Conventional dual-frequency fringe projection algorithm often suffers fromphase unwrapping failure when the frequency ratio between the high frequencyand the low one is too large. Zhang et.al. proposed an enhanced two-frequencyphase-shifting method to use geometric constraints of digital fringeprojection(DFP) to reduce the noise impact due to the large frequency ratio.However, this method needs to calibrate the DFP system and calculate theminimum phase map at the nearest position from the camera perspective, theseprocedures are are relatively complex and more time-cosuming. In this paper, weproposed an improved method, which eliminates the system calibration anddetermination in Zhang's method,meanwhile does not need to use the lowfrequency fringe pattern. In the proposed method,we only need a set of highfrequency fringe patterns to measure the object after the high frequency isdirectly estimated by the experiment. Thus the proposed method can simplify theprocedure and improve the speed. Finally, the experimental evaluation isconducted to prove the validity of the proposed method.The results demonstratethat the proposed method can overcome the main disadvantages encountered byZhang's method.
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