COLOR QUANTIZATION BASED ON DESIRED UPPER BOUND FOR RELATIVE QUANTIZATION STEP

摘要

A computer system (810) receives a desired upper bound δ_Smax for a relative quantization step ∥S′−S″∥/∥S′∥ to be used when quantizing any color in some range of colors. Here S′ and S″ are adjacent colors in the set of colors to be made available for the quantized image, and ∥•∥ is a norm in a 70%-orthonormal linear color coordinate system, the norm being the square root of the sum of squares of the tristimulus values. The computer system determines (510) suitable quantization steps for the brightness coordinate (B) and the chromatic coordinates (e,ƒ) in a non-linear color coordinate system, and quantizes (520) the brightness and chromatic coordinates accordingly.