title: Graphviz seems doesn't support png and map
body: <p>Hi I must convert a graph (a .dot)  to a map and to a png because I must generate dependencies graph with doxygen using graphviz.   But I have a error:</p>
  
  <pre><code> error: problems opening map file
  </code></pre>
  
  <p>If I do dot -v I have</p>
  
  <pre><code>dot - graphviz version 2.38.0 (20140413.2041)
  libdir = "/usr/local/lib/graphviz"
  Activated plugin library: libgvplugin_dot_layout.so.6
  Using layout: dot:dot_layout
  Activated plugin library: libgvplugin_core.so.6
  Using render: dot:core
  Using device: dot:dot:core
  The plugin configuration file:
  /usr/local/lib/graphviz/config6
  was successfully loaded.
  render  :  dot fig map pic pov ps svg tk vml xdot
  layout  :  circo dot fdp neato nop nop1 nop2 osage patchwork sfdp
  twopi
  textlayout  : 
  device  :  canon cmap cmapx cmapx_np dot eps fig gv imap imap_np ismap                    
  pic plain plain-ext pov ps ps2 svg svgz tk vml vmlz xdot xdot1.2 
  loadimage   :  (lib) eps gif jpe jpeg jpg png ps svg
  </code></pre>
  
  <p>There isn't map and png for render</p>
  
  <p>Moreover if I do   dot -Tpng     </p>
  
  <pre><code>Format: "png" not recognized. Use one of: canon cmap cmapx cmapx_np   
  dot eps fig gv imap imap_np ismap pic plain plain-ext pov ps ps2 svg 
  tk vml vmlz xdot xdot1.2 xdot1.4
  </code></pre>
  
  <p>It seem that I have not the library for png and map.
  How can I fix the problem?
  (I do not remember how at the time I installed grapghviz)
  (I'm working on Linux SO)</p>