title: Understanding BufferedImage.getRGB output values
body: <p>I'm getting an integer value for the pixel in an image using this method:</p>
  
  <pre><code>int colour = img.getRGB(x, y);
  </code></pre>
  
  <p>Then I'm printing out the values and I see that black pixels correspond to a value like "-16777216", a kind of blue to something like "-16755216", etc. Can someone please explain me the logic behind this value? </p>