An important caveat is if you have any images in the canvas, they should be hosted on the same domain or you have to resort to CORS workarounds http://en.wikipedia.org/wiki/Cross-origin_resource_sharing
An important caveat is if you have any images in the canvas, they should be hosted on the same domain or you have to resort to CORS workarounds http://en.wikipedia.org/wiki/Cross-origin_resource_sharing