Index assignment for 3-description lattice vector quantization based on A2 lattice

Multiple description lattice vector quantization (MDLVQ) is an effective technique to realize multiple description coding. In this paper, we investigate a 3-description lattice vector quantization (LVQ) design using A(2) lattice, which finds a 3-tuple combination of sublattice points to represent each fine lattice point, based on two principles that: each edge of the triangle formed by the 3-tuple points needs to be as short as possible, and the gravity center of the triangle is as close as possible to the fine lattice point. Following a delicate sublattice partition, a well-designed construction and mapping of each fine lattice point to a 3-tuple of sublattice points is developed to minimize the side distortion. The proposed index assignment is shown to achieve smaller distortion (up to 0.58 dB for Gaussian source) than some other 3-description index assignments, the 3-description LVQ achieves better expected Compared with a 2-description LVQ p rate-distortion performance in most cases of high description loss rates, while it also exhibits more graceful coding results with significantly smaller side distortions. Numerical analysis on Gaussian source and the simulations on image source validate the effectiveness of our proposed index assignment scheme. (C) 2008 Elsevier B.V. All rights reserved.