title: ImageIO.read() returns null
body: <p>I have a problem regarding the ImageIO.read() function:</p>
  
  <pre><code>URL imageURL = this.getClass().getResource(sheetPath);
  spriteSheet = ImageIO.read(imageURL); 
  </code></pre>
  
  <p>The ImageIO function returns null even though the URL is correct (it leads to a .png file).
  I've tried to put the getResource() as a parameter for the read function, but that didn't work either. Has anyone encountered a similar problem and maybe found a solution?</p>
  
  <p>Regards</p>
  
  <p><strong>Edit:</strong></p>
  
  <p>sheetPath is "/images/pizzaGirl.png"</p>
  
  <p>imageURL is "file:/Users/Kevin/Dropbox/workspace/PizzaGirl/bin/images/pizzaGirl.png"</p>
  
  <p>images is in the "res" folder which I added to the classpath via the eclipse's run configurations</p>