Xerox to patch scanner glitch that can alter numbers

The problem was uncovered last week by a computer science student in Germany. He used a Xerox WorkCentre scanner to create a PDF of a building floor plan, and noticed some of the fine print in the document had been reproduced incorrectly in the PDF. The text that gave the area size of each room had been duplicated in some cases, so that all the rooms were given the same area.

The error resulted from how the scanner’s JBIG2 image compression algorithm works at high compression settings. If it determines two parts of a document are identical, it makes one compressed version and reuses it across all the similar areas.
Xerox acknowledged the problem Tuesday and on Wednesday said it would issue a software patch.

“Xerox is developing a software patch that can be remotely downloaded to each device,”the company said in a blog post. “The software patch will disable the highest compression mode thus completely eliminating the possibility for character substitution. Xerox will begin rolling out the patch within a few weeks.”

The problem does not occur when the machines are used for printing, copying or sending faxes. It only occurs when scanning, and when the highest compression and lowest image quality are selected, which has to be done manually, the company said.

“You will not see a character substitution issue when scanning with the factory default settings. We provide safeguards to avoid problems such as these. Customers should check their device(s) to ensure the factory default settings have not been changed,” it said.

Xerox said it is also developing a guide to help customers check their current scanner settings. It will be available this week.

“We apologize for any confusion and inconvenience this has caused our customers. We are working tirelessly to address these issues—working closely with our partners and customer service teams across the globe to both proactively inform customers as well as help them solve the issue,” the company said.