Some suggestion about conversion from pixel coordinate to window (object) coordinate

Hello everybody,
I have extracted some points using OpenCV from video. The imager esolution is ( 640X 480). The extracted coordinates are in pixel coordinates i.e. it looks like follows:

(x, y) : ( 403, 303)
(x, y): (414, 297)


Now I would like to display the coordinates in 3D space using OpenGL. I know I need some transformation which involves rotation and translation for conversion from OpenCV to OpenGL pixel coordinates.

In my OpenGL, I also made the window resolution ( 640X480).

Now after transformation of pixel coordinates from OpenCV to OpenGL workspace, I need to display them in 3D object coordinate. Could any one let me know what I have to do for that purpose?

Thanks in advance.