title: What is the fastest way to modify an image file in java
body: <p>What is the fastest way to modify an image file (apply filters, change resolution, etc..) in java.</p>
  
  <p>I tried to open a file with <code>ImageIO</code> and modify with <code>java.awt.image</code></p>
  
  <pre><code>ColorConvertOp op = new ColorConvertOp(ColorSpace.getInstance(ColorSpace.CS_GRAY), null);
  op.filter(bufferedImage, bufferedImage);
  </code></pre>
  
  <p>It took a lot of time, do you have any faster method to do it?</p>