1. A method using quantization parameters of a color video image, the method including: utilizing 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; utilizing a first QP value for a Y luminance channel of the color video image for a first macroblock; and utilizing a second QP value for at least one of U and V color channels of the color video image for said first macroblock, wherein said second QP value is determined by at least applying a bias value to the first QP value to provide a first intermediate result.