Image decoding method and device for coding chroma quantization parameter offset-related information
AssigneeLG Electronics Inc.
InventorsJie Zhao, Seunghwan Kim, Seethal Paluri
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Abstract
An image decoding method performed by a decoding device according to the present document comprises the steps of: obtaining CU chroma QP offset-related information for a current chroma block on the basis of the size and tree type of the current chroma block; deriving a chroma QP for the current chroma block on the basis of the CU chroma QP offset-related information; deriving residual samples for the current chroma block on the basis of the chroma QP; and generating a reconstructed picture on the basis of the residual samples, wherein the CU chroma QP offset-related information includes a CU chroma QP offset flag and a CU chroma QP offset index for the current chroma block.
Claims3
An image decoding method, performed by a decoding apparatus, comprising:
- obtaining Coding Unit (CU) chroma Quantization Parameter (QP) offset related information for a chroma component of a current coding unit based on a tree type and a size of the current coding unit;
- deriving a chroma QP for the current coding unit based on the CU chroma QP offset related information;
- deriving residual samples for the current coding unit based on the chroma QP;
- and
- generating a reconstructed picture based on the residual samples,
- wherein the CU chroma QP offset related information includes a CU chroma QP offset flag and a CU chroma QP offset index for the current coding unit,
- wherein based on at least one of a width and a height of the current coding unit being greater than 64 and the tree type being not a dual tree luma, the CU chroma QP offset flag is obtained, and
- wherein based on the CU chroma QP offset flag representing that an entry in a CU QP offset list is used to determine a value of a CU chroma QP offset, the CU chroma QP offset index is obtained.
An image encoding method, performed by an encoding apparatus, comprising:
- generating Coding Unit (CU) chroma Quantization Parameter (QP) offset related information for a chroma component of a current coding unit based on a tree type and a size of the current coding unit;
- and
- encoding image information including the CU chroma QP offset related information,
- wherein the CU chroma QP offset related information includes a CU chroma QP offset flag and a CU chroma QP offset index for the current coding unit,
- wherein based on at least one of a width and a height of the current coding unit being greater than 64 and the tree type being not a dual tree luma, the CU chroma QP offset flag is signaled, and
- wherein based on the CU chroma QP offset flag representing that an entry in a CU QP offset list is used to determine a value of a CU chroma QP offset, the CU chroma QP offset index is signaled.
A method for data for image, the method comprising:
- generating a bitstream of image information including Coding Unit (CU) chroma Quantization Parameter (QP) offset related information for a chroma component of a current coding unit;
- and
- transmitting the data including the bitstream of the image information including the CU chroma QP offset related information,
- wherein the CU chroma QP offset related information is generated based on a tree type and a size of the current coding unit,
- wherein the CU chroma QP offset related information includes a CU chroma QP offset flag and a CU chroma QP offset index for the current coding unit,
- wherein based on at least one of a width and a height of the current coding unit being greater than 64 and the tree type being not a dual tree luma, the CU chroma QP offset flag is signaled, and
- wherein based on the CU chroma QP offset flag representing that an entry in a CU QP offset list is used to determine a value of a CU chroma QP offset, the CU chroma QP offset index is signaled.
Dependencies are inferred from the claim text.