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Identifying Manipulated Images

Posted by CmdrTaco on from the check-that-out dept.

Jamie found a cool story at MIT Tech Review. (As an aside, it sits behind an interstitial ad AND on 2 pages: normally I reject websites that do that, but it's a slow news day, so I'm letting it through.) Essentially, software is used to analyze light patterns in still photographs. Once you can figure out where the light sources are, it becomes a lot easier to determine if an image has been photoshopped.

9 of 162 comments (clear)

  1. Detector == Quality Control by Anonymous Coward · · Score: 5, Interesting

    People who manipulate images will use these tools for quality control: When the fabrication passes all tests, it is ready to be released.

  2. Everything is photo-shopped! by jimboindeutchland · · Score: 5, Funny

    Duh!

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  3. No ads, all on one page by wile_e_wonka · · Score: 5, Informative

    The printer-friendly version:

    http://www.technologyreview.com/printer_friendly_article.aspx?id=20423

  4. Colombo did this on his 1970's TV show by jimwelch · · Score: 5, Interesting

    Someone wore a photo mask and tripped a speed camera to give their partner proof that they were across town (LA) at the time of the murder. He noticed the shadow under the nose was wrong by comparing previous and following pictures from the same camera.
    I am not sure which episode it was. Peter Falk as Det. Lt. Colombo

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    Never trust a man wearing a coat and tie!
  5. Uh Oh by Missing_dc · · Score: 5, Funny

    This bodes ill for all those geeks out there with "out-of-state" girlfriends!!

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  6. Re:Steganography by L4t3r4lu5 · · Score: 5, Funny

    *Somewhere in the middle of the NSA / MI6 buildings, a check mark is put next to an IP address.*

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  7. Finding Photoshopped Pics for Fun by Dan+East · · Score: 5, Interesting
    Does anyone else have a habit at looking at pictures and trying to see how they've been manipulated? These types of pictures are rampant in advertising. Pick up any magazine and start looking, and the poorly edited pictures will jump out quickly. The more professionally edited pictures have much more subtle problems, and can take a bit of poring over to find. Many product images (on packaging and in catalogs) are the same way, and are usually the worst edited of the bunch. Some things I look for:
    • An object rubber-stamped in multiple places. Each copy is identical, which gives it away. They are often scaled, rotated or mirrored to make them look more unique.
    • Lighting and shadows, which is what the algorithm in this story deals with specifically.
    • Focus. Often multiple objects will be in focus at varying distances impossible with a single shot.
    • The same image of a person is used in multiple shots. This is most prevalent in product images in catalogs.
    • Poor masking, where edges of objects are over or under processed, either clipping part of the object (hair can be particularly tough to do), or showing some color edges from the original background.

    Anyway, that's just the geek in me I guess, because I really do enjoy finding flaws in images. What I hate is an image that has a sort of surreal perfection to it that I know must be composited, but I can't find any smoking gun.
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  8. Re:That should help by sm62704 · · Score: 5, Informative
    It's not needed and won't help. Most of the UFO photos are pre-Photoshop and were done with different methods:
    • Have a small model of the UFO and fling it into the air high enough that there's no context. Although those CAN be detected, they can't by this software.
    • The objects are secret military aircraft, not alien craft. The hoax of alien craft is started by the government (pick one) to mask the true meaning of the object photoed. This software won't help with that, either
    • It's something else flying around up there. Is it a bird? Is it a plane? Is it a weather balloon? Is it ball lightning? Who knows? If it's a flying thing and you don't know what it is, then it's an Unidentified Flying Object. This tool won't help here, either.
    This tool can't do anything someone trained in art can't do. The first thing you learn in art school is how to see. You can't draw if you can't see, and that's usually the biggest reason most people can't draw.

    As one of my instructors used to say, "I don't know what I like but I know what art is."

    -mcgrew
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    mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest
  9. Re:Apollo by lena_10326 · · Score: 5, Funny

    I love how the first comment is asking if the apollo landing photos were photoshopped.
    Photoshop was HUGE in 69. Huge.

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