How to Tell If a Photo Has Been Corrected
Almost every photo on the Internet has been edited in one way or another, be it cropping, filtering, compressing, color grading, or other generally harmless retouching. But many people try to pass fake images as true, leading to hoaxes, crazy theories and more than one trip to Snopes to check the facts. You can do the world a favor by helping others distinguish real photos from fake ones. Here’s how:
Look for bad editing first
Glaring mistakes should be the first way to identify a forged photograph. If you think something has changed, it is helpful to look around the area that you think has been changed. Deformation around an object is a pretty clear sign of photo manipulation.
Look out for hands, feet and faces, and common areas where you may find poorly worn objects such as jewelry, stains or debris. Low-resolution images can be more difficult to spot errors, so be suspicious of blurry camera photos and videos.
Lighting is the key to success
If two people standing next to each other burn differently, one of them could have been inserted after the fact. It’s the same with objects added to photographs. If the light hitting the subject does not correlate with the rest of the highlights in the photo, it has probably been edited.
Check for duplicate pixels
You can have a photo of a bright blue sky, but each blue pixel is slightly different and cannot be simply replaced with a blue brush. Some tools, like the brush or the clone tool in Photoshop, rely on using identical pixels to reproduce whatever you clone or paint.
According to former Adobe chief Kevin Connor, nothing is perfectly painted in life, and spots of suspiciously similar pixels on a photo may indicate a photo was tampered with. Poor cloning also leaves behind repetitive artifacts such as clouds or even the worst offenders’ fingers. Obvious distributions, of course.
EXIF data is your friend
After you take a close look at a photo for editing, you may still not be sure. That’s when you should take a look at the EXIF data of a photo, the metadata embedded in the photo when it’s taken.
Cameras store metadata in photos associated with the make and model of the camera, the settings used to create the photo (including ISO, focus, and shutter speed), among other information. Photo editing and photo copying tools can remove bits of metadata or add metadata to indicate that a photo has been modified. Lack of metadata often means that it has been removed, making it difficult to identify the source of the image and verify its validity. If someone is trying to pass off an insincere photo as true and there is no metadata on it, be careful about the source.
Sites like Exifdata and Metapicz are websites for checking the EXIF data of your photos. Suspicious metadata you should look for often includes the date the image was created, which could be the day the modified photo was taken, not the day it was taken.