Method and device for processing video signal
Provided is a method for decoding a video signal. The method includes generating a first prediction sample by performing intra prediction on a current block, determining an intra prediction pattern of a current block, partitioning the current block into a plurality of sub-blocks based on the determined intra prediction pattern, generating a first prediction sample for a sub-block by performing intra prediction, determining an offset for the sub-block to obtain a second prediction sample, and generating the second prediction sample for the sub-block by using the first prediction sample and the offset.
1. A method of decoding a video, the method comprising:
generating prediction samples based on an intra prediction mode of a current transform block; and
determining whether an update process of the prediction samples in the current transform block is applied or not,
wherein when it is determined to apply the update process, the prediction samples in the current transform block are updated based on their respective offset,
wherein, in a first sub-region in the current transform block, an offset is adaptively determined based on at least one reference sample adjacent to the current transform block,
wherein, in a second sub-region in the current transform block, an offset is derived to 0 regardless of the at least one reference sample adjacent to the current transform block,
wherein at least one of a size or a shape of the first sub-region is different between when the intra prediction mode of the current transform block is a non-directional mode and when the intra prediction mode of the current transform block is a directional mode, and
wherein at least one of a size or a shape of the second sub-region is different between when the intra prediction mode of the current transform block is a non-directional mode and when the intra prediction mode of the current transform block is a directional mode.
2. The method of claim 1 ,
wherein when the intra prediction mode of the current transform block is the non-directional mode, one of the first sub-region and the second sub-region has a rectangle shape and the other of the first sub-region and the second sub-region has a non-rectangle shape, and
wherein when the intra prediction mode of the current transform block is the directional mode, both the first sub-region and the second sub-region have the rectangle shape.
3. The method of claim 1 , wherein the current transform block has a size of 8×8, 16×16, 32×32 or 64×64.
4. A method of encoding a video, the method comprising:
generating prediction samples based on an intra prediction mode of a current transform block; and
determining whether an update process of the prediction samples in the current transform block is applied or not,
wherein when it is determined to apply the update process, the prediction samples in the current transform block are updated based on their respective offset,
wherein, in a first sub-region in the current transform block, an offset is adaptively determined based on at least one reference sample adjacent to the current transform block,
wherein, in a second sub-region in the current transform block, an offset is derived to 0 regardless of the at least one reference sample adjacent to the current transform block,
wherein at least one of a size or a shape of the first sub-region is different between when the intra prediction mode of the current transform block is a non-directional mode and when the intra prediction mode of the current transform block is a directional mode, and
wherein at least one of a size or a shape of the first sub-region is different between when the intra prediction mode of the current transform block is a non-directional mode and when the intra prediction mode of the current transform block is a directional mode.
5. The method of claim 4 ,
wherein when the intra prediction mode of the current transform block is the non-directional mode, one of the first sub-region and the second sub-region has a rectangle shape and the other of the first sub-region and the second sub-region has a non-rectangle shape, and
wherein when the intra prediction mode of the current transform block is the directional mode, both the first sub-region and the second sub-region have the rectangle shape.
6. A non-transitory computer-readable medium for storing computer-readable instructions such that, when executed, cause a process of a computer to perform a method of
encoding a video, the method comprising:
generating prediction samples based on an intra prediction mode of a current transform block; and
determining whether an update process of the prediction samples in the current transform block is applied or not,
wherein when it is determined to apply the update process, the prediction samples in the current transform block are updated based on their respective offset,
wherein, in a first sub-region in the current transform block, an offset is adaptively determined based on at least one reference sample adjacent to the current transform block,
wherein, in a second sub-region in the current transform block, an offset is derived to 0 regardless of the at least one reference sample adjacent to the current transform block,
wherein at least one of a size or a shape of the first sub-region is different between when the intra prediction mode of the current transform block is a non-directional mode and when the intra prediction mode of the current transform block is a directional mode, and
wherein at least one of a size or a shape of the first sub-region is different between when the intra prediction mode of the current transform block is a non-directional mode and when the intra prediction mode of the current transform block is a directional mode.