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Domain: dkriesel.com

Stories and comments across the archive that link to dkriesel.com.

Comments · 6

  1. Re:Facsimile. by MrMr · · Score: 1 · on The Fax is Not Yet Obsolete (theatlantic.com)

    No need for sloppy transcribing: The scanner compression can do that automaticaly for you: http://www.dkriesel.com/en/blo...

  2. Example of the JBIG2 compression fiasco by Guppy · · Score: 4, Interesting · on Google's New Compression Tool Uses 75% Less Bandwidth Without Sacrificing Image Quality (thenextweb.com)

    Let's hope Google has had the forethought to have the image recognition algorithm pre-screen for images containing numbers, letters, and diagrams. Pattern-matching compression can be pretty scary when it decides two patterns are close enough:

    http://www.dkriesel.com/en/blo...

  3. This problem may affect more than just Xerox... by Colin+Douglas+Howell · · Score: 4, Informative · on Xerox Confirms To David Kriesel Number Mangling Occuring On Factory Settings
    An earlier blog posting from Kriesel on this issue says that a reader reported similar behavior from a Brother copier:

    http://www.dkriesel.com/en/blog/2013/0808_number_mangling_not_a_xerox-only_issue

    And one of the comments to that posting says:

    I have experimented with the open source jbig2enc library available at http://github.com/agl/jbig2enc, which has a encoding parameter called the “threshold”, described like this:

    “sets the fraction of pixels which have to match in order for two symbols to be classed the same. This isn't strictly true, as there are other tests as well, but increasing this will generally increase the number of symbol classes”

    The included command tool accepts values for this parameter between 0.4 and 0.9, with 0.85 as the default.

    I have found replaced digits in single-page numerical tables encoded with this parameter set as high as 0.82. As with the other examples you have found, the errors are not in any ways obvious to the eye which is, of course, the real problem.

    Since JBIG2 has been supported in PDF since 2001, it would be surprising if only Xerox have fallen into this trap.

  4. Update by hweimer · · Score: 1 · on Xerox Photocopiers Randomly Alter Numbers, Says German Researcher

    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.

    The guy who came up with this posted several updates to his blog.

    1. The setting is not the default.
    2. There is a warning when you change the settings in the web frontend.
    3. Xerox's support staff was not aware of this problem and could not come up with a solution.

  5. Update by hweimer · · Score: 1 · on Xerox Photocopiers Randomly Alter Numbers, Says German Researcher

    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.

    The guy who came up with this posted several updates to his blog.

    1. The setting is not the default.
    2. There is a warning when you change the settings in the web frontend.
    3. Xerox's support staff was not aware of this problem and could not come up with a solution.

  6. Re:I call BS by Guy+Harris · · Score: 3, Informative · on Xerox Photocopiers Randomly Alter Numbers, Says German Researcher

    I work for Xerox. I specifically support these machines in a tier 3 capacity. I have not seen or heard a single case of this.

    So does Francis Tse, and he's apparently heard of it.

    My group handles calls from all of North America, and some South.

    You might want to talk to somebody who handles calls from Western Europe - Germany, in particular.