ImageUtils.java

package streamExample.handler;

import java.awt.image.BufferedImage;

public class ImageUtils {
    /**
     * Convert a {@link java.awt.image.BufferedImage} of any type, to {@link java.awt.image.BufferedImage} of a
     * specified type. If the source image is the same type as the target type,
     * then original image is returned, otherwise new image of the correct type is
     * created and the content of the source image is copied into the new image.
     *
     * @param sourceImage the image to be converted
     * @param targetType  the desired BufferedImage type
     * @return a BufferedImage of the specifed target type.
     * @see java.awt.image.BufferedImage
     */

    public static BufferedImage convertToType(BufferedImage sourceImage,
                                              int targetType) {
        BufferedImage image;

        // if the source image is already the target type, return the source image

        if (sourceImage.getType() == targetType)
            image = sourceImage;

            // otherwise create a new image of the target type and draw the new
            // image

        else {
            image = new BufferedImage(sourceImage.getWidth(),
                    sourceImage.getHeight(), targetType);
            image.getGraphics().drawImage(sourceImage, 0, 0, null);
        }

        return image;
    }
}