This thread in Adobe's Photoshop Users forum details a rather unusual feature that debuted with the release of the latest incarnation of popular image-editing software Photoshop. The latest version uses an image-analysis algorithm to detect the presence of an image of United States or European Union currency, and disables access to the file. The motivation is obviously to curb growing computer-enhanced counterfeit currency, but the implementation is causing a furor with consumers who don't appreciate such intrusive prior restraint.
The algorithm operates by examining the blue alpha channel of an image, attempting to scale and transform reference eigenvectors into corresponding patterns in the image being analysed. The reference pattern which produces the most accurate results has been found to be a series of small circles on the currency, similar to the EuroStar pattern in EU currency. Their distance and distribution across the note is also factored into the analysis.
Technical operation aside, two arguments are commonly raised against the inclusion of this 'feature': 1) legitimate artistry will be prevented due to either a) a false-positive match; or b) the introduced limitation upon subject matter; and 2) being government works, the images aren't protected by copyright, are important symbolic items, and are legally able to be maintained in digital form, so what right does a software manufacturer have to restrict this use?
To test the first claim, I downloaded several images of US currency: firstly, a high-resolution picture of a $1 note; secondly, a lower-resolution compressed image of a $5 note; thirdly, a zoomed-in portion of a note; fourthly, the government seal and serial number; fifthly, a picture of a pile of money; sixthly, an unfurled group of notes such as might appear in a person's hand in the background of a photograph. Loading each of them into the latest build of Photoshop CS, not a single image was blocked.
However, the above image - which depicts an abstract green blob completely unlike a bank note - was detected as fraudulent. One user on the Photoshop forums has devised a workaround to avoid detection: simply open the file in an older version of Photoshop (or ImageReady), add a layer of black above the money/false-positive layer, then save and reopen in Photoshop CS. You should now be able to open the file, unhide the top layer, and proceed to perform your evil deeds normally. Ahem.
With regard to the second argument, while it is true that - though fraudulent intent alone is sufficient to constitute a felony under Title 18, Section 472 of the United States Code - it is only an offense to produce a printed reproduction of a (Title 18, Section 474), studies have shown that more than 40 percent of currency forgery now begins with a digitally edited image. Adobe has every right to include or restrict access to any aspect of their product. I'm surprised that there has not been more fervent advocacy for a similarly-premised child pornography filter -- though if current pornography detection algorithms are as inaccurate as this article indicates, there would be some interesting results.
Given the inability of the algorithm to detect low or even medium resolution images of banknotes in typical environments, the algorithm poses little threat to creativity. In fact, (though I've yet to actually see a note positively identified) all the check really seems good for is preventing access to images that would really only be used for non-philatelic, artistic, or academic purposes. To this end, the software is consistent with the governing legislation:
s 472 - Uttering counterfeit obligations or securities
Whoever, with intent to defraud, passes, utters, publishes, or sells, or attempts to pass, utter, publish, or sell, or with like intent brings into the United States or keeps in possession or conceals any falsely made, forged, counterfeited, or altered obligation or other security of the United States, shall be fined under this title or imprisoned not more than 20 years, or both.
[...] There must be sufficient resemblance to the genuine article to deceive a person using ordinary caution. [emphasis added]
Clearly, any low-resolution image will not satisfy the requirement of sufficient resemblance, so the check does not intrude upon non-infringing activities.
Whilst I'd stop short of congratulating Adobe for their inclusion of a government regulatory function in privately owned software, the check will - based on my initial tests - hinder very few (if any) legitimate ends. Of course, the efficacy of the measure at preventing real counterfeiting taking place remains dubious; firstly, the would-be counterfeiter would need to be using the latest, inordinately expensive, retail version of Adobe's software (and not, as would be far more likely, an older, pirated version). Secondly, there are numerous alternatives (such as The GIMP) without the check. Thirdly, the main problem in counterfeiting notes is not obtaining or producing the correct image (high resolution scanners are very cheap these days, and incorporate no such protection), but obtaining the correct paper and printing it.
This is not the first time prior restraint has been exercised by a software manufacturer over end users. Jasc Software's Paint Shop Pro incorporates similar anti-fraud protection measures in its more recent versions. DVD players have Macrovision compulsorily built in to prevent unauthorised copying or stream capture, despite potentially non-infringing uses. What, then, is so remarkable about Adobe's (flawed) implementation?