- Documents were changed when they were compressed, Xerox found
- Company posts a blog by its senior engineer to explain why it happens
- Xerox criticised for not ordering a recall when implications could be colossal
By Helen Collis
PUBLISHED: 12:48 EST, 8 August 2013 | UPDATED: 04:05 EST, 9 August 2013
A researcher in Germany has discovered a major glitch in Xerox copier machines which have shown to substitute the wrong numbers when scanning documents.
After scanning a blueprint document from an architect, David Kriesel, a computer science researcher at the University of Bonn in Germany, thought the firm was pulling his leg when they accused him of altering some figures.
But sure enough, on three occasions, the number six had been replaced with an eight.
Changing numbers: David Kriesel noticed that in some of the numbers he scanned in with a ’66’ sequence (pictured on the left) they had changed to ’86’ (pictured on the right)
Technical error: Again, the numbers which feature a 6 on the original document (left) have been changed to an 8 (pictured right). The table shows that 54,60 (left) turns into 54,80 (right) and 65,40 (left) becomes 85,40 (right)
Outrage: When Mr Kriesel noticed the error and the company explained, he took to Twitter to spread his concern
He told ABC News: I thought they were kidding. But I tried it myself.. and the numbers changed (after being scanned).’
Alarmed, Mr Kriesel contacted the U.S. firm, but found no one knew anything about it.
In response, the company’s principle engineer posted a five paragraph blog on its website explaining the situation and how to avoid it.
Frances Tse said the issue had been detected in certain machines when scan- quality and resolution settings were altered; when files were compressed, and the quality reduced.
Each page is scanned as a number of small patches, and the machine replaced each patch with one that best fits from a library of symbols.
However, when the file quality is reduced, there is a subsequent ‘tradeoff’ in accuracy, Mr Tse said.
He wrote on his blog: ‘The Xerox design utilizes the recognized industry standard JBIG2 compressor which creates extremely small file sizes with good image quality, but with inherent tradeoffs under low resolution and quality settings.’
He explains that for ‘data integrity purposes’, the company recommends using the factory default settings for scanning, with quality level set to ‘higher’.
‘In cases where lower quality/higher compression is desired for smaller file sizes, we provide the following message to our customers next to the quality settings within the device web user interface: “The normal quality option produces small file sizes by using advanced compression techniques. Image quality is generally acceptable, however, text quality degradation and character substitution errors may occur with some originals.”,’ he said
Coverage: Mr Krisesl said he thinks the glitch should get some airtime on a late night satirical programme
Numerous Xerox machines are affected by the glitch, including this ColorQube a 87XX / 89XX model
The potential implications of the Xerox scanning glitch could be very serious, especially if they affect construction documents or medical developments, customers point out (stock image of an office)
Mr Tse’s blog, titled ‘Always Listening To Our Customers: Clarification On Scanning Issue‘ has not been well received however, by those who fear the potential fallback from this issue could be colossal.
S. Basinger questioned what will happen when people find engineering documents are released for construction with numbers switched by Xerox’s machines, or medical documents have used with switched figures.
‘A lame response like this suggests that some of the ignorance of the consequences may be willful and that your senior leadership is hoping that this will somehow go away,’ the comment continues.
‘Heaven forbid as time continues to tick away and you delay a proper recall that people die as a result of your inaction.’
Others criticise the company for failing to explicitly say which machines are affected, another points out that the warning message did not show up on his machine when he followed the instructions.
When one client called the customer services for advice, he found no one knew what he was talking about.
In response, Mr Tse later added some extra details in answer to his blog comments.
He pointed out that the product families affected were numerous: ColorQube 87XX / 89XX, ColorQube 92XX / 93XX, WorkCentre 57XX, WorkCentre 76XX, WorkCentre 58XX, WorkCentre 77XX, WorkCentre 5030/5050, WorkCentre 6400, WorkCentre 78XX, WorkCentre 51XX, WorkCentre 7220/7225, WorkCentrePro 2XX / BookMark 40/55, WorkCentre 56XX and WorkCentre 75XX
He also drew attention to the fact that unless default settings had not been changed, the problem would not arise.
He said the company was taking the issue very seriously. He said from people’s feedback ‘we will look for ways to help our customers better manage their scanning application needs’.
German researcher Mr Krisesl, who has spoken to both Mr Tse and Xerox’s vice president Rick Dastin, is still concerned about the consequences.
He told ABC News: ‘This problem is dangerous. If something is compressed with JBIG2 and I claim it’s incorrect, you can’t prove me wrong.’
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