Image effect for adding a drop shadow.
This algorithm is from the phpThumb project available at http://phpthumb.sourceforge.net and all credit for this script should go to James Heinrich firstname.lastname@example.org. Modifications made to the code to fit it within the Horde framework and to adjust for our coding standards.
Author: Michael J. Rubinsky email@example.com
Located at Horde/Image/Effect/Gd/DropShadow.php