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US 2022/0046281 A1Published application
Image coding using transform index
AssigneeLG Electronics Inc.
InventorsJunghak NAM, Jaehyun LIM, Moonmo KOO, Seunghwan KIM
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Abstract
An image decoding method according to the present document comprises the steps of: receiving image information including residual information for a current block; and generating residual samples of the current block on the basis of the residual information, wherein the residual information includes information on transform coefficients of the current block, and the residual samples are generated from the information on the transform coefficients on the basis of low-frequency non-separable transform (LFNST) index information.
Claims13
An image decoding method performed by a decoding apparatus, the method comprising:
- receiving image information including residual information for a current block;
- deriving prediction samples of the current block based on intra prediction;
- generating residual samples of the current block based on the residual information;
- and
- generating reconstructed samples for the current block based on the prediction samples and the residual samples,
- wherein the image information includes intra prediction type information for the current block,
- the intra prediction type information includes a matrix based intra prediction (MIP) flag representing whether MIP is applied to the current block,
- based on an intra mode being applied to the current block and the MIP flag representing that the MIP is not applied, the image information includes low frequency non-separable transform (LFNST) index information related to one of transform kernels in an LFNST transform set for the current block,
- the residual information includes information on quantized transform coefficients of the current block, and
- the residual samples are generated based on the information on the quantized transform coefficients by using the LFNST index information.
7 more elements
An image encoding method performed by an encoding apparatus, the method comprising:
- generating prediction samples of a current block by performing intra prediction on the current block;
- generating intra prediction type information for the current block based on the performed intra prediction;
- generating residual samples of the current block based on the prediction samples;
- generating residual information including information on quantized transform coefficients for the current block based on the residual samples;
- and
- encoding image information including the intra prediction type information and the residual information,
- wherein the intra prediction type information includes a matrix based intra prediction (MIP) flag representing whether MIP is applied to the current block,
- based on an intra mode being applied to the current block and the MIP flag representing that the MIP is not applied the image information includes low frequency non-separable transform (LFNST) index information related to one of transform kernels in an LFNST transform set for the current block.
5 more elements
A non-transitory computer-readable storage medium storing a bitstream generated by an encoding method, the method comprising:
- determining an intra prediction type for a current block;
- generating prediction samples of a current block by performing intra prediction on the current block;
- generating intra prediction type information for the current block based on the performed intra prediction;
- generating residual samples of the current block based on the prediction samples;
- generating residual information including information on quantized transform coefficients for the current block based on the residual samples;
- and
- encoding image information including the intra prediction type information and the residual information,
- wherein the intra prediction type information includes a matrix based intra prediction (MIP) flag representing whether MIP is applied to the current block,
- based on an intra mode being applied to the current block and the MIP flag representing that the MIP is not applied the image information includes low frequency non-separable transform (LFNST) index information related to one of transform kernels in an LFNST transform set for the current block.
6 more elements
A transmission method of data for an image, the method comprising:
- obtaining a bitstream for the image, the bitstream is generated by performing determining an intra prediction type for a current block, generating prediction samples of a current block by performing intra prediction on the current block, generating intra prediction type information for the current block based on the performed intra prediction, generating residual samples of the current block based on the prediction samples, generating residual information including information on quantized transform coefficients for the current block based on the residual samples, and encoding image information including the intra prediction type information and the residual information to generate the bitstream;
- and
- transmitting the data comprising the bitstream,
- wherein the intra prediction type information includes a matrix based intra prediction (MIP) flag representing whether MIP is applied to the current block,
- based on an intra mode being applied to the current block and the MIP flag representing that the MIP is not applied the image information includes low frequency non-separable transform (LFNST) index information related to one of transform kernels in an LFNST transform set for the current block.
2 more elements
Dependencies are inferred from the claim text.