US-12621478-B2 - Methods and devices for decoder-side intra mode derivation

US12621478B2US 12621478 B2US12621478 B2US 12621478B2US-12621478-B2

Abstract

Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for video coding. In one method, a decoder obtains a first flag that indicates whether a template-based intra mode derivation (TIMD) mode is applied to a current video block; and in response to determining that the TIMD mode is applied to the current video block based on the first flag, the decoder obtains a set of candidate list for the TIMD mode, where the set of candidate list includes a set of reference line list or a set of template candidate list.

Inventors

HONG-JHENG JHU
Xiaoyu Xiu
Yi-Wen Chen
Wei Chen
Che-Wei KUO
Ning Yan
Han Gao
Xianglin Wang
Bing Yu

Assignees

Beijing Dajia Internet Information Technology Co., Ltd.

Dates

Publication Date: 20260505
Application Date: 20240717

Claims (12)

1 . A method for video decoding, comprising: obtaining a first flag that indicates whether a template-based intra mode derivation (TIMD) mode is applied to a current video block; and in response to determining that the TIMD mode is applied to the current video block based on the first flag, obtaining a set of candidate lists for the TIMD mode and selecting a candidate list from the set of candidate lists based on a quantization parameter applied to one coding unit (CU), wherein the set of candidate lists comprises a set of reference line candidate lists or a set of template candidate lists.
2 . The method for video decoding of claim 1 , wherein the quantization parameter is included in coded information of the current video block, wherein the coded information of the current video block further comprises at least one of a block size, transform types, prediction mode types associated with a transform block (TB) or a coding block (CB), or a slice or profile.
3 . The method for video decoding of claim 1 , further comprising: selecting a reference line candidate list based on a set of predefined thresholds for the quantization parameter and a set of predefined reference line candidate lists; or selecting a template candidate list based on a set of predefined thresholds for the quantization parameter and a set of predefined template candidate lists.
4 . An apparatus, comprising: one or more processors; and a memory configured to store instructions; wherein the one or more processors, upon execution of the instructions, are configured to: obtain a first flag that indicates whether a template-based intra mode derivation (TIMD) mode is applied to a current video block; and in response to determining that the TIMD mode is applied to the current video block based on the first flag, obtain a set of candidate lists for the TIMD mode and select a candidate list from the set of candidate lists based on a quantization parameter applied to one coding unit (CU), wherein the set of candidate lists comprises a set of reference line candidate lists or a set of template candidate lists.
5 . The apparatus of claim 4 , wherein the quantization parameter is included in coded information of the current video block, wherein the coded information of the current video block comprises at least one of, a block size, transform types, prediction mode types associated with a transform block (TB) or a coding block (CB), or a slice or profile.
6 . The apparatus of claim 4 , wherein the one or more processors are further configured to: select a reference line candidate list based on a set of predefined thresholds for the quantization parameter and a set of predefined reference line candidate lists, or select a template candidate list based on a set of predefined thresholds for the quantization parameter and a set of predefined template candidate lists.
7 . A method for video encoding, comprising: obtaining a first flag that indicates whether a template-based intra mode derivation (TIMD) mode is applied to a current video block; in response to determining that the TIMD mode is applied to the current video block based on the first flag, obtaining a set of reference line candidate lists for the TIMD mode and selecting a candidate list from the set of candidate lists based on a quantization parameter applied to one coding unit (CU), wherein the set of candidate lists comprises a set of reference line candidate lists or a set of template candidate lists; and encoding video information regarding the current video block into a bitstream.
8 . The method of claim 7 , wherein the quantization parameter is included in coded information of the current video block, wherein the coded information of the current video block comprises at least one of a block size, transform types, prediction mode types associated with a transform block (TB) or a coding block (CB), or a slice or profile.
9 . The method of claim 7 , further comprising: selecting a reference line candidate list based on a set of predefined thresholds for the quantization parameter and a set of reference line predefined candidate lists, or selecting a template candidate list based on a set of predefined thresholds for the quantization parameter and a set of predefined template candidate lists.
10 . A non-transitory computer-readable storage medium storing a bitstream generated by the method for video encoding according to claim 7 .
11 . A method for storing a bitstream, comprising: performing the method for video encoding according to claim 7 to generate the bitstream; and storing the bitstream on a non-transitory computer-readable storage medium.
12 . A method for transmitting a bitstream, comprising: performing the method for video encoding according to claim 7 to generate the bitstream; and transmitting the bitstream.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation of PCT Application PCT/US2023/011187 filed on Jan. 19, 2023, which is based on and claims the benefit of U.S. Provisional Application No. 63/301,477 filed on Jan. 20, 2022, both disclosures of which are incorporated herein by reference in their entireties for all purposes. TECHNICAL FIELD This disclosure is related to video coding and compression. More specifically, this disclosure relates to decoder-side intra mode derivation (DIMD). BACKGROUND Digital video is supported by a variety of electronic devices, such as digital televisions, laptop or desktop computers, tablet computers, digital cameras, digital recording devices, digital media players, video gaming consoles, smart phones, video teleconferencing devices, video streaming devices, etc. The electronic devices transmit and receive or otherwise communicate digital video data across a communication network, and/or store the digital video data on a storage device. Due to a limited bandwidth capacity of the communication network and limited memory resources of the storage device, video coding may be used to compress the video data according to one or more video coding standards before it is communicated or stored. For example, video coding standards include Versatile Video Coding (VVC), Joint Exploration test Model (JEM), High-Efficiency Video Coding (HEVC/H.265), Advanced Video Coding (AVC/H.264), Moving Picture Expert Group (MPEG) coding, or the like. Video coding generally utilizes prediction methods (e.g., inter-prediction, intra-prediction, or the like) that take advantage of redundancy inherent in the video data. Video coding aims to compress video data into a form that uses a lower bit rate, while avoiding or minimizing degradations to video quality. SUMMARY Examples of the present disclosure provide methods and apparatus for video decoding with an intra prediction coding mode. According to an aspect of the present disclosure, a method for video decoding is provided. The method may include: obtaining a first flag that indicates whether a template-based intra mode derivation (TIMD) mode is applied to a current video block; and in response to determining that the TIMD mode is applied to the current video block based on the first flag, obtaining a set of reference line candidate list for the TIMD mode. According to an aspect of the present disclosure, a method for video decoding is provided. The method may include: obtaining a first flag that indicates whether a template-based intra mode derivation (TIMD) mode is applied to a current video block; and in response to determining that the TIMD mode is applied to the current video block based on the first flag, obtaining a set of template candidate list for the TIMD mode. According to an aspect of the present disclosure, the obtaining the set of the template candidate list may further include selecting the template candidate list according to coded information of the current video block. According to an aspect of the present disclosure, the coded information of the current video block may include at least one of a quantization parameter, a block size, transform types, prediction mode types associated with a transform block (TB) or a coding block (CB), or a slice or profile. According to an aspect of the present disclosure, the obtaining the set of the template candidate list may further include selecting the template candidate list according to a second flag associated with transform block (TB), coding block (CB), slice, picture, or sequence level. According to an aspect of the present disclosure, the second flag may be signaled according to coded information of the current video block. According to an aspect of the present disclosure, the coded information of the current video block may include at least one of a quantization parameter, a block size, transform types, prediction mode types associated with a transform block (TB) or a coding block (CB), or a slice or profile. According to an aspect of the present disclosure, the method may further include adjusting the template candidate list based on a quantization parameter applied to one coding unit (CU). According to an aspect of the present disclosure, the method may further include determining the template candidate list based on a set of predefined thresholds for the quantization parameter and a set of predefined template candidate lists. According to an aspect of the present disclosure, the method may further include adjusting the template candidate list based on a block size applied to one coding unit (CU). According to an aspect of the present disclosure, the method may further include determining the template candidate list based on a set of predefined thresholds for the block size and a set of predefined template candidate lists. According an aspect of the present disclosure, a method for video coding is provided. The method may include: signaling, by an encoder, a first f