according to the docs: when you perform read it should look like the following:

  use Image::Magick; 
  p = new Image::Magick;
  p->Read("imagefile");
  p->Set(attribute => value, ...)
  ($a, ...) = p->Get("attribute", ...)
  p->routine(parameter => value, ...)
  p->Mogrify("Routine", parameter => value, ...)
  p->Write("filename");
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this is straight off cpan. try not using the Read( file => \*$fh ) and just use p->Read("imagefile");