Detecting North Korea’s doctored photos
By Roland de Courson
This photograph, released on March 26 by the official Korean Central News Agency, purportedly shows landing and anti-landing drills conducted by North Korean naval units the previous day on the country’s east coast. It is one of dozens of images and videos released in recent weeks which – even by Pyongyang’s bellicose standards – represent a new level of saber-rattling, especially against the "imperialist" United States and its "scum puppets" in South Korea.
But a careful analysis using forensic software called Tungstene reveals that the image has been manipulated. Specifically, several of the large hovercraft have been added digitally, presumably in an effort to inflate North Korea’s fleet of landing vessels beyond its actual size.
For the most part, KCNA is the sole source of news and images coming out of the country, which is off limits to foreign press except on rare and carefully stage-managed occasions. Like other news agencies and media, AFP purchases photos provided by the Pyongyang regime's propaganda apparatus. In distributing them to our media clients, we clearly indicate the source and recommend that the images be regarded with due circumspection.
AFP Photo/M. Hood
KCNA photos that have been obviously altered are not distributed to our clients. But some have been doctored in ways that are nearly undetectable, even to a trained eye. That was the case with the image above of the hovercraft landing. When AFP released the photo, we had no reason to think that it had been faked.
Alerted by a client who raised questions about the plausibility of the naval forces depicted, AFP conducted an in-depth analysis using forensic software that revealed unmistakable signs of manipulation.
We immediately removed the image from our online database and sent out a "MANDATORY KILL" notice, instructing clients that had already downloaded the picture that it should not be used.
Tungstene demonstrated its worth in 2011 when AFP unmasked a faked photo widely circulated on Internet that claimed to show Osama bin Laden dead. In the case of the hovercraft image from KCNA, "proving the falsification was not easy. Several methods were used to doctor the image,” explains Antonin Thuillier, a journalist at AFP trained to use the forensic software. "It's like being confronted with a corpse and needing to show as quickly as possible that a crime has been committed."
It took more than 90 minutes of careful analysis to conclude, beyond a reasonable doubt, that the photo had been manipulated. (Using Tungstene requires a solid grip on mathematics.) The results revealed that the angle of the two hovercraft about to hit the beach – in relation to the land and the light – are identical, a near statistical impossibility, Antonin said.
Also, the vessel on the beach in the foreground was "reconstructed" with elements duplicated from another hovercraft in the photo, the software showed. An additional function can determine the "age" of pixels, making it possible to isolate those that have been added after the original image was taken.
The software also showed (below) that the picture had been subdivided into tiny digital squares - not normally present - that are not visible to the naked eye. It is not known what purpose they serve.
The inescapable conclusion was that many elements in the image had been cut-&-pasted, albeit very skilfully.