Improving the quality of stripes in structured-light three-dimensional profile measurement

Measuring objects with high dynamic range (HDR) reflectivity by coded structured-light, captured stripes are usually seriously distorted by reflectivity, causing inaccurate measurement results. A stripe enhancement method is proposed to deal with the problem. The method is based on the correspondence between phase and intensity of the stripe. First, the phase map of the captured stripe pattern is retrieved by phase-shift algorithm and multiexposure method, where saturation and low contrast of the stripe are eliminated; then, the modulation of stripes is normalized to eliminate the influence of reflectivity; finally, the enhanced stripe is obtained by assembling the modulation and the phase map. Experimental results demonstrate that the method is efficient for objects with HDR reflectivity and achieves high accuracy.