Another option, is converting Jpeg to Bitmap, editing, then converting them back to Jpeg. This works fine for displaying the photo on a screen.Not sure if the printed image would be grainy as a result.
I use Corels Paintshop Pro X3 more than Photoshop.
Here is an image i converted from Jpg to Bmp. Its not a Photo,it was done in Vue d'Esprit,a 3D image software, but it edits exactly the same.This image has been reduced too fit. The original is 32Mb in size.
The slight etherial fogginess you see near ground, was done using a plugin associated with Photoshop, called Melancholytron, by Flaming Pear software.