private XmlDocument ConvertImageMetadata(imageio.metadata.IIOMetadata metaData) {
			string [] formatNames = metaData.getMetadataFormatNames();
			dom.Element rootNode = (dom.Element) metaData.getAsTree(formatNames[0]);

			XmlDocument _metadataDocument = new XmlDocument();
			XmlConvert(rootNode, _metadataDocument);

			return _metadataDocument;
		}
		private void WriteImage(imageio.IIOImage iio) {
			if (NativeStream == null)
				throw new Exception("Output stream not specified");

			NativeWriter.write( iio );
		}