This plugin is designed to overcome one thing:

Getting the image data from images you own, into a canvas on a server not on the same domain as the image host.
This is only an issue when your image host doesn't support CORS.  Amazon s3 does not support CORS, so if you have any volume of images you need some way to get at this data.

This plugin requires a little work.

On your image host - In my case s3:
copy the files in the /s3 folder onto your s3 image host, in the directory where your images live

In your application:

include the plugin, and you can now do this

$("img")s3ImageProxy(s3remote:"https://s3.amazonaws.com/bucket/path/to/image/directory")

Now, on every image you performed the proxy on, the original src attribute will be replaced with the actual data bytes.

Many thanks Irina Dumitrascu
https://github.com/dira/cross-domain-image-proxy
Most of the proxy code came from here, I just wrapped it in a jquery plugin so I could use it the way I wanted to and made some changes to be able to track the individual proxy requests.