WordPress : Getting All Categories

gistfile1

<?php
	$args = array(
		'type'                     => 'post',
		'child_of'                 => 0,
		'parent'                   => '',
		'orderby'                  => 'name',
		'order'                    => 'ASC',
		'hide_empty'               => 1,
		'hierarchical'             => 1,
		'exclude'                  => '',
		'include'                  => '',
		'number'                   => '',
		'taxonomy'                 => 'category',
		'pad_counts'               => false
	);
		//Getting all Categories
		$categories = get_categories( $args );
			foreach ($categories as $category) {
				$separator = ' ';
				$output = '';
				$output .= '
					<a href="'.get_category_link( $category->term_id ).'" title="' . esc_attr( sprintf( __( "View all posts in %s" ), $category->name  ) ) . '">
					<img src="'.$category->description.'"></a>'.$separator;//using category description as in image url
				echo trim($output);
			}
?>