Wow! It looks very promising
Right now PixInsight has no implementation of any transformation to the Fourier space (read, FFT, DCT or any other transform), but it is in our "to-do" list. I think that this will be one of the first application using Fourier that will be implemented.
I cannot guarantee that it will be included in the Limited Edition of PixInsight, but surelly you'll find it in the Standard Edition (when avalaible). Thank you very much for poiting us this technique.