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US-20260129248-A1 - RELATION BETWEEN PARTITION CONSTRAINT ELEMENTS

US20260129248A1US 20260129248 A1US20260129248 A1US 20260129248A1US-20260129248-A1

Abstract

The present disclosure relates generally to video coding and picture partitioning methods. In particular, the disclosure is concerned with relations between partition constraint elements, by setting partitioning rules for different picture partitioning methods. The disclosure provides devices and corresponding methods for generating or processing a bitstream including encoded pictures, particularly for setting and including partition constraint element into the bitstream. One of the devices is configured to determine a minimum luma size of a leaf block resulting from quadtree splitting (−MinQtSizeY), determine a maximum luma size of a coding block where partitioning using a binary tree splitting is allowed (MaxBtSizeY) based on the MinQtSizeY, and include information for the determined MinQtSizeY into the bitstream.

Inventors

  • Han Gao
  • Semih ESENLIK
  • Jianle Chen
  • Anand Meher KOTRA
  • Biao Wang
  • Zhijie ZHAO

Assignees

  • HUAWEI TECHNOLOGIES CO., LTD.

Dates

Publication Date
20260507
Application Date
20250801

Claims (4)

  1. 1 . A device for decoding a video bitstream, the device comprising circuitry configured to: obtain, from the bitstream, a syntax element based on determining that a maximum hierarchy depth for coding units resulting from multi-type tree splitting is not equal to zero; obtain information for a minimum size in luma samples of a luma leaf block resulting from quadtree splitting; and determine a maximum size in luma samples of a luma root block to be split using a binary tree splitting based on the information for the minimum size in luma samples of the luma leaf block resulting from quadtree splitting and the syntax element.
  2. 2 . The device according to claim 1 , wherein the circuitry is further configured to: determine the maximum size in luma samples of the luma root block to be split using the binary tree splitting based on considering that a lower limit of the maximum size in luma samples of the luma root block is a minimum size in luma samples of the luma leaf block resulting from quadtree splitting.
  3. 3 . The device according to claim 1 , wherein the syntax element is a syntax element of a difference between the base 2 logarithm of the minimum size in luma samples of the luma leaf block resulting from quadtree splitting and the base 2 logarithm of the maximum size in luma samples of the luma root block to be split using the binary tree splitting.
  4. 4 . The device according to claim 1 , wherein the syntax element is a syntax element of a difference between the minimum size in luma samples of the luma leaf block resulting from quadtree splitting and the maximum size in luma samples of the luma root block to be split using the binary tree splitting, and the syntax element of the difference is signalled in logarithmic scale with base 2.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 18/402,444, filed on Jan. 2, 2024, which is a continuation of U.S. patent application Ser. No. 17/955,229, filed on Sep. 28, 2022, now U.S. Pat. No. 11,910,027, which is a continuation of U.S. patent application Ser. No. 17/169,175, filed on Feb. 5, 2021, now U.S. Pat. No. 11,477,494, which is a continuation of International Application No. PCT/CN2019/104260, filed on Sep. 3, 2019. The International Application claims priority to U.S. Provisional Application No. 62/733,053, filed on Sep. 18, 2018, U.S. Provisional Application No. 62/726,423, filed on Sep. 3, 2018, and U.S. Provisional Application No. 62/818,996, filed on Mar. 15, 2019. All of the afore-mentioned patent applications are hereby incorporated by reference in their entireties. TECHNICAL FIELD The present disclosure relates generally to video coding, decoding and picture partitioning methods. BACKGROUND The amount of video data needed to depict even a relatively short video can be substantial, which may result in difficulties when the data is to be streamed or otherwise communicated across a communications network with limited bandwidth capacity. Thus, video data is generally compressed before being communicated across modern day telecommunications networks. The size of a video could also be an issue when the video is stored on a storage device because memory resources may be limited. Video compression devices often use software and/or hardware at the source to code the video data prior to transmission or storage, thereby decreasing the quantity of data needed to represent digital video images. The compressed data is then received at the destination by a video decompression device that decodes the video data. With limited network resources and ever increasing demands of higher video quality, improved compression and decompression techniques that increase the compression ratio with little to no sacrifice in image quality are desirable. Conventionally, there exist a multitude of partition constraint elements, each element constraining the partitioning of pictures (like of a video) with respect to different types of partitioning methods. These different types of partitioning methods include particularly binary tree partitioning, quadtree partitioning, and ternary tree partitioning. The partition constraint elements are typically signalled included in the bitstream including the encoded pictures. In the following, some important partition constraint elements are described. A minimum coding block size (MinCbSizeY) may be defined. As an example, the MinCbSizeY can be equal to 8, which means that a parent block that has a size 8×8 cannot be split using any of the partitioning (splitting) methods, since the resulting child block is guaranteed to be smaller than the MinCbSizeY (in either width or height). According to a second example, if the MinCbSizeY is equal to 8, a parent block that has a size 8×16 cannot be partitioned using e.g. quadtree splitting (partitioning), since the resulting four child blocks would have a size of 4×8 (width equal to 4 and height equal to 8), and the width of the resulting child blocks would be smaller than the MinCbSizeY. In the second example it was assumed that the MinCbSizeY applies to both width and height of the block, although two different syntax elements can be used to independently to limit the width and height. A maximum coding tree block size (CtbSizeY) may indicate the size of a maximum coding block in terms of a number of luma samples. A maximum binary tree size (MaxBtSizeY) may be defined as the maximum luma size (width or height), in terms of a number of samples, of a coding block that can be split using a binary partitioning method. As an example, if the MaxBtSizeY is equal to 64, a coding block that is bigger in size, either in width or height, cannot be split using binary splitting. This means that a block that has a size 128×128 cannot be split using binary splitting, whereas a block that has a size 64×64 can be split using binary splitting. A minimum binary tree size (MinBtSizeY) may be defined as the minimum luma size (width or height), in terms of a number of samples, of a coding block that can be split using a binary partitioning method. As an example, if the MinBtSizeY is equal to 16, a coding block that is smaller or equal in size, either in width or height, cannot be split using binary splitting. This means that a block that has a size 8×8 cannot be split using binary splitting, whereas a block that has a size 32×32 can be split using binary splitting. A minimum quadtree size (MinQtSizeY) may be defined as the minimum luma size of a leaf block resulting from quadtree splitting of a Coding Tree Unit (CTU). The size can indicate either the width or height of the block in number of samples. It might also indicate the width and the height together in the case of square blocks. As an example, i