Reset Dynamic Title/Header Creation Cache

That title might be confusing, let me explain.

My site, don’t know if all wordpress sites do this, dynamically create an image based on the title of the post or page. ” Legend ” is the CSS tag associated with this creator. It creates images and put them in site.com/wp-includes/theme/themename/images/text/????
And the php which is calling and creating these images is

<h1 id="legend" style="background-image: url('<?php bloginfo('stylesheet_directory'); ?>/images/text/header/<?php echo urlencode(trim(strtolower(wp_title('', false))));?>');"><?php wp_title();?></h1>

I recently moved my site and these images which end up with names like “7b7a342e08b36caa48b8cd60116558c2.png’ are still there but the posts and/or pages do not see them.

Is there a way to reset these so that they are re-created? Or can I re-link them one at a time? What can I do?

Thank you