Two-dimensional phase-measuring profilometry.

An improved method is proposed to perform contouring of an object based on phase-measuring profilometry with a grid grating. Two phases unwrapped in perpendicular directions are obtained with the help of an adaptive bandpass filter and are used to unwrap the phases and to appoint the edge points of a shaded area and the object area. The height distribution of the object is obtained with the geometric relationship between coordinates and phases. The main axis of the projector and the main axis of the camera are not crossed and are also not in the same plane in order to arrange a measuring system easily and conveniently. The experimental results show that this technique is available for practical applications.