EdgeRenderer edgeRenderer = new ArrowEdgeRenderer();
edgeRenderer.setNormalColor("olivedrab");
image.getNanograph().setDefaultNodeRenderer(nodeRenderer);
image.getNanograph().setDefaultEdgeRenderer(edgeRenderer);
FileOutputStream fout = new FileOutputStream(f);
image.storeAsJpeg(fout);
fout.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {