Rotating BufferedImage in Java without change size

Question

I am trying to rotating a BufferedImage in Java without changing size. width = 232 height = 174

width = 232 height = 174

I using this code but my image don`t rotate:

AffineTransform at = new AffineTransform();
at.translate(four2.getWidth() / 2, four2.getHeight() / 2);
at.rotate(Math.PI/2);
at.scale(0.5, 0.5);
at.translate(-four2.getWidth()/2, -four2.getHeight()/2);
Graphics2D g2d = (Graphics2D) four2.getGraphics();
g2d.drawImage(four2, at, null);
g2d.dispose();

Answer 1

Rotating a non-square image within the same boundaries will crop the image.

You could change the Graphics clipping bounds, but this is dangerous, as you could actually end up painting outside of the visible bounds available to the Graphics context, which results in some very weird and generally not welcomed results.

A simpler solution might be to just generate a new image from the original and rotate it within it's own confines, for example...

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class Test {

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

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                try {
                    JFrame frame = new JFrame("Testing");
                    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    frame.add(new TestPane());
                    frame.pack();
                    frame.setLocationRelativeTo(null);
                    frame.setVisible(true);
                } catch (IOException iOException) {
                    iOException.printStackTrace();
                }
            }
        });
    }

    public class TestPane extends JPanel {

        private BufferedImage master;
        private BufferedImage rotated;

        public TestPane() throws IOException {
            master = ImageIO.read(new File("/Volumes/Disk02/Dropbox/MegaTokyo/issue142.jpg"));
            rotated = new BufferedImage(master.getWidth(), master.getHeight(), BufferedImage.TYPE_INT_ARGB);
            Graphics2D g2d = rotated.createGraphics();
            AffineTransform at = new AffineTransform();
            at.rotate(Math.PI / 2, master.getWidth() / 2, master.getHeight() / 2);
            g2d.setTransform(at);
            g2d.drawImage(master, 0, 0, this);
            g2d.dispose();
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(master.getWidth() * 2, master.getHeight());
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            int x = (getWidth() - (master.getWidth() * 2)) / 2;
            int y = (getHeight() - master.getHeight()) / 2;
            g2d.drawImage(master, x, y, this);
            g2d.drawImage(rotated, x + master.getWidth(), y, this);
            g2d.dispose();
        }

    }

}