The optimal projection intensities determination strategy for robust strip-edge detection in adaptive fringe pattern measurement

Adaptive digital fringe projection (AFP) technique is a traditional approach to measure the high dynamic range (HDR) surface. However, the projected light intensities are difficult to determine. And there are some discrepancies occurred in the location of detected strip-edge. In this paper, a projection intensities determination strategy was proposed to minimize the influence of camera response nonlinear distortion and improve the robustness of strip-edges detection. To determine the relationship between the projected gray level and the captured gray level, the mapping function between the projector and the camera is established. To evaluate the distortion degree of the captured image, the camera response nonlinear distortion model is proposed. Compared with the traditional AFP method, the proposed method is relatively simple and flexible. And the proposed method could be satisfying the different user demands. The experiment shows that the influence of nonlinearity of camera response was reduced and the robustness of strip-edge detection is improved.