Image encoding/decoding method and device, and recording medium on which bitstream is stored
An image decoding/encoding method and device according to the present disclosure enable: an intra prediction mode of the current block to be determined on the basis of whether the intra prediction mode of the current block is derived on the basis of a cost of a template area adjacent to the current block; a reference sample of the current block to be determined; and a prediction sample of the current block to be generated on the basis of the intra prediction mode and the reference sample.
1 . An image decoding method, comprising:
deriving an intra prediction mode of a current block based on a flag of the current block, the flag indicating whether the intra prediction mode of the current block is derived based on a template region of the current block;
determining a reference sample of the current block; and
generating a prediction sample of the current block based on the intra prediction mode and the reference sample,
wherein based on the template region of the current block being available, the flag is signaled from a bitstream, and
wherein based on the template region of the current block not being available, the flag is not signaled from the bitstream and is derived as 1.
2 . The method of claim 1 , wherein based on the flag being derived as 1, the intra prediction mode of the current block is set to a planar mode.
3 . The method of claim 1 , wherein based on the flag being derived as 1, the intra prediction mode of the current block is set to a DC mode.
4 . An image encoding method, comprising:
determining whether an intra prediction mode of a current block is determined based on a template region of the current block;
determining the intra prediction mode of the current block based on the determination;
determining a reference sample of the current block; and
generating a prediction sample of the current block based on the intra prediction mode and the reference sample,
wherein a flag indicating whether the intra prediction mode of the current block is determined based on the template region is encoded into a bitstream based on whether the template region of the current block is available,
wherein based on the template region of the current block being available, the flag is encoded into the bitstream, and
wherein based on the template region of the current block not being available, the flag is not encoded into the bitstream and is derived as 1.
5 . A transmitting data for an image, comprising:
generating a bitstream for the image, wherein the bitstream is generated based on determining whether an intra prediction mode of a current block is determined based on a template region of the current block, determining the intra prediction mode of the current block based on the determination, determining a reference sample of the current block, and generating a prediction sample of the current block based on the intra prediction mode and the reference sample; and
transmitting the data including the bitstream,
wherein a flag indicating whether the intra prediction mode of the current block is determined based on the template region is encoded into the bitstream based on whether the template region of the current block is available,
wherein based on the template region of the current block being available, the flag is encoded into the bitstream, and
wherein based on the template region of the current block not being available, the flag is not encoded into the bitstream and is derived as 1.