How to bulk update image alt and title?
The basic logic goes like this:

$nodes = entity_load('node', FALSE, array('type' =&gt; 'the_type'));

foreach ($nodes as $node) {
  $node-&gt;field_image[$node-&gt;language][0]['alt'] = $node-&gt;title;
  $node-&gt;field_image[$node-&gt;language][0]['title'] = $node-&gt;title;

  node_save($node);
}


You should probably split that up into a batch job if you have a lot of nodes.

I'm also pretty sure you could make a quicker solution using VBO and some custom PHP but I don't have time to flesh that out right now.