“…The past several decades have seen revolutionary developments in three-dimensional (3D) optical shape measurement techniques [1,2], which are now widely used across many different fields, including reverse engineering, 3D games, digitization of cultural relics, clothing, biometrics and other biological fields [3][4][5][6][7][8][9]. In the area of structured light techniques, phase-calculation-based fringe pattern projection has made rapid progress so far, because it has the advantages of full-field measurement, non-contact operation, automatic data processing, and fast data acquisition [10][11][12][13]. Nevertheless, there are a large number of specular objects that need to be measured [14].…”