FIR compaction filters: new design methods and properties

Energy compaction has proven to be an essential concept in signal-adapted data compression. In particular, optimization of orthonormal subband coders for a given power spectrum directly leads to optimal energy compaction filters. We consider some new design methods and properties of optimal FIR energy compaction filters. In particular, we propose a very efficient method called the window method for the general M-channel case. The method does not involve any sophisticated optimization tools and terminates in a finite number of elementary steps. Compaction gains achieved by the method are very close to the optimal ones. As the filter order increases the filters of the proposed method converge to the optimum ideal compaction filters.