html - What php download script I can use to save canvas as png to local computer? -

i able download html2canvas image file using php download script only. page have sliding bar shapes user select exercise. webpage displayed results needs capture , saved image file.

below script used embedded in html code.

function triggerpull() {     if (document.getelementbyid('name').value != "") {         html2canvas(document.getelementbyid('body'), {             onrendered: function(canvas) {                 var dataurl = canvas.todataurl('img/png');                 canvas.src = dataurl;                 document.getelementbyid('url').value = dataurl;                 document.download.submit();             }         });     } else {         alert('please fill in name first.');     } } 

i tried script below downloader.php file. blank image file named downloader.php.png please help!

header('content-type: image/png'); header('content-disposition: attachment; filename="' . $_post['name'] .'"'); $encoded = $_post['img']; $encoded = str_replace(' ', '+', $encoded); $decoded = base64_decode($encoded); echo $decoded; ?> 

try code

$file = $_post['url']; $file = str_replace(' ', '+', $file); header('content-description: file transfer'); header('content-type: application/octet-stream'); header('content-disposition: attachment; filename=chart.png'); header('content-transfer-encoding: binary'); readfile($file);