How to make grayscale

"David R. Snell" <[email protected]> Thu, 15 Nov 2007 14:18:06 -0800 (PST)

Newsgroups	gmane.comp.video.image-magick.devel
Message-ID	<[email protected]>

What's the most efficient way to use PerlMagick to make a color image
grayscale?  I've been trying:

  $photo->Tint(fill=>'SlateGray3',opacity=>'50%');
  $photo->Tint(fill=>'SlateGray3',opacity=>'0.5');

But both of them generate "Internal Server Error" when called via browser, I
don't know why!?