title: Rmagick Fails To Manipulate PNG
body: <p>Following the Railscast episode on <a href="http://railscasts.com/episodes/253-carrierwave-file-uploads" rel="nofollow">CarrierWave</a>: </p>
  
  <p>I installed <code>ImageMagick</code> on Mountain Lion via homebrew, exported the following path:</p>
  
  <pre><code>export PKG_CONFIG_PATH="/opt/local/lib/pkgconfig:$PKG_CONFIG_PATH"
  </code></pre>
  
  <p>Symlinked the following:</p>
  
  <pre><code>ln -s /usr/local/include/ImageMagick/wand /usr/local/include/wand
  ln -s /usr/local/include/ImageMagick/magick /usr/local/include/magick
  </code></pre>
  
  <p>And installed <code>rmagick</code> via bundler.</p>
  
  <p>In my <code>uploader</code> I have the following:</p>
  
  <pre><code>include CarrierWave::RMagick
  version :thumb do
       process :resize_to_limit =&gt; [85, 85]
  end
  </code></pre>
  
  <p>Which creates thumbnails just fine, but not for <code>png</code> files. I've tried a handful of <code>png</code> images and it always fails with this error:</p>
  
  <pre><code> Failed to manipulate with rmagick, maybe it is not an image? Original Error: no decode delegate for this image format `&lt;path&gt;/public/uploads/tmp/20121022-2133-9885-3333/thumb_cat_vs_internet.png' @ error/constitute.c/ReadImage/544
  </code></pre>
  
  <p><code>jpeg</code> images work just fine.</p>
  
  <p><strong>EDIT</strong></p>
  
  <p><code>identify -list format | grep -i png</code> returns nothing, indicating the png decode delegate is probably missing.  Now what?</p>