Fourier commands

    

Note that the commands fft2, visualfft and conv require matrixes to have the names "real", "imag", "spec" and "angle". And all matrixes have to be stored under a single data frame (which is an argument to the commands below).

This is a one-dimensional Fourier transformation.

This command makes a two-dimensional Fourier transformation for matrixes.

This command visualizes a frame containing "real" and "imag" matrixes (usually after fft-transform).

This command makes a convolution between two frames (both including at least a "real" matrix).

Example (ex6.1):

...
# 2-dimensional fft-transform
NDA> fft2 -in mask -out maskfft -width 128 -height 128
NDA> fft2 -in matrix -out matrixfft 
# convolution and result visualization
NDA> conv -in1 matrixfft -in2 mask -out convmatrix 
NDA> visualfft -in convmatrix -out convimage -width 128 -height 128 -scale
...