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