Subband/VQ coding in perceptually uniform color spaces
Robert E. Van Dyck, Sarah A. Rajala · 1992
A subband/VQ coder that combines the three color components of each subband pixel into a length 3 vector and then vector quantizes each subband is presented. Perceptual weights derived from subjective visual experiments are used along with the rate-distortion curves to determine a perceptually optimal bit allocation. Advantages of this method are that fewer codebooks need to be designed and the resulting bit allocation problem is simplified. Preliminary results show that this method achieves results comparable to the more standard subband/VQ method where the color components of each subband are vector quantized separately using the perceptually optimal bit allocation algorithm. To obtain the required compression ratio and the high color fidelity required for HDTV applications, the vector quantization is done in a perceptually uniform color space.>