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

In the specs it says:

Whenever the toDataURL() method of a canvas element whose origin-clean flag is set to false is called, the method must raise a SECURITY_ERR exception.

If the image is coming from another server I don't think you can use toDataURL()