Phase edge match algorithm for phase unwrapping based on combination of gray-code and phase-shift light projection

An edge match algorithm for phase unwrapping based on combination of gray-code and phase-shift light projection is presented, which is indispensable to retrieve the object absolute phase. The algorithm is made up of two consecutive steps: the phase jump edges are firstly thinned, and then the phase jump edges are matched. When thinning, the blurred edge pixels are Incorporated Into a unique edge pixel employing a suitable estimated rule, the real edge pixel is kept, the pseudo one is discarded, and the originally unique edge pixel is directly regarded as the real edge pixel. When matching, firstly, all the coordinates of wrapped phase edge and gray-code phase edge are taken out, and then the two corresponding match pixels are searched out and the coordinates of gray-code edge pixel are rectified based on edge position of wrapped phase map. The validity of proposed algorithm has been testified by lots of experiments.