Jigsaw solver

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  • bearophileHUGS@lycos.com

    #1

    Jigsaw solver

    This can be interesting:
    leighklotz writes "Jeff Breidenbach and 200 lines of Python code have brought us the Glyphsaw Puzzle solver. Hold a puzzle piece up to a webcam, and the display sgiws exactly where in the puzzle the piece belongs. The solver uses the Python Imaging Library (PIL), Numerical Python, and the PARC Da...


    Bearophile

  • mensanator@aol.com

    #2
    Re: Jigsaw solver


    bearophileHUGS@ lycos.com wrote:[color=blue]
    > This can be interesting:
    > http://science.slashdot.org/science/.../2340238.shtml
    >
    > Bearophile[/color]

    Hey, that DataGlyph demo works pretty neat.

    <quote>
    Decoding your DataGlyph.

    DataGlyph decoded successfully.

    four score and seven years ago our fathers brought
    forth on this continent a new nation conceived in
    liberty and dedicated to the proposition that all
    men are created equal

    To test the robustness and error correction DataGlyphs
    provide, you might want to "damage" a DataGlyph by
    editing it with paint program, obscuring some of the
    marks and uploading the damaged image for decoding.

    Serious aficionados have been known to print out
    their DataGlyph, spill some coffee on it, tear off
    small pieces, fold it into a paper airplane, run over
    it with a car, light small portions on fire, then scan
    the document back in and try to extract the message.
    If you are such an enthusiast, have fun, be safe, and
    remember even great technologies have their limits.
    </quote>


    Of course, being an old System Test Engineer whose job it
    was to figure out how to break software, I couldn't let
    this challenge go unanswered.

    So, picking up the gauntlet, I broke it in 5 seconds.

    <quote>
    Decoding your DataGlyph.

    Decoding dataglyph59683-2.bmp...
    Unable to decode this dataglyph

    Top 5 reasons a DataGlyph might fail to decode

    1. Hey... that's not a DataGlyph
    2. Not enough of the DataGlyph is present
    3. Way too much damage
    4. Trouble locating the DataGlyph
    5. Cosmic rays

    Usually if a human being can make out the individual
    marks, the decoding software should also be able to
    do so. This online decoder is optimized for scanned
    images from a paper documents.

    If you are a technical user evaluating DataGlyphs,
    please be aware that this online DataGlyph decoder
    is expecting mainstream DG500 DataGlyphs. This online
    decoder will not work if you are testing a specialized
    DataGlyph variant such as serpentone, yellow DataGlyph
    or address carpet.

    Finally, note that a customized image processing
    front-end or a customized DataGlyph locator algorithm
    might yield better results in application scenarios
    such as handheld camera images with severe perspective
    distortion.
    </quote>

    Naturally, the real answer is none of the above.

    And the damage can be undone in 5 seconds also.

    And, under the right circumstances, an undamaged
    DataGlyph could suffer the same fate (which also implies
    that the damaged DataGlyph could be read under the
    same circumstances).

    ObPuzzle: how did I "damage" the image?

    Comment

    • Tim Churches

      #3
      Re: Jigsaw solver

      mensanator@aol. com wrote:
      [color=blue]
      >bearophileHUGS @lycos.com wrote:
      >
      >[color=green]
      >>This can be interesting:
      >>http://science.slashdot.org/science/.../2340238.shtml
      >>
      >>Bearophile
      >>
      >>[/color]
      >
      >Hey, that DataGlyph demo works pretty neat.
      >
      >[/color]
      ....
      [color=blue]
      >Of course, being an old System Test Engineer whose job it
      >was to figure out how to break software, I couldn't let
      >this challenge go unanswered.
      >
      >So, picking up the gauntlet, I broke it in 5 seconds.
      >
      >[/color]
      ....
      [color=blue]
      >Naturally, the real answer is none of the above.
      >
      >And the damage can be undone in 5 seconds also.
      >
      >And, under the right circumstances, an undamaged
      >DataGlyph could suffer the same fate (which also implies
      >that the damaged DataGlyph could be read under the
      >same circumstances).
      >
      >ObPuzzle: how did I "damage" the image?
      >
      >[/color]
      You created a mirror image.

      The system can be made resistant to that problem by only allowing
      palindromic messages to be encoded, such as "Madam I am Adam.", 'Able
      was I ere I saw Elba." and "Named under a ban, a bared nude man."

      Seriously, I am surprised that the Xerox demo does not try flipping the
      image around various axes. It would be trivial to add these
      transformations . Well, trivial to flip images along a few, obvious axes,
      but not along every possible axis.

      What I want to know is whether any open source implementations of this
      technology are available. No doubt it is patented to death by Xerox.

      Tim C

      Comment

      • mensanator@aol.com

        #4
        Re: Jigsaw solver


        Tim Churches wrote:[color=blue]
        > mensanator@aol. com wrote:
        >[color=green]
        > >bearophileHUGS @lycos.com wrote:
        > >
        > >[color=darkred]
        > >>This can be interesting:
        > >>http://science.slashdot.org/science/.../2340238.shtml
        > >>
        > >>Bearophile
        > >>
        > >>[/color]
        > >
        > >Hey, that DataGlyph demo works pretty neat.
        > >
        > >[/color]
        > ...
        >[color=green]
        > >Of course, being an old System Test Engineer whose job it
        > >was to figure out how to break software, I couldn't let
        > >this challenge go unanswered.
        > >
        > >So, picking up the gauntlet, I broke it in 5 seconds.
        > >
        > >[/color]
        > ...
        >[color=green]
        > >Naturally, the real answer is none of the above.
        > >
        > >And the damage can be undone in 5 seconds also.
        > >
        > >And, under the right circumstances, an undamaged
        > >DataGlyph could suffer the same fate (which also implies
        > >that the damaged DataGlyph could be read under the
        > >same circumstances).
        > >
        > >ObPuzzle: how did I "damage" the image?
        > >
        > >[/color]
        > You created a mirror image.[/color]

        Damn. Too easy. But think how much fun you could have
        with a salesman if your DataGlyph was printed on a
        transparency (hence, the right circumstances being
        right side up or upside down).

        I once made an employee id badge that I would slip
        into the salesman's stack of test badges. The employee's
        name was CHECKSUM ERROR. What a laugh riot.
        [color=blue]
        >
        > The system can be made resistant to that problem by only allowing
        > palindromic messages to be encoded, such as "Madam I am Adam.", 'Able[/color]
        [color=blue]
        > was I ere I saw Elba." and "Named under a ban, a bared nude man."[/color]

        Why couldn't they simply encode your input as a palindrome?

        Input: Mary had an aeroplane
        Encoding: Mary has an aeroplaneenalpo rea na dah yraM

        And then simply divide in half when decoding.
        [color=blue]
        >
        > Seriously, I am surprised that the Xerox demo does not try flipping[/color]
        the[color=blue]
        > image around various axes. It would be trivial to add these
        > transformations . Well, trivial to flip images along a few, obvious[/color]
        axes,[color=blue]
        > but not along every possible axis.[/color]

        That's why it took me all of 5 seconds - the time needed to
        select the Flip Horizontal menu item in Windows Paint.
        [color=blue]
        >
        > What I want to know is whether any open source implementations of[/color]
        this[color=blue]
        > technology are available. No doubt it is patented to death by Xerox.[/color]

        Has that ever stopped anybody?
        [color=blue]
        >
        > Tim C[/color]

        Comment

        • Tim Churches

          #5
          Re: Jigsaw solver

          mensanator@aol. com wrote:
          [color=blue]
          >Tim Churches wrote:
          >
          >[color=green]
          >>mensanator@ao l.com wrote:
          >>
          >>[color=darkred]
          >>>ObPuzzle: how did I "damage" the image?
          >>>
          >>>[/color]
          >>You created a mirror image.
          >>
          >>[/color]
          >
          >Damn. Too easy.
          >[/color]
          There is another explanation for the rapidity with which your brain
          teaser was solved, but modesty prevents me from mentioning it.
          [color=blue][color=green]
          >>The system can be made resistant to that problem by only allowing
          >>palindromic messages to be encoded, such as "Madam I am Adam.", 'Able was I ere I saw Elba." and "Named under a ban, a bared nude man."
          >>
          >>[/color]
          >
          >Why couldn't they simply encode your input as a palindrome?
          >
          > Input: Mary had an aeroplane
          >Encoding: Mary has an aeroplaneenalpo rea na dah yraM
          >
          >[/color]
          I should have been more precise and said "natural language palindrome",
          the rules for which promulgated by Martin Gardiner of Scientific
          American fame are that capitalisation, whitespace and punctuation are
          ignored and that each word must be a recognised word or commonly used
          proper noun in the target language (and it must read the same forwards
          and backwards).

          I wonder, do ideographic languages have palindromes?
          [color=blue][color=green]
          >>No doubt it is patented to death by Xerox.
          >>
          >>[/color]
          >
          >Has that ever stopped anybody?
          >
          >[/color]
          Ask the Xerox legal department.

          Tim C

          Comment

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