// NOTE: does not use writeGraphicsSave and writeGraphicsRestore since these
// delete pen and brush
protected void writeImage(RenderedImage image, AffineTransform xform,
Color bkg) throws IOException {
os.writeTag(new SaveDC());
AffineTransform imageTransform = new AffineTransform(
1.0, 0.0, 0.0, -1.0, 0.0, image.getHeight());
imageTransform.preConcatenate(xform);
writeTransform(imageTransform);