I took quality pictures of my art work to document them, but now I need them to be straightened out and rectangular in frame without taking out content out of the picture. All my shots have some part of the paper that is out of the alignment. What could I do to improve the picture's frame like how it would look if viewed straight on like a scanned paper.
Picture: http://i574.photobucket.com/albums/ss186/johnclee90/test.jpg