RotateImage45Degrees.java Source code

Introduction

Here is the source code for RotateImage45Degrees.java

Source

/*
    
Java Media APIs: Cross-Platform Imaging, Media and Visualization
Alejandro Terrazas
Sams, Published November 2002, 
ISBN 0672320940
*/

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Insets;
import java.awt.MediaTracker;
import java.awt.Toolkit;
import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;

import javax.swing.JFrame;

/**
 * RotateImage45Degrees.java - 1. scales an image's dimensions by a factor of
 * two 2. rotates it 45 degrees around the image center 3. displays the
 * processed image
 */
public class RotateImage45Degrees extends JFrame {
    private Image inputImage;

    private BufferedImage sourceBI;

    private BufferedImage destinationBI = null;

    private Insets frameInsets;

    private boolean sizeSet = false;

    public RotateImage45Degrees(String imageFile) {
        addNotify();
        frameInsets = getInsets();
        inputImage = Toolkit.getDefaultToolkit().getImage(imageFile);

        MediaTracker mt = new MediaTracker(this);
        mt.addImage(inputImage, 0);
        try {
            mt.waitForID(0);
        } catch (InterruptedException ie) {
        }

        sourceBI = new BufferedImage(inputImage.getWidth(null), inputImage.getHeight(null),
                BufferedImage.TYPE_INT_ARGB);

        Graphics2D g = (Graphics2D) sourceBI.getGraphics();
        g.drawImage(inputImage, 0, 0, null);

        AffineTransform at = new AffineTransform();

        // scale image
        at.scale(2.0, 2.0);

        // rotate 45 degrees around image center
        at.rotate(45.0 * Math.PI / 180.0, sourceBI.getWidth() / 2.0, sourceBI.getHeight() / 2.0);

        /*
         * translate to make sure the rotation doesn't cut off any image data
         */
        AffineTransform translationTransform;
        translationTransform = findTranslation(at, sourceBI);
        at.preConcatenate(translationTransform);

        // instantiate and apply affine transformation filter
        BufferedImageOp bio;
        bio = new AffineTransformOp(at, AffineTransformOp.TYPE_BILINEAR);

        destinationBI = bio.filter(sourceBI, null);

        int frameInsetsHorizontal = frameInsets.right + frameInsets.left;
        int frameInsetsVertical = frameInsets.top + frameInsets.bottom;
        setSize(destinationBI.getWidth() + frameInsetsHorizontal, destinationBI.getHeight() + frameInsetsVertical);
        show();
    }

    /*
     * find proper translations to keep rotated image correctly displayed
     */
    private AffineTransform findTranslation(AffineTransform at, BufferedImage bi) {
        Point2D p2din, p2dout;

        p2din = new Point2D.Double(0.0, 0.0);
        p2dout = at.transform(p2din, null);
        double ytrans = p2dout.getY();

        p2din = new Point2D.Double(0, bi.getHeight());
        p2dout = at.transform(p2din, null);
        double xtrans = p2dout.getX();

        AffineTransform tat = new AffineTransform();
        tat.translate(-xtrans, -ytrans);
        return tat;
    }

    public void paint(Graphics g) {
        if (destinationBI != null)
            g.drawImage(destinationBI, frameInsets.left, frameInsets.top, this);
    }

    public static void main(String[] args) {
        new RotateImage45Degrees("fruits.png");
    }

}