Setting resolution when writing an image - svar gerne på dansk

Svar gerne på dansk. Se evt. http://forum.java.sun.com/thread.jsp?forum=31&thread=319666 for pænere kodeopsætning.

Nuvel, her kommer spørgsmålet:

In a Java application I need to write a tiff-image in a specific resolution, e.g. 300 pixels/inch (dpi), and at size of for example 5 x 2 cm. This implies the pixel-dimension to be approx. 583 x 237 pixels. The tiff-file must be a bitmap, i.e. 1-bit colors (b/w).

My present code is (a modified version of code found at http://access1.sun.com/techarticles/ImagingApps/JImage.html ):

import java.awt.*;
import java.awt.event.*;
import com.sun.image.codec.jpeg.*;
import com.sun.media.jai.codec.*;
import javax.media.jai.*;
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.awt.image.DataBuffer;
import java.awt.geom.GeneralPath;
import java.io.*;
import javax.swing.*;
import java.awt.image.renderable.ParameterBlock;


public class TIFFJai extends JApplet {
   
    public static final String DEFAULT_FILE = "white.tif";
    private static RenderedImage img;
   
    public void init() {
        setBackground(Color.blue);
   
    String fileName = DEFAULT_FILE;
   
    // Read the image from the designated path.
    System.out.println("load image from '" + fileName+"'");
    img =  (RenderedImage)JAI.create("fileload", fileName);
    }


    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
    Dimension d = getSize();
        g2.setBackground(getBackground());
        g2.clearRect(0, 0, d.width, d.height);
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setRenderingHint(RenderingHints.KEY_RENDERING,
                            RenderingHints.VALUE_RENDER_QUALITY);
    int w = d.width;
    int h = d.height;
   
   
    RenderedImageAdapter ria = new RenderedImageAdapter(img);
        BufferedImage bi = ria.getAsBufferedImage();
   
        Graphics2D big = bi.createGraphics();
   
        big.setFont(new Font("Dialog", Font.PLAIN, 10));
        big.setColor(Color.black);
        big.drawString("This is the text!!!", 4, 50);

        g2.drawImage(bi, 0, 0, this);
   


        try {
        File file = new File("images", "test1.tif");
        FileOutputStream out = new FileOutputStream(file);
           
        TIFFEncodeParam params = new TIFFEncodeParam();
        params.setCompression(TIFFEncodeParam.COMPRESSION_NONE);
        ImageEncoder encoder = ImageCodec.createImageEncoder("TIFF",out, params);
        if(encoder == null) {
                System.out.println("imageEncoder is null");
                System.exit(0);
        }
        encoder.encode(bi);
       

        } catch (Exception ex) {
            g2.setColor(Color.red);
            g2.drawString("write permissions on images/test1.tif?", 5, h*2-5);
        }
   
       
    }


    public static void main(String argv[]) {
        final TIFFJai demo = new TIFFJai();
        demo.init();
        JFrame f = new JFrame("JAI Demo - TIFFJai");
        f.addWindowListener(new WindowAdapter() {
        public void windowClosing(WindowEvent e) {System.exit(0);}
        });
        f.getContentPane().add("Center", demo);
        f.pack();
        f.setSize(new Dimension(400,300));
        f.show();
    }
}

The loaded tiff-file 'white.tif' is 300 dpi and 5 x 2 cm and 583 x 237 pixels. But the written tiff-file 'test1.tif' is 72 dpi and 20.6 x 8.3 cm and 583 x 237 pixels. Both have 1-bit colors as needed.

I would very much like 'test1.tif' to have the same measures as 'white.tif'. How is it done?

(It is not a demand that 'white.tif' is loaded as a background. It's only a white-colored image, loaded to get the right dimensions.

A better solution would be to write only the Graphics2D g2 as tiff-file with the right settings.

But how is that done?)

Please write if anything needs to be clarified.

Thanking you all in anticipation - Svend/Birger