Color space choice for nearly reversible image compression
Albert A. Deknuydt, J. Smolders, Luc Van Eycken, A. Oosterlinck · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1992
In applications where nearly reversible color image compression is required, the choice of an appropriate color space is a major factor determining the attainable compression ratio. The optimal choice would satisfy the following conditions: (1) Decorrelate the data as much as possible. (2) Minimize the total number of bits in the data path needed for a certain quality level (assuming a truly reversible component compression scheme). (3) Need no calculations with critical accuracy. We compared several known linear color transformations (under the assumption that the original data was represented in RGB) with respect to these conditions. Decorrelation and entropy reduction were calculated. The number of bits required to guarantee a certain quality level measured in (Delta) Lab units was determined. The effects of transformation coefficient quantization were checked. As a result, a simple transformation needing no multipliers at all is proposed.