Issue with displaying categories only from top level

Hello,

I try to show only the top level categories. This is my current code:

<?php
$terms = apply_filters( 'taxonomy-images-get-terms', '', array('depth'=>1) );
if ( ! empty( $terms ) ) {

    print '<ul class="categoriewrap">';
    foreach( (array) $terms as $term ) {
        print '<li class="categorie"><a href="' . esc_url( get_term_link( $term, $term->taxonomy ) ) . '">' . wp_get_attachment_image( $term->image_id, 'category' ) .  '</a></li>';
    }
    print '</ul>';
}
?>

what am I doing wrong in this case?

Joost

http://wordpress.org/extend/plugins/taxonomy-images/