On regularized dequantizers for DCT-based transform coding of images

We have recently proposed a new dequantization scheme for DCT-based transform coding based on regularization principles [1]. The new approach sharply reduced blocking artifacts in decoded images and the performance of thenew dequantization scheme has been evaluated against the standard JPEG, MPEG and H.263+ in terms of the peak-signal-to-noise ratio (PSNR) with our own definition of the blockiness measure (BM). Basically, the proposed dequantizer maps the received data to within the range ′ (quantizer spacing/2), so that the final decompressed image is "smooth" in the sense of minimizing the cost functional including the stabilizing term weighted by a regularization parameter. In this paper, we focus on several important aspect of this regularized dequantizer, namely the selection of the regularization parameter and the convergence of the dequantization algorithm.