title: convert: Postscript delegate failed - converting text PDFs
body: <p>This one has me stumped.</p>
  
  <p>I need to convert PDFs into jpgs.  I do so using the following commands : </p>
  
  <pre><code>$cmd = "convert ".$upload-&gt;pdf_name." -geometry 80x80 -density 80x80 -quality 100 ".$upload-&gt;thumb_name." 2&gt;&amp;1";
  exec($cmd,$results);
  
  $cmd_gif = "convert ".$upload-&gt;pdf_name." -geometry 640x640 -density 640x640 -quality 100 ".$upload-&gt;gif_name." 2&gt;&amp;1";
  exec($cmd_gif,$results);
  </code></pre>
  
  <p>If I upload a PDF which is mostly image then I have no problems.  I get the thumbnail and preview.
  If I upload a PDF which is mostly text, and print_r $results I get :</p>
  
  <pre><code>Array([0] =&gt; convert: no decode delegate for this image format `/tmp/magick-wSgqd1Vp-00000001' @ error/constitute.c/ReadImage/532. 
  [1] =&gt; convert: Postscript delegate failed `/var/www/vhosts/site/uploadedfiles/tmp/2_77.pdf': @ error/pdf.c/ReadPDFImage/664. 
  [2] =&gt; convert: no decode delegate for this image format `/tmp/magick-8foOHRJR' @ error/constitute.c/ReadImage/532. 
  [3] =&gt; convert: missing an image filename `/var/www/vhosts/site/uploadedfiles/tmp/2_77_thumb.jpg' @ error/convert.c/ConvertImageCommand/3015. 
  [4] =&gt; convert: no decode delegate for this image format `/tmp/magick-M-zHuvtS-00000001' @ error/constitute.c/ReadImage/532. 
  [5] =&gt; convert: Postscript delegate failed `/var/www/vhosts/site/uploadedfiles/tmp/2_77.pdf': @ error/pdf.c/ReadPDFImage/664. 
  [6] =&gt; convert: no decode delegate for this image format `/tmp/magick-rJ8G814k' @ error/constitute.c/ReadImage/532. 
  [7] =&gt; convert: missing an image filename `/var/www/vhosts/site/uploadedfiles/tmp/2_77.jpg' @ error/convert.c/ConvertImageCommand/3015. )
  </code></pre>
  
  <p>I have Ghostscript 8.70 installed and imagemagick 6.7.1-0
  My linux distro is CentOS release 5.6</p>