Passive specular surface measurements from virtual images of pattern boards

This paper describes a new approach for passive measurements of specular surfaces, in which the range and shape of specular surfaces are obtained from virtual images of pattern boards taken by the camera. In the approach, structured patterns displayed on two boards are acquired with a camera through the specular surface and each reflection point on the object is located geometrically using the triangulation principle without any prior knowledge of the coordinates of other reflection points. This feature enables us to obtain a high spatial resolution of detection with a high accuracy.