Computation of shape and reflectance of 3D object using moire´ phase and reflection model

Compared with passive methods, the moire´ method for restoring three-dimensional shape is advantageous with respect to the stability of the estimated shape and processing time. However, the fundamental problem associated with moire´ analysis is that the absolute number of the base fringe cannot be determined directly. Here the authors focus on the method by which the absolute number of the base fringe is determined using shading information. For this method, the conventional approach simply adopts Lambert's reflection model and excludes the specular reflection factor, thus the result tends to differ slightly from the true value. The authors propose a method that uses a reflection model which combines Lambert's and specular reflection. The proposed method gives a result closer to the true value and can also determine optimal relative reflectance. The effectiveness of the proposed method is confirmed by simulation and experiment