Phase feedback fringe projection profilometry for shiny objects

Diffuse objects have suitable optical properties for accurate three-dimensional reconstruction by fringe projection profilometry. In contrast, shiny objects, such as glossy plastic items and metallic workpieces, are difficult to reconstruct due to image saturation. In this paper, the recursive structure of the hierarchical multi-frequency fringe projection profilometry is exploited to prevent saturation by a feedback loop. Novel functions for saturation, low-modulation, and grating intensity correction, suited to adjust the projector pixels inducing saturation, are proposed. The usefulness of the proposal is verified experimentally, confirming the high performance of the proposed phase feedback approach for the reconstruction of shiny objects.