title: "Unable to open image" error when using ImageMagick's Filename References
body: <p>I'm using ImageMagick to do some image processing from the commandline, and would like to operate on a list of files as specified in foo.txt. From the instructions here: <a href="http://www.imagemagick.org/script/command-line-processing.php" rel="nofollow">http://www.imagemagick.org/script/command-line-processing.php</a> I see that I can use Filename References from a file prefixed with @. When I run something like:</p>
  
  <blockquote>
    <p>montage @foo.txt output.jpg</p>
  </blockquote>
  
  <p>everything works as expected, as long as foo.txt is in the current directory. However, when I try to access bar.txt in a different directory by running:</p>
  
  <blockquote>
    <p>montage /some_directory/@bar.txt
    output2.jpg</p>
  </blockquote>
  
  <p>I get:</p>
  
  <blockquote>
    <p>montage: unable to open image
    /some_directory/@bar.txt: No such file
    or directory @ blob.c/OpenBlob/2480.</p>
  </blockquote>
  
  <p>I believe the issue is my syntax, but I'm not sure what to change it to. Any help would be appreciated.</p>