Method and system for improving compressed image chroma information

摘要

Methods, systems, and computer programs for improving compressed image chroma information. In one aspect of the invention, a resolution for a red color component of a color video image is used that is higher than the resolution for a blue color component of the color video image. Another aspect includes utilizing a lower or higher value of a quantization parameter (QP) for one or more chroma channels as compared to the luminance channel. Another aspect is use of a logarithmic representation of a video image to benefit image coding. Another aspect uses more than two chroma channels to represent a video image.

主权项

1. A video image system using quantization parameters of a color video image, the system including:
a data storage system; a decoder configured to interact with the data storage system to execute instructions to:
receive a bias value at a decoder as part of a compressed bit stream;utilize a variable quantization step size and a quantization parameter (QP) to represent a size of a step where an increase in the QP corresponds to a larger quantization step size;utilize a first QP value for a Y luminance channel of the color video image for decoding a first macroblock;utilize a second QP value for at least one of U and V color channels of the color video image for decoding said first macroblock, wherein said second QP value is determined by at least applying the bias value to the first QP value to provide a first intermediate result.