I've been trying to add a watermark to files as they are uploaded to SharePoint. I tried using several events: ItemAdding, ItemUpdating, ItemCheckedIn.
In ItemUpdating and ItemCheckedIn the file is already in the DB. so I can add a watermark - but it's just a waste of DB read/write (The whole file is written, then I read it, then I re-save it to the db).
the ItemAdding event looks good, it does rise before the content is saved to the DB, but I do not have the content itself (SPItemEventProperties doesn't have any "content" attribute or something similar)