US 10,432,936 B2 · Apparatus and methods for perceptual quantization parameter (QP) weighting for display stream compression

Abstract

Methods and apparatus for coding video information having a plurality of video samples are disclosed. Blocks for video data are coded by an encoder based upon a quantization parameter (QP) for each block. The video data may be coded in a particular color space, such as YCoCg, wherein different QP values may be used for coding different color components of the video data. Because the human eye is generally more sensitive to differences in luma compared to chroma, and more sensitive to differences in chromatic green than chromatic orange, when the YCoCg color space is used to code the video data, different QP values may be determined for each color component channel. By coding each color component using different QP values, loss from quantization may be reduced while also reducing the appearance of visual artifacts in the coded video data.

Claims25

Dependent claims

An apparatus for coding video data using display stream compression, comprising:

an encoder configured to code a current block of video data using the YCoCg color space comprising a luma channel, a chrominance orange (Co) channel, and a chrominance green (Cg) channel;
and
a rate controller comprising a hardware processor, the rate controller configured to:
determine a luma quantization parameter (QP) for quantizing the luma channel of the current block of video data;
and
based upon the determined luma QP, determine a Cg QP for quantizing the Cg channel of the current block of video data and a Co QP for quantizing the Co channel of the current block of video data, wherein the Cg QP and the Co QP are greater than the luma QP, and wherein the rate controller is configured to determine the Co QP such that the Co QP will always be greater than the Cg QP;
wherein the encoder is configured to encode the current block of video data based upon the determined luma QP, Co QP, and Cg QP to form a video data bitstream for display or transmission.

4 more elements

An apparatus for coding video data using display stream compression, comprising:

means for receiving a current block of video data to be coded using the YCoCg color space comprising a luma channel, a chrominance orange (Co) channel, and a chrominance green (Cg) channel;
means for determining a luma quantization parameter (QP) for quantizing the luma channel of the current block of video data;
means for based upon the determined luma QP, determining a Cg QP for quantizing the Cg channel of the current block of video data and a Co QP for quantizing the Co channel of the current block of video data, wherein the Cg QP and the Co QP are greater than the luma QP, and wherein the means for determining the Co QP comprises means for determining the Co QP such that the Co QP will always be greater than the Cg QP,
means for encoding the current block of video data based upon the determined luma QP, Co QP, and Cg QP to form a video data bitstream for display or transmission.

1 more element

Dependencies are inferred from the claim text.

Apparatus and methods for perceptual quantization parameter (QP) weighting for display stream compression

Life of this patent

Apparatus and methods for perceptual quantization parameter (QP) weighting for display stream compression

Life of this patent

Abstract

Claims25