if (size == null) size = new Point(overlayImageData.width, overlayImageData.height);
		public WOImageDescriptor(Image image, String overlayImageFilename) {			baseImageData = image.getImageData();			size = new Point(baseImageData.width, baseImageData.height);			overlayImageData =				ImageDescriptor					.createFromFile(						WOLabelDecorator.class,						overlayImageFilename)					.getImageData();		}