<title>Variable-rate predictive residual vector quantization</title>

Abstract

A major problem with a VQ based image compression scheme is its codebook search complexity. Recently a Predictive Residual Vector Quantizer (PRVQ) was proposed in Ref. 8. This scheme has a very low search complexity and its performance is very close to that of the Predictive Vector Quantizer (PVQ). This paper presents a new VQ scheme called Variable-Rate PRVQ (VR-PRVQ) which is designed by imposing a constraint on the output entropy of the PRVQ. The proposed VR-PRVQ is found to give an excellent rate-distortion performance and clearly outperforms the state-of-the-art image compression algorithm developed by Joint Photographic Experts Group (JPEG).