iPhoto has several Special Effects ready to play with, accessed with a tap on the little sparkly icon, the fifth from the left in the lower left corner of iPhoto on the iPad. Tap that, and a fan of special effects swatches will rise up from the bottom of the screen. There are six filters there, including Warm & cool, Duotone, Black & White, Aura, Vintage. and Artistic. Tap on a swatch you’d like to apply, and then tap or drag along the strip to select the effect that you prefer. Many of the filters can be further tweaked by pinching or dragging around in the photo itself. For example, the Vignette effect, found at the right within the Black & White strip, can be enlarged with a pinching out gesture, and moved around to a new center point with a simple drag. Play around and have fun here. Tap the question mark icon at the top for a tooltip for each of the effect swatches.
Once you’ve got the effect the way you like it? You can copy that effect with a tap on the little gear icon at the lower right of the effects screen. Tap Copy Effect when in the photo you’ve just perfected all your effect tweaks in. Then open a different photo and enter Special Effects mode. Tap the gear icon again and then tap Paste Effect. Boom! Your masterpiece set of effects will be applied to the new photo.
Got too many edits? You have three ways of going about undoing them. First, you can remove all the edits from a photo by tapping the gear icon (you might need to tap the Edit button first, though). Then you’ll see the Revert to Original button. Tap it!
The second way is just for when you want to undo specific effects on the photo. Make sure you’re in Edit mode in a photo that has edits in it, then tap any of the editing icons you’ve used (the ones in the lower left). Hit the gear icon in the bottom right and tap Remove Effect. The end, all gone.
When you’re all done with applying all the effects and edits you want, go ahead and tap and hold on the Show Original icon in the upper right of your screen, right next to the Edit button. This will drop an overlay of the original photo on top of your edited one, so you can see the final difference. Stop tapping the icon to make the overlay go away.
Source: Laptop Mag