Printing big Image throws OutOfMemoryError

Question

Hello,
I am new to "Java Printing", this is my first attempt to print somthing in Java, I am trying to print several JTextPanes and a big PNG image as a background for them. Sometimes everything work fine, but sometimes it throws java.lang.OutOfMemoryError, full message is: Exception in thread "Image Fetcher 0" java.lang.OutOfMemoryError: Java heap space. I use JDK 1.5_06.
I use the following code to print Image and JTextPanes:
PrinterJob printerJob = PrinterJob.getPrinterJob();
printerJob.setPrintService(servicesName);
PrintRequestAttributeSet pras = new HashPrintRequestAttributeSet();
pras.add(new PrinterResolution(200, 200, ResolutionSyntax.DPI));
PageFormat pf = printerJob.defaultPage();
Paper paper = pf.getPaper();
paper.setSize(1654D,2339D);//A4 page size with 200 DPI
paper.setImageableArea(0D,0D,1654D,2339D);
pf.setPaper(paper);
printerJob.setPrintable(documentPanel, pf);
printerJob.print(pras);documentPanel is instance of class DocumentPanel:
/*Panel that contains my JTextPanes */
public class DocumentPanel extends JPanel implements Printable{
/*overriden method print*/
public int print(Graphics g, PageFormat pf, int index) throws PrinterException {
        if (index > 0) { /* We have only one page, and 'page' is zero-based */
                return NO_SUCH_PAGE;
            Graphics2D g2d = (Graphics2D) g;
            g2d.translate(leftMargin, topMargin);
            //draw the background image
            g2d.drawImage(iipmt().getImage(),0,0,null);
            g2d.scale(1.667D, 1.667D); /*this is to make children  JTextPanes bigger.
            As I see after printing  this line doesn�t affect size of image, which is set above.*/
            /* Now print all children - JTextPanes without parent*/
            this.printChildren(g2d);
            /* tell the caller that this page is part of the printed document */
            return PAGE_EXISTS;
static ImageIcon iipmt(){
         return  new ImageIcon("image.png");
} If I change image to another one with smaller size and use 72 DPI instead of 200 my program always work fine. Also it seams that extending java heap space with -Xmx256 can solve this problem (I don't know exactly because error doesn't repeat always and I can�t determine some special conditions for this error).
I don�t want to extend heap space and I think it is not necessary for printing images, so I would like to know, is there better way to print Images mixed with Swing components? Or what mistakes did I make?

Answer 1

A printer setting of 600 dpi doesn't mean 600 pixels per inch. It's a relative quantity of how much ink you want the printer to use to faithfully reproduce the pixels on the page. So for example, you start to achieve photo quality around 250 pixels per inch, but would need to set the printer to 1200+ dpi if you ever hope for it to print out correctly. Trying to achieve 600 pixels per inch would be suicide for your printer.
That being said, you're not actually doing anything with this dpi or ppi stuff. In your code you're ultimately just drawing the image, scaled to the page's size using nearest neighbor interpolation, and printing it at 72 pixels per inch. In the code you commented out, you have the interpolation fine but miss the mark on the scaling. Specifically, you scale the graphics correctly, but then two lines later you set the transform to something else.
Try this:
double scale = 72/...;  //be reasonable, 600 won't work, 72 pixels-per-inch may be just fine
Graphics2D g2d = (Graphics2D) printerGraphics;
g2d.scale(scale,scale);
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
                     RenderingHints.VALUE_INTERPOLATION_BICUBIC);
g2d.drawImage(image,xMargin,yMargin,
        (int) Math.floor(pageFormat.getWidth()/scale),
        (int) Math.floor(pageFormat.getHeight()/scale),null); This should (in theory) scale the image to the page's size using bicubic interpolation, and print it at what ever pixels-per-inch you specify. The crappy output you were getting could of been the nearest neighbor interpolation, the 72 ppi, or some combination of both.