I built a widget that enables keyboard commands on a data grid. It was focused on selecting one or many rows using commands like you would use in Excel.
It listens to the up and down arrow keys to select rows. If that meets your needs – awesome. If not, you could use some of the code here to understand how to programmatically change the selection in a data grid.
Why do you want to use a (listening) data grid in this case? Seems to me you may also solve this with a template grid, which you configure in such whay that it has paging buttons, and 1 row and 1 column. Within the template grid you can set you image and you can navigate with the paging buttons to the next or previous image.