Image decoding method using context-coded sign flag in image coding system and apparatus therefor
AssigneeLG Electronics Inc.
InventorsSunmi Yoo, Jin Heo, Jungah Choi, Seunghwan Kim
Life of this patent
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Abstract
An image decoding method performed by a decoding device according to the present document comprises the steps of: deriving a context model for a sign flag of a current residual coefficient of a current block; and decoding the sign flag on the basis of the context model, wherein the context model for the sign flag is derived on the basis of a sign flag of a residual coefficient decoded before the current residual coefficient in the current block.
Claims16
An image decoding method, performed by a decoding apparatus, comprising:
- receiving residual information for a current block;
- deriving a prediction sample of the current block;
- deriving a context model for a sign flag of a current residual coefficient of the current block;
- decoding the sign flag based on the context model;
- deriving the current residual coefficient based on the sign flag;
- deriving a residual sample based on the current residual coefficient;
- and
- generating a reconstructed picture based on the prediction sample and the residual sample,
- wherein the context model for the sign flag is derived based on a sign flag of a residual coefficient decoded prior to the current residual coefficient in the current block.
An image encoding method, performed by an encoding apparatus, comprising:
- deriving a residual sample of a current block;
- deriving a current residual coefficient of the current block based on the residual sample;
- deriving a context model for a sign flag of the current residual coefficient;
- encoding the sign flag based on the context model;
- and
- generating a bitstream including the sign flag,
- wherein the context model for the sign flag is derived based on a sign flag of a residual coefficient encoded prior to the current residual coefficient in the current block.
A non-transitory computer-readable storage medium storing a bitstream generated by a method, the method comprising:
- deriving a residual sample of a current block;
- deriving a current residual coefficient of the current block based on the residual sample;
- deriving a context model for a sign flag of the current residual coefficient
- encoding the sign flag based on the context model;
- and
- generating the bitstream including the sign flag,
- wherein the context model for the sign flag is derived based on a sign flag of a residual coefficient encoded prior to the current residual coefficient in the current block.
A transmission method of data for image, the method comprising:
- obtaining a bitstream of image information including a sign flag of a current residual coefficient of a current block;
- and
- transmitting the data including the bitstream of the image information including the sign flag,
- wherein the current residual coefficient is derived based on a residual sample of the current block,
- wherein the sign flag is encoded based on a context model for the sign flag, and
- wherein the context model for the sign flag is derived based on a sign flag of a residual coefficient encoded prior to the current residual coefficient in the current block.
Dependencies are inferred from the claim text.