Method and apparatus for three dimensional surface contouring and ranging using a digital video projection system

摘要

A three dimensional surface contouring and ranging system (10) based on a digital fringe projection (18) and phase shifting technique is disclosed. In the system, three phase-shifted fringe patterns and an absolute phase mark pattern are used to determine the absolute phase map of the object (12). The phase map is then converted to the absolute x, y, and z coordinates of the object surface by a transformation algorithm. A calibration procedure is used to determine accurate values of system parameters required by the transformation algorithm. The parameters are initially indirectly measured through experiments to determine their approximate values. A calibration plate is then measured by the system at various positions. An iteration algorithm is then used to estimate the system parameters.