Shape from focus for large image fields

Shape from focus is a method for the accurate measurement of the geometrical shape of objects. The measurement principle is the local focus search. The method is suitable only for objects with a texture (optically rough surface). The longitudinal coordinate of a surface point is determined from the maximum of the focus measure function. The focus measure function expresses the quality of focus in a small image area. The measurement is fast because the focus measure function shows no oscillations. Thus, a large sampling step can be used. We present experimental results that demonstrate the capability of the proposed method.