Survey of odd and even length filters in tree-structured filter banks for subband image compression

The performance of subband image coders depends on proper choice of lter banks. Although odd length lters in the lter banks produce waveform type artifacts, this can be alleviated by enforcing a smooth interpolation property to the synthesis lowpass lter. Evaluation of even, odd, and combinations of even and odd length lters in tree-structured lter banks, where the lter coe cients are obtained by optimizing for coding gain at each stage, is done for image coding purposes. Favorable results are obtained when a combination of odd and even length lters are used.