Digikam
Digikam is a KDE-based image organizer with built-in editing features via a plugin architecture.
Installation
Digikam can be installed with the package digikam, available in the official repositories.
Optionally, install kdemultimedia-mplayerthumbs to generate thumbnails for video files.
Troubleshooting
Video playback
As a Phonon backend will have been installed as a dependency of Digikam, multimedia codecs for the backend may be missing. If you are using the phonon-qt4-gstreamer backend, try installing one or more of its plugins with pacman -S gstreamer0.10-{good,bad,ugly,ffmpeg}
.