upload canvas data to s3

Now since the amazon has enabled CORS I was wondering if this is possible.

Can the html canvas data (on client browser) be converted to a something and uploaded to s3 directly ?

I am sure I can make a PUT request to amazon but that requires a File .

I can get base64 encoded image data or even a Blob but is there a way to save this as an image to S3 from the client browser ?

Is there a way to convert canvas to File so that I can make a PUT request or a way that amazon understands Blob and saves it as an image ?