Title :
A comparison of the Z, E/sub 8/, and Leech lattices for quantization of low-shape-parameter generalized Gaussian sources
Author :
Gao, Zheng ; Belzer, Ben ; Villasenor, John
Author_Institution :
Dept. of Electr. Eng., California Univ., Los Angeles, CA, USA
Abstract :
In lattice vector quantization, the distortion associated with a given lattice is often expressed in terms of the G number, which is a measure of the mean square error per dimension generated by quantization of a uniform source. Subband image coefficients, however, are best modeled by a generalized Gaussian distribution, leading to distortion characteristics that are quite different from those encountered for uniform, Laplacian, or Gaussian sources. We have calculated the distortion associated with Z, E/sub 8/, and Leech (1967) lattice quantization for coding of generalized Gaussian sources and show that for low bit rates, the Z lattice offers both the best performance and the lowest implementational complexity.<>
Keywords :
Gaussian distribution; Gaussian processes; image coding; image reconstruction; lattice theory; source coding; vector quantisation; E/sub 8/ lattice; G number; Laplacian sources; Leech lattice quantization; Z lattice; distortion characteristics; generalized Gaussian distribution; image coding; implementational complexity; lattice vector quantization; low bit rates; low-shape-parameter generalized Gaussian sources; mean square error per dimension; performance; source coding; subband image coefficients; uniform source; uniform sources; Bit rate; Distortion measurement; Gaussian distribution; Image reconstruction; Laplace equations; Lattices; Mean square error methods; Rate-distortion; Shape; Vector quantization;
Journal_Title :
Signal Processing Letters, IEEE
