Color-encoded fringe projection for 3D shape measurements.

A novel technique using color-encoded stripes embedded into a sinusoidal fringe pattern for finding the absolute shape of an object is proposed. Phases of the projected fringes on the surface are evaluated by Fourier transform method. Unwrapping is then performed with reference to the color-encoded stripes. When surfaces of interest contain large depth discontinuities, the color-encoded stripes can easily identify the fringe order. Compared with other phase unwrapping schemes, this method offers many major advantages, including: (1) very low computation cost for the 3D reconstruction, (2) reliable phase unwrapping to complex objects, especially for surfaces with large depth discontinuities, (3) only one-shot measurement is required, and (4) robust performance to analyze dynamic objects.