Why does canvas.toDataURL() throw a security exception?

Question

Did I not get enough sleep or what? This following code

var frame=document.getElementById(\"viewer\");
frame.width=100;
frame.height=100;

var ctx=frame.getC         


        

Answer 1

Seems there is a way to prevent that if image hosting able to provide the following HTTP headers for the image resources and browser supports CORS:

access-control-allow-origin: *
access-control-allow-credentials: true

It is stated here: http://www.w3.org/TR/cors/#use-cases