Hardly anything is known to us about Peterson’s life and work, except for his short term collaboration with Walter Heinz Allner, the famous graphic designer. This collaboration resulted in a portrait of William Charles Norris, at the time president of the Control Data Corporation, Peterson was working for.
Peterson had used the technique before to generate one of the best known works of early digital art, the “Digital Mona Lisa”.
Similar to what Ken Knowlton did (and later others, particularly in “ASCII art”), Peterson’s idea was clear and simple: Generate an image by composing it as a grid of pictorial elements picked from a given collection (repertoire) of primitive elements. Those elements were called micro-signs and they were what you found on a line printer, i.e. the characters of an extended character set. The simple aesthetics was to generate a superordinate figure (usually representational: portraits, buildings, quite popular were nude girls) from the given characters by simulating grey scales.