You're right, it's ok for a project. I guess what I meant was it's quite easy compared to the problems my company deals with every day. 30 images in 24 hours

You're right, it's ok for a project. I guess what I meant was it's quite easy compared to the problems my company deals with every day. 30 images in 24 hours (I think it said) is kind of a problem. Given the constraints of the asker (all available in OpenCV), the solution I would suggest first is SIFT + homography, both easy to use and in OpenCV (sample code is around). Yes, there's a lot of other possibilities, but this would be an improvement over the original.