Absolute 3D sensor with single fringe-pattern recording

A new depth-from-defocus type co-axial 3-D sensor is proposed that permits shade-free absolute 3-D shape measurement from the contrast information of a frequency-multiplexed single fringe pattern. The Fourier transform method is used for spatial frequency demultiplexing and extracting the fringe contrast. Experimental results are presented that demonstrate the validity of the principle.