Detection periodic elements in image I am working on a university project in which I need to find a periodic net element in an image.

The net is a set of diagonal lines in a specific angle ( which I don't know in advance ) on a noisy image. They are hard to detect so I would like to use all the information I can get my hands on.



My current algorithm is based on using edge detection + hough transform to find lines at specific angle range.

I was wondering if there is any way to detect periodic signals in image? Something based on ff2 or something like that...

Thanks,
You could apply a 2d FFT. You will get a frequency spectrum as z values on a 2d plane:

 ← That's log(abs(fftshift(fft2(image))))) where image is from the question, but with white borders trimmed

From the z values you can determine the highest peak and calculate its position on the 2d plane. With some geometric calculation, you can derive wavelength, direction and phaseshift from this.