Fast Factorizations of Discrete Sine Transforms of Types Vi and Vii

Discrete Sine Transforms of types VI and VII (DST-VI/VII) have recently received considerable interest in video coding. In particular, it was shown that DST-VII offers good approximation for KLT of residual signals produced by spatial (Intra) prediction process. In this paper, we offer an additional argument for use of such transforms by showing that they allow fast computation. Specifically, we establish a mapping between N -point DST-VI/VII and an 2N + 1-point Discrete Fourier Transform (DFT), apply known factorization techniques for the DFT, and show how unused parts of the resulting flowgraph can be pruned, producing factorizations of DST-VI/VII.