2D Discrete Fourier Transform fixes rainbows on manga on color eInk Kaleido 3

An interesting application of the 2D DFT to manga on color eink Kaleido 3 with math theory explained! Kobo Colour images.

Most of the slides are based on the DFT chapter in Digital Image Processing: A Practical Approach by Nick Efford. I learned DFT to understand this algorithm.