Images from computers and microfilm plotters

Digital computers are widely used for the processing of information and data of all kinds, including the pictorial information contained in photographs and other graphical representations. Efficient conversion facilities for putting graphical information into the computer and retrieving it in graphical form are therefore much needed. One of the most commonly employed devices for obtaining permanent graphical output from digital computers is the microfilm plotter. Regrettably, present models have no provision for producing images with a continuous gray scale or “halftones.” In this note several programming techniques are described for obtaining halftone pictures from a microfilm plotter under the control of a digital computer. Illustrative examples of several methods are given.