Active shape from projection defocus profilometry

Fringe projection profilometry (FPP) using a vertical scanning setup has the merit of avoiding occlusions and shadows over triangulation based approaches. However, very few methods with a vertical scanning setup has revealed the supporting physical model to explicate the relationship between depth and the level of defocus of fringe patterns. In this paper, we propose a novel active shape from projection defocus profilometry (ASPDP) method that reconstructs the 3D shape by directly quantifying the physical depth-defocus relationship of squared binary structures. To the best of our knowledge, this is the first ever method that explicitly reveals the physical model relating the shape and the level of defocus of active fringe projection. Experiments show that the proposed ASPDP method can achieve an accuracy up to 14 mu m.