Method and an apparatus for encoding/decoding residual coefficient
The encoding/decoding method and apparatus according to the present invention derives a residual coefficient of a residual block, calculates a quantization parameter for a residual block, performs dequantization on a residual coefficient using a quantization parameter, and performs inverse transform on a dequantized residual coefficient to reconstruct a residual sample of a residual block.
1. A method for decoding a video signal, comprising:
deriving a residual coefficient of a residual block;
calculating a quantization parameter for the residual block;
performing inverse-quantization on the residual coefficient by using the calculated quantization parameter; and
generating a residual sample of the residual block by performing inverse-transform on the inverse-quantized residual coefficient,
wherein an encoded residual coefficient for a partial region in the residual block is not transmitted from an encoding apparatus,
wherein a residual sample of the partial region in the residual block is set equal to a default value pre-defined at a decoding apparatus,
wherein the default value is 0,
wherein the setting to the default value is performed based on at least one of a size or a shape of the residual block, and
wherein the partial region is representative of a region excluding at least one of N columns from a left side of the residual block or M rows from a top side of the residual block.
2. The method of claim 1 , wherein N and M are derived based on information which is encoded to specify a size or a position of the partial region.
3. The method of claim 1 , wherein the residual block is representative of a block resulting from dividing based on at least one of a quad-tree, a binary-tree or a ternary-tree.
4. An apparatus for encoding a video signal, comprising:
an entropy encoding unit configured to encode a residual coefficient of a residual block;
an inverse-quantization unit configured to calculate a quantization parameter for the residual block and perform inverse-quantization on the residual coefficient by using the calculated quantization parameter; and
an inverse-transform unit configured to reconstruct a residual sample of the residual block by performing inverse-transform on the inverse-quantized residual coefficient,
wherein a residual coefficient for a partial region in the residual block is not encoded,
wherein a residual sample of a partial region in the residual block is set equal to a default value pre-defined at an encoding apparatus,
wherein the default value is 0,
wherein the setting to the default value is performed based on at least one of a size or a shape of the residual block, and
wherein the partial region is representative of a region excluding at least one of N columns from a left side of the residual block or M rows from a top side of the residual block.
5. The apparatus of claim 4 , wherein the entropy encoding unit is configured to entropy-encode information for specifying a size or a position of the partial region.
6. The apparatus of claim 4 , wherein the residual block is representative of a block resulting from dividing based on at least one of a quad-tree, a binary-tree or a ternary-tree.
7. A non-transitory computer-readable storage medium having instructions stored thereon that, when executed, cause one or more processors to:
derive a residual coefficient of a residual block;
calculate a quantization parameter for the residual block;
perform inverse-quantization on the residual coefficient by using the calculated quantization parameter; and
reconstruct a residual sample of the residual block by performing inverse-transform on the inverse-quantized residual coefficient,
wherein an encoded residual coefficient for a partial region in the residual block is not transmitted from an encoding apparatus,
wherein a residual sample of a partial region in the residual block is set equal to a pre-defined default value
wherein the default value is 0,
wherein the setting to the default value is performed based on at least one of a size or a shape of the residual block, and
wherein the partial region is representative of a region excluding at least one of N columns from a left side of the residual block or M rows from a top side of the residual block.
8. The non-transitory computer-readable storage medium of claim 7 , wherein N and M are derived based on information which is encoded to specify a size or a position of the partial region.
9. The non-transitory computer-readable storage medium of claim 7 , wherein the residual block is representative of a block resulting from dividing based on at least one of a quad-tree, a binary-tree or a ternary-tree.