Intraframe image decoding based on a nonlinear variational approach

Despite advances in the domain of source coding, little recent work has been devoted to the problem of joint coding and decoding. In particular, to our knowledge, the design of decoders has been little investigated. In this article, we focus on decoding for intraframe images of video data. In our approach, we propose a new method for decoding by nonlinear filtering. Here, we break with the usual approach of perfect reconstruction filters at the decoder, and instead pose the reconstruction model as a minimization problem. The solution can be viewed as an inverse problem with the optimization of the transform/quantization/decoding structure formulated using a variational approach. We introduce sufficient conditions on the design of the decoder involving a priori assumptions on the solution and knowledge of the coder (transformation and quantization). We develop an optimization method for the reconstruction filters at the decoder to account for effects due to quantization noise. Experiments using this nonlinear inverse dynamic filtering demonstrate peak signal‐to‐noise ratio gains over standard linear inverse filtering as well as appreciable visual improvements. © 1998 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 9, 369–380, 1998