Add image to RSS feed

gistfile1.php

add_action('rss_item', 'wp_rss_img_include');
add_action('rss2_item', 'wp_rss_img_include');

function wp_rss_img_include (){

	global $post;
	if( has_post_thumbnail( $post->ID ) ) {

		$thumbnail_id = get_post_thumbnail_id( $post->ID );

		$img = wp_get_attachment_image_src( $thumbnail_id, 'full' );

		if ( !empty( $img ) ) {

			$url = parse_url( $img[0] );
			$path = ABSPATH . ltrim( $url['path'], '/' );

			if ( file_exists( $path ) ) {
				echo '<media:content url="' . $img[0] . '" width="' . $img[1] . '" height="' . $img[2] . '" medium="image" type="'. get_post_mime_type( $thumbnail_id ) . '" />';
			}
		}
	}
}