A new approach to the compensation of aliasing in transform and subband coders

Filter banks for transform and subband coding are usually designed so as to achieve perfect reconstruction without considering distortions induced by inevitable or even desired effects such as filter implementation, subband quantization, and transmission. Other design algorithms minimize the distortion using more or less realistic models of quantizers. In contrast, we propose a new type of alias compensation based on the reasonable assumption that perfect or even near-perfect reconstruction in general cannot be attained if the subband signals are manipulated in some way. Therefore, a mostly time-invariant behaviour of the overall system seems to he more desirable. The proposed algorithm is capable of designing a compensation filter bank which reduces aliasing while the desired time-invariant part of the original system is preserved as far as possible