FULL PRODUCT VERSION :
java version "1.6.0_10"
Java(TM) SE Runtime Environment (build 1.6.0_10-b33)
Java HotSpot(TM) Client VM (build 11.0-b15, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
Image rendering in 1.6.0 update 10 has become about 10 times slower when compared to rendering speed in 1.6.0 update 07.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the included test code. Move the zoom slider back and forth until the average image paint time is printed in the console. In 1.6.0_10 this may take a while, in 1.6.0_07 it will be much faster (about 10 times faster when in full-screen).

I could reproduce average paint times of about 100 millisec. for update 10 (both in initial frame size or full-screen frame) and between 2 millisec.(initial frame size) and 10  millisec. (full-screen) for update 07.

(Remark: Running this test in 1.7.0-ea-b39 seems to be almost impossible)


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
package test;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;

/**
 *
 */
public class ImageTest extends JFrame {
    AffineTransform Trns;
    BufferedImage Img;

    JSlider VwZmSlider;
    JPanel PaintPanel;

    protected void setZoom(double newZoom) {
        Trns.setToScale(newZoom, newZoom);
    }

    public ImageTest() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Trns = new AffineTransform();
        Img = new BufferedImage(6500, 2500, BufferedImage.TYPE_3BYTE_BGR);

        Graphics g = Img.getGraphics();
        try {
            for (int i = 0; i < 6500; i += 50) {
                g.setColor(Color.WHITE);
                g.drawLine(0, i, 6500, i);
                g.drawLine(i, 0, i, 2500);
            }
        } finally {
            g.dispose();
        }

        PaintPanel = new JPanel() {
            private int paintCount;
            private long paintTime;

            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                Graphics2D g2d = (Graphics2D) g;

                g2d.transform(Trns);
                long time = -System.nanoTime();
                g2d.drawImage(Img, 0, 0, this);
                time += System.nanoTime();
                paintTime += time;
                paintCount++;

                if (paintCount == 1) {
                    System.out.println("First paint time = " + (paintTime / paintCount) + " nanosec");
                }
                if ((paintCount % 100) == 0) {
                    System.out.println("Average image paint time on " + paintCount + " paints = " + (paintTime / paintCount) + " nanosec");
                }
            }
        };

        Dimension Size = new Dimension(500, 500);
        PaintPanel.setPreferredSize(Size);
        PaintPanel.setMinimumSize(Size);
        PaintPanel.setMaximumSize(Size);

        VwZmSlider = new JSlider(0, 100, 50);
        VwZmSlider.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent changeEvent) {
                int val = VwZmSlider.getValue();
                switch (val) {
                    case 0:
                        setZoom(0.1);
                        break;

                    case 15:
                        setZoom(0.5);
                        break;

                    case 30:
                        setZoom(0.75);
                        break;

                    case 50:
                        setZoom(1.0);
                        break;

                    case 70:
                        setZoom(1.5);
                        break;

                    case 85:
                        setZoom(2.0);
                        break;

                    case 100:
                        setZoom(3.0);
                        break;

                    default:
                        if (val > 0 && val < 15) {
                            setZoom(((0.39 / 14.0) * (val - 1)) + 0.1);
                        } else if (val > 15 && val < 30) {
                            setZoom(((0.24 / 14.0) * (val - 15)) + 0.5);
                        } else if (val > 30 && val < 50) {
                            setZoom(((0.24 / 19.0) * (val - 30)) + 0.75);
                        } else if (val > 50 && val < 70) {
                            setZoom(((0.49 / 19.0) * (val - 50)) + 1.0);
                        } else if (val > 70 && val < 85) {
                            setZoom(((0.49 / 14.0) * (val - 70)) + 1.5);
                        } else {
                            setZoom(((0.99 / 14.0) * (val - 85)) + 2.0);
                        }
                        break;
                }
                PaintPanel.repaint();
            }
        });

        JPanel FillPanel = new JPanel();
        FillPanel.setLayout(new BorderLayout());

        FillPanel.add(PaintPanel, BorderLayout.CENTER);
        FillPanel.add(VwZmSlider, BorderLayout.SOUTH);

        getContentPane().add(FillPanel);
        pack();
        show();
    }

    public static void main(String[] args) {
        new ImageTest();
    }
}

---------- END SOURCE ----------

Release Regression From : 6u6
The above release value was the last known release where this 
bug was not reproducible. Since then there has been a regression.