Non-phase-shifting Fourier transform profilometry using single grating pattern and object image

A new white light non-phase-shifting method for eliminating unwanted background in Fourier transform profilometry (FTP) is proposed by using an object image being measured and a single grating image deformed by this object. The background signal of the deformed grating image can be eliminated by using the object image scaled by a contrast ratio of the two images. The proposed method has an advantage over color-encoded FTPs in that the contrast value can be simply calculated from the image itself, regardless of image sensors. Experimental verifications of the proposed method are presented.