S. Tramini et al., INTRAFRAME IMAGE DECODING BASED ON A NONLINEAR VARIATIONAL APPROACH, International journal of imaging systems and technology, 9(5), 1998, pp. 369-380
Despite advances in the domain of source coding, little recent work ha
s been devoted to the problem of joint coding and decoding. In particu
lar, to our knowledge, the design of decoders has been little investig
ated. In this article, we focus on decoding for intraframe images of v
ideo data. In our approach, we propose a new method for decoding by no
nlinear filtering. Here, we break with the usual approach of perfect r
econstruction filters at the decoder, and instead pose the reconstruct
ion model as a minimization problem. The solution can be viewed as an
inverse problem with the optimization of the transform/quantization/de
coding 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 (transformatio
n and quantization). We develop an optimization method for the reconst
ruction filters at the decoder to account for effects due to quantizat
ion noise. Experiments using this nonlinear inverse dynamic filtering
demonstrate peak signal-to-noise ratio gains over standard linear inve
rse filtering as well as appreciable visual improvements. (C) 1998 Joh
n Wiley & Sons, Inc.