On the Computation of the Discrete Cosine Transform
Madihally J. Narasimha, A. M. Peterson · IRE Transactions on Communications Systems · 1978
AnN-point discrete Fourier transform (DFT) algorithm can be used to evaluate a discrete cosine transform by a simple rearrangement of the input data. This method is about two times faster compared to the conventional method which uses a2N-point DFT.