Stop images from getting wrapped in <p> tags when they are displayed with the_content()

functions.php

/**
 * Stop images from getting wrapped in the_content()'s <p> tags
 */
function remove_img_ptags($content){
  return preg_replace('/<p>\s*(<a .*>)?\s*(<img .* \/>)\s*(\/a>)?\s*<\/p>/iU', '\1\2\3', $content);
}
add_filter('the_content', 'remove_img_ptags');