IMAGE COMPRESSION USING NONLINEAR PYRAMID VECTOR QUANTIZATION

In this paper, we present a new image compression scheme that exploits the VQ technique in a hierarchical nonlinear pyramid structure. We us e multistage median filters (MMF) to build the image pyramids. Image p yramids generated by MMF show a better details preservation than the o nes generated by Burt's kernel. It is shown that MMF effectively decor relates the difference pyramids, resulting in smaller first order entr opy. Our simulations on natural images show that NPVQ yields a higher SNR as well as better image quality, in comparison with LPVQ. The NPVQ scheme is also appropriate for progressive image transmission.