How do you clone a BufferedImage

Something like this?

static BufferedImage deepCopy(BufferedImage bi) {
 ColorModel cm = bi.getColorModel();
 boolean isAlphaPremultiplied = cm.isAlphaPremultiplied();
 WritableRaster raster = bi.copyData(null);
 return new BufferedImage(cm, raster, isAlphaPremultiplied, null);
}

I do this:

public static BufferedImage copyImage(BufferedImage source){
    BufferedImage b = new BufferedImage(source.getWidth(), source.getHeight(), source.getType());
    Graphics g = b.getGraphics();
    g.drawImage(source, 0, 0, null);
    g.dispose();
    return b;
}

It works fairly well and it is simple to use.

The previously mentioned procedure fails when applied to sub images. Here is a more complete solution:

public static BufferedImage deepCopy(BufferedImage bi) {
    ColorModel cm = bi.getColorModel();
    boolean isAlphaPremultiplied = cm.isAlphaPremultiplied();
    WritableRaster raster = bi.copyData(bi.getRaster().createCompatibleWritableRaster());
    return new BufferedImage(cm, raster, isAlphaPremultiplied, null);
}

Another way is to use the Graphics2D class to draw the image onto a new blank image. This doesn't really clone the image, but it results in a copy of the image being produced.

public static final BufferedImage clone(BufferedImage image) {
    BufferedImage clone = new BufferedImage(image.getWidth(),
            image.getHeight(), image.getType());
    Graphics2D g2d = clone.createGraphics();
    g2d.drawImage(image, 0, 0, null);
    g2d.dispose();
    return clone;
}

I know that this question is pretty old, but for future visitors, here's the solution I'd use:

Image oldImage = getImage();
Image newImage = oldImage.getScaledInstance(oldImage.getWidth(null), oldImage.getHeight(null), Image.SCALE_DEFAULT);

Please correct me if changing the just obtained newImage also affects the original image in any way.
--> Javadoc for getScaledInstance
--> Javadoc for SCALE_DEFAULT (the other constants are listed just below that one)

Class BufferedImage does not implement the Cloneable interface. Thus the clone method is not overriden. Here's an alternative for a deep copy technique: Java Tip 76: An alternative to the deep copy technique

The following solution using arraycopy is about 3-4 times faster than the accepted answer:

public static BufferedImage copyImage(BufferedImage source){
    BufferedImage bi = new BufferedImage(source.getWidth(), source.getHeight(), source.getType());
    byte[] sourceData = ((DataBufferByte)source.getRaster().getDataBuffer()).getData();
    byte[] biData = ((DataBufferByte)bi.getRaster().getDataBuffer()).getData();
    System.arraycopy(sourceData, 0, biData, 0, sourceData.length);
    return bi;
}

By the way, the answers using Graphics2D provide similarly good results.

Here is a solution I wrote many years ago for JFreeChart.

It will also copy any Properties which may be present in the BufferedImage.

I believe it was tested with all known Colour Models (Image Types).

Whether it will work with Image Type 0 discussed by @JoséRobertoAraújoJúnior I don't know.
But: Image Type 0 is invalid & should not occur.

/**
 * Copied from
 * <a href=https://github.com/jfree/jfreechart/blob/master/src/main/java/org/jfree/chart/util/PaintAlpha.java>JFreeChart PaintAlpha</a>
 * 
 * @param   srcImage
 * @return  
 */
public static BufferedImage cloneImage(final BufferedImage srcImage) {

    final WritableRaster srcRaster = srcImage.getRaster();
    final WritableRaster dstRaster = srcRaster.createCompatibleWritableRaster();
    /*
     * This is the code that actually COPIES the pixels...
     */
    dstRaster.setRect(srcRaster);
    /*
     * Images hardly ever have Properties, but we copy them anyway...
     */
    final String[]                  propNames = srcImage.getPropertyNames();
    final Hashtable<String, Object> props;

    if (propNames == null) {
        props     =  null;
    } else {
        props     =  new Hashtable<>();

        for (int i = 0; i < propNames.length; i++) {
            props.put(propNames[i], srcImage.getProperty(propNames[i]));
        }
    }
    /*
     * That's it folks! Return the new clone...
     */
    return new BufferedImage(srcImage.getColorModel(), dstRaster, srcImage.isAlphaPremultiplied(), props);
}