getImageData causes “Uncaught Error: NOT_SUPPORTED_ERR: DOM Exception 9”

Question

I'm trying to get a feel for some image manipulation in HTML5. I am finding that when I try and use the getImageData method I get this JS exception thrown. I am using Chrome and running on localhost.

Thanks!

Answer 1

Okay figured out what the problem was. All I have to say is "derp". I was using

getImageData(x, x) 

but the way I was intending to use this requires 4 arguments

getImageData(x,x,x,x)

Answer 2

It could be an issue with editing files on your local system using Chrome. You can close Chrome and reopen it using flags --allow-file-access-from-files to allow local file editing.

Came across this post when I ran into a similar issue and it helped.