Design of Near Perfect Reconstruction Non-Uniform Filter Banks

Subband coding is widely used to compress speech, audio and video signals. In some applications, for example audio compression, a non-uniform splitting of the spectrum of a digital signal can be preferable to a uniform one. Some techniques that allow to implement a non-uniform width subband decomposition are here discussed, design methods based on the cosine-modulation of more than one prototype are described and some examples of filter bank design are given.