$re = '~{{[^}]+?(?:,?img:([^,}]+))?(?:,?alt:([^,}]+),)?(?:,?ht:(\d+))?(?:,?wd:(\d+))?(?:,?align:(\w+))?}}~i';
$str = 'juices vegetables including {{smartpro=img:hippo-1.jpg,alt:Hippocrates,ht:217,wd:247,align:left}} wheatgrass, leafy greens, parsley, aloe vera & other herbs';
$subst = "<img src=\"www.abc.com/media/images/$1\" alt=\"$2\" width=\"$3\" height=\"$4\" align=\"$5\">";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php