How do I find 2 points crossing each other in OpenCV?

See more:

Mobile

Android

OpenCV

, +

I'm building an app using OpenCV4Android, I want to identify the position of the object w.r.t the line drawn on the frame(line drawn to check the pixel position after the movement detected).

I want to identify the position of the face ( or it can be any object detected, I detect object/face using haar classifiers).

For eg. if the face is moved say, 50/100 pixels either right or to left, it has to be identified.( I assume the face or object will be in the same position).

Is there anyway I can implement this.