Comparison and evaluation of correspondence finding methods in 3D measurement systems using fringe projection

Three different methods to realize point correspondences in 3D measurement systems based on fringe projection are described and compared concerning accuracy, sensitivity, and handling. Advantages and disadvantages of the three techniques are discussed. A suggestion is made to combine the principles in order to achieve an improved completeness of the measurements. The principle of a virtual image point raster which is the basis of the combination of the methods is explained. A model to describe the random error of a 3D point measurement for the three methods is established and described. Simulations and real measurements confirm this error model. Experiments are described and results are presented.