Image Upload and Modification in Javascript - repost

We are looking to develop a image customisation tool very similar to this example - [login to view URL] The above example uses Flash but we require the system to work in modern browsers and iOS devices. We would prefer the use of the canvas element and loading images on the client side rather than requiring a full upload of each file for manipulation although this is negotiable. We are open to any JS library and would like to know how you would implement this solution before making a decision. We will also provide the full design layout. We are an australian digital agency and have a lot more work for any skilled people.