code: public void generateDataUriCss(String dir) throws IOException {
  		final String path = (dir == null) ? "" : dir + "/";
  		final PrintWriter out = new PrintWriter(path + "DataUriCss.html");
  
  		try {
  			out.append("<html>\n<head>\n\t<style>");
  
  			for (OptimizerResult result : results) {
  				final String name = result.fileName.replaceAll("[^A-Za-z0-9]", "_");
  				out.append('#').append(name).append(" {\n")
  						.append("\tbackground: url(\"data:image/png;base64,")
  						.append(result.dataUri).append("\") no-repeat left top;\n")
  						.append("\twidth: ").append(String.valueOf(result.width)).append("px;\n")
  						.append("\theight: ").append(String.valueOf(result.height)).append("px;\n")
  						.append("}\n");
  			}
  			out.append("\t</style>\n</head>\n<body>\n");
  
  			for (OptimizerResult result : results) {
  				final String name = result.fileName.replaceAll("[^A-Za-z0-9]", "_");
  				out.append("\t<div id=\"").append(name).append("\"></div>\n");
  			}
  
  			out.append("</body>\n</html>");
  		} finally {
  			if (out != null) {
  				out.close();
  			}
  		}
  	}
docs: Get the css containing data uris of the images processed by the optimizer