Hierarchical Predictive Vq for Color Image Compression

A hierarchical predictive VQ algorithm for color image compression is proposed in this paper. For encoding large size blocks, instead of using conventional bilinear interpolation, a new interpolation technique which make use of the neighboring reconstructed pixels and the lower right comer pixel is employed. The coding strategies for different block sizes are investigated, which involves the choice of color space and the use of combined or separate color components for vector quantization. Simulation results show that no significant blocking artifacts appear at the block boundaries. In addition, the encoding complexity for large size blocks can be maintained to an acceptable level.