大きいjpegの色調調整

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.awt.image.RescaleOp;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;

public class RescaleSample {
    private BufferedImage src;
    private RescaleOp rescapeOp;

    public RescaleSample(String filename, float scale, float offset) {
        try {
            JComponent comp = initImage(filename, scale, offset);

            JFrame frame = new JFrame("Rescale");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setSize(800, 400);

            frame.getContentPane().add(comp);

            frame.setVisible(true);
        } catch (IOException ex) {
            ex.printStackTrace();
            System.exit(1);
        }
    }
    
    private JComponent initImage(String filename, float scale, float offset) throws IOException {
        // 入力画像の読み込み
        src = ImageIO.read(new File(filename));

        // スケーリングファクタ、オフセットの準備
        // RGB に対してそれぞれスケーリングを行う
        float[] scales = new float[] {scale, scale, scale};
        float[] offsets = new float[] {offset, offset, offset};
        rescapeOp = new RescaleOp(scales, offsets, null);

        // 出力画像を用意しておく
        BufferedImage dest = new BufferedImage(src.getWidth(), src.getHeight(), src.getType());

        // フィルタ処理
        rescapeOp.filter(src, dest);

        // 後は GUI に貼るだけ
        JLabel srcLabel = new JLabel(new ImageIcon(src, "Before"));
        srcLabel.setMinimumSize(new Dimension(200, 200));

        JLabel destLabel = new JLabel(new ImageIcon(dest, "After"));
        destLabel.setMinimumSize(new Dimension(200, 200));
        
        JSplitPane splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,
                                              new JScrollPane(srcLabel), new JScrollPane(destLabel));
        splitPane.setContinuousLayout(true);
        splitPane.setOneTouchExpandable(true);

        splitPane.setDividerLocation(400);

        return splitPane;
    }

    public static void main(String[] args) {
        String filename = args[0];
        float scale = Float.parseFloat(args[1]);
        float offset = Float.parseFloat(args[2]);

        new RescaleSample(filename, scale, offset);
    }
}

                     Image I/O                       JPEGImageDecoder
              RescapeOp なし RescapeOp あり  RescapeOp なし  RescapeOp あり
-------------------------------------------------------------------------
 550万画素        28,859       34,877           22,926         46,694
1100万画素        54,047       69,055           44,424         92,344
2200万画素       105,765      137,423           87,313        183,575