FYI Johannes both your sourceforge and git links were dead. You mean
>
> Hello community,
>
> recently the problem cropped up in a discussion with fellow developers,
> how to run a batch macro on a machine (such as a node on a
> cluster[*1*]...) that does not have any graphics environment installed.
>
> [if you're interested only in the solution, you might want to skip forward
> to the short explanation...]
>
> <warning: detailed explanation on Java level follows>
> At least on Linux, such a batch run will inevitably stop early, namely
> when the class ij.Menus tries to instantiate a Menu. For some reason, it
> seems, the Java developers decided in their infinite wisdom that a Menu
> cannot live without a graphics environment. Even if you don't ever show
> the Menu.
>
> Oh, well.
>
> I tried to get rid of the java.awt.Menu instances, but realized then, that
> most plugins use a GenericDialog, which is directly derived from
> java.awt.Dialog. An indeed, Java refuses to instantiate a Dialog (even if
> it is never shown!) in the absence of a graphics environment.
>
> But then, there _are_ plugins out in the wild, which depend on
> GenericDialog to be derived from java.awt.Dialog, because they actually
> update some preview or do other stuff that cannot be done directly with
> the methods of the GenericDialog.
>
> So there is the dilemma. Some plugins will not run _without_ GenericDialog
> being a java.awt.Dialog, and headless operation will _not_ run _with_
> GenericDialog being a java.awt.Dialog.
> </warning>
>
> A workaround, if you do not use any plugins that manipulate the
> java.awt.Dialog directly (there are only a few out there, you know who you
> are!), is to replace both ij.Menus and ij.gui.GenericDialog by classes
> that will not instantiate anything graphical.
>
> This workaround is available as "headless.jar", to be prepended to
> the classpath, available from
http://sourceforge.net/imageja/ in
> binary form, or in source from from branch "headless" on
>
http://repo.or.cz/imageja.git.
>
> Whew. That was a long explanation.
>
> Short explanation:
>
> To start a batch macro on a machine without graphics environment, you have
> to download
>
>
http://downloads.sourceforge.net/imageja/headless.jar?use_mirror=osdn>
> and prepend the downloaded "headless.jar" to the classpath before ij.jar,
> like this:
>
> java -classpath headless.jar:ij.jar ij.ImageJ -batch <macro>
>
> On Windows, you have to replace the ":" between "headless.jar" and
> "ij.jar" by a ";", although you are much more unlikely to run something
> headlessly on Windows.
>
> Somehow, I seem to be unable to come up with a better solution. If someone
> has an idea how to do it in a less ugly way, please enlighten me.
>
> Ciao,
> Dscho
>
> [*1*] ... and I mean a cluster here. Not something Microsoft conveniently
> redefined to be a hot standby. No, a real cluster. Microsoft calls it a
> grid. But it used to be called a cluster until recently.
>