Edge enhancement for subband-coded images

Subband coding is a well-established technique. Coding algorithms, however, rarely try to exploit residual similarities between subbands in order to g et both coding gain and improvement in visual appearance. In this work we p ropose a simple postprocessing technique for edge enhancement and ringing-a rtifact reduction in subband-coded images. The proposed technique employs m orphological filtering for preliminary image simplification and uses a nove l dual-window nonlinear operator for subsequent edge enhancement. Visual ap pearance and numerical results confirm tile validity of the approach. A sim ple coding scheme, designed to test the efficiency of the approach, gives g ood results. (C) 2001 Society of Photo-Optical instrumentation Engineers.