This report is divided into two sections. In the first section, the focus is on adaptive transform-based image compression and motion compensation at low bit rates. A new adalptive algorithm for image representation and coding is introduced. This algorithm is based on the concept of segmented orthogonal matching pursuits (SOMP), and adaptively selects the best representation from an overcomplete dictionary of wavelet functions. In the second section, the pre-processing and post-processing of images and video streams are focused on. A new robust nonlinear filter based on the theory of generalized maximum likelihood and order statistics (GMLOS) is introduced. It is shown that this filter is an 1,- optimal order statistics filter and some of its properties are proved. A novel algorithm based on wavelet decomposition, variable size kernel GMLOS filters, and soft thresholding for removing the blocking effects in block-based transform coding techniques is introduced. Finally, a simple algorithm for cell packing in ATM networks is inti-oduced, and a novel algorithm for error concealment of images and video streams, based on Multi-directional Recursive Nonlinear Filtering (MRNF) with GMLOS filters is inti-oduced.

Date of this Version

November 1996