Photoshop, and I use this other program which I don't know the name to and I can't look it up because it's in my desktop, which is not on, so I can't tell you.
Rambling on bunch of useless information, yes, I know. I find that funny...hehhehe. The other program, right-click, resize, choose either small, medium, large. Simple, to the point, and serves its specific purpose. I will get the info for Spexxvet tomorrow because I think he'll like it.