Discrete Fourier Transformation (DFT)


Sources of images: Adam Ferriss, Complex Geometry, Victor Vasarely, own, and some unknown

Given a picture of N1 x N2 dimensions, its pixel values are f [p,q], the DF tarnsform of this picture is D[m,n], (1) shows how to compute, (2) is the inverse transformation. D[m,n] is a complex number. (3) is the base of a computational speedup: first we compute the sum of the inner sum for each row, then the outer sum for each column.

Further explanation is in every Image processing and Signal processing book.

SMBC fun

Last modification: 2014 march 26