Imagecache Custom Actions - Imagemagick I cannot get my imagecache custom actions to work at all?

When returning $image in any way, it gives me an error, which can be resolved by adding in the first line here:

if (!$image_context['entity']) { return 'No referring entity'; }
$image-&gt;ops[0] = "-resize 1600x1600";
return $image;


That should simply just resize my images now?

Essentially, my end goal is to check the value of a field submitted with the node which also submitted the original image, and then based on its value, apply a watermark. I am just toying about with custom PHP right now... but I can't seem to get any custom actions to work right now... Any help would be great, thanks! :D
Juste return "TRUE", not "$image", It is works for me.

 $image-&gt;ops[] = "-resize 1600x1600";
 return TRUE;