Abstract: System for positioning objects relative to one another comprising taking an image of a group of marks formed on the medium, an analog-to-digital converter connecting the image-taking equipment to digital recording memories, and a data processing system for limiting the recorded image to a scan window including a fixed reference point corresponding to a predetermined mark for centering the image in the scan window for measuring the separations relative to two perpendicular axes between the reference point and the positions of the corresponding marks in the scan window, and for generating separation correction signals for displacing the objects.