Systems and methods for coding video data using adaptive component scaling
A method of encoding and decoding video data is described. According to an aspect of an invention, luma and chroma components may have separate quadtree plus binary tree (QTBT) structures and a scaling parameter for a chroma coding block is determined based on one or more properties of a luma component.
1. A method of decoding video data, the method comprising:
parsing a slice level flag indicating chroma scaling which is applied to a current chroma coding block;
mapping a top-left sample of the current chroma coding block to a corresponding sample location of a luma component sample based on a luma and chroma component spatial resolution relation;
determining an average luma value for reconstructed luma sample values;
determining a chroma scaling parameter according to a look-up table, wherein the look-up table provides the chroma scaling parameter by using the average luma value; and
scaling residual data corresponding to a chroma component of the current chroma coding block by using the determined chroma scaling parameter.
2. The method of claim 1 , wherein the look-up table provides a chroma scaling parameter of 64 for an average luma value 450 .
3. The method of claim 1 , wherein the look-up table provides a chroma scaling parameter of 128 for an average luma value 900 .
4. A device for decoding video data, the device comprising one or more processors configured to:
parse a slice level flag indicating chroma scaling which is applied to a current chroma coding block;
mapping a top-left sample of the current chroma coding block to a corresponding sample location of a luma component sample based on a luma and chroma component spatial resolution relation;
determine an average luma value for reconstructed luma sample values;
determine a chroma scaling parameter according to a look-up table, wherein the look-up table provides the chroma scaling parameter by using the average luma value; and
scale residual data corresponding to a chroma component of the current chroma coding block by using the determined chroma scaling parameter.
5. The device of claim 4 , wherein the look-up table provides a chroma scaling parameter of 64 for an average luma value 450 .
6. The device of claim 4 , wherein the look-up table provides a chroma scaling parameter of 128 for an average luma value 900 .