Processing image of laser pointer on a ruler

[jm1010]

Hi all! hobbyist newbie here and not an image processing guru, so please be understanding if my question seems basic or absurd.

If I am projecting a laser line or dot on the same ruler all the time, is it easy to train the image processor to identify the exact measurement of the laser line on that ruler? For example recognize the value where the laser is aiming on the picture attached. I would like to develop an app for iphone or arduino that could do that. Any help is very appreciated.

Jean