I\'m using Nihilogic\'s \"Canvas2Image\" JavaScript tool to convert canvas drawings to PNG images. What I need now is to turn those base64 strings that this tool generates,
It worth to say that discussed topic is documented in RFC 2397 - The "data" URL scheme (https://tools.ietf.org/html/rfc2397)
Because of this PHP has a native way to handle such data - "data: stream wrapper" (http://php.net/manual/en/wrappers.data.php)
So you can easily manipulate your data with PHP streams:
$data = 'data:image/gif;base64,R0lGODlhEAAOALMAAOazToeHh0tLS/7LZv/0jvb29t/f3//Ub//ge8WSLf/rhf/3kdbW1mxsbP//mf///yH5BAAAAAAALAAAAAAQAA4AAARe8L1Ekyky67QZ1hLnjM5UUde0ECwLJoExKcppV0aCcGCmTIHEIUEqjgaORCMxIC6e0CcguWw6aFjsVMkkIr7g77ZKPJjPZqIyd7sJAgVGoEGv2xsBxqNgYPj/gAwXEQA7';
$source = fopen($data, 'r');
$destination = fopen('image.gif', 'w');
stream_copy_to_stream($source, $destination);
fclose($source);
fclose($destination);