Dynamic 3D surface profilometry using a novel colour pattern encoded with a multiple triangular model

In this paper, a novel active structured fringe method for dynamic 3D surface profilometry is presented using a colour fringe pattern encoded with multiple phase-shifted triangular modulations. Rapid 3D surface profilometry is extremely important to automatic optical inspection (AOI), especially for in situ optical surface profilometry. In the proposed approach, three-step phase shifting can be simultaneously performed by encoding and analyzing components of red, green and blue colours in the projected colour fringe patterns. A significant advantage can be obtained in eliminating arctangent calculation and one-shot imaging for obtaining dynamic full-field 3D surface profile reconstruction. Experimental tests were conducted to verify the capability of the developed method in achieving high-speed 3D measurement with an average measurement error of less than 2.8% of the overall detection range