, thereby reducing the memory constraint. Tiles can be distributed to different threads while processing in parallel. Therefore, the parallel architecture can benefit from this partitioning mechanism.

[171] In another example, the maximum transmission unit (MTU) size matching is reviewed. The coded pictures transmitted through the network are subject to fragmentation when the coded pictures are larger than the MTU size. It can be different. Similarly, if the coded segments are small, the IP (Internet Protocol) header can become important. Packet fragmentation can lead to loss of error resiliency. The picture is taken to mitigate the effects of packet fragmentation. When dividing into tiles and packing each tile/tile group as a separate packet, the packet may be smaller than the MTU size.

[172] In another example, error resilience is reviewed. Error resilience is motivated by the requirements of some applications that apply Unequal Error Protection (UEP) to coded tile groups. Can be given.

[173] As described above, the structure of tiles for partitioning pictures can be efficiently A method for signaling is required, which is described in detail in Figs. 13 to 21.

[175] According to this specification, in tiling for partitioning a picture into a plurality of tiles, flexible tiling can be achieved by using a predefined rectangular area.

[176] In the case of the existing tiling, it was performed according to the raster scan order, but the tiling structure according to this method has recently been applied to video programs for video conferencing

There are aspects that are not suitable for application to programs.

[177] Fig. 13 shows an example of a picture in a video program for video conferencing when a video conference with multiple participants is held. In this case, the participant is speaker l (Speaker 1), speaker 2 (Speaker 2), speaker 3 (Speaker 3) and Speaker 4 (Speaker 4) The area corresponding to each participant in the picture can correspond to each of the preset areas, and each of the preset areas can be coded as a single tile or a group of tiles. have. When a participant changes in a video conference, the single tile or group of tiles corresponding to the participant may also change.

Referring to FIG. 14, an area assigned to speaker 1 participating in a video conference may be coded as a single tile. Similarly, the areas assigned to each of Speaker 2, Speaker 3, and Speaker 4 can be coded as a single tile.

[180] As shown in Fig. 14, the area allocated to each participant is

In the case of coding, it is possible to enable efficient coding as spatial dependency is improved. In addition, this division method can be applied to 360 video data, which will be described later in Fig. 15.

15 is a diagram illustrating an example of partitioning a picture into tiles or tile groups based on a Motion Constrained Tile Set (MCTS).

[182] In Fig. 15, a picture can be acquired from 360 degree video data. 360 video can mean video or image content that is captured or played back in all directions (360 degrees) at the same time required to provide VR (Virtual Reality). %0 video can refer to a video or image that appears in various types of 3D space depending on the 3D model. For example, a 360 video can be displayed on a spherical surface.

[183] A two-dimensional space (2D) picture obtained from 360-degree video data can be encoded with at least one spatial resolution. For example, a picture can be encoded with a first resolution and a second resolution, and the first resolution. May be higher than the second resolution. Referring to FIG. 15, a picture can be encoded in two spatial resolutions, each having a size of 1536x1536 and 768x768, but the spatial resolution is not limited thereto and may correspond to various sizes. [184] At this time, a 6x4 size tile grid may be used for bitstreams encoded at each of the two spatial resolutions. In addition, a motion constraint tile set (MCTS) for each position of the tiles may be coded and used. As described above with reference to FIGS. 13 and 14, each of the MCTSs may include tiles positioned in respective areas set for a picture.

[185] MCTS may contain at least one tile to form a set of square tiles.

A tile can represent a rectangular area composed of coding tree blocks (CTBs) of a two-dimensional picture. A tile can be classified based on a specific tile row and tile column within a picture. A specific MCTS in the encoding/decoding process When inter prediction is performed on the blocks within, the blocks within the specific MCTS may be restricted to refer only to the corresponding MCTS of the reference picture for motion estimation/motion compensation.

[186] For example, referring to 15, the 12 first MCTSs 1510 are of 1536x1536.

It is derived from a bitstream encoded with a spatial resolution having a size, and 12 second MCTSs 1520 may be derived from a bitstream encoded with a spatial resolution having a size of 768x768. That is, the first MCTSs 1510 May correspond to a region having a first resolution in the same picture, and the second MCTSs 1520 may correspond to a region having a second resolution in the same picture.

[187] The first MCTSs may correspond to the viewport area in the picture. The viewport area may refer to the area that the user is viewing in the 360-degree video. Or, the first MCTSs may correspond to the ROI (Region in the picture). of Interest). The ROI area can refer to the area of interest of users, suggested by the 360 content provider.

[188] At this time, MCTSs received in a single time are merged into one merged picture (merged

picture), for example, the first MCTSs 1510 and the second

The MCTSs 1520 can be merged and merged into a 1920x4708-sized merge picture 1530, and the merge picture 1530 can have four tile groups.

[189] Table 9 below shows an example of the PPS syntax.

2020/175908 1 ^» (：1/10公020/002733

[19] [Table 9]

[191] The table below shows an example of English semantics for the above syntax.

[193]

ti le_addr_val [i ][ j] specifies the ti le_group_address value of the tile of the i-th tile row and the j— th tile column. The length of ti le_addr_val [i ][ j] is ti le_addr_len_minusl + 1 bits. _*

For any integer m in the range of 0 to num_t i 1 e_co 1 umns_m i nu s 1 inclusive, and any integer n in the range of 0 to num_t i le_rows_minusl, inclusive, ti le_addr_val [i ][ j] shall not be equal to ti le_addr_val [m ][ n] when i is not equal to m or j is not equal to n. num_mcts_in_pic_minusl plus 1 specifies the number of MCTSs in the picture 2020/175908 1»（：1/10公020/002733

[194]

[195] In one embodiment, when there are multiple tiles within a picture, a syntax element unifoml_tile_spacing_flag indicating whether tiles having the same width and height are to be derived by dividing the picture uniformly may be parsed. The syntax element above.

The unifoml_tile_spacing_flag can be used to indicate whether the tiles in the picture are divided in a uniform manner. When the syntax element unifoml_tile_spacing_flag is enabled, the width of the tile row and the height of the tile row can be parsed, i.e., the syntax indicating the width of the tile column. Element 1: _（：011111111_\¥1（1111_1111111181 and a syntax element representing the height of the tile row (116_1'0\¥_11 寒11（：_1111111181 can be signaled and/or parsed).

[196] In one embodiment, the tiles in the picture

Syntax element indicating whether to form 111 8_:^Can be parsed.

If so, it may indicate that the tiles or groups of tiles in the picture may or may not form a square tile set, and that the use of sample values or variables outside the rectangular tile set is restricted or unrestricted. 111 If _:^^ is 1, it can be indicated that the picture is divided into ■刀.

[197] In addition, the syntax element 1111111_111（：18_：11 in 1（：_1111111181 may represent the number. In one embodiment, when 111_£ is 1,

In the case of dividing by, the syntax element num_mcts_in_pic_minusl can be parsed. 2020/175908 1»(：1/10公020/002733 There is.

[198] In addition, the syntax element top_left_tile_addr[ i] in the i-th MCTS

The tile_group_address value, which is the position of the tile located at the top-left, can be indicated. Similarly, the syntax element bottom_right_tile_addr[ i] is the i-th

In MCTS, the tile_group_address value, which is the location of the tile located at the bottom-right, can be displayed.

[199] Table 11 below shows an example of the tile group data syntax. In Table 11, tile group data can be replaced with slice data.

[20] [Table 11]

[201] Table 12 below shows English semantics for the tile group data syntax.

Give an example.

2020/175908 1»(：1/10公020/002733

[202] [Table 12]

[203] On the other hand, the scanning process of the order of decoding the tiles in the picture (

have.

2020/175908 1»(：1/10公020/002733

[204] [Table 13]

16 is a diagram showing an example of dividing a picture based on an R region.

[206] According to the present specification, in tiling for partitioning a picture into a plurality of tiles, flexible tiling based on a region of interest (ROI) can be achieved. Referring to FIG. 16, a picture is in R this region. Based on this, it can be divided into multiple tile groups.

[207] Table 14 below shows an example of the PPS syntax.

2020/175908 1»(：1/10公020/002733

[208] [Table 14]

[209] Table 15 below shows an example of English semantics for the above syntax.

[210] [5.15]

2020/175908 1»(：1/10公020/002733

[211]

In one embodiment, a syntax element tile_group_info_in_pps_flag indicating whether tile group information related to tiles included in the tile group exists in or in a tile group header referring to may be parsed.

If tile_group_info_in_pps_flag is 1, it can be indicated that the tile group information exists in 客 and does not exist in the tile group header referring to 客. In addition, when tile_group_info_in_pps_flag is 0, the tile group information does not exist in 客 and refers to In the tile group header, it can indicate its presence.

have.

[213] In addition, the syntax element niim_tile_groups_in_pic_minusl may indicate the number of tile groups in the picture referring to.

[214] In addition, the syntax element pps_first_tile_id] can represent the tile 11) of the first tile of the first tile group, and the syntax element pps_last_tile_id can represent the tile 11) of the last tile of the first tile group.

[216] According to the present specification, coding for tiling that divides a picture into a plurality of tiles Flexible tiling can be achieved by considering tiles smaller than the size of the tree unit (0X1). The tiling structure according to this method can be usefully applied to recent video applications such as video conferencing programs.

[217] Referring to FIG. 17, a picture may be partitioned into a plurality of tiles, and a plurality of

At least one of the tiles may be smaller than the size of the coding tree unit (0X1), e.g. tile 1 (1¾ 1), tile 2 (1¾ 2), tile 3 (1¾ 3) and tile 4 (1116). 4) It can be dug, and among them, tile 1 (1¾ 1), tile 2 (1116 2) and tile 4 (11 no 4) are smaller than that.

[218] Table below

It shows an example of tax.

[219] [Table 16]

[22] Table 17 below shows an example of English semantics for the PPS syntax.

[221] [Table 17]

[222] In one embodiment, the syntax element tile_size_unit_idc may represent the unit size of the tile. For example, if tile_size_unit_id is 0, 1, 2..., the height and width of the tile is a coding tree block (CTB) can be defined as 4, 8, 16...

18 is a flow chart showing an operation of a decoding device according to an embodiment, and FIG. 19 is a block diagram showing a configuration of a decoding device according to an embodiment.

Each step disclosed in FIG. 18 may be performed by the decoding device 300 disclosed in FIG. 3. More specifically, S1800 and S1810 are entropy disclosed in FIG.

It may be performed by the decoding unit 3W, S1820 may be performed by the prediction unit 330 disclosed in FIG. 3, and S1830 may be performed by the addition unit 340 disclosed in FIG. 3. In addition, operations according to S1800 to S1830. These are based on some of the contents described above in Figs. 1 to 17. Therefore, specific contents overlapping with the contents described above in Figs. 1 to 17 will be omitted or simplified.

[225] As shown in Fig. 19, the decoding apparatus according to the embodiment is

It may include a decoding unit (3W), a prediction unit 320 and an addition unit 340. However, in some cases, all of the components shown in Fig. 19 may not be essential components of the decoding device, and the decoding device is It may be implemented by more or less components than the components shown in FIG. 19.

[226] In the decoding apparatus according to an embodiment, the entropy decoding unit (3W), the prediction unit 330, and the addition unit 340 are each implemented as a separate chip, or at least two or more components are It can also be implemented through a chip.

[227] The decoding apparatus according to an embodiment includes partition information for a current picture.

information) and image information including prediction infomiation about the current block included in the current picture can be obtained from the bitstream.

More specifically, the entropy decoding unit (3W) of the decoding device can obtain image information including segmentation information for the current picture and prediction information for the current block included in the current picture from the bitstream. In one example, the division information includes information for dividing the current picture into a plurality of tiles, information for dividing the current picture into a plurality of tile groups, or dividing the current picture into a plurality of slices. It may include at least one of the information for this purpose. The prediction information may include at least one of information on intra prediction for the current block, information on inter prediction, or information on CIIP (Combined Inter Intra Prediction).

[228] The decoding apparatus according to an embodiment, the division information for the current picture

Based on the basis, the partitioning structure of the current picture based on a plurality of tiles can also be reduced (S18W). More specifically, the entropy decoding unit 3W of the decoding device includes the A partitioning structure of the current picture based on a plurality of tiles may be provided based on the partitioning information for the current picture. [229] The decoding apparatus according to an embodiment may derive prediction samples for the current block based on the prediction information for the current block included in one of the plurality of tiles (S1820). More specifically, the prediction unit 330 of the decoding apparatus may derive prediction samples for the current block based on the prediction information for the current block included in one of the plurality of tiles.

[23 The decoding apparatus according to this embodiment, based on the predicted samples,

The picture can be restored (S1830). More specifically, the adding unit 340 of the decoding device can restore the current picture based on the prediction samples.

[231] In one embodiment, the division information on the current picture is, lag information on whether the current picture is divided into motion constrained tile sets (MCTS), and the number of MCTSs in the current picture It may include at least one of information, location information of a tile positioned at the top-left for each of the MCTSs, or location information of a tile positioned at the bottom-right for each of the MCTSs. .

The decoding apparatus according to an embodiment may derive MCTSs for the current picture based on the division information. In addition, the decoding apparatus merges the MCTSs to form a merged picture, and the The merged picture can be decoded based on MCTSs. At this time, the first MCTS among the MCTSs corresponds to a region having a first resolution, and the second MCTS of the MCTSs may correspond to a region having a second resolution. The first resolution may be higher than the second resolution.

In one embodiment, the current picture is acquired from 360-degree video data, and the first MCTSs may correspond to a viewport area in the current picture.

In one embodiment, each of the MCTSs may include tiles located in each of preset regions in the current picture.

[235] In one embodiment, the split information on the current picture is based on whether or not tile group information on tiles included in at least one tile group exists in the PPS or a tile group header referring to the PPS. Information can be included.

In one embodiment, the division information on the current picture may include information on unit sizes of the plurality of tiles.

In one embodiment, at least one tile size among the plurality of tiles may be smaller than the size of a coding tree unit (CTU).

[238] According to the above-described main disclosure, a picture can be flexibly partitioned into a plurality of tiles. Further, according to this disclosure, the efficiency of picture partitioning can be improved based on the division information for the current picture.

20 is a flow chart showing the operation of the encoding apparatus according to an embodiment, and FIG. 21 is a block diagram showing the configuration of the encoding apparatus according to the embodiment.

[24] The encoding device according to FIGS. 20 and 21 is a decoding device according to FIGS. 18 and 19 2020/175908 1» (: 1^1{2020/002733) Corresponding operations can be performed. Therefore, the operations of the encoding device to be described later in Figs. 20 and 21 can be applied in the same way to the decoding device according to Figs. 18 and 19. have.

Each step disclosed in FIG. 20 may be performed by the encoding apparatus 200 disclosed in FIG. 2. More specifically, 82000 and 32010 may be performed by the image dividing unit 210 disclosed in FIG. 2, and ₃ 2020. And 32030 may be performed by the prediction unit 220 disclosed in FIG. 2, and 82040 may be performed by the entropy encoding unit 240 disclosed in FIG. 2. In addition, operations according to 82000 to 32040 are described above in FIGS. 1 to 17. It is based on some of the contents described above. Therefore, specific contents overlapping with the contents described above in Figs. 1 to 17 will be omitted or simplified.

As shown in FIG. 21, the encoding apparatus according to an embodiment may include an image division unit 210, a prediction unit 220, and an entropy encoding unit 240. However, in some cases, All of the components shown in 21 may not be essential components of the encoding device, and the encoding device may be implemented by more or less components than the components shown in FIG.

[243] In the encoding apparatus according to an embodiment, the image division unit 210, the prediction unit 220, and the entropy encoding unit 240 are each implemented as a separate chip, or at least two or more components are It can also be implemented through the chip.

[244] The encoding apparatus according to an embodiment can divide a current picture into a plurality of tiles.

2000). More specifically, the image dividing unit 210 of the encoding device may divide the current picture into a plurality of tiles.

The encoding apparatus according to an embodiment may generate segmentation information for the current picture based on the plurality of tiles. More specifically, the image segmentation unit (0) of the encoding device is the above. Split information for the current picture may be generated based on a plurality of tiles.

[246] The encoding apparatus according to an embodiment may derive prediction samples for the current block included in one of the plurality of tiles 2020). More specifically, the prediction unit 220 of the encoding apparatus includes: Prediction samples for the current block included in one of the plurality of tiles can be derived.

[247] The encoding apparatus according to an embodiment may generate prediction information for the current block based on the prediction samples 2030). More specifically, the prediction unit 220 of the encoding apparatus is based on the prediction samples. With this, prediction information for the current block can be generated.

The encoding apparatus according to an embodiment may encode image information including segmentation information on the current picture and prediction information on the current block 2040). More specifically, it is possible to encode image information including at least one of division information for the current picture or prediction information for the current block. [249] In one embodiment, the division information on the current picture is, the current picture is

Always lag information on whether or not it is divided into MCTS (motion constrained tile sets), information on the number of MCTSs in the current picture, information on the location of a tile located at the top-left for each of the MCTSs Or, for each of the MCTSs, at least one of the location information of the tile located at the bottom-right side may be included.

[25] The encoding apparatus according to this embodiment, based on the division information, for the current picture

In addition, the encoding apparatus may combine the MCTSs to form a merged picture and encode the merged picture based on the MCTSs. At this time, the first MCTSs among the MCTSs It corresponds to a region having a first resolution, and among the MCTSs, second MCTSs may correspond to a region having a second resolution. The first resolution may be higher than the second resolution.

[253] In an embodiment, the split information for the current picture is determined whether or not tile group information for tiles included in at least one tile group exists in a PPS or a tile group header referring to the PPS. Information can be included.

In an embodiment, the division information on the current picture may include information on a unit size of the plurality of tiles.

[256] In the above-described embodiment, the methods are described on the basis of a flow chart as a series of steps or blocks, but this disclosure is not limited to the order of the steps, and certain steps may be performed in a different order from those described above or In addition, those skilled in the art will understand that the steps shown in the flowchart are not exclusive, other steps may be included, or one or more steps in the flowchart may be deleted without affecting the scope of this disclosure.

[257] The above-described method according to this disclosure can be implemented in the form of software, and the encoding device and/or decoding device according to this disclosure can perform image processing such as TV, computer, smartphone, set-top box, and display device. It can be included in a device that performs.

[258] In this disclosure, when the embodiments are implemented as software, the above-described method is

It can be implemented as a module (process, function, etc.) that performs a function. Modules are stored in memory and can be executed by the processor. The memory can be inside or outside the processor, it is well known and can be connected to the processor by various means. . Processor is ASIC (application-specific integrated circuit), other chipset, logic circuit And/or data processing devices. The memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media and/or other storage devices, i.e., The embodiments described in the present disclosure may be implemented and performed on a processor, microprocessor, controller, or chip. For example, the functional units shown in each diagram may be implemented and performed on a computer, processor, microprocessor, controller or chip. In this case, information for implementation (ex. information on instructions) or algorithms can be stored on a digital storage medium.

[259] In addition, the decoding device and the encoding device to which this disclosure is applied are multimedia broadcasting.

Transmission/reception device, mobile communication terminal, home cinema video device, digital cinema video device, surveillance camera, video conversation device, real-time communication device such as video communication, mobile streaming device, storage medium, camcorder, video-on-demand (VoD) service provider device , OTT video (Over the top video) device, Internet streaming service providing device,

3D (3D) video device, VR (virtual reality) device, AR (argumente reality) device, video phone video device, transportation terminal (ex. vehicle (including self-driving vehicle) terminal, airplane terminal, ship terminal, etc.) and It can be included in medical video equipment, etc., and can be used to process video signals or data signals. For example, OTT video (Over the top video) devices include game consoles, Blu-ray players, Internet access TVs, home theater systems, It can include smartphones, tablet PCs, and DVR (Digital Video Recoder).

[26 In addition, the processing method to which this disclosure is applied can be produced in the form of a program executed by a computer, and can be stored in a computer-readable recording medium. Multimedia data having a data structure according to the present disclosure can also be produced by a computer. The computer-readable recording medium includes all kinds of storage devices and distributed storage devices in which computer-readable data is stored. The computer-readable recording medium is, for example, a computer-readable recording medium. For example, it can include Blu-ray disk (BD), universal serial bus (USB), ROM, PROM, EPROM, EEPROM, RAM, CD-ROM, magnetic tape, floppy disk and optical data storage device. The temporary readable recording medium includes media implemented in the form of a carrier (for example, transmission via the Internet). In addition, the bitstream generated by the encoding method is on a computer readable recording medium

It can be stored or transmitted over a wired or wireless communication network.

Further, an embodiment of the present disclosure may be implemented as a computer program product using a program code, and the program code may be executed in a computer by an embodiment of the present disclosure. The program code is a carrier readable by a computer. Can be stored on

[262] Figure 22 shows an example of a content streaming system to which the disclosure of this document can be applied.

Show.

[263] Referring to FIG. 22, the content streaming system to which this disclosure is applied is a large encoding server, streaming server, web server, media storage, user device and multimedia input May contain devices.

[264] The above encoding server inputs multimedia such as smartphones, cameras, camcorders, etc.

It plays a role of generating a bitstream by compressing the content input from the devices into digital data and transmitting it to the streaming server. As another example, multimedia input devices such as smartphones, cameras, and camcorders directly generate the bitstream. In this case, the encoding server may be omitted.

The bitstream may be generated by an encoding method or a bitstream generation method to which the present disclosure is applied, and the streaming server may temporarily store the bitstream while transmitting or receiving the bitstream.

[266] The streaming server transmits multimedia data to a user device based on a user request through a web server, and the web server serves as a medium that informs the user of what services exist. When a service is requested, the web server delivers it to the streaming server, and the streaming server transmits multimedia data to the user. At this time, the content streaming system may include a separate control server, in which case the control server is the above. It controls the command/response between devices in the content streaming system.

[267] The streaming server can receive content from a media storage and/or encoding server. For example, when receiving content from the encoding server, it can receive the content in real time. In this case, a seamless streaming service In order to provide a, the streaming server may store the bitstream for a predetermined time.

[268] Examples of the user device, mobile phones, smart phones (smart phone), notebook

Computer (laptop computer), digital broadcasting terminal, PDA (personal digital assistants), PMP (portable multimedia player), navigation, slate PC, tablet PC, ultrabook, wearable device (Wearable devices, for example, smartwatch, smart glass, head mounted display), digital TV, desktop computer, digital signage, etc.

Each server in the content streaming system can be operated as a distributed server, and in this case, data received from each server can be distributed and processed.

[27] The claims in this specification can be combined in various ways. For example, the technical features of the method claims of this specification can be combined to be implemented as a device, and the technical features of the apparatus claims of this specification can be combined in a way. Can be implemented. In addition, the technical characteristics of the method claim of this specification and the technical characteristics of the apparatus claim may be combined to be implemented as a device, and the technical characteristics of the method claim of this specification and the technical characteristics of the device claim may be combined to be implemented in a method.

Claims

2020/175908 1»（：1/10公020/002733 Claims

[Claim 1] In the video decoding method performed by the decoding device,

Acquiring from a bitstream image information including partition information on a current picture and, for example, prediction information on a current block included in the current picture;

Reducing a partitioning structure of the current picture based on a plurality of tiles based on the division information for the current picture;

Deriving prediction samples for the current block based on the prediction information for the current block included in one of the plurality of tiles; And

Including the step of restoring the current picture based on the prediction samples,

The division information on the current picture is, lag information on whether the current picture is divided into motion constrained tile sets (MCTS), information on the number of MCTSs in the current picture, and information on each of the MCTSs. A video decoding method comprising at least one of location information of a tile positioned at the top-left or location information of a tile positioned at a bottom-right with respect to each of the MCTSs.

[Claim 2] The method of claim 1,

Further comprising the step of deriving MCTS for the current picture based on the division information,

The first MCTS among the MCTSs corresponds to a region having a first resolution, the second MCTS among the MCTSs corresponds to a region having a second resolution, and the first resolution is higher than the second resolution. Way.

[Claim 3] In paragraph 2,

The current picture is obtained from 360 degree video data, and the first MCTSs correspond to a viewport area in the current picture.

[Claim 4] The method of claim 1,

Each of the MCTSs,

An image decoding method comprising tiles positioned in each of the regions set as the current picture.

[Claim 5] The method of claim 1,

The division information for the current picture,

Tile group information about tiles included in at least one tile group is displayed in a PPS (Picture Parameter Set) or a tile group header referring to the PPS. Video decoding method, including flag information about whether it is present or not.

[Claim 6] The method of claim 1,

The division information for the current picture,

Including information on the unit size (unit size) of the plurality of tiles, image decoding method.

[Claim 7] The method of claim 1,

At least one tile size among the plurality of tiles is smaller than the size of a coding tree unit (CTU).

[Claim 8] In the video encoding method performed by the encoding device,

Dividing the current picture into a plurality of tiles;

Generating segmentation information for the current picture based on the plurality of tiles;

Deriving prediction samples for the current block included in one of the plurality of tiles;

Generating prediction information for the current block based on the prediction samples; And

Including the step of encoding image information including segmentation information on the current picture and prediction information on the current block,

The division information on the current picture is, lag information on whether the current picture is divided into motion constrained tile sets (MCTS), information on the number of MCTSs in the current picture, and information on each of the MCTSs. An image encoding method comprising at least one of the location information of the tile located at the top-left or the location information of the tile located at the bottom-right with respect to each of the MCTSs.

[Claim 9] The method of claim 8,

The first MCTS among the MCTSs corresponds to a region having a first resolution, the second MCTS among the MCTSs corresponds to a region having a second resolution, and the first resolution is higher than the second resolution. Way .

[Claim 10] In paragraph 9,

The first MCTSs correspond to a viewport area in the current picture for 360 degree video data.

[Claim 11] The method of claim 8,

Each of the MCTSs,

An image decoding method comprising tiles positioned in each of predetermined regions in the current picture.

[Claim 12] In clause 8, The division information for the current picture,

A video encoding method comprising flag information on whether tile group information on tiles included in at least one tile group exists in a PPS (Picture Parameter Set) or a tile group header referring to the PPS.

[Claim 13] The method of claim 8,

The division information for the current picture,

Including information on the unit size (unit size) of the plurality of tiles, video encoding method.

[Claim 14] In paragraph 8,

[Claim 15] In a storage medium readable by a decoder for storing image information encoded by an image encoding method, the image encoding method comprises: dividing a current picture into a plurality of tiles;

The division information on the current picture is, lag information on whether the current picture is divided into motion constrained tile sets (MCTS), information on the number of MCTSs in the current picture, and information on each of the MCTSs. A storage medium comprising at least one of location information of a tile positioned at the top-left or location information of a tile positioned at a bottom-right with respect to each of the MCTSs.