upload an spreadsheet and receive an image

I am looking for a way to do the following, any help is heartly
appreciated.
drive to the server. The server will do some calculation based on the
data in the file and return an image. So the user will see an image
displayed/updated on the same web. To follow the ajax approach, I do
not want to refresh my web page in the who approach.

How can I do it?

Thanks,

ff