Method and apparatus for color transform in VVC

A video decoder for video decoding, comprising:

• processing circuitry configured to:
• receive a coded video bitstream including a current picture,
• perform an inverse quantization on a current block included in the current picture,
• perform, after performance of the inverse quantization, an inverse transform on the current block,
• determine whether a predetermined condition is satisfied, and
• in response to a determination that the predetermined condition is satisfied, perform an inverse color transform on the current block,
• wherein the predetermined condition is satisfied in response to a determination that different color components of the inverse color transform are coded using a same coding unit partitioning tree, and
• wherein the inverse color transform is applied only for intra coded blocks when different color components share the same coding unit partitioning tree.

A non-transitory computer readable medium having instructions stored therein, which when executed by a processor in a video decoder causes the video decoder to execute a method comprising:

• receiving a coded video bitstream including a current picture;
• performing an inverse quantization on a current block included in the current picture;
• performing, after performing the inverse quantization, an inverse transform on the current block;
• determining whether a predetermined condition is satisfied;
• and
• in response to determining that the predetermined condition is met, performing an inverse color transform on the current block,
• wherein the predetermined condition is satisfied in response to a determination that different color components of the inverse color transform are coded using a same coding unit partitioning tree, and
• wherein the inverse color transform is applied only for intra coded blocks when different color components share the same coding unit partitioning tree.