Color fringe projection profilometry using geometric constraints

Color profilometry techniques: A review

“…These techniques can be generated using a combination of binary fringes, color-coded discrete fringes, sinusoidal patterns, and phase-shifting [30][31][32][33][34][35][36][37][38][39][40]. There are different variations of hybrid phase-shifting, for either a single-shot or multi-shot method.…”

“…The difference is that more images are taken, thus requiring more processing and analysis. To estimate the phase of a surface, the three-step phaseshifting method is usually tested [34][35][36].…”

“…Cheng et al [34] developed a different approach to the traditional phase-shifted technique, where three phase-shifted sinusoidal patterns are combined with a group of six color fringes as shown in Fig. 13.…”

“…Some techniques encode a different sequence or codeword onto the pattern based on its color, not necessarily using the De Bruijn sequence [30,[32][33][34][53][54][55]. Fig.…”

“…A code table contains the fringe's color and numeric values facilitating the order identification even on surfaces with pronounced discontinuities. Fong et al [32][33] and Cheng et al [34] present the use of color fringes to improve the absolute phase retrieval. Six adjacent color fringes are treated as one group, and according to the order the wrapped phase range can be extended.…”