On computing the 2-D FFT

A a new implementation of the two-dimensional FFT (2-D FFT) is proposed. Compared with the usual separable solution, the new realization of the 2-D FFT has reduced arithmetic complexity. Computational savings are achieved because the 2-D case enables, after some modifications of the basic separable algorithm, scaling and inverse scaling of butterfly operators. The new improvement is also applied to other 2-D transforms: DCT-IV, DCT, and lapped transforms.