Dependencies between coding gain and filter length in paraunitary filter banks designed using quaternionic approach

In this paper, we investigate the performance limits of four-channel paraunitary filter banks designed using quaternionic approach. Our aim is to reveal how the maximum achievable coding gain depends on the filter length, linearity of the phase responses, and system one-regularity. We also try to obtain some additional insight into coefficient synthesis for paraunitary filter banks, which is often a difficult optimization problem. The results may provide useful advice for the designers who intend to employ filter banks in subband image coding as well as in other applications.