Part of my iOS app is based upon taking a photo of an object with an euro coin near and I would like the app itselt to recognize the coin (in particular 2€, 1€, 0.50€) and put a sort of UIView upon it. To have an idea, the following screenshot might be a possibile final result:
Obviously, it's not necessary for the app to be extremely precise because, as you can see, I give the user further ways to adjust the UIView as much as possibile.
To get this aim, I am trying to understand how OpenCV works and to integrate it in my app. It's not a problem for me to write C++/Objective-C code even if my app is developed in Swift but I need your help to get a sort of skeleton-code. My teacher told me that OpenCV algorithms can be "learned" not only to look for particular shapes/forms but also to recognize a specific pattern image, such as euro coins, by giving them some other images as reference.
Would you please write some come for me from where to start from and tell me which OpenCV routines I need the most?