Bug 322273

I badly miss the option in gwenview to view pictures darker or lighter (and maybe even with more or less contrast). I once used a picture viewer, I guess it was kuickshow (not sure), where I could press some keys to change the brightness of the shown picture, e.g. B+ to increase brightness by one step, B++ to increase it a little further (three steps IMHO) and B- the other way round (and C+/- for contrast). 

It really would be great if gwenview would have that option/s too, preferably via hotkeys but buttons for the toolbar or context menu entries would also be ok... By now I always have to fire up Gimp to see if a picture which is too dark can be kept or should be trashed, when I just want to quickly control the photos just taken.

Reproducible: Always