ChBg is for changing desktop backgrounds in a given period. It can render images with 10 modes (such as tiled, centered, scaled, etc.). It uses Imlib1, Imlib2, or gdk_pixbuf for loading images, so it supports many image formats. ChBg has a windowed setup program, is able to load setup files, can be used as slideshow picture previewer in its own window or as a desktop background, and can be used as screensaver or as an xscreensaver hack. It has a dialog for fast previewing of pictures and very usable thumbnail previews.
Gwenview is a fast and easy to use image viewer/browser for KDE. All common image formats are supported. Standard features include slideshow, full screen view, image thumbnails, drag'n'drop, image zoom, and full network transparency using the KIO framework. It also provides image and directory KParts components for use in applications such as Konqueror. Additional features are provided by the KIPI image framework.
Krusader is an advanced twin-panel (commander-style) file-manager for KDE 3.x, but with many extras. It provides all the file-management features you could possibly want. It also features extensive archive handling, mounted filesystem support, FTP, an advanced search module, a text viewer/editor, directory synchronization, support for file content comparisons, powerful batch renaming, and much more. It supports the following archive formats: tar, zip, bzip2, gzip, rar, ace, arj, and rpm. It can also handle other KIOSlaves such as smb:// or fish://.
Wallpaper Control is a non-window manager-specific wallpaper manager for the X Window System. It aims to be a full featured utility for managing and setting your images you use as wallpaper. Features include a preview window, directory listing, and deletion of graphics from hard drive.
KuickShow is a very fast image viewer that lets you easily browse large galleries. A builtin filebrowser and manager is also available. Its usage is somewhat inspired by ACDSee. It supports many file formats, including JPEG, GIF, PNG, PSD, BMP, TIFF, XPM, XBM, XCF, EIM, etc. It can zoom, mirror, rotate images, adjust brightness, contrast, and gamma, and do a slideshow. It is fully configurable through dialogs. It offers a filebrowser with basic filemanager capabilities like renaming, deleting, creating directories, etc.
libAfterImage is an image import, storage, manipulation, and output library for X. It features support for antialiased, TrueTypei, and X text, a 128-bit internal graphics engine, in-memory RLE image compression, high quality image scaling/flipping/blending, multipoint linear gradients, superior quality image output on X drawables, and much more.