• autocorr - Autocorrelate an image.
• carith - Multiply or divide complex images.
• crosscor - Cross-correlate two images.
• factor - Display prime factors of a number.
• fconvolve - Convolve two images.
• forward - Compute forward Fourier transform of an image.
• frompolar - Convert amplitude & phase to real & imaginary parts.
• inverse - Compute inverse Fourier transform of an image.
• listprimes - Display first N prime numbers.
• powerspec - Compute the power spectrum of an image.
• shift - Shift an image by a specified number of pixels.
• taperedge - Apply a cosine bell or linear taper to image edges.
• topolar - Convert real & imaginary parts to amplitude & phase.

(Type "help fourier option=sysdoc" for general information about the 'fourier' package).