Set default images for categories

add_filter('genesis_get_image','default_category_image');
function default_category_image($output) {
if ( !$output ) {
	if ( in_category('1') ) {
		$output = '<img height="150" width="200" title="default-categoryone-image" alt="default-categoryone-image" class="'alignleft post-image" src="'.get_bloginfo('stylesheet_directory').'/images/cat-thumbs/categoryone-graphic.png">';
	}
	elseif ( in_category('2') ) {
		$output = '<img height="150" width="200" title="default-categorytwo-image" alt="default-categorytwo-image" class="'alignleft post-image" src="'.get_bloginfo('stylesheet_directory').'/images/cat-thumbs/categoryone-graphic.png">';
	}
}
return $output;
}

Function Info: add_filter(), get_bloginfo(), genesis_get_image()