<?php if ( has_post_thumbnail() ) { ?>
  <div class="post-thumb">
  <?php
    $blog_url = get_bloginfo('url');
    $large_image_arr = wp_get_attachment_image_src(
 
    get_post_thumbnail_id( $post->ID ), 'large-thumb' );
 
    $large_image_url = $large_image_arr[0];
    $large_image_url = str_replace($blog_url, 'http://kody.wig.pl/zdjecia/', $large_image_url);
 
    echo '<img src="' . $large_image_url . '"
    width="'.$large_image_arr[1].'"
    height="'.$large_image_arr[2].'"
    title="' . the_title_attribute( 'echo=0' ) . '"
    class="attachment-large-thumb wp-post-image" >';
   ?>
   </div>
<?php } ?>