posted on Jan, 26 2011 @ 05:15 PM
When a digital image is saved or compressed as a JPEG, and the more it's compressed, (common on the internet), the more pixelation occurs and it
occurs most noticeably at edges. So when people just hand out that a picture was Photoshopped that they see on the internet I have to laugh, because
every picture you see on the internet has usually undergone a 'loosy' compression and the JPEG is the most commonly used. You can filter the heck
out of a JPEG image and find all kinds of artifacts, due to it's compression.
Wiki JEPG (Joint Photographic Experts Group) compression and find out yourself what it can do to images, and again, primarily at edges.