/* HTML STRUCTURE - WP CAPTIONS - FOR REFERENCE ONLY
<dl class="gallery-item">
    <dt class="gallery-icon">
        <a href="IMAGE LINK" title="" class="fancybox" rel="gallery">
            <img src="THUMBNAIL-LINK" class="attachment-thumbnail" alt="" title="">
        </a>
    </dt>
    <dd class="wp-caption-text gallery-caption">
        CAPTION HERE
    </dd>
</dl>
*/
/* JQUERY CODE */
jQuery( 'a[href$=".jpg"], a[href$=".jpeg"], a[href$=".gif"], a[href$=".png"]' ).each( function () {
        var imageTitle = '';
        if ( jQuery( this ).next().hasClass( 'wp-caption-text' ) ) {
            imageTitle = jQuery( this ).next().text();
        }

        jQuery( this ).attr( 'title', imageTitle );
    });