RegexSimple

       include_once 'lib/Simple_html_dom.php';


        $string = '
            <p>Aliquam vehicula faucibus tellus. Praesent condimentum commodo libero,
            sit amet pellentesque metus bibendum sit amet. Donec commodo tortor in
            libero consequat suscipit. Maecenas eget augue vulputate neque pulvinar lobortis.
            Fusce posuere lorem scelerisque, facilisis velit eu, vehicula nulla. Mauris
            vestibulum vulputate justo, et tincidunt neque imperdiet eget.</p>
            <img alt="" src="/upload/ckeditor/CARTOAEROMED2.jpg" style="width: 800px; height: 648px;" />
            <img alt="" src="/upload/ckeditor/CARTOAEROMED2.jpg" style="width: 800px; height: 648px;" />
            <img alt="" src="/upload/ckeditor/CARTOAEROMED2.jpg" style="width: 800px; height: 648px;" />';

         $html = new Simple_html_dom($string);
         $result = new stdClass;
         foreach($html->find('img') as $img)
         {
             $src = '"" src="/common/function/thumb.php?url=../..' . $img->src . '" class="img-responsive img-rounded" ';
             $result = preg_replace('/src([=]|\s=)"(.*)"/', $src, $string);
         }

         print_r($result);