Issue No.10 - October (1978 vol.27)
B.D. Tseng , Department of Electrical Engineering, University of Windsor
Haralick has shown that the discrete cosine transform of N points can be computed more rapidly by taking two N-point fast Fourier transforms (FFT's) than by taking one 2N-point FFT as Ahmed had proposed. In this correspondence, we show that if Haralick had made use of the fact that the FFT's of real sequences can be computed more rapidly than general FFT's, the result would have been reversed. A modified algorithm is also presented.
real FFT, Complex FFT, complex operations, discrete cosine transform
B.D. Tseng, "On Computing the Discrete Cosine Transform", IEEE Transactions on Computers, vol.27, no. 10, pp. 966-968, October 1978, doi:10.1109/TC.1978.1674977