Posted: Sat Nov 18, 2017 3:14 am Post subject: How identify superimposed photos
We see hundreds or even thousands of images a day, and almost all of them have been digitally manipulated in some way. Some have gotten basic color corrections or simple Instagram filter effects, while others have received full on Photoshop jobs to completely transform the subject. It turns out humans arenít very good at recognizing when an image has been manipulated, even if the change is fairly substantial. Here a few tips for authenticating images on our own. First is try reverse image searching. It means that looks for images that are exact matches, as well as those that are thematically similar. Second is look for weirdness. Fight the urge to zoom in too far to examine an image. This unedited image shows weirdness and artifacts when you're up this close. You don't have the CSI "enhance" tool.
Third, check the EXIF data. When a digital camera captures an image, it appends a whole array of information called EXIF data to the image file. This data includes all the critical camera settings, as well as other info like GPS data if itís available (which is typically the case with smartphone photos, unless the person has intentionally turned location settings off). For example, if you have the location of the photo, you can plug it into Google Maps and use Street View to get a general idea of what the location might actually look like. The Street View scene wonít necessarily be 100 percent accurate and up-to-date, but it can be a good starting point. You can see the EXIF data for a photo by opening it in Photoshop or another image editing program, but there are also websites that will show you the data, like Exifdata.com. Photo-sharing site Flickr also displays a lot of metadata when itís available. Both Windows and Mac can also give you some metadata if you right click on the file in Explorer or Finder.
Fourth, examine the shadows. The image has been edited to flip the man's face, which creates a clear contradiction in the direction of the shadows. It was part of a study to determine how well people can recognize faked photos. Fifth, be wary of online tools. There are some websites that can read the software tags, like this one that can tell you exactly what actions were taken in Lightroom when editing a photo. Thatís more useful, but you still need an understanding of the software itself to make an accurate interpretation. There is software out there that can identify these more complex manipulations, but itís typically only available commercially, for security and law enforcement operations.
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum