OSX Google Chrome - SecurityError

[MrSrsen]

I'am getting this error in sample (Chrome osx). I did not change anything:
"grade.js:38 Uncaught SecurityError: Failed to execute 'getImageData' on 'CanvasRenderingContext2D': The canvas has been tainted by cross-origin data."

Full error object:

grade.js:38 Uncaught SecurityError: Failed to execute 'getImageData' on 'CanvasRenderingContext2D': The canvas has been tainted by cross-origin data.
    getImageData @ grade.js:38
    render @ grade.js:111
    readImage @ grade.js:33
    Grade @ grade.js:25
    (anonymous function) @ grade.js:121
    module.exports @ grade.js:120
    (anonymous function) @ index.html:109

[kgengler]

Did you just open the index.html in the browser? you're going to get a security error since there is no domain for the document.

try running python -m SimpleHTTPServer 3000 in the docs directory and then visiting http://localhost:3000

[MrSrsen]

So this will not work without webserver?

[kgengler]

that would be the preferred method. otherwise see http://stackoverflow.com/questions/4409901/how-can-access-and-the-origin-policy-in-chrome-as-im-not-using-a-server

[danielfonda]

I can confirm that it works with wamp - launched from a server, rather than desktop.