I'm working on Image processing issue and I need to take picture from automotive glass.the camera is mounted at top and the glass lays down at the bottom. I put a black textile at the back of glass . the main problem is how can I cancel reflection of camera image into the glass? how should I light the object to give best result and have no shadow and reflection of near objects? thanks
When you have a reflective surface like glass, the angle of incidence of the light equals the angle of reflection. So if the light comes from 45 degrees from the right, it will reflect back 45 to the left. If it's directly over the glass, it will reflect straight back (at the camera then).
So you want your lights far enough to the sides that you cannot see that reflection (I'd use at least two lights, one on either side). In the figure below, if P is your light source, the light will reflect off the glass to Q. If the camera is in the middle (where it says "normal") it will not see the glare of the reflection (this assume a narrow beam of light- with larger lights, rather than one narrow line between P and Q there is a much wider band of light.
In order to remove the reflection of your camera, as James Youngman said, a polarising filter will reduce it. To eliminate it you want to do one (or both) of two things:
A good source for all of this is the book Light, Science and Magic