With regards to the thread talking about the image being photoshopped because of "halos", they're a direct result of image compression for JPGS..
Short version of image compression, comparing 3 different common internet file types.
BMP = Completely uncompressed, BMPS are bitmaps, where every pixel is assigned a specific location and color value. These files are large, which is
why we use the following two types frequently..
GIF - image has reduced color depth, limiting the number of colors used in the image, allowing there to simply be a color key, and then assigning each
pixel in an image a value from the color key. Fewer colors, smaller file
JPG - Uses a funky algorithm to compare areas of documents - an area that's mostly one color will get chopped up into one big block of color, and
more detailed areas use more of the file size. The artifacts mentioned are a direct result of JPG compression and smoothing, which is why you should
never actually repeatedly save JPGs with an image editing program, because the artifacts will increase and the detail will decrease.
So yeah, artifacts are not a sign of being "photoshopped", if anything, it's harder to fake artifacts when you're photoshopping something, unless
you're really aware of the basic details I just mentioned, you can make an image look too smooth, by only editing one particular area. The eye will
notice this and your editing will be revealed.. (in a former life, I occasionally removed digital watermarks from video game screenshots for blog
reviews, so I've had a bit of practice with this sort of thing)
Not to say it can't be done, but artifacts do not equal proof one way or the other. A talented forger with the right tools can do almost anything
nowadays.


Sounds like an open mind, all right!

(joke) 
