Fast Radix-q and Mixed-Radix Algorithms for Type-IV DCT

Abstract

This letter proposes a fast radix-q algorithm to compute type-IV discrete cosine transform (DCT) of the length q(lambda), where q is an odd positive integer. The proposed fast radix-q algorithm has merits in computational complexity, parallelism, and numerical stability over existing algorithms. Furthermore, the fast radix-q algorithm is used to develop the fast mixed-radix type-II/type-IV DCT algorithm for composite lengths.