AppleScript: The Missing Manual

iPhoto

Included with Mac OS X, or as part of iLife ($50)

www.apple.com/ilife/iphoto/

Good. Although iPhoto doesn't have the number of advanced filters that Photoshop does, iPhoto does have the advantage of being quite easy to use. And, as described on iPhoto allows a number of useful AppleScript commands.

Photoshop

$650

www.adobe.com/products/photoshop/

Very Good. Photoshop puts a huge range of AppleScript commands at your disposal. Sure, Photoshop isn't as easy to use as iPhotobut if you're a graphics pro, power trumps ease of use.