How save image from canvas tag to php server?

Question

I have a javascript code like this

var testCanvas = document.getElementById(\'canvas-1\');
var canvasData = testCanvas.toDataURL(\"image/png\");
var ajax = n         


        

Answer 1

I had to do this recently myself.

First I put my canvasData into a hidden field and posted it to my PHP page.

It comes back in this format: data:image/png;base64,iVBORw0......

You need to split the data up first, as this: data:image/png;base64, is header information. The rest is the encoded data.

$rawData = $_POST['imageData'];
$filteredData = explode(',', $rawData);

$unencoded = base64_decode($filteredData[1]);

I then create the image on my server:

//Create the image 
$fp = fopen('sigs/test1.png', 'w');
fwrite($fp, $unencoded);
fclose($fp); 

And then read it to do whatever I want with it.

$file_name = 'test1.png';
$file_size = strlen($filteredData[1])/1024; //This may be wrong, doesn't seem to break for me though.


$fh = fopen('sigs/test1.png', 'r');
$content = fread($fh, $file_size);
$content = base64_encode($content);
fclose($fh);

I'm more than sure there is a much more elegant solution to this, but this has been working for me!

Check this for more info (possibly): My own question