setting background image by shell command?

[Ulli Horlacher]

Is it possible to change the background image by a shell command?
I know, it is possible via Settings Manager, but I want it scriptable.

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Ullrich Horlacher              Informationssysteme und Serverbetrieb
Rechenzentrum IZUS/TIK         E-Mail: horlacher at tik.uni-stuttgart.de
Universitaet Stuttgart         Tel:    ++49-711-68565868
Allmandring 30a                Fax:    ++49-711-682357
70550 Stuttgart (Germany)      WWW:    http://www.tik.uni-stuttgart.de/
REF: <20130430161704.GA3138 at rus.uni-stuttgart.de>