BDPCM-based image coding method and device therefor
AssigneeGuangdong Oppo Mobile Telecommunications Corp., Ltd.
InventorsMoonmo Koo, Jaehyun Lim, Junghak Nam, Seunghwan Kim
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Abstract
An image decoding method according to the present document comprises the steps of: deriving a quantized transform coefficient for a current block on the basis of BDPCM; deriving a transform coefficient by performing dequantization on the quantized transform coefficient; and deriving a residual sample on the basis of the transform coefficient, wherein, when the BDPCM is applied to the current block, inverse non-separable transform is not applied to the transform coefficient.
Claims19
An image decoding method performed by a decoding apparatus, the method comprising:
- deriving quantized transform coefficients for a component block based on a BDPCM (Block-based Delta Pulse Code Modulation);
- deriving transform coefficients by performing a dequantization on the quantized transform coefficients;
- and
- deriving residual samples based on the transform coefficients;
- wherein based on the BDPCM being applied to the component block including one or more non-zero transform coefficients, a value of a transform index for an inverse non-separable transform is inferred to be 0.
An image encoding method performed by an image encoding apparatus, comprising:
- deriving prediction samples for a component block;
- deriving residual samples for the component block based on the prediction samples;
- performing quantization on the residual samples;
- deriving quantized residual information based on Block-based Delta Pulse Code Modulation (BDPCM);
- and
- encoding the quantized residual information and coding information for the component block;
- wherein the coding information includes BDPCM flag information indicating whether the BDPCM is applied to the component block and direction information on a direction in which the BDPCM is performed;
- wherein based on the BDPCM being applied to the component block including one or more non-zero transform coefficients, a transform index for a non-separable transform is not encoded.
A non-transitory computer-readable digital storage medium storing thereon a computer program and a video bitstream, wherein when processed by one or more processors, the computer program causes the one or more processors to implement the following to generate the video bitstream:
- deriving prediction samples for a component block;
- deriving residual samples for the component block based on the prediction samples;
- performing quantization on the residual samples;
- deriving quantized residual information based on Block-based Delta Pulse Code Modulation (BDPCM);
- and
- encoding the quantized residual information and coding information for the component block;
- wherein the coding information includes BDPCM flag information indicating whether the BDPCM is applied to the component block and direction information on a direction in which the BDPCM is performed;
- wherein based on the BDPCM being applied to the component block including one or more non-zero transform coefficients, a transform index for a non-separable transform is not encoded.
Dependencies are inferred from the claim text.