final Graphics2D g2 = image.createGraphics();
g2.setPaint(Color.white);
g2.fill(rect);
final PageDrawable pageDrawable = prc.getPageDrawable(i);
pageDrawable.draw(g2, rect);
g2.dispose();
// convert to PNG ...
final PngEncoder encoder = new PngEncoder(image, true, 0, 9);
final byte[] data = encoder.pngEncode();