Keyboard shortcuts for viewing the previous/next image

I'm building a free (FOSS) image viewing application and would like for the user to be able to control both the panning of the image as well as changing to the previous or next image via the keyboard (for ease of use)

By default the graphical framework that I'm working with (Qt) uses left, right, up and down arrows as well as page up/down for panning, and I'd like to keep these as they are

However I'd also like to make it easy for the user to go to the next and previous image. What keys or key combinations can you recommend? Is there a standard that can be followed?

So far I've thought of using the N and P keys, or the ctrl or alt key modifier together with the left and right arrows

Grateful for help with this! Tord