Intensity modulated moire and its intensity-phase analysis

Moire topography has the advantage that it just requires a single image, but it cannot discern the fringe order. So, it is difficult to discern the connection among fringes in the case where the fringe orders are not continuous. In our work, an intensity modulated moire is presented. By modulating the transmission of projection and observation grating, the moire pattern whose fringe intensity changes with its order can be produced. The fringe order can be obtained easily from its intensity, so the skeleton of fringes in every order can be extracted to discern the global 3-D shape by intensity analysis. In the same time, we can segment the moire pattern by its fringe order. In every segment, the accurate 3-D shape among the skeletons can be calculated by phase analysis.