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Xerox Photocopiers Randomly Alter Numbers, Says German Researcher
First time accepted submitter sal_park writes "According to a report from German computer scientist D. Kriesel, some Xerox WorkCentre copiers and scanners may alter numbers that appear in scanned documents. Having analyzed the output of two such devices, the Xerox WorkCentre 7535 and 7556, Kriesel found that "patches of the pixel data are randomly replaced in a very subtle and dangerous way": in particular, some numbers appearing in a document may be replaced by other numbers when it is scanned."
Caused by misconfigured JBIG2 compression. When pixel error rate is low enough, similar looking features get printed with the same subimage.
Maybe you should read the article.
Liberty in your lifetime
Scanning an article without comprehension and your complaining about your misinterpretation. Really?
Could also be a problem with an overly aggressive hole filling algorithm. http://www.mathworks.com/help/images/ref/imfill.html
I'd expect there's nothing nefarious going on. It's very likely an overly aggressive image processing algorithm.
Now the question becomes: what moron made this setting the default? Maybe a setting that can undetectably corrupt your data can be provided if appropriate warnings are given, but it sure as hell should never be the default. I would've thought that was obvious.
That's "Normal" quality? That could be *very* misleading. If you have an option that has negative side-effects such as this then the option should be titled something to indicate the risk - "Super-compressed", "dangerously small" or the like.
Though I'm surprised Xerox would even allow such a compression if such an obvious issue occurs. People would expect image quality to suffer - but full character substitution?
"Ignorance more frequently begets confidence than does knowledge"
- Charles Darwin
Especially with such an international audience.
You must have missed the memo. Slashdot is a US site that tolerates international visitors. These are not, however, encouraged to return.
Seems a little dangerous for that algorithm to be the default, doesn't it? Plus, burying the warning deep in the documentation.
And an insufficient warning, at that.
Something more like:
Normal/Small Mode may not be suitable for documents where faithful reproduction of the original text, numbers or illustrations is critical. Examples would include legal documents (contracts, wills, articles of incorporation, etc.), medical documents (patient charts, orders, medication lists, etc.), financial documents (bills, invoices, statements, reconciliations, etc.), business documents (HR records, meeting minutes, memoranda, etc.), engineering documents (drawings, plans, change orders, instructions, bills of material, etc.) or any other document where incorrect data could result in financial loss, injury, death, property damage or destruction, legal liability, loss of reputation or other harm. These examples should not be considered an exhaustive list of documents not suited for scanning, copying or faxing using Normal/Small mode.
would be more appropriate.
I am not a crackpot.
Too much XKCD?
There is no such thing as "too much XKCD".
So say we all