A lattice vector quantizer for generalized Gaussian sources

A fixed-rate lattice vector quantizer for generalized Gaussian (GG) sources is presented. By using the contour of counstant probability of a generalized Gaussian source to bound the integer lattice, this vector quantizer in the limit of high dimension achieves optimal boundary gains for GG sources. Low-complexity techniques for rate control, optimal codevector search and enumeration are developed. This coder acheives 8.60 dB for a generalized Gaussian source with shape parameter of 0.5 at l bit/sample (compared with a rate distortion bound of 9.23 dB) and 32.62 dl3 for the 512x512 "lena" image at 0.25 bpp without the use of entropy coding. By using two small lookup tables, the nearest codeword search operation can be performed multiply-free and the overall quantization process costs one multiply and a few adds per sample.

• Type: Conference
• Year: 1995
• Where: ICIP
• Authors: Feng Chen, Zheng Gao, John D. Villasenor
• Keywords: Generalized Gaussian Source, ICIP 1995, Image Processing, Lattice Vector Quantizer, Rate Distortion Bound