How to alter text filters conditionally based on content type?
You could go with the following code inside your filter's callback function:

if(arg(0) == 'node' &amp;&amp; arg(1) &gt; 0){
  $result = db_select('node', 'n')
  -&gt;fields('n', array('type'))
  -&gt;condition('nid', arg(1),'=')
  -&gt;execute()
  -&gt;fetchAssoc();
  dsm($result['type']);
}


Good luck!