US 12,219,175 B2
Transformation method, encoder, decoder, and storage medium
Junyan Huo, Dongguan (CN); Xinwei Li, Dongguan (CN); Wenhan Qiao, Dongguan (CN); Yanzhuo Ma, Dongguan (CN); Shuai Wan, Dongguan (CN); and Fuzheng Yang, Dongguan (CN)
Assigned to GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD., Guangdong (CN)
Filed by GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD., Guangdong (CN)
Filed on Jun. 17, 2022, as Appl. No. 17/842,995.
Application 17/842,995 is a continuation of application No. PCT/CN2019/130157, filed on Dec. 30, 2019.
Prior Publication US 2022/0329862 A1, Oct. 13, 2022
Int. Cl. H04N 19/61 (2014.01); H04N 19/176 (2014.01); H04N 19/593 (2014.01); H04N 19/70 (2014.01)
CPC H04N 19/61 (2014.11) [H04N 19/176 (2014.11); H04N 19/593 (2014.11); H04N 19/70 (2014.11)] 12 Claims
OG exemplary drawing
 
1. A transform method, applied to an encoder, the method comprising:
determining a prediction mode parameter of a current block;
determining a Matrix-based Intra Prediction (MIP) parameter when the prediction mode parameter indicates that MIP is used for the current block to determine an intra prediction value;
determining an intra prediction value of the current block according to the MIP parameter and calculating a residual value between the current block and the intra prediction value;
determining a Low-Frequency Non-Separable Transform (LFNST) transform kernel used for the current block according to the MIP parameter when an LFNST is used for the current block, setting an LFNST index, and signalling the LFNST index in a video bitstream; and
performing a transform processing on the residual value by using the LFNST transform kernel;
wherein the MIP parameter comprises a MIP mode index, the MIP mode index is used for indicating a MIP mode used for the current block, and the MIP mode is used for indicating a calculation and derivation mode for determining the intra prediction value of the current block by using MIP; wherein different MIP modes have different MIP mode indices;
wherein determining the LFNST transform kernel used for the current block according to the MIP parameter when the LFNST is used for the current block comprises:
determining a value of an LFNST intra prediction mode index according to a value of the MIP mode index, and selecting one LFNST transform kernel candidate set from a plurality of LFNST transform kernel candidate sets according to the value of the LFNST intra prediction mode index; or,
selecting one LFNST transform kernel candidate set from a plurality of LFNST transform kernel candidate sets according to a value of the MIP mode index;
wherein the LFNST transform kernel candidate set contains two or more preset LFNST transform kernels.