Video encoding/decoding method and device using BDPCM, and method for transmitting bitstream
An image encoding/decoding method and apparatus are provided. An image decoding method according to the present disclosure may include parsing, from a bitstream, first information specifying whether block difference pulse code modulation (BDPCM) applies to an intra-predicted current block, determining a prediction direction of BDPCM for the current block and generating a residual block of the current block based on the determined prediction direction of BDPCM, based on the first information specifying that BDPCM applies to the current block, generating a prediction block of the current block, by performing intra prediction based on an intra prediction mode of the current block, and reconstructing the current block based on the residual block and the prediction block.
1 . An image decoding method performed by an image decoding apparatus, the image decoding method comprising:
determining whether block difference pulse code modulation (BDPCM) applies to a chroma block;
when BDPCM applies to the chroma block, determining a prediction direction of BDPCM for the chroma block;
determining an intra prediction mode of the chroma block based on the prediction direction of BDPCM for the chroma block;
generating a residual block of the chroma block based on the prediction direction of BDPCM for the chroma block;
generating a prediction block of the chroma block, by performing intra prediction based on the intra prediction mode of the chroma block; and
reconstructing the chroma block based on the residual block and the prediction block.
2 . The image decoding method of claim 1 , wherein determining whether BDPCM applies to the chroma block comprises:
parsing, from a bitstream, first information specifying whether BDPCM applies to the chroma block.
3 . The image decoding method of claim 1 , wherein determining the prediction direction of BDPCM for the chroma block comprises:
parsing, from a bitstream, second information specifying the prediction direction of BDPCM for the chroma block.
4 . The image decoding method of claim 1 , wherein the prediction direction of BDPCM for the chroma block includes a horizontal direction or a vertical direction.
5 . The image decoding method of claim 1 , wherein determining the intra prediction mode of the chroma block based on the prediction direction of BDPCM for the chroma block comprises:
when the prediction direction of BDPCM is a horizontal direction, the intra prediction mode of the chroma block is determined to be a horizontal direction mode;
when the prediction direction of BDPCM is a vertical direction, the intra prediction mode of the chroma block is determined to be a vertical direction mode.
6 . The image decoding method of claim 1 , wherein when BDPCM does not apply to the chroma block, determining the intra prediction mode of the chroma block based on prediction information of the chroma block signaled through a bitstream.
7 . An image encoding method performed by an image encoding apparatus, the image encoding method comprising:
determining whether block difference pulse code modulation (BDPCM) applies to a chroma block;
when BDPCM applies to the chroma block, determining a prediction direction of BDPCM for the chroma block;
determining an intra prediction mode of the chroma block based on the prediction direction of BDPCM for the chroma block;
generating a residual block of the chroma block based on the prediction direction of BDPCM for the chroma block;
generating a prediction block of the chroma block, by performing intra prediction based on the intra prediction mode of the chroma block; and
encoding the residual block of the chroma block based on the prediction direction of BDPCM for the chroma block.
8 . The image encoding method of claim 7 , wherein the prediction direction of BDPCM for the chroma block includes a horizontal direction or a vertical direction.
9 . The image encoding method of claim 7 , wherein determining the intra prediction mode of the chroma block based on the prediction direction of BDPCM for the chroma block comprises:
when the prediction direction of BDPCM is a horizontal direction, the intra prediction mode of the chroma block is determined to be a horizontal direction mode;
when the prediction direction of BDPCM is a vertical direction, the intra prediction mode of the chroma block is determined to be a vertical direction mode.
10 . A non-transitory computer-readable storage medium storing thereon a computer program and a bitstream, wherein when processed by one or more processors, the computer program causes the one or more processors to implement:
determining whether block difference pulse code modulation (BDPCM) applies to a chroma block;
when BDPCM applies to the chroma block, determining a prediction direction of BDPCM for the chroma block;
determining an intra prediction mode of the chroma block based on the prediction direction of BDPCM for the chroma block;
generating a residual block of the chroma block based on the prediction direction of BDPCM for the chroma block;
generating a prediction block of the chroma block, by performing intra prediction based on the intra prediction mode of the chroma block; and
encoding the residual block of the chroma block based on the prediction direction of BDPCM for the chroma block.
11 . The non-transitory computer-readable storage medium of claim 10 , wherein the prediction direction of BDPCM for the chroma block includes a horizontal direction or a vertical direction.
12 . The non-transitory computer-readable storage medium of claim 10 , wherein determining the intra prediction mode of the chroma block based on the prediction direction of BDPCM for the chroma block comprises:
when the prediction direction of BDPCM is a horizontal direction, the intra prediction mode of the chroma block is determined to be a horizontal direction mode;
when the prediction direction of BDPCM is a vertical direction, the intra prediction mode of the chroma block is determined to be a vertical direction mode.