# Fourier based operations

### From Endrov

Operations based on the Fourier Transform. For these operations to yield the full speed the image should be a power of 2 (you can crop them, or expand them)

- (Inverse) Fourier 2D/3D

Takes an image and optionally another image as the complex value, and produces the (inverse) transform

- Difference of Gaussian

This is also known as the Mexican Hat wavelet transform, and is a very good feature detector for the given length scale.

- Circular convolution 2D/3D

A fast convolution, based on the Fourier assumption that the image is cyclic along the borders.

- Gaussian convolution 2D/3D

Short-cut to a circular convolution by a Gaussian, given the variance

TODO: allow complex part to not be connected