Dyadic-based factorizations for regular paraunitary filter banks [image coding examples]

M-channel paraunitary filter banks (PUFBs) can be designed and implemented using either degree-one or order-one dyadic-based factorization. This paper summarizes how regularity of a desired degree is structurally imposed on such factorizations for any number of channels M≥2 and any phase responses. The regularity conditions are found to be conveniently expressed in terms of recently reported M-channel lifting structures, which allow fast and reversible implementations. Design examples are presented and they outperform previously reported ones in transform-based image coding.