<?php
$html ='<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2//EN">
<html><head><title>Title</title></head>
<body>
<p><img src="img.png"></p>
</body></html>';
$config = array('accessibility-check' => 3,
'alt-text' => 'some text');
$tidy = new tidy();
$tidy->parseString($html, $config);
var_dump($tidy->getOpt('accessibility-check')); //integer
var_dump($tidy->getOpt('lower-literals')); //boolean
var_dump($tidy->getOpt('alt-text')); //string
?>
Результат выполнения данного примера:
int(3)
bool(true)
string(9) "some text"