Marvin Beans and applications can import and export PDF files. If PDF file serves as input, Marvin converts the chemical names in the text into structures. The pictures are also converted if OSRA is installed and it can recognize the picture as a chemical structure. See well known limitations of OSRA here. If a structure is exported in PDF format, Marvin saves it as a vector graphical image.
The PdfExport module recognizes the common image export options.
PdfExport uses the VectorGraphics package of FreeHEP Java Library that is an "Open Source" library distributed under the terms of the GNU Lesser General Public License (LGLP) . You can freely modify and recompile the source of this library, then replace the binaries in Marvin with your own version, according to the requirements of the LGLP.
To update Marvin with your own version of FreeHep library, substitute the proper jar files (freehep-base.jar, freehep-graphics2d.jar, freehep-graphicsio.jar, freehep-graphicsio-pdf.jar) in your Marvin package.