Digital Forensics: 5 Ways to Spot a Fake Photo

SloYerRollSloYerRoll Registered Users Posts: 2,788 Major grins
edited June 5, 2008 in The Big Picture
A short but interesting read from Scientific American.

http://www.sciam.com/article.cfm?id=5-ways-to-spot-a-fake&print=true

Comments

  • jzieglerjziegler Registered Users Posts: 420 Major grins
    edited June 5, 2008
    Interesting article. Although, I found that it was a little odd that they seem to consider enhancing the contrast to be "doctoring" an image. It's interesting that they can detect the contrast enhancement, but I'm not sure that they should care about that. I doubt that many people would consider contrast enhancement to be doctoring like cloning and compositing is.
  • frosty111frosty111 Registered Users Posts: 55 Big grins
    edited June 5, 2008
    i enhance a lot of my photos using paint shop pro
    it really makes the picture stand out more

    i wouldnt call it fake

    its just what photographers do in digital dark rooms.
    i mean thats what they do rite.
  • DavidTODavidTO Registered Users, Retired Mod Posts: 19,160 Major grins
    edited June 5, 2008
    Great read!

    Thanks for posting that, SLO!
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  • dbddbd Registered Users Posts: 216 Major grins
    edited June 5, 2008
    jziegler wrote:
    Interesting article. Although, I found that it was a little odd that they seem to consider enhancing the contrast to be "doctoring" an image. It's interesting that they can detect the contrast enhancement, but I'm not sure that they should care about that. I doubt that many people would consider contrast enhancement to be doctoring like cloning and compositing is.
    Doctoring begins as soon as you point the camera and exclude the parts of the image that don't fall on the sensor. Does it matter? It depends on the conclusions you wish to draw. The authors of the article have algorithms that determine the positions of the light sources that created the scene in an image. Contrast enhancenent can produce images where there is no place the light sources could have been and created the brightnesses displayed in the image, so their algorithm notices, so they care. Does it put people in the picture who were not there? No. Does it mislead a forensic analysis? Yes.

    Are you taking your pictures for forensic analysis? If not, YMMV.

    Dale B. Dalrymple
    http://dbdimages.com
    "Give me a lens long enough and a place to stand and I can image the earth."
    ...with apology to Archimedies
  • TangoTango Registered Users Posts: 4,592 Major grins
    edited June 5, 2008
    photos can be altered?eek7.gif
    Aaron Nelson
  • DavidTODavidTO Registered Users, Retired Mod Posts: 19,160 Major grins
    edited June 5, 2008
    photos can be altered?eek7.gif


    Good news for you, my friend! deal.gif




    :hide
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  • TangoTango Registered Users Posts: 4,592 Major grins
    edited June 5, 2008
    rolleyes1.gif
    Aaron Nelson
  • NikolaiNikolai Registered Users Posts: 19,035 Major grins
    edited June 5, 2008
    He forgot to mention few more clues:
    1) fringing/halo effect on the edges when a background is replaced
    2) different DOF/focusing distance in different parts of a composed image
    .. etc :-)
    "May the f/stop be with you!"
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