import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.UnsupportedFlavorException;

static class TransferableImage implements Transferable {
  Image i;

  *(Image *i) {}

  public Object getTransferData( DataFlavor flavor )
  throws UnsupportedFlavorException, IOException {
      if ( flavor.equals( DataFlavor.imageFlavor ) && i != null ) {
          return i;
      }
      else {
          throw new UnsupportedFlavorException( flavor );
      }
  }

  public DataFlavor[] getTransferDataFlavors() {
      DataFlavor[] flavors = new DataFlavor[ 1 ];
      flavors[ 0 ] = DataFlavor.imageFlavor;
      return flavors;
  }

  public boolean isDataFlavorSupported( DataFlavor flavor ) {
      DataFlavor[] flavors = getTransferDataFlavors();
      for ( int i = 0; i < flavors.length; i++ ) {
          if ( flavor.equals( flavors[ i ] ) ) {
              return true;
          }
      }

      return false;
  }
}

see http://stackoverflow.com/questions/4552045/copy-bufferedimage-to-clipboard