A refined fast 2-D discrete cosine transform algorithm with regular butterfly structure

[[abstract]]In this paper, a fast computation algorithm for the two-dimensional discrete cosine transform (2-D DCT) is derived based on index permutation. As a result, only the computation of N N-point 1-D DCT's and some post-additions are required for the computation of an (NxN)-point 2-D DCT. Furthermore, as compared with [7], the derivation of the refined algorithm is more succinct, and the associated post-addition stage possesses a more regular butterfly structure. The regular structure of the proposed algorithm makes it more suitable for VLSI and parallel implementations.[[note]]SC