Forensic Analysis Reveals Al-Qaeda's Image Doctoring

WerewolfOfVulcan writes "Wired reports that researcher Neal Krawetz revealed some very interesting things about the Al-Qaeda images broadcast in the mass media. Analysis shows that they're heavily manipulated, a discussion meant to illustrate a new technique that can spot forgery in digital media. 'Krawetz was ... able to determine that the writing on the banner behind al-Zawahiri's head was added to the image afterward. In the second picture above showing the results of the error level analysis, the light clusters on the image indicate areas of the image that were added or changed. The subtitles and logos in the upper right and lower left corners ... were all added at the same time, while the banner writing was added at a different time, likely around the same time that al-Zawahiri was added, Krawetz says.'"

Comments

msm

[stoolpigeon]

I think it has been pretty well documented in the blogging community that many of the images that the main stream media picks up and propogates are heavily altered, faked, or come from completely different events than what they claim to depict. This is not just with al-quaeda, but governments and any group that has an agenda and is media savvy - foreign or domestic.

Re:msm

[samkass]

Even before Photoshop, inappropriate use of stock footage or using visual scenes of the wrong event was pretty common and made for more exciting news. I remember in the late 80's reports of a student riot in South Korea... my father was there at the time. There may have been a few disgruntled students there at the time, but his pictures are completely different (no violence or anything.) Turns out the news companies heard about a student protest and just looked for random footage of asian students rioting and put it on the air when talking about the situation.

Of course, Final Cut Studio and Photoshop make it even easier, but the news has always been more about entertainment than information.

Re:msm

[Jimithing DMB]

This is very common. My dad worked for a power company and one of the local news organizations did a story on pollution. So after my dad talked about their scrubbers and other emissions controls (which he was very instrumental in putting in) the reporter decided that it wasn't sensationalist enough so he pulled a dirty trick. One of their power plants was right next to a steel mill so instead of the reporter doing his monologue with the power plant in the background, he and his camera man simply turned around and put the steel mill right next door in the background then proceeded to open up with "I'm here at .. generating station."

He didn't technically lie; after all he was on the property of the generating station. But the images didn't reflect the nearly nonexistant exhaust of the powerplant (a little NOx which shows up brown on certain days) but instead reflected the constant fires and smoke billowing out of the steel mill. No photoshop required.

Re:msm

[networkBoy]

What's so hard to believe?
If they shot in front of a fixed color backdrop there are automated tools to overlay images (weather guy on the local news anyone?)
Even if they didn't all a video is, is a series of still images shown in rapid succession.
Sure it takes a while, but it is *very* doable.
-nB

Re:Software - Good thing.

[Hijacked Public]

Most forensic photography is digital these days and the resulting images run through verification software to prove that they are 'straight from the camera'.

The SLRs I shoot are Canons and they provide the option of "Add Original Decision Data" in their settings. Combined with Canon's data verification kit any of the images I shoot can be demonstrated to be originals, with minimal in camera image processing.

And anyone who thinks image alteration in the film world is too hard to undertake to swing a court case can't be taken seriously.

Re:Uh... "Forensic Analysis" my foot

[Hays]

Mod parent up.

Take off your tin-foil hats long enough to ask how accurate this "forensic analysis" is. Has it been independently verified? Tested with known manipulated videos? The outputs of the forensic analysis don't even look reasonable for these segments.

There has been some real (peer reviewed) research on detecting digital forgeries by Dr. Hany Farid and his lab at Dartmouth:
http://www.cs.dartmouth.edu/~farid/research/tamper ing.html

Re:Just keeping up with the US press...

[dkf]

Steel doesn't melt (~2700 degrees F) at temperatures reached by puddles of burning petroleum fuel (~1200 degrees F) You should be aware specifically that while it takes a great deal of heat to melt steel, it takes a lot less to soften it a lot. After all, without that particular feature there wouldn't have been blacksmiths producing steel going back thousands of years (or did you think that the Roman legionaries' gladius was made by casting molten steel?) and hence the fact that a jet-fuel fire softened the steel enough in a high-stress application to cause catastrophic failure is not especially surprising. This sort of thing is a problem in many other buildings made with reinforced concrete that have undergone fires, and is an effect that has been well-known for decades.

If you're going to be a kook on the topic of the 9/11 collapse, don't use the melting point of steel as part of your argument as it is a factually weak link. It's less damaging to your overall case to ignore this part. :-)

Re:Software - Good thing.

[Anonymous Coward]

I hate to burst you bubble, but I do a lot of work with computer assisted microscopy, and I can tell you that altering the binary data without touching the header would be a no-brainer (provided that one knows what format the header is in). If there is e.g. a checksum in the header, updating that (to match the new image data) is also not a big deal ("1337" crackers do that sort of thing as a matter of routine).

If there's only one copy of a file, it can be manipulated to contain just about any data that one desires, including falsified "verification" information, and no one (except for the one who did the manipulation) could prove otherwise (assuming that said data manipulation was performed competently).

Re:Just wipe out the Exif?

[mikael]

Here's a good few:

http://isis.poly.edu/~forensics/pubs/icme2007.pdf

http://www.ws.binghamton.edu/fridrich/Research/Luk FriSPIE06_v9.pdf

http://www.ws.binghamton.edu/fridrich/Research/dou ble.pdf

http://ieeexplore.ieee.org/iel5/10206/32570/101109 TIFS2006873602.pdf?arnumber=101109TIFS2006873602

The actual signatures can be retrieved from signal processing methods. I wouldn't have believed that each
camera has its own unique signature (although I have noticed that one or two pixels will be fixed to a particular colour), and that this can be recovered even after JPEG compression.

Re:Software - Good thing.

[necro81]

You might also check out the research of Hany Farid, a CS researcher at Dartmouth who has come up with algorithms to detect if an image has been doctored.

Forensic analysis my ass

[Anonymous Coward]

Apparently this guy doesn't understand how DCT compression works. Or he's hoping that no one else does, and that they'll think he's a genius.

Not only is what he proposes to do impossible (unless he has access to the uncompressed video master, he cannot distinguish source quantization from final video quantization), but what his "custom software" is doing is simply increasing the brightness in areas with high DCT coefficients for high frequencies (which happen wherever there is high contrast, fine detail or pixel noise).

In other words, he's basically written an "edge detect" filter that operates on the DCT tables. It's what compression experts describe as "DUH!"

As someone wrote as a comment on the blog, "al-Zawahiri's beard also shows up as "altered". Perhaps secret messages of terror are secluded within the beard. Pogonophobes everywhere should remain vigilant!"

BTW, the first image in this article is a chroma-key. You don't need any "custom software" to figure that out; just look at the blue spill on his beard. The entire background is fake. It was probably taped in some cave, with a blue background, and then they decided to put him in a "library" to make him look more intellectual. They used a cheap chroma filter, so there's no spill removal.

The fact that the "custom software" shows only the high-detail parts of the background as "altered" proves that it is nothing but a high-DCT-frequency detector.

photoshopping vs videoshopping

[Jtheletter]

Video is still kind of difficult to alter like these photos were, but it's certainly possible for someone with the resources of a government of international organization behind them.

Although I totally agree with you, I must point out government-level resources are not required to reasonably fake video. Remember the movie Kung Pow? Amazing work done in that film placing modern actors in an old kung-fu flick. The budget was only around $10 million USD, and that was for a complete movie. Imagine how little it would cost to get the same effects for a clip only a few minutes long? A professional studio is all you need to make something convincing enough to fool anyone other than video experts, probably any news studio could do it. Scary, really.