Yes its possible without rooting. There was an .APK floating around the XDA forums a while back and it just so happens that I still have it in my dropbox. Put this on your SD card and allow installs from unknown sources. Install it then open a picture, go to the menu and it will be an option under "advanced edit". This isn't something I created. I'm just passing it along. I've given you all the info I have and it worked for me with no issues at all and I'd assume the same for you ... if it doesn't, I wouldn't know what to tell you so whatever risk your taking (however small it may be) is on you.
BTW .. yes the file name is in another language (looks like French?) dont worry about that. It was that way when I downloaded it.
Photo Editor APK
Enjoy