Discrete Fourier Transform over Hexagonally Sampled Data

Data represented on hexagonally sampled lattices have many interesting properties.
Most importantly, when a hexagonally sampled image is represented in the form of a vector, the neighboring regions in the image space are mapped to neighboring regions in the vector. Hence, the image processing takes a condensed form of 1-dimensional signal processing.

The provided codes implement the DFT and IDFT algorithms for hexagonally sampled lattices.