source code for 2d cross-correlation fx?

[DonRoth]

I know this is a long shot but does anyone have the c or c++ code to compute the 2d (image) cross-correlation fx? (I know that IMAQ VISION has the cross-correlation routine but I am looking to potentially modify the 2d correlation routine to compute something called non-symmetry coefficient and would need to start with the source code). Or, labview source code for this operation would also be quite acceptable and in fact preferred!!

Thanks,

Don

[alkazaa]

I don't have the 2D cross correlation in labview, but... isn't the cross correlation very similar to an FFT? In that case a 2D FFT could maybe help since it shows how the 2D FFTs are derived from 1D FFTs in labview. I attach an llb where 2D FFT is done. I don't know where I got it from, maybe I even wrote it myself sometime in the dark past (probably translating it from some piece of C source code from the 'Numerical Recipes' book).

Maybe it is of some help for you...

-Franz

[DonRoth]

thanks, i will take a look...The correlation fx uses the FFT so I suppose if starting from scratch with the FFT and knowing the algorithm for correlation, I can make the modifications as needed. Cross-correlation involves multiplying the FFT of one fx by the complex conjugate of the FFT of the second fx (I believe). Since LabVIEW and IMAQ have all these operations, I should be able to work with this.

Sincerely,

Don