Digital Mona Lisa

Computer-aided drawing, produced on a Calcomp 30-inch plotter.

Because of the technique of its generation, the Digital Mona Lisa is also known as Mona by Numbers.

H. Philip Peterson of Control Data Corporation (CDC) utilized a CDC 3200 computer and a scanner (he called “flying-spot”) to create in 1964 a digital transposition of Leonardo da Vinci’s painting, “Mona Lisa” (done in 1503/04). He thus created a digital representation of the analog original. The production process took 14 hours to complete the image of 100,000 pixels. They were plotted on a Calcomp plotter using numerals, sometimes overprinted by others, to approximate the required grey level density (cf. www.digitalmonalisa.com). See also
www.computer-history.info/Page1.dir/pages/Michael.html

The production procedure was, most likely, this: A photographic reproduction of the original painting (a slide) was scanned, thus generating a large array of grey-level pixels; the grey values were represented by numeral characters, and perhaps printed over to get good enough an approximation to the grey value; on the plotter paper, these numerals became the material making visible the digital encoding.

The three illustrations are showing the image in increasing detail. The numerals become visible in the left-most version.

drawing, b/w, computer-aided
size: 129 × 80 cm