NON-EXPANSIVE EXTENSION METHODS FOR BIORTHOGONAL FILTER BANKS

摘要

In this paper we study linear extension of signals as a technique for processing finite length signals via biorthogonal filter banks. It is known that some signal extension methods, such as symmetric extension, assure perfect reconstruction (PR) of the original signal, but only when using linear phase filters. Thus, considering any biorthogonal 2-channel FIR filter bank as transformation cell, we give a new characterization of all the extension methods that provide PR without need of extra subband samples. In other words, we characterize all non-expansive extension methods. We also illustrate some biorthogonal boundary filters (both in the analysis and in the synthesis stage) which are associated to the proposed transform.