Depth estimation based on thick oriented edges in images

The field of contact free 3D measure is particularly open since current measuring devices use lines or points. In this domain, cameras are the preferential sensors to develop global 3D measurement system. Many methods have been developed to obtain the 3D coordinates of objects using images and all exploit the variations of acquisition parameters. Acquisition parameters of the system or of the luminous environment, controlled or not are the essential information to establish a relationship between the image and the real scene. This article deals with a spatial approach to depth estimation by analysis of edges in images. A depth from defocus method is explained and the physical process is described. Theoretical developments are made to apply it on thin or thick edges and for height orientations of the edge profile. Some results on images are presented to illustrate the efficiency and the influence of the conditions of use.