Applying Circular Cross Correlation in MATLAB
Cross correlation can be implemented in the frequency domain using FFT by multiplying signals.
For a cyclic cross correlation you can use:
cc = ifft(fft(x).*conj(fft(y)));
You can also calculate the linear cross correlation using FFT by zero-padding the signals before the FFT.
Related: Cross correlation with FFT and fftshift
Edit:
In order to calculate the cross correlation of two images you have 2 options:

x and y should be the grayscale representation of the images
Repeat the process 3 times. Each time x and y are a single channel (r,g or b) from each image