Pixellate Plugin Example
On the left is the Golde Gate Bridge in all its beauty, while on the right
two areas of the image have been pixellated. A rectangular section
around the left tower with a 16-by-16 size and 100% opacity, and a
freehand section on the right with a 24-by-24 size and 75% opacity
(meaning the orignal image still shines through a bit).