Graphic Data Compressor for Plotting Instruments

A relatively simple programmable controller is described suitable for graphic data compression while at the same time providing a human operator with a means for steering and drawing within the stereo model formed in certain photogrammetric instruments. Lines joining coordinate points, circles, circular and parabolic arcs, and symbols in any orientation require only up to a few bytes of information for their execution. Symbols are preprogrammed into the controller from a telephone-type keyboard.