How to convert ImageIcon to read/write it on db

Hi everybody,
I'm working on a swing app which have to read/write from a MySql
database, using JPA. The image is displayed on a JLabel. The problem
is that for using data binding I need to create a converter to convert
the image "to" and "from" the database...

I wrote this converter, but I get runtime casting exceptions:

public class ImageConverter extends Converter
{
    //byte to image
    public ImageIcon convertForward(Object arg)
    {
        Image image = new ImageIcon( ( byte[] ) arg ).getImage()
                            .getScaledInstance( 50, 50,
Image.SCALE_SMOOTH );

        return new ImageIcon( image );
    }

    //image to byte
    public byte[] convertReverse(Object arg)
    {
        ByteArrayOutputStream bStream = new ByteArrayOutputStream();
        ObjectOutputStream oStream = null;
        try {
            oStream = new ObjectOutputStream(bStream);
            oStream.writeObject(arg);
        } catch (IOException ex) {
            Logger.getLogger(ConvertitoreImage.class.getName()).log
(Level.SEVERE, null, ex);
        }
        byte[] byteVal = bStream. toByteArray();

        return new ImageIcon(byteVal);
    }

}

I hope you can help me. Thank you very much for your help!