Hello Odoo Community,

I’m currently working on a Document Management System (DMS) project in Odoo 15 CE and have received a request from the client to automatically apply a watermark to every image or PDF file when it is either:

• Downloaded from the server (client-side, using JavaScript), or
• Uploaded or saved in the database (server-side, using Python/Odoo).

The goal is to secure the documents by embedding user-specific information (e.g., user name, timestamp, etc.) as a watermark, especially when downloading files.