title: ImageWriteParam set compression quality not working
body: <p>I am trying to create an app that combines several JPG into one big JPG without any compression. But in my test sample, when I combine 8 images (800KB), the output is only 280KB.</p>
  
  <p>I used <a href="https://stackoverflow.com/questions/17015197/quality-loss-using-imageio-write">this</a> as reference in writing the code. But no matter what value I inserted to param.setCompressionQuality(...), the output is always 280KB and doesn't change.</p>
  
  <pre><code>String name = dir.getName();
  System.out.println("Combining images... #" + name);
  BufferedImage result = combine(dir);
  
  ImageWriter writer = ImageIO.getImageWritersByFormatName("jpeg").next();
  ImageWriteParam param = writer.getDefaultWriteParam();
  param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
  param.setCompressionQuality(1.0F); // set highest quality
  try {
      File outputFile = new File(outputFolder + "\\" + name + ".JPG");
      ImageOutputStream ios = ImageIO.createImageOutputStream(outputFile);
      writer.setOutput(ios);
      writer.write(result);   
  } catch (IOException e) {
      e.printStackTrace();
  }
  </code></pre>
  
  <p>dir is a File type variable indicating my source folder location.
  combine() is a method that returns BufferedImage.</p>