edit and save image in google app engine

Question

Hi,

In my GAE Java, I would like the user to be able to edit the images that I serve, using Javascript, and then upload that image back into the GAE.

The reason I am thinking of using Javascript is that GAE Java does not have many image editing capabilities.

1. Original image is stored as Blob in DataStore.
2. Image is served (currently) just using
3. Currently user can only view the image, but i want user to be able to edit the images (adding text and lines at most, no complex transformation needed).
4. User can save the image back into the web application.

What is the quickest way to do this? Will it be easy to integrate with 3rd party javascript ie Snipshot bookmarklet (which has the editing tools already)

Thanks