<?php
    header("Content-type: image/jpeg");
    $descriptorspec = array(0 => array("pipe", "r"), 1 => array("pipe", "w"));
    $convert = proc_open("/usr/bin/convert -quality 100 svg:- jpg:-", $descriptorspec, $pipes);
    fwrite($pipes[0], "<?xml version=\"1.0\" standalone=\"no\"?><svg width=\"100%\" height=\"100%\" version=\"1.1\"><circle cx=\"100\" cy=\"50\" r=\"40\" stroke=\"black\" stroke-width=\"2\" fill=\"red\"/></svg>");
    fclose($pipes[0]);
    while(!feof($pipes[1]))
        $jpg .= fread($pipes[1], 1024);
    fclose($pipes[1]);
    proc_close($convert);
    echo $jpg;
?>