title: Problem with imagecreatefrompng (PHP)
body: <p>in one of my PHP projects, imagecreatefrompng complains, that the image "is not a valid PNG file". </p>
  
  <pre><code>Warning: imagecreatefrompng() [function.imagecreatefrompng]:
  '/.../...png' is not a valid PNG file in /.../...php on line ...
  </code></pre>
  
  <p>I'm pretty sure, the file is valid, because I can open it in any program. So I was wondering what else could cause this warning.</p>
  
  <p>Does anybody know the details behind imagecreatefrompng or has had a similar problem before?</p>
  
  <p>Thanks for your help,</p>
  
  <p>Timo</p>