I can calibrate my android device camera and get camera matrix and distortion coefficient . In my android project I want to augment a virtual object on a marker.I can generate the bitmap of marker in runtime and save it in sd card. I am a beginner in opencv. I have some question ,and I really be appreciate if you give me some example code in android as answer. How Can I detect the marker in video by using opencv in android ( with this attention that I have the stored bitmap of marker in sd card) How Can I augment virtual object on marker with OpenGl ?(with this attention that I have camera matrix and distortion coefficient.)