WordPress: Show custom image sizes in new WordPress 3.5

<?php
function wpmidia_custom_image_sizes( $sizes ) {
  global $_wp_additional_image_sizes;
  if ( empty($_wp_additional_image_sizes) )
    return $sizes;

  foreach ( $_wp_additional_image_sizes as $id => $data ) {
    if ( !isset($sizes[$id]) )
      $sizes[$id] = ucfirst( str_replace( '-', ' ', $id ) );
  }

  return $sizes;
}
add_filter( 'image_size_names_choose', 'wpmidia_custom_image_sizes' );