Co-design of an active depth from defocus camera for surface inspection

Abstract

Structured illumination combined with a monocular 3D camera leveraging on the estimation of the defocus blur has been proposed in the literature for industrial surface inspection. The accuracy of such active depth from defocus (ADFD) system depends on the camera/projector and processing parameters. Here, we propose to optimize the settings of an ADFD system, using a performance model that can predict the theoretical depth estimation accuracy for a given set of optical/projector/processing parameters. The accuracy of the optimized system is then experimentally evaluated. Moreover, we provide experimental results on real objects, including metallic parts, compared to a reference depth map obtained with an active stereoscopic camera.