Image property "Info" is incomplete when using @ImagePlus

I found a strange behavior when working with the method getProperty("Info") of an ImagePlus object. My dm3 files contain a lot of metadata that I search for useful information (here is the Java code). Testing the code, using the main function, everything is fine.

Now I want to use this Java class in a Jython script. To get the ImagePlus object I use a script parameter (@ImagePlus imp). But the image properties of this ImagePlus instance do not contain the information I need. All dm3 metadata is gone.

Using imp = IJ.getImage() instead, everything is fine. The ImagePlus object gives the full metadata when using getProperty("Info").

Lately I found out, that I can get the full metadata when using imp.getOriginalFileInfo() on the ImagePlus the script parameter populates.