Simple Transparent Backgrounds; seriously simple.
Forget about Powerpoint, Preview, and even Processing, if you need PNG files with transparent backgrounds in a jiffy, fire up the terminal! Here is the command:
>>>convert INPUT.jpg -channel RGBA -bordercolor white -border 1x1 -fill none -floodfill +0+0 white -fuzz 20% -shave 1x1 +antialias OUTPUT.png
DONE! One minor catch, you need to install an awesome (and free) image toolkit named ImageMagick. I’ve been designing a lot of UI objects from scratch in advance of a new iOS app release, all of which needed transparent backgrounds. Full credit goes to “lsintampa” at the ImageMagick forum; Merci! Huge time saver; especially when done in a big giant batch script with hundreds of images.