CPC H04N 19/46 (2014.11) [H04N 19/103 (2014.11); H04N 19/136 (2014.11); H04N 19/176 (2014.11)] | 17 Claims |
1. An image decoding method performed by a decoding apparatus, the image decoding method comprising:
obtaining image information including a transform skip flag and residual information for a current block, wherein the transform skip flag represents whether the current block is a transform skip block;
determining whether the current block is the transform skip block based on the transform skip flag;
based on the current block being the transform skip block, deriving a context model for a sign flag of a current residual coefficient in a current sub-block of the current block based on a sign flag of a residual coefficient decoded prior to the current residual coefficient in the current sub-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 residual sample.
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