How can I detect small (less than 1° ) rotations using FFT phase correlation?

Hi, I'm trying to detect sub-pixel differences between 2 images. All working so far with translation. The rotation method however isn't so accurate with small angles esp the ones that really inteerst me (0.1~ 3). I also upsample my images for better results but still not so accurate. Any advice on what I should edit : log-polar interpolation.. add a filter .. ? Thanks Dana

Answer 1

[Matt J]

Rotation in image space induces translation in radon space. Take the RADON transform of your image and apply the phase correlator to that.

Answer 2

[Alex Taylor]

If you have R2014a and the Image Processing Toolbox? You should look at imregcorr. It implements phase correlation based registration.

http://www.mathworks.com/help/images/ref/imregcorr.html