"John J" wrote in message
Gary Edstrom wrote:
Just Curious: Is this a real Photoshop message, or is it just a doctored image?
http://www.funpic.hu/files/pics/00035/00035722.jpg
It is real. Try it yourself. Scan a US bill and open it. The same works for several currencies besides the USA.
There are documents that describe how it works. Rather clever in its simplicity – it requires, in part, incorporating certain patterns in the notes.
Similarly, on some of the higher resolution Canon colour photocopiers in the 1990’s, there was a feature built in that would prevent the photocopying of banknotes.
It worked by recognising tightly clustered parallel lines of the same colour, and when it detected such a thing, the entire machine would just shut down and display a "Call engineer" message. When you called him, he would come out, issue a penny lecture and unlock the machine for you while sending a log of the attempted copy off to the police.
The office I worked in at the time was in the business of working with mapping, and there were certain Ordnance Survey 1:50000 Landranger sheets, especially around Snowdonia and the Scottish Highlands which would regularly lock up the machine, as it kept mis-interpreting the contour lines on the mountains as a banknote.
In the end, the engineer was being called out so often that the feature was disabled on our copiers.