Remove <p> from Wordpress images. Add to functions.php

functions.php

function filter_ptags_on_images($content){
	return preg_replace('/<p>\s*(<a .*>)?\s*(<img .* \/>)\s*(\/a>)?\s*<\/p>/iU', '\1\2\3', $content);
}
add_filter('the_content', 'filter_ptags_on_images');