What program do you use? Gimp? If you don't have one of the commercial ones like PS, I recommend going GIMP. It's free, multi-platform, and does everything the others do. The filter thing on text and such is a snap with GIMP. Each text box will by default be in its own layer. You just select that layer and then select a filter from the top bar menu and monkey with the settings if you want and then poof, it's done for that layer.