If you’ve ever visited a forum on the Web, you’re familiar with how easily a single photo can spark a debate over whether the photo has been altered. Funny cat photos and car accidents pics have been questioned–even if the poster was the person who took the photo.
Now you can help settle the debate when one flares up in your online community with JPEGsnoop, an app that can pull out the EXIF and metadata from a photo, and do a simple analysis of the image to see if it’s been obviously altered in ways the untrained eye can’t see.
Despite its name, JPEGsnoop supports multiple image types, including JPG, THM, AVI movies, DNG files, MOV movies, various RAW photo formats, and even Adobe PDF documents. The developer makes a point to clarify that the app cannot tell if a movie has been altered, just that those movie files are containers for multiple images that the app can examine one at a time as long as they’re supported.
The app is freeware, but the developer happily takes donations to fund additional development of the application. While you can use JPEGsnoop to determine the origin of an image and see if it’s been altered, you can also use the app to browse EXIF data and metadata that can help you learn more about an image or even pick up the photographer’s tricks.
For example, the app can examine an image and compare it against known compression signatures to see if it has been edited and recompressed using a desktop image editing program like Photoshop. Once the analysis is complete, JPEGsnoop can even tell you if the app was created by software or from a specific digital camera. In addition to helping you determine the authenticity of an image, you can also use JPEGsnoop to pull out the quality setting of the image, original resolution settings, RGB histograms, and a wealth of other information specifically of interest to photographers and graphic designers.
JPEGsnoop is remarkably powerful for a free application, and useful not just for those folks who want to end the “obviously photochopped” debate on their favorite blogs or forums. If you’re a photographer or just want to know how your favorite photographer works with their images to make them look so good, JPEGsnoop can help you find out. The app is Windows only, and supports just about every version.