Friday, June 4, 2021

Hidden image emerges from Télémécanique stock certificate

The first time I inspected this 37 year old stock certificate from La Télémécanique Électrique I saw that it was a rather plain print. Somehow, I felt that there was more in the design than one could see at first sight. 

The share is illustrated hereby. You can click the image to enlarge it. You may not detect anything special. Perhaps - and this is the same experience as if you would have the certificate right in front of you in real - some very faint lines in the lower right corner may attract your scrutinizing look. 

Télémécanique was known as a pioneer in industrial automation. Its starts in 1924 when Michel le Gouellec acquired the Manufacture d´Appareillage Électrique in Nanterre, France. That same year MAE inventor André Blanchet files his patent for a contactor. This was an electrically-controlled switch used for switching on and off electric motors, lighting, heating, etc. The company adopted the name Télémécanique Électrique in 1928. 

The company evolved into a developer of process control computers. In 1967 it acquired the Automation Division of MORS, which had developed the MAT 01 industrial computer.  Two years later Télémécanique started introducing their own mini-computers. In 1975 their Solar 16 model was well received and competed against the PDP-11 and the Nova from American competitors DEC and Data General.

So far for a bit of history. Now, I told you that there was more to see on that Télémécanique stock certificate. The nice trick that I am going to tell you about can be used not only for share certificates but also for old prints, maps and even vintage photographs. 

In Reduce Contrast to Reveal a Hidden Underprint, see here, I showed how you can use image editing software to apply reduced contrast to an image with a subtle underprint. Decreasing contrast, yields more visible shades of darker and lighter pixels, with a clearer image as a result. However, that approach did not work in this example. The color print was too faint for these basic contrast functions to be effective.

The software tool I needed now had to offer a a stronger contrast and color altering feature. That tool was GIMP.

GIMP is a free and open-source raster graphics editor used for image editing and many more specialized tasks. It was initially developed at the University of California, Berkeley, and named General Image Manipulation Program. You can download it here at .

The functionality I used here was located under the "Colors" Menu, named 'Levels'. It makes an image lighter or darker, changes contrast or corrects a predominant color cast (unwanted tint). The graph - a histogram - shown when invoking the function represents the statistical distribution of color values in the image. You can play around with three triangles as sliders: one black for dark tones (Shadows), one grey for midtones (Gamma), and one white for light (Highlights) tones. 

The image above shows the result, a pretty dramatic evolution of my nice scan. It revealed more details of that underprint though most still not clear, except for a clearly identifiable computer shown in the lower right corner. Mission completed !

What has become of the Télémécanique company? Well, under général de Gaulle, the French government had been trying to establish a strong computer industry, one that could thrive independently from the big American computer companies. 

Under that government pressure Télémécanique had to merge its computer division in 1976 with the mini-computer division from Compagnie Internationale pour l'Informatique (CII), into a separate company called Société Européenne de Mini-informatique et Systèmes (SEMS). 

The group Schneider Electric absorbed the remaining company in 1988. Télémécanique is now a major brand within that group involved in industrial automatisation.


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