"Pixel-wise absolute phase unwrapping using geometric constraints of structured light system," Opt. Express, (2016)

[87] Y. An, J. -S. Hyun, and S. Zhang, "Pixel-wise absolute phase unwrapping using geometric constraints of structured light system", Opt. Express, 24(15), 18445-18459, 2016; doi: 10.1364/OE.24.018445

This paper presents a method to unwrap phase pixel by pixel by solely using geometric constraints of the structured light system without requiring additional image acquisition or  another camera. Specifically, an artificial absolute phase map, Φ_{min},  at a given virtual depth plane z = z_{min}, is created from geometric constraints of the calibrated structured light system; the wrapped phase is pixel-by-pixel unwrapped by referring to Φ_{min}. Since Φ_{min} is defined in the projector space, the unwrapped phase obtained from this method is absolute for each pixel.  Experimental results demonstrate the success of this proposed novel absolute phase unwrapping method.