FourMatch: A Photoshop Plugin That Can Spot Manipulated Photos
Earlier this year, we wrote about a new company called Fourandsix (pronounced “forensics”), a collaboration between a former Photoshop product manager and a professor who’s an expert in digital forensics. The goal of the new startup was to build powerful tools that would make detecting digital photo manipulation easy. Well, the first Fourandsix product is now available.
Called FourMatch, it’s an extension for Photoshop CS5/CS6 that “instantly distinguishes unmodified digital camera files from those that may have been edited.”
Unlike the duo’s other secretly brewing projects that haven’t been announced yet, FourMatch doesn’t take a photograph’s content itself into consideration. Instead, it peers into the file’s metadata to search for indications of tampering. The company explains,
FourMatch leverages the fact that there is nearly endless variety to exactly how hardware and software products can choose to store a JPEG file. This variety results in a distinctive set of “signatures” from each hardware and software product. Once an image has been edited and resaved from a software product, this signature is changed to match the software rather than the original capture device. Thus, when a file signature correctly matches a known signature from the device that captured the photo, you can be confident that the photo has not been edited.
Fourandsix has built a database of more than 70,000 signatures representing more than 2,400 camera models and mobile devices, as well as signatures from a variety of image editing programs and online services. When you purchase a copy of FourMatch, you’re also purchasing access to this valuable database, which is updated frequently as new devices become available. Loaded with this database, FourMatch can quickly assess the authenticity of many images.