If your image is not a reproduction of someones work - in this case a photographers photo you are ok and would be considered. If you use the original stock as reference and not as a model your ok. If you come too close in interpretation your now walking a fine line as it may come down to a judge's interpretation as to whether your new artwork is a copy (illegal) or a new image (ok) and there is a lot of room for subjectivity in it. There have been wildly fantasized images of copyrighted works abused in this manner that lost their position as well. In example, Carl Barks with Disney tried to do this years ago and stirred the pot with his recreated images of Batman as a smurf. Disney challenged the paintings as infringement and Barks was ordered to cease - that case is a little different as Barks worked for Disney at one point as an artist.
BMAN LLC is known for C&D letters, they actively defend their copyrighted and trademarked materials. Infringement is a complaint driven system, the local sheriff and LE agencies are not out verifying anything. If no one complains, then you can do what you want. No complaint does not make it legal though. There is also a cost to defend as well and that should be factored into any sales. Derivative images is what your talking about Check out section 107 for a wayyyy better explanation.
Satire and parody is also protected - Our favorite smut peddler Larry Flint won in the US Supreme Court in Falwell versus Flynt saw to that. So if your art consisted of the burningman dancing with Larry Harvey you would have another leg to argue as well as to why it is free for use and does not infringe on copyrighted material. It could be debated that Larry and the Mans image are popular icons enough to grant the same protection that the fake Jerry Falwell Campari ad elicited in 1983.
Last - some characters are so widely known that their image is protected in its entirety. Draw a Mickey Mouse character and try to sell it in any form and Disney has claim and the protections on many characters is legally extended every time it is about to expire. Is the man at that point as an icon to where legal protections get stronger with time? I dont know.
My advice - ask permission; or make the new image obviously not a copy. I am not an attorney either, I just stayed at a holiday inn.
FLYNT http://law2.umkc.edu/faculty/projects/f ... stler.html
CMPARI http://law2.umkc.edu/faculty/projects/f ... ampari.jpg
Section 107 http://www.avvo.com/legal-answers/if-i- ... 16396.html