If I download a copyrighted photograph of prominent person (e.g. a politician or celebrity) and hire an artist to make a portrait of that person, using the photo as a guide, is that legal?
I'm thinking of the famous Obama "HOPE" poster. If I remember correctly, the person who made it was sued because it was based on a copyrighted picture. However, I'm guessing it was illegal because he essentially modified a copyrighted image, rather than making a "free style" rendition.
To put it another way, if I opened a copyrighted image in Photoshop and used some filters to alter it, I would be pirating a copyrighted item - even if my work didn't look like the original. But if I use a pen (or a computer graphics program) to draw someone's portrait while using an actual photo as a guide, would that be legal?
This kind of begs another question: If you hire an artist to create a portrait - either realistic or a caricature - how can you tell if they created the final product free style or by simply modifying the original image?
But I guess that's a question for a graphics forum.