Center of mass / center of gravity on vision assistant

Hello,

I am on a project where I have to compute a deformation on an object for that I proceed by displacement detection using sequences of photos where I have written markings on each object, for the detection of the displacement which is of the order of2 microns I proceed by calculates center of gravity using centroid under vision assistant but for that after I do not know how to proceed to put it in comparison between the different image of the sequence knowing that after the creation of the script I convert it into code c underlabwindows cvi

Are there any of you who have already made this kind of application or ideas for the procedure

Thanks for your help