Efficient prime factor decomposition algorithm and address generation techniques for the computation of discrete cosine transform [image compression]

An efficient prime factor algorithm for the discrete cosine transform is introduced. In this approach, we formulate the decomposition directly, by using the proposed input and output mapping, and derive a novel in-place address generation scheme, whilst the formulations in the literature require multiple stages or have to be done via the DFT. This approach requires one output index mapping only while the conventional algorithms require two mappings. Hence, by using the proposed mappings and address generation techniques, less temporary storage is required during the computation. A comparison of the address generation time between our approach and the conventional non-in-place approach is also shown.