Image Style Deliver 404

Display the standard themeable Drupal 404 response instead of a bare 500 when an image style derivative cannot be generated.

If you have a website with many images and image styles your site will be indexed by Google Image Search and other image search engines. If images or image styles change your vistor will see a bare "Error generating image." on the resulting 500 status page. Terrible UX right there. This module corrects the situation by returning the standard themeable Drupal 404 page.

Futher details here: http://drupal.stackexchange.com/questions/15348/how-can-i-theme-error-ge...

This:

  else {
    watchdog('image', 'Unable to generate the derived image located at %path.', array('%path' => $derivative_uri));
    drupal_add_http_header('Status', '500 Internal Server Error');
    print t('Error generating image.');
    drupal_exit();
  }

Changed to this:

  else {
    watchdog('image', 'Unable to generate the derived image located at %path.', array('%path' => $derivative_uri));
    drupal_not_found();
    drupal_exit();
  }