Hi,

> Before compiling the main package I placed the jpg-package named 
> 'ImageMagick.jpeg.tar.gz' in a subdirectory named 'jpeg' and compiled it 
> there.
> ImageMagick then compiled without warnings, but I can't read jpg-file.
> When invoking with 'display foobar.jpg' it complains, that it can't open the
> jpg-library.

First of all, follow exactly the (hopefully present :-) instructions
on compiling with jpg-support.

Second, please show the invokation line and the exact error message.
like:

smaug> imageMagic foobar.jpg
ldd: imagejpg.so.1.34 not found

> Where does it look for this library? I made a softlink from jpeglib.a to
> /usr/locale/X11R6.1/lib/ but that didn't help.

.a libraries are linked statically, thus they are not needed are the link
phase. Either link the binary with the .a library, or put the .so library
somewhere into your library path. LD_LIBRARY_PATH contains the directories
which are searched for libs. Use ldd <nameOfTheBinary> to see which 
libraries are needed and which are found.

> Some ideas?

yep, see above :-)

  Guenther