Greetings, Telecentric;
Certainly, you will most likely need to set up a calibration (possibly for each image) and then set up a coordinate system and measure the object and save the result to a variable. Repeat for each image; and then subtract the variables.
You might want to do this in at least two distinct states ( one per image ).
There is a three part article that goes over a relatively similar application; take a look and give it a try:
http://www.ni.com/white-paper/6714/en
http://www.ni.com/white-paper/6852/en
http://www.ni.com/white-paper/6854/en
I wish you a great day!
National Instruments
Applications Engineer