TextureMaker's Fourier function is used to remove frequency ranges from the texture. Removing high frequencies results in smoother textures, while removing low frequencies is useful to get rid of illumination gradients.

The lower and upper limit is controlled at the Frequency Cut panel. Both values' unit is 0.01 Hertz. The width and the height of the texture is interpreted as one second.

The Fourier function works with the HSV color channels. Usually only the Brightness channel is modified.

After the frequencies are removed, the resulting texture's contrast can be increased with the Amplify value. This is useful if you have removed the lower frequencies.