how to find autocorrelation of image in horizontal ,vartical & digonal direction?

hi, i want to find the auto correlation & cross correlation in horizontal ,vertical & in diagonal direction of the output image obtain after doing the quantization of image*(*this image is obtain after taking the FFT of image & then finding the magnitude of that image)in to four level(quantization is done by dividing the minimum to maximum range in to four level and replacing each level with 1,2,3& 4 respectively) the output image who's auto correlation is to be find.consist of image array of size 256x384 having the values ranging from 1 to 4 only please help me to find it because i don't have any idea how to find it

Answer 1

[Image Analyst]

Did you look at xcorr2()?

[Image Analyst]

or normxcorr2()?

[Ganesh]

It's not working...can u give me another function?

[Walter Roberson]

Are you getting an error message? If so, then what?

If you are not getting an error message, what difference do you observe between what you expect and what you get?