I've been stumbling along with Imagemagick for some time now and can get most of what I need done, despite what I see as limited help from docs/user groups, etc.. Most of the info available seems to be command line related and of little or (usuall) no help to me...

One thing you have to keep in mind with packages like Image::Magick, is that it is a very thin perl shell over a C api ... there aren't a lot of docs on the individual methods, because the C versions are allready heavily documented.

One great resource is the perl section of the ImageMagick site. You should also search the C++ docs for DPI where you'll find that you want the set the "density" attribute (and then check the perl docs to see how to do that).