Image scaling problem

Question

Hello,
I have been trying to scale an image to create a thumbnail. The thumbnail image size is around 200*200. The thumbnail is to be rendered on a web browser. My code is:
public static byte[] getScaledImage(InputStream imageData) throws IOException {
       Image origImg = ImageIO.read(imageData);
       int origImgHeight = origImg.getHeight(null);
       int origImgWidth = origImg.getWidth(null);
       int newImgHeight /*determined by custom logic*/;
       int newImgWidth /*determined by custom logic*/;
      /* code for determining newImgHeight and newImgWidth  keeping the aspect ratio */
       origImg = origImg.getScaledInstance(newImgWidth, newImgHeight,
                                           Image.SCALE_AREA_AVERAGING);
       BufferedImage bimage = null;
       bimage = new BufferedImage(origImg.getWidth(null), origImg.getHeight(null),
                                  BufferedImage.TYPE_INT_RGB);
       Graphics g = bimage.createGraphics();
       g.drawImage(origImg, 0, 0, null);
       g.dispose();
       ByteArrayOutputStream os = new ByteArrayOutputStream(10);
       ImageIO.write(bimage, "jpg", os);
       return os.toByteArray();
}The calling method is:
FileCopyUtils.copy(ImageUtils.getScaledImage(lobHandler.getBlobAsBinaryStream(rs, 1)),
                                      imageContent);here imageContent is the http response's outputstream.
Now the problem is the resulting image displayed on the web page becomes distorted. I first thought that this is due to the thumbnail size. But the scaling done by gimp does not distort the image.
I have also tried this:
BufferedImage thumbImage = new BufferedImage(newImgWidth, newImgHeight, BufferedImage.TYPE_INT_RGB);
       Graphics2D graphics2D = thumbImage.createGraphics();
       graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
       graphics2D.drawImage(origImg, 0, 0, newImgWidth, newImgHeight, null);instead of using getScaled instance.
What could be the problem? This is a problem I need to solve immediately. So I am at a loss. Please help me here.

Answer 1

Try scaling your source image like this:
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;
public class ScalingToSize {
    int W = 200;
    int H = 200;
    int SCALE_TO_FIT  = 0;
    int SCALE_TO_FILL = 1;
    private JPanel getContent(BufferedImage image) {
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(5,5,5,5);
        gbc.weightx = 1.0;
        panel.add(wrap(image), gbc);
        panel.add(wrap(scale(image, SCALE_TO_FIT)), gbc);
        panel.add(wrap(scale(image, SCALE_TO_FILL)), gbc);
        return panel;
    private BufferedImage scale(BufferedImage src, int style) {
        int type = BufferedImage.TYPE_INT_RGB;
        BufferedImage dest = new BufferedImage(W, H, type);
        Graphics2D g2 = dest.createGraphics();
        if(style == SCALE_TO_FIT) {
            g2.setBackground(UIManager.getColor("Panel.background"));
            g2.clearRect(0,0,W,H);
        double scale = getScale(src, style);
        double x = (W - scale*src.getWidth())/2;
        double y = (H - scale*src.getHeight())/2;
        AffineTransform at = AffineTransform.getTranslateInstance(x, y);
        at.scale(scale, scale);
        g2.drawRenderedImage(src, at);
        g2.dispose();
        return dest;
    private double getScale(BufferedImage image, int style) {
        double xScale = (double)W/image.getWidth();
        double yScale = (double)H/image.getHeight();
        return (style == SCALE_TO_FIT) ? Math.min(xScale, yScale)
                                       : Math.max(xScale, yScale);
    private JLabel wrap(BufferedImage image) {
        ImageIcon icon = new ImageIcon(image);
        return new JLabel(icon, JLabel.CENTER);
    public static void main(String[] args) throws IOException {
        String path = "images/cougar.jpg";
        BufferedImage image = ImageIO.read(new File(path));
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(new ScalingToSize().getContent(image));
        f.pack();
        f.setVisible(true);
}