D – 3D Vision-based depth-from-focus approach
Because the limitation of the depth-of-field of the optical microscope, it is impossible to completely perceive a 3D object. The focus must be continuously adjusted to view the region of interest (ROI). To compensate this drawback, the proposed depth-from-focus method can be used to get a full 3D representation of the object. That method consists in computing the focused area of every image of the scene image sequence. Each image is acquired at a different focus (corresponding to a depth) from the same point of view. It can be noticed that a video microscope with a motorized focus enables to obtain equidistant focal planes. Next, the focused areas are stacked up according to their position to give the 3D reconstruction of the scene (see, Fig. 6).