An objective automated method for digitizing pictorial material for computer manipulation

An inexpensive device to digitize existing pictorial material in conjunction with a digital computer is described. Slides (35-mm) are used as source material, and the slide is scanned to produce a two-level output (i.e., dot present or dot absent). The system has spatial resolution of approximately 1 mm and a complete scan (30 times 19 points) is completed in about 20 sec. Although we are using the system to produce only two level outputs, there is no reason a gray scale could not be constructed.