Method and apparatus for video intra prediction involving filtering reference samples based on wide-angle mode
AssigneeHuawei Technologies Co., Ltd.
InventorsAlexey Konstantinovich Filippov, Vasily Alexeevich Rufitskiy, Jianle Chen
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Abstract
A method of intra prediction of a block in a picture of a video is provided. The method includes obtaining an intra prediction mode of the block; determining whether the intra prediction mode of the block is a wide-angle mode; filtering reference samples for the block based, at least in part, upon determining that the intra prediction mode of the block is the wide-angle mode; and generating predicted samples of the block based on filtered reference samples.
Claims18
A method of intra prediction of a block in a picture of a video, the method performed by a video encoder or a video decoder, the method comprising:
- obtaining an intra prediction mode of the block;
- determining the intra prediction mode of the block is a wide-angle mode;
- filtering reference samples for the block based, at least in part, upon determining that the intra prediction mode of the block is the wide-angle mode;
- generating predicted samples of the block based on the filtered reference samples;
- and
- performing position-dependent prediction combination (PDPC) for the filtered reference samples;
- when the wide angle mode is a top-right diagonal mode, PDPC weights wT and wL satisfy:
- wT=32>>((y′<<1)>>shift), wL=0;
- or
- when the wide angle mode is a bottom-left diagonal mode, PDPC weights wT and wL satisfy:
- wL=32>>((x′<<1)>>shift), wT=0;
- wherein wT is the weight for filtered reference samples located at the top of the block, wL is the weight for filtered reference samples located at the left of the block, (x′, y′) are coordinates of the predicted samples predSamples, and shift is a variable based on a size of the block.
An apparatus for intra prediction of a block of a picture in a video, the apparatus comprises:
- a non-transitory computer-readable storage medium containing instructions;
- and
- one or more processors in communication with the non-transitory computer-readable storage medium and upon execution of the instructions, configured to:
- obtain an intra prediction mode of the block;
- determine the intra prediction mode of the block is a wide-angle mode;
- filter reference samples for the block based, at least in part, upon determining that the intra prediction mode of the block is the wide-angle mode;
- generate predicted samples of the block based on the filtered reference samples;
- and
- perform position-dependent prediction combination (PDPC) for the filtered reference samples;
- when the wide angle mode is a top-right diagonal mode, PDPC weights wT and wL satisfy:
- wT=32>>((y′<<1)>>shift), wL=0;
- or
- when the wide angle mode is a bottom-left diagonal mode, PDPC weights wT and wL satisfy:
- wL=32>>((x′<<1)>>shift), wT=0;
- wherein wT is the weight for filtered reference samples located at the top of the block, wL is the weight for filtered reference samples located at the left of the block, (x′, y′) are coordinates of the predicted samples predSamples, and shift is a variable based on a size of the block.
A non-transitory storage medium comprising a bitstream of a video generated by an encoder or processed by a decoder, the bitstream of the video comprising:
- first information representing an intra prediction mode of a block of the video;
- second information representing residual of the block based on predicted samples of the block generated using filtered reference samples for the block, the filtered reference samples being generated by filtering reference samples for the block based, at least in part, upon the intra prediction mode of the block being a wide-angle mode;
- and
- the bitstream of the video further comprises information indicating position-dependent prediction combination (PDPC) is performed for the filtered reference samples for the block;
- when the wide angle mode is a top-right diagonal mode, PDPC weights wT and wL satisfy:
- wT=32>>((y′<<1)>>shift), wL=0;
- or
- when the wide angle mode is a bottom-left diagonal mode, PDPC weights wT and wL satisfy:
- wL=32>>((x′<<1)>>shift), wT=0;
- wherein wT is the weight for filtered reference samples located at the top of the block, wL is the weight for filtered reference samples located at the left of the block, (x′, y′) are coordinates of the predicted samples predSamples, and shift is a variable based on a size of the block.
Dependencies are inferred from the claim text.