digikam works great on KDE4, but you need a SlackBuild for digikam 0.10 and KDE4 as the old one currently on SlackBuilds.org is for the kde3 version.
All the dependencies are now in vanilla -current (including jasper which got included today - hurray) with one optional exception. Note that this means you should not
compile libkdcraw or any of the other kde3 dependencies as these are included in KDE4 and should not be compiled/installed again.
All you need is
- lensfun (optional, for lens correction)
I have posted the SlackBuilds for KDE4 here:
Notice that I host only the SlackBuilds, not the actual sources.
Works like a charm here and digikam seems very stable in the few days I've used it so far.
Good luck - I hope this helps!