A REGRESSIVE STRUCTURE FOR ONLINE COMPUTATION OF ARBITRARY LENGTH DCT-IV AND DST-IV TRANSFORMS

In this correspondence, we demonstrate that the forward and inverse ty pe-IV discrete cosine transform (DCT-IV/IDCT-IV) and type-IV discrete sine transform (DST-IV/IDST-IV) can be efficiently computed by a regre ssive structure, In our approach, we suggest using the recursive sinus oidal formulas corresponding to the transform kernels of these transfo rms to obtain an IIR filter structure, The novel structure is then use d for Parallel computation of arbitrary length DCT-IV/IDCT-IV and DST- IV/DST-IV. Since the architecture can be highly parallel, simple, and regular, it is most suitable for VLSI implementation. Moreover, we do not need to permute the input sequence, which makes the approach parti cularly suitable for on-line computation.