private byte[] writeMetadataToImage(ByteArrayOutputStream baos) throws Exception {
		
		InputStream in = new ByteArrayInputStream(baos.toByteArray());
		BufferedImage bImageFromConvert = ImageIO.read(in);
		
		ImageWriter writer = ImageIO.getImageWritersByFormatName("png").next();

		ImageWriteParam writeParam = writer.getDefaultWriteParam();
		ImageTypeSpecifier typeSpecifier = ImageTypeSpecifier.createFromBufferedImageType(BufferedImage.TYPE_INT_RGB);

		IIOMetadata metadata = writer.getDefaultImageMetadata(typeSpecifier, writeParam);
		
		IIOMetadataNode textEntry = new IIOMetadataNode("tEXtEntry");
		textEntry.setAttribute("keyword", "Blup");
		textEntry.setAttribute("value", "Flup");

		IIOMetadataNode text = new IIOMetadataNode("Oleg");
		text.appendChild(textEntry);


	    IIOMetadataNode root = new IIOMetadataNode("javax_imageio_png_1.0");
	    root.appendChild(text);


		ByteArrayOutputStream baos2 = new ByteArrayOutputStream();
		ImageOutputStream stream = ImageIO.createImageOutputStream(baos2);

		writer.setOutput(stream);
		writer.write(metadata, new IIOImage(bImageFromConvert, null, metadata), writeParam);
		
		stream.close();

		return baos2.toByteArray();

	}