Patching Xerox's number-changing photocopy phlaw will take weeks

Xerox has told its customers that their copiers may continue churning out dodgy numbers for a few weeks unless they change the settings on their hardware.

"To hear and see this frustration and confusion goes against all that's core to Xerox's heritage and future," wrote Rick Dastin, president of Xerox's office and solutions business group in a statement. "We apologize for any confusion and inconvenience this has caused our customers. We are working tirelessly to address these issues."

Last week, German computer science student David Kriesel discovered that when copying documents using low resolution and a small font size, two models of Xerox WorkCentre were changing the numeral 6 to an 8; other digits were also being altered. The problem was discovered when Kriesel was copying some building plans and noticed the dimensions of the rooms had changed.

Xerox confirmed Kriesel's suspicions that the problem was in the JBIG2 compression system used on those models, but said that the problem only occurred at low resolutions and was due to "inherent tradeoffs under low resolution and quality settings."

On Wednesday, Xerox issued an update, saying the problem only occurred with a small number of customers and could be fixed if the user changed the scanning settings to the factory default for higher quality output instead of what Xerox lists as normal resolution.

Dastin said that "within a few weeks" Xerox would be pushing out a patch to fix the issue by disabling the highest compression mode used by JBIG2, which should fix the problem.

Dastin told the BBC that 14 models dating back to 2005 use the JBIG2 compression, and that the company had been aware of possible problems with the standard for years. He told the BBC that Xerox has flagged the issue in the user manual, was thus surprised at the furor that broke out after Kriesel's blog post, and insisted this was a minor problem.

"There's zero chance of this happening if you are photocopying and not trying to store a digital image," he said. "You'll never get into this problem if you use the standard fax. ... or if you're just trying to print." ®