$dom = new domDocument;
$dom->loadHTML($html);
$dom->preserveWhiteSpace = false;
$images = $dom->getElementsByTagName('img');
foreach ($images as $image) {
  echo $image->getAttribute('src');
}

$doc=new DOMDocument();
$doc->loadHTML(\"Test<br><img src=\"myimage.jpg\" title=\"title\" alt=\"alt\"></body></html>\");
$xml=simplexml_import_dom($doc); 
$images=$xml->xpath(\'//img\');
foreach ($images as $img) {
    echo $img[\'src\'] . \' \' . $img[\'alt\'] . \' \' . $img[\'title\'];
}

preg_match_all(\'/<img[^>]+>/i\',$html, $result);

print_r($result);

Array
(
    [0] => Array
        (
            [0] => <img src=\"logo.png\"  />

        )
)