Average optimal vector transform for VQ-based image and video compression

We present an average sense optimal vector transform (AOVT) for vector quantization (VQ)-based coding of square block vectors. We introduce new notions of average intervector correlations and exploit the new structure of the intervector correlation matrix in deriving our AOVT. We present the results of applying our AOVT to many real images and demonstrate the superiority of the AOVT in terms of better preservation of the intravector correlation in the transform domain. We also present coding results on a variety of images to demonstrate the fact that the above-mentioned advantage of AOVT translates into coding gains since the performance of VQ increases if the transform domain vectors have more intravector dependencies.