Block-lifting factorization of M-channel biorthogonal filter banks with an arbitrary McMillan degree

A block-lifting factorization of M-channel biorthogonal filter banks (BOFBs) with degree-N building blocks and even/odd M (M ≥ 2) for lossless-to-lossy image coding is introduced in this paper. In the previous work, block-lifting factorization of M-channel BOFBs has been proposed. Since the block-lifting structure does not require the restriction of determinant of each building block, it achieves better coding performance than the conventional methods. However, the factorization is not completed because McMillan degree in each building block is fixed M/2 (M is even). This paper proposes a block-lifting factorization without restrictions for a fixed degree and even block size. Our proposal is validated by several filter designs and their application to lossless-to-lossy image coding.