JDeskew
(c) 2009, Roland Quast and contributors.
Java Image Deskewer
This is a Java port of the deskew code found at http://www.codeproject.com/Articles/13615/How-to-deskew-an-image
I wrote this with at the time for use with ImageIO, but it would probably be helpful if there were some abstraction for this.
It is released under the Code Project Open License: http://www.codeproject.com/info/cpol10.aspx