A German scientist at Bonn University has discovered that Xerox photocopiers sometimes alter numbers on documents as they copy.
The anomaly was discovered by David Kriesel, a computer scientist, as he examined scanned copies of building plans. The copies had different room dimensions from the original.
Xerox responded to the problem with a statement on Tuesday, saying “The problem stems from a combination of compression level and resolution setting. The devices mentioned are shipped from the factory with a compression level and resolution that produces scanned files which are optimized for viewing or printing while maintaining a reasonable file size. We do not normally see a character substitution issue with the factory default settings however, the defect may be seen at lower quality and resolution settings.”
You can read full details of the problem, and David Kriesel’s communications with Xerox on his website.