Image decoding method and apparatus therefor
AssigneeLG Electronics Inc.
InventorsSunmi Yoo, Junghak Nam, Jaehyun Lim, Naeri Park, Jangwon Choi
Life of this patent
Estimating the term…
Abstract
An image decoding method performed by a decoding apparatus according to the present document comprises the steps of: deriving an intra prediction mode of a current block; scaling neighboring samples for the current block so as to derive modified neighboring reference samples for the current block; deriving prediction samples for the current block on the basis of the intra prediction mode and the modified neighboring reference samples; deriving a reconstructed block for the current block on the basis of the prediction samples; and upscaling the reconstructed block so as to derive a modified reconstructed block.
Claims13
A method for an image decoding, the method performed by a decoding apparatus and comprising:
- deriving an intra prediction mode of a current block;
- deriving modified neighboring reference samples for the current block by scaling neighboring samples for the current block;
- deriving prediction samples for the current block based on the intra prediction mode and the modified neighboring reference samples;
- deriving a reconstructed block for the current block based on the prediction samples;
- and
- deriving a modified reconstructed block by upscaling the reconstructed block,
- wherein the deriving the modified neighboring reference samples for the current block comprises:
- scaling the neighboring samples of the current block based on a scale factor of the current block;
- and
- deriving the scaled neighboring samples as neighboring reference samples of the current block,
- wherein the scale factor for a width of the current block is a, and the scale factor for a height of the current block is b,
- wherein left neighboring samples of the current block are derived as modified left neighboring reference samples for the current block by subsampling by 1/a, and
- wherein upper neighboring samples of the current block are derived as modified upper neighboring reference samples for the current block by subsampling by 1/b.
A method for an image encoding, the method performed by an encoding apparatus and comprising:
- deriving a modified current block by scaling a current block;
- deriving an intra prediction mode of the modified current block;
- deriving modified neighboring reference samples for the modified current block by scaling neighboring samples for the modified current block;
- deriving prediction samples for the modified current block based on the intra prediction mode and the modified neighboring reference samples;
- encoding image information including intra prediction related information for the modified current block;
- and
- generating a bitstream including the image information,
- wherein the deriving the modified neighboring reference samples for the current block comprises:
- scaling the neighboring samples of the current block based on a scale factor of the current block;
- and
- deriving the scaled neighboring samples as neighboring reference samples of the current block,
- wherein the scale factor for a width of the current block is a, and the scale factor for a height of the current block is b,
- wherein left neighboring samples of the current block are derived as modified left neighboring reference samples for the current block by subsampling by 1/a, and
- wherein upper neighboring samples of the current block are derived as modified upper neighboring reference samples for the current block by subsampling by 1/b.
A computer-readable digital storage medium which stores a bitstream generated by a specific method, wherein the specific method comprises:
- deriving a modified current block by scaling a current block;
- deriving an intra prediction mode of the modified current block;
- deriving modified neighboring reference samples for the modified current block by scaling neighboring samples for the modified current block;
- deriving prediction samples for the modified current block based on the intra prediction mode and the modified neighboring reference samples;
- encoding image information including intra prediction related information for the modified current block;
- and
- generating the bitstream including the image information,
- wherein the deriving the modified neighboring reference samples for the current block comprises:
- scaling the neighboring samples of the current block based on a scale factor of the current block;
- and
- deriving the scaled neighboring samples as neighboring reference samples of the current block,
- wherein the scale factor for a width of the current block is a, and the scale factor for a height of the current block is b,
- wherein left neighboring samples of the current block are derived as modified left neighboring reference samples for the current block by subsampling by 1/a, and
- wherein upper neighboring samples of the current block are derived as modified upper neighboring reference samples for the current block by subsampling by 1/b.
Dependencies are inferred from the claim text.