Comments for "Text_CAPTCHA"

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  • Stefan Neufeind  [2004-05-28 08:16 UTC]

    Image_Text already does support rotation - have a look at the option "angle" - or do you mean rotation of single characters (no, do you)?

    Could you provide a demo-image (or two) as well?

    Is there a real "algorithm" that the creators of CAPTCHA describe, that makes test best readable by humans but not OCR? Or does everybody implement it his way?

    Generally I like the idea of having such a package - although lately on another mailinglist a blind person said that having such images is "not funny" ... so it should be used with care (and that could maybe be mentioned in the docs/readme).
  • Antônio Carlos Venâncio Júnior  [2004-05-28 12:11 UTC]

    Nice proposal and take a look at this:

    Breaking a Visual CAPTCHA
  • Martin Jansen  [2004-06-11 12:33 UTC]

    A few points:

    - You are using var_dump() at some point in the code, which is probably not desired.

    - Can you replace NULL with null?

    - The comment

    * Image_CAPTCHA - see above
    * see above
    * @package Image_Text

    is misleading, because in the API documentation there may be no text "above", because the blocks are split up into multiple files.

    - Inside a for-loop, you do not make use of the 4-spaces indentation.

    Apart from that the code seems to be fine.
  • Tobias Schlitt  [2004-06-22 13:07 UTC]

    I recently saw truing using ASCII art like output. That's also a nice alternative. Maybe one could rework the package structure to implement a driver backend, rename it to Text_Turing (or similar) and provide several backends for the turing?

    There's an example for ASCII truing in Wez's blog:

    Colin Viebrock has published some experiences on audio turing:

    Would be nice to have those methods in one package. I would be happy to help out with some stuff (ASCII art driver?), if you like.
  • Daniel Convissor  [2004-06-23 15:48 UTC]

    Please take a look at this posting and the links therein.

    They say their system "solves a lot of the issues I dealt with in breaking captchas on various sites to automate singins etc."

    While I haven't checked out their code or yours, there's a possibility that their code may prove helpful to this proposal.
  • Jason Lotito  [2004-07-12 16:32 UTC]

    "I have also experimented with other effects like color gradients."

    Look at using Image_Color::getRange() for color gradients, as well as being able to determine which color you should use for text against a certain background color with Image_Color::getTextColor().

    I can also look into providing Image_Color with support for color blind protection, so you don't end up mixing colors that would be a problem for color blind people.
  • Daniel Convissor  [2004-07-20 20:38 UTC]

    It'd be great if this package can get approved soon. just had a spate of spam submitted via the comment form. CAPTCHA's would be helpful in reducing that problem.

    Also, minor nit to pick: you use double quotes in several places that don't need to be evaluated, therefore single quotes would be better.

  • Daniel Convissor  [2004-07-20 20:41 UTC]

    Another tidbit that might be helpful, using audio to transmit the data:

    Haven't read it myself.
  • Justin Patrin  [2004-07-21 20:37 UTC]

    Looks good. Could you give source for the driver as well. :-)
  • Daniel Convissor  [2004-07-22 17:11 UTC]

    Very important points to keep in mind when designing CAPTCHAs that are hard to reverse-engineer: