I have 2 images, say bigImage and smallImage. I want to detect whether the smallImage is there anywhere in the bigImage, irrespective of its orientation or transforms(rotations). If its there, it should return true and otherwise return false. I have been going through the template matching (cvMatchTemplate) method in openCV, but haven't reach anywhere since there aren't much difference between the output for a true and a false match. Is my requirement still possible using cvMatchTemplate or are there any other methods in openCV for getting to this.
This is a very general and very hard problem, with lots of solutions out there. None of them are silver bullets; hopefully, one of them will work for your particular problem. Try taking a look at SIFT, color histogram matching, SURF, HoG, Viola-Jones, DOT, ORB. Some of these have OpenCV implementations; others don't. You should read up on the available options and their strengths and weaknesses, and then try some out.
来源：https://stackoverflow.com/questions/8083866/image-matching-detection-in-iphone-using-opencv