CN-121985121-A - Method and apparatus for advanced image division and image encoding/decoding

CN121985121ACN 121985121 ACN121985121 ACN 121985121ACN-121985121-A

Abstract

The present invention provides methods and apparatus for advanced image segmentation and image encoding/decoding. A method and apparatus in which division information of a current picture is encoded/decoded, and the current picture is divided into at least one of a sub-picture unit, a slice unit, and a tile unit according to the encoded/decoded division information.

Inventors

JIN ZAIKUN
Du Zhixun
Pu Duxuan
YIN YONGXU

Assignees

韩华视觉株式会社

Dates

Publication Date: 20260505
Application Date: 20200811
Priority Date: 20190812

Claims (11)

1. An image decoding method, comprising: decoding partition information of a current picture from a bitstream, and Dividing the current picture into at least one slice by using the decoded division information, Wherein the division information includes slice division information, Wherein decoding the slice division information includes: Obtaining a fifth flag indicating whether the slice is divided in a rectangular mode or a raster scan mode; obtaining information indicating the number of slices belonging to the current picture based on the fifth flag, and Based on information indicating the number of slices belonging to the current picture, information indicating the width and height of each slice is obtained, Wherein, in response to the [ SliceTopLeftTileIdx [ i ]/NumTileColumns ] th tile row having a height greater than 1, information indicating the height of each slice within a tile made up of a plurality of slices is adaptively decoded based on the information indicating the width and height of each slice, Wherein SliceTopLeftTileIdx [ i ] represents the tile index of the ith slice and NumTileColumns represents the number of tile columns, an Wherein the bitstream includes sub-picture division information including sub-picture width information indicating a width of a sub-picture and sub-picture height information indicating a height of the sub-picture.
2. The method according to claim 1, Wherein the division information further includes sub-picture division information, and Decoding the sub-picture division information includes: Obtaining a first flag indicating whether the current picture is composed of only one sub-picture, and Based on the first flag, at least one of information indicating the number of sub-pictures constituting the current picture or a second flag indicating whether the sub-pictures are equally divided is obtained.
3. The method of claim 2, wherein decoding the sub-picture division information further comprises: Based on at least one of information indicating the number of the sub-pictures or the second flag indicating whether the sub-pictures are equally divided, information indicating a size of each sub-picture constituting the current picture is obtained, Wherein the information indicating the size of each sub-picture is encoded in units of a size of a Coding Tree Block (CTB) predefined in the decoding apparatus.
4. The method according to claim 1, Wherein the division information further includes sub-picture division information, and Wherein the sub-picture division information is obtained from a Sequence Parameter Set (SPS), and Wherein the sub-picture is made up of a plurality of Coded Tree Blocks (CTBs).
5. The method according to claim 1, Wherein the partition information includes tile partition information, an Wherein decoding the tile partition information comprises: obtaining a third flag indicating whether to perform division on the current picture, wherein when a value of the third flag is 1, division is not performed on the current picture, and when the value of the third flag is 0, the current picture is divided into a plurality of tiles or a plurality of slices; Obtaining information about the number of tile line widths constituting the current picture and information about the number of tile column heights constituting the current picture based on the third flag, and Based on the obtained information, information indicating the width and height of each tile is obtained.
6. The method of claim 5, wherein the tile partition information is obtained from a Picture Parameter Set (PPS).
7. The method of claim 1, wherein decoding the slice-partition information further comprises: obtain information indicating a difference between an index of a tile including an upper left CTB in a next slice and an index of a tile including an upper left CTB in a current slice, Wherein the tile index is determined based on information indicative of the difference, an Wherein the position of the slice is specified based on the tile index.
8. The method of claim 7, wherein the information indicative of the difference is decoded for only some of a plurality of slices comprising the current picture.
9. The method of claim 7, wherein the information indicating the difference is decoded based on a fourth flag indicating whether the information indicating the difference exists, Wherein the fourth flag is decoded only when the number of slices constituting the current picture is greater than or equal to a predetermined threshold number.
10. An image encoding method, comprising: Dividing the current picture into at least one slice, and Coding partition information for the partitioning of the current picture, Wherein the division information includes slice division information, Wherein a fifth flag of the slice division information indicating whether a slice is divided in a rectangular mode or a raster scan mode is encoded, Wherein information indicating the number of slices belonging to the current picture is encoded based on whether the slices are divided in the rectangular mode or the raster scan mode, Wherein information indicating a width and a height of each slice is encoded based on the number of slices belonging to the current picture, Wherein, in response to the [ SliceTopLeftTileIdx [ i ]/NumTileColumns ] th tile row having a height greater than 1, information indicating a height of each slice within a tile made up of a plurality of slices is adaptively encoded based on the width and height of each slice, Wherein SliceTopLeftTileIdx [ i ] represents the tile index of the ith slice and NumTileColumns represents the number of tile columns, an Wherein the bitstream includes sub-picture division information including sub-picture width information indicating a width of a sub-picture and sub-picture height information indicating a height of the sub-picture.
11. A method of transmitting a bitstream generated by an encoding method, the encoding method comprising: Dividing a current picture into at least one slice; Encoding partition information for the partitioning of the current picture into the bitstream, and The bit stream is transmitted in a manner such that, Wherein the division information includes slice division information, Wherein a fifth flag of the slice division information indicating whether a slice is divided in a rectangular mode or a raster scan mode is encoded, Wherein information indicating the number of slices belonging to the current picture is encoded based on whether the slices are divided in the rectangular mode or the raster scan mode, Wherein information indicating a width and a height of each slice is encoded based on the number of slices belonging to the current picture, Wherein, in response to the [ SliceTopLeftTileIdx [ i ]/NumTileColumns ] th tile row having a height greater than 1, information indicating a height of each slice within a tile made up of a plurality of slices is adaptively encoded based on the width and height of each slice, Wherein SliceTopLeftTileIdx [ i ] represents the tile index of the ith slice and NumTileColumns represents the number of tile columns, an Wherein the bitstream includes sub-picture division information including sub-picture width information indicating a width of a sub-picture and sub-picture height information indicating a height of the sub-picture.

Description

Method and apparatus for advanced image division and image encoding/decoding The present application is a divisional application of application having a national application number 202080057189.1, an international application date 2020, an 8 th month 11 th day, an entering country date 2022, an 2 nd month 11 th day, and an application name of "method and apparatus for advanced image division and image encoding/decoding". Technical Field The present disclosure relates to an image encoding/decoding method and apparatus. Background Video images, which may be transmitted over a communication line or stored in a form suitable for a storage medium, are compression-encoded by removing spatial and temporal redundancy and inter-view redundancy. Disclosure of Invention Technical problem An object of the present disclosure is to improve the coding efficiency of video signals. Technical solution To solve the above problems, the present disclosure provides a method and apparatus for dividing a high-level image and encoding/decoding division information. The present disclosure provides a higher level syntax (high level syntax) partitioning method based on compression encoding/decoding. The present disclosure provides a more flexible structure by providing equal or unequal sub-picture/tile/brick/slice partitioning when performing partitioning based on a high level syntax. The present disclosure proposes a method of signaling with fewer bits in height and width by configuring sub-pictures in units of tile, brick, or CTB sizes to perform encoding/decoding when configuring sub-picture partitions. The present disclosure provides a method for reducing bit loss when only one of the height and width of a tile is equally divided in encoding/decoding of tile division. The present disclosure proposes a method for reducing bits without reliance on parsing by using information signaled at the same level in encoding/decoding of brick partitions. The present disclosure proposes a method for reducing signaling overhead by sending tile/brick partitions as size differences and symbols instead of size information. In the present disclosure, when encoding/decoding tile/brick/slice partitions, a method of reducing encoding/decoding bits by introducing some of the information indicating the partition configuration without signaling. Advantageous effects The video signal processing method and apparatus according to the present disclosure can improve video signal encoding efficiency by advanced image division and efficient encoding/decoding of division information. By configuring the sub-picture division in units of tile or brick sizes, the sizes of height and width can be signaled with fewer bits, and boundaries can be easily aligned with sub-images. The present disclosure provides a more flexible structure by providing equal or unequal sub-picture/tile/brick/slice partitioning, etc. when configuring advanced partitioning. It is checked whether the height and width of each of the partitioned components of the tile are equal and only one size value is signaled for the same size. With equal division into only one size, fewer bits can be signaled than in the related art. Bits can be reduced without transmission dependencies by using information signaled at the same level when encoding/decoding the brick partitions. The signaling overhead may be reduced by encoding/decoding information about tile or brick partitioning into smaller values than before. Bit signaling may be reduced by introducing some information during encoding/decoding of tile/brick/slice partition information without signaling such information. Drawings Fig. 1 illustrates a method of encoding image division information in an image encoder related to the present disclosure. Fig. 2 illustrates an advanced image division method in an image decoder related to the present disclosure. Fig. 3 and 4 show examples of equal divisions of a sub-picture. Fig. 5 shows an example of unequal division of sub-pictures. Fig. 6 illustrates a method of configuring a sub-picture using equally divided blocks. Fig. 7 (a) shows a case where slices are configured in a rectangular mode, and fig. 7 (b) shows an example when slices are configured in a raster scan mode. Fig. 8 is a block diagram showing a configuration of a video encoding apparatus according to an embodiment of the present disclosure. Fig. 9 is a block diagram showing a configuration of a video decoding apparatus according to an embodiment of the present disclosure. Detailed Description The video decoding method and apparatus according to the present disclosure may decode partition information of a current picture from a bitstream, and divide the current picture into at least one unit of a sub-picture, a slice, or a tile by using the decoded partition information. In the video decoding method and apparatus according to the present disclosure, the partition information may include at least one of sub-picture partition information, slice partiti