opencv finding image cordinates on another image

Question

How to find image "A" coordinates on image "B" which contains image "A".

I wrote this program which is only checking pixel values, does anyone know is there any library tool do this.

Answer 1

As Throwback1986 suggested, you will probably want to use matchTemplate. Here is one of my answers showing how to detect the Sun from virtual spacecraft. Here is the newer tutorial from OpenCV on using matchTemplate. Now, there are some caveats for using the matchTemplate approach. If image "A" can be at an arbitrary pose (e.g., changes in scale, rotation, perspective, etc) in image "B", then matchTemplate isn't going to work very well. If that happens to be the case, you will want to use to go the feature detection route as suggested by Adrian Popovici.