Java BufferedImage Rotate rotate(final BufferedImage image, final int angle)

Description

Rotates given image to given angle.

License

Apache License

Parameter

Parameter	Description
image	image to be rotated.
angle	angle to rotate image to

Return

rotated image.

Declaration

public static BufferedImage rotate(final BufferedImage image, final int angle) 

Method Source Code

//package com.java2s;
//License from project: Apache License 

import java.awt.Graphics2D;

import java.awt.geom.AffineTransform;

import java.awt.image.BufferedImage;

import java.util.HashMap;

import java.util.Map;

public class Main {
    /**//from ww w  . j av  a 2s.c  o m
     * Rotates given image to given angle.
     * @param image image to be rotated.
     * @param angle angle to rotate image to
     * @return rotated image.
     */
    public static BufferedImage rotate(final BufferedImage image, final int angle) {
        if (image == null) {
            throw new IllegalArgumentException("\"image\" param cannot be null.");
        }
        final int imageWidth = image.getWidth();
        final int imageHeight = image.getHeight();
        final Map<String, Integer> boundingBoxDimensions = calculateRotatedDimensions(imageWidth, imageHeight,
                angle);

        final int newWidth = boundingBoxDimensions.get("width");
        final int newHeight = boundingBoxDimensions.get("height");

        final BufferedImage newImage = new BufferedImage(newWidth, newHeight, image.getType());
        final Graphics2D newImageGraphic = newImage.createGraphics();

        final AffineTransform transform = new AffineTransform();
        transform.setToTranslation((newWidth - imageWidth) / 2, (newHeight - imageHeight) / 2);
        transform.rotate(Math.toRadians(angle), imageWidth / 2, imageHeight / 2);
        newImageGraphic.drawImage(image, transform, null);
        newImageGraphic.dispose();

        return newImage;
    }

    private static Map<String, Integer> calculateRotatedDimensions(final int imageWidth, final int imageHeight,
            final int angle) {
        final Map<String, Integer> dimensions = new HashMap<String, Integer>();
        // coordinates of our given image
        final int[][] points = { { 0, 0 }, { imageWidth, 0 }, { 0, imageHeight }, { imageWidth, imageHeight } };

        final Map<String, Integer> boundBox = new HashMap<String, Integer>() {
            {
                put("left", 0);
                put("right", 0);
                put("top", 0);
                put("bottom", 0);
            }
        };

        final double theta = Math.toRadians(angle);

        for (final int[] point : points) {
            final int x = point[0];
            final int y = point[1];
            final int newX = (int) (x * Math.cos(theta) + y * Math.sin(theta));
            final int newY = (int) (x * Math.sin(theta) + y * Math.cos(theta));

            //assign the bounds
            boundBox.put("left", Math.min(boundBox.get("left"), newX));
            boundBox.put("right", Math.max(boundBox.get("right"), newX));
            boundBox.put("top", Math.min(boundBox.get("top"), newY));
            boundBox.put("bottom", Math.max(boundBox.get("bottom"), newY));
        }

        // now get the dimensions of the new box.
        dimensions.put("width", Math.abs(boundBox.get("right") - boundBox.get("left")));
        dimensions.put("height", Math.abs(boundBox.get("bottom") - boundBox.get("top")));
        return dimensions;
    }
}

Related

1. rotate(BufferedImage img, int angle)
2. rotate(BufferedImage img, int angle)
3. rotate(BufferedImage img, int b, int a, int angle)
4. rotate(BufferedImage source, int angle)
5. rotate(BufferedImage src)
6. rotate(Graphics2D g, BufferedImage newImg, int x, int y, int width, int height, int angle, int originX, int originY)
7. rotate90(BufferedImage bi)
8. rotate90(BufferedImage img, boolean left)
9. rotate90ToRight(BufferedImage inputImage)