Smooth side-match and smooth overlap-match vector quantizers for image coding

The side-match Vector quantizer (SMVQ) is a well known method for image cod ing. We propose the smooth side-match vector quantizer (SSMVQ). The SSMVQ i mproves coding quality by making smoother the transition of the gray levels of the adjacent blocks. Moreover, the smooth overlap-match vector quantize r (SOMVQ) is proposed to improve the performance of the overlap-match vecto r quantizer (OMVQ). Experimental results reveal that SSMVQ and SOMVQ have t he higher peak SNR (PSNR) values, better visual perception quality, and low er bit rate than SMVQ and overlap-match vector quantizer (OMVQ), respective ly. (C) 2000 Society of Photo-Optical Instrumentation Engineers. [S0091-328 6(00)03407-3].