Hello everyone,

I have a question about FFT of an image.

I have two 2d singrating images and I want to mathematically find the phase shift between these images.

theoretically I know that there is a 120 degree phase difference between each image.

I have a few problems that I do not understand in my analysis in imagej.

1.bmp (2.1 MB)

some of the things I would like to ask for the region marked yellow in the fft spectrum image;

what does mean **r** value exactly (what is pixel per cycle), in figure r value is equal 6.04,

I know that theta value because this stripe orientation is 60 degree,

and last question,

I have two images like this, how can I calculate the phase difference between these two images?

Thank you all, and have a nice work.

Musa.