doug23838 wrote:
What was your clue that this was a photoshop job?
http://www.sentex.net/~mwandel/jhead/
http://libiptcdata.sourceforge.net/docs/libiptcdata-jpeg.html
Photoshop adds header information to images.
You can get around it by stripping your headers completely. But that will look suspicious. So just strip off the photoshop part.
Another, and more accurate, way is to use the basis for digital fingerprinting to determine if the image has been photoshopped.
http://www.physorg.com/news64638499.html
Digital cameras have non-uniform pixel alignments (we're talking pixel alignment errors in the range of micro to picometers), unnoticeable to human eyes. If you do a pixel analysis of the digital image and you notice a particular section where the pixel alignment is either perfect (added section was entirely fabricated in photoshop) or a thin section that is perfect next to a section that is also differently misaligned (extracted from another picture and pasted in, then the area touching the pasted region was manipulated in photoshop to be a perfect merge of pixels), you know something fishy is going on.
Thorough enough for you?
Of course, I just employ the "Does that look shopped to me?" eye test.