US-12621468-B2 - Methods and apparatus for video encoding and decoding binary sets using adaptive tree selection

US12621468B2US 12621468 B2US12621468 B2US 12621468B2US-12621468-B2

Abstract

Methods and apparatus are provided for encoding and decoding binary sets using adaptive tree selection. In one exemplary encoding method embodiment, picture data is encoded for a block in a picture; in which one of a plurality of trees structures is selected to code a binary set of data for indicating coefficient significance for the block. In another exemplary encoding method embodiment, picture data is encoded for a block in a picture, in which one or more trees are used to encode a binary set of data for indicating coefficient significance for the block, the one or more trees each having a plurality of nodes, at least one of the nodes of the one or more trees being modified responsive to at least one parameter.

Inventors

Joel Sole
Peng Yin
Yunfei Zheng
Xiaoan Lu
Qian Xu

Assignees

INTERDIGITAL VC HOLDINGS, INC.

Dates

Publication Date: 20260505
Application Date: 20241212

Claims (8)

1 . A non-transitory storage media for storing instructions for encoding video data, said encoded video data comprising: a binary set of data for indicating coefficient significance for a block in a picture, wherein the binary set of data is encoded using one or more tree structures, the one or more tree structures, comprising one or more sub-trees, each of the tree structures having a plurality of nodes, wherein, a set of sub-trees is used to encode a particular part of a significance map, said significance map indicating coefficient significance for the block, wherein each sub-tree is a data structure used to convey a particular significance map for a set of scanned coefficients, the coefficient significance is mapped to nodes of the tree structures, linked to neighboring coefficients from two dimensions, and wherein some nodes of the tree structures are processed to encode non-zeros, while other nodes of the tree structures are processed to encode zeros, and a flag indicates at least one significant coefficient in said block corresponding to the significance map.
2 . The non-transitory storage media of claim 1 , wherein said encoding comprises at least one tree structure from among the one or more tree structures.
3 . The non-transitory storage media of claim 1 , wherein the one or more tree structures are selected responsive to at least one metric, the at least one metric comprising at least one of a bit rate value and a rate distortion value ( 525 ).
4 . The non-transitory storage media of claim 1 , wherein the selected one or more tree structures is conveyed as side information ( 530 ).
5 . The non-transitory storage media of claim 1 , wherein said encoding selects from among the one or more tree structures responsive to at least one of a prediction mode, a transform, decoded data for one or more previously decoded blocks, and other decoded data for the block ( 710 , 720 ).
6 . The non-transitory storage media of claim 1 , wherein the binary set of data is divided into a plurality of subsets and the plurality of subsets are encoded, wherein the encoding of the plurality of subsets is accomplished by selecting from among a plurality of subtree structures ( 900 , 910 ).
7 . The non-transitory storage media of claim 6 , wherein at least one of the plurality of subtree structures has an additional node to indicate a zero value or a non-zero value of remaining lower nodes in the at least one of the plurality of subtree structures ( 925 , 930 ).
8 . The non-transitory storage media of claim 7 , wherein at least one of the plurality of subtree structures is a terminal sub-tree such that a selection of the terminal sub-tree indicates that all remaining portions of the binary set of data are equal to zero ( 930 , 950 ).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is continuation of co-pending U.S. patent application Ser. No. 13/439,006 filed on Apr. 4, 2012; which is a continuation application of U.S. Non-Provisional patent application Ser. No. 13/381,149, filed Dec. 28, 2011; which is a national stage entry of PCT/US10/01809, filed on Jun. 23, 2010, which itself claims the benefit of U.S. Provisional Application Ser. No. 61/222,729, filed Jul. 2, 2009, each of which is incorporated by reference herein in their respective entireties. TECHNICAL FIELD The present principles relate generally to video encoding and decoding and, more particularly, to methods and apparatus for video encoding and decoding binary sets using adaptive tree selection. BACKGROUND The block-based discrete transform is a fundamental component of many image and video compression standards including, for example, the Joint Photographic Experts Group, the International Telecommunication Union, Telecommunication Sector (ITU-T) H.263 Recommendation (hereinafter the “H.263 Recommendation”), the International Organization for Standardization/International Electrotechnical Commission (ISO/IEC) Moving Picture Experts Group-1 (MPEG-1) Standard, the ISO/IEC MPEG-2 Standard, the ISO/IEC MPEG-4 Part 10 Advanced Video Coding (AVC) Standard/ITU-T H.264 Recommendation (hereinafter the “MPEG-4 AVC Standard”), as well as others, and is used in a wide range of applications. Most modern video coding standards employ transforms to efficiently reduce the correlation of the residue in the spatial domain. The discrete cosine transform (DCT) is the most extensively used block transform. After the transform process, the transform coefficients are quantized. Then, the quantized coefficients are entropy encoded to convey the information of their level and sign. The percentage of zeroed coefficients is very high, so the encoding process is efficient when divided into two steps. In a first step, the locations of the non-zero coefficients are signaled. In a second step, the level and sign of these coefficients are signaled. An efficient way to encode the locations involves using tree structures. Nevertheless, sending the location of the coefficients can still be quite expensive, because the video content data has varying statistics and properties, and the transform coefficients significance also has different properties depending on the position of the coefficient. However, conventional tree-based encoding of the significance does not properly take into account these varying statistics and properties across the coefficients and the content. SUMMARY These and other drawbacks and disadvantages of the prior art are addressed by the present principles, which are directed to methods and apparatus for video encoding and decoding using adaptive tree selection. According to an aspect of the present principles, there is provided an apparatus. The apparatus includes a video encoder for encoding picture data for at least a block in a picture. The video encoder selects from among a plurality of trees to code a binary set of data for indicating coefficient significance for at least the block. According to another aspect of the present principles, there is provided a method in a video encoder. The method includes encoding picture data for at least a block in a picture. The encoding step includes selecting from among a plurality of trees to code a binary set of data for indicating coefficient significance for at least the block. According to yet another aspect of the present principles, there is provided an apparatus. The apparatus includes a video decoder for decoding picture data for at least a block in a picture. The video decoder selects from among a plurality of trees to code a binary set of data for indicating coefficient significance for at least the block. According to still another aspect of the present principles, there is provided a method in a video decoder. The method includes decoding picture data for at least a block in a picture. The decoding step includes selecting from among a plurality of trees to code a binary set of data for indicating coefficient significance for at least the block. According to a further aspect of the present principles, there is provided an apparatus. The apparatus includes a video encoder for encoding picture data for at least a block in a picture. One or more trees are used to encode a binary set of data for indicating coefficient significance for at least the block. The one or more trees each have a plurality of nodes. At least one of the nodes of at least one of the one or more trees is modified responsive to one or more parameters. According to a still further aspect of the present principles, there is provided a method in a video encoder. The method includes encoding picture data for at least a block in a picture. One or more trees are used to encode a binary set of data for indicating coefficient significance for at least the block. The o