title: How do I read pixels from a PNG file?
body: <p>I know how to capture a screenshot by using Robot, Windowtester or FEST. I also know how to read a pixel from the screen by using robot.</p>
  
  <pre><code>int x = 10;
  int y = 10; 
  Color px = getPixelColor(int x, int y);
  </code></pre>
  
  <p>However, I don't know how to read a pixel from an image that is already captured. I'm planning to compare a current image, with an image from file. Lets say both are PNG. Are there any frameworks that I can use to compare images pixel by pixel?</p>