Feh is one of the alternatives wallpaper setter which uses by fbsetbg under fluxbox. Yet, feh is a very nice image viewer, with many modes available for manipulation which can be specified through command line options. With mouse and key control, it gives users very flexible on manipulate on images during viewing them.
By default, it is slide show mode, which the images are shown in original size. You can drag your mouse to surf through the entire image, you can press space or left click to go next, arrow key to go next and previous, scroll your mouse did the same too. Right click gives you more functions with menu, where you can save the image, set as wallpaper etc. Pressing x to close the windows, pressing q to quit feh.
Let say you have a folder call wallpaper all your images in it, do as bellow to gives you slide show mode
I find full screen mode nice, it screw your images into full screen.
feh -F wallpaper
You can open images into separate windows, which is multiwindow mode.
feh -w wallpaper
With all modes, I find thumbnail mode the best. It place your images nicely with smaller preview, when you click on it, it opens another windows with full size.
feh -t wallpaper
You can add more settings, to make the thumbnail mode even nicer. For me I prefer Full screen mode + thumbnail and tweak a bit the width and height of each thumb.
feh -tF --thumb-width 120 --thumb-height 120 wallpaper
Press x to close the window of selected image that you have clicked.
Besides those mode, you can create mortage, it creates creates a new image consisting of a grid of thumbnails of the images with specified list. Again, you can use thumb height and width to control the size of each thumb.
feh -m --thumb-width 120 --thumb-height 120 wallpaper
By specifying recursive, it display the images in sub folder, else it won’t display.
feh -r wallpaper
Try to read the manual, I find the manual helpful and complete, it includes some command line examples at the end of the manual too.
Last example, mortage all my icon under .icons folder
feh -mr --thumb-height 32 --thumb-width 32 .icons