Simulated annealing and codebook design

The application of simulated annealing to the design of a codebook for a vector quantizer (VQ) that is used to code images are studied. The traditional method for VQ codebook design is to use the generalized Lloyd algorithm (GLA), an iterative optimization procedure where an initial codebook is continually refined so that each iteration reduces the distortion involved in coding a given training set. However, this algorithm easily gets trapped in local minima of the distortion, resulting in a suboptimal codebook. Simulated annealing is a procedure that uses randomness in a search algorithm and tends to skirt relatively poor local minima in favor of better ones. The mean-squared-error (MSE) is used as the distortion measure during the design, and coded images are evaluated both subjectively and in terms of the peak-signal-to-noise ratio