Large Print Job Size with Alpha Blending

Question

A while ago, I wrote some java code to print portions of a graph (from JGraph). In the original design, I painted directly to the Graphics object in the Printable.print method. However, the resulting print job size was around 50MBs per page (which is unacceptable when tens of pages are spooled). Nevertheless, the results were perfect. A second attempt to reduce the print size rendered the output to a BufferedImage before drawing to the Graphics object. The print jobs were now ~500KBs per page, but were pixelated. Because of time constraints we used the latter method.
Recently, I revisited this problem and discovered the large print size is due to a color using alpha blending. Having transparent pieces is important, but I'd like to improve the print quality. Does anyone know how to "flatten" or otherwise reduce the print size?
Thanks in advance.

Answer 1

I've run into this same problem and I can't figure a way around it. I mocked up a simple class to test the difference in sizes of print jobs that are printing a display with translucent colors and those that don't and the difference seems a little extreme. Here's my code:
import java.awt.*;
import java.awt.print.*;
public class SimpleTest implements Printable {
  public static void main(String[] args) {
    PrinterJob job = PrinterJob.getPrinterJob();
    job.setPrintable(new SimpleTest());
    if(job.printDialog()) {
      try {
        job.print();
      catch(Exception e) {
        e.printStackTrace();
  public int print(Graphics g, PageFormat pf, int pageIndex)
      throws PrinterException {
    if(pageIndex >= 10) {
      return Printable.NO_SUCH_PAGE;
    g.setColor(new Color(0f, 1f, 0f, 0.5f));
    g.drawRect(25, 25, 300, 300);
    return Printable.PAGE_EXISTS;
}On the call to g.setColor, if I set the alpha argument to 1f, the print job size is 64 KB. However, if I set the alpha argument to 0.5f, the print job size bumps up to 239 MB. That's close to 3000x larger!
So, is there a way around this? I tried changing the PrintQuality and PrinterResolution attributes but neither seemed to have any effect. Maybe I did something wrong? I used the following to change the PrintQuality:
PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet();
aset.add(PrintQuality.DRAFT);
if(job.printDialog(aset)) {Is that the right way to do it? If so, what other options do I have?
Thanks,
David