Fast 15x15 Transform for Image and Video Coding Applications

Abstract

We derive factorization of DCT-II transform of size 15 which requires only 14 multiplications, 67 additions, and 3 multiplications by rational dyadic constants (implementable by shifts). This transform is significantly less complex than DCT-II of nearest dyadic size (16), and we suggest considering it for future image and video coding applications that can benefit from using larger (than 8x8) block sizes.