Transforms
- idct — Inverse discrete cosine transform.
- idst — Inverse discrete sine transform.
- ifft — Inverse fast Fourier transform.
- fft2 — two-dimension fast Fourier
transform
- fftshift — rearranges the fft output, moving the zero frequency to the center of the spectrum
- hilb — FIR approximation to a Hilbert transform filter
- ifftshift — inverse of fftshift