c2patool Python service example

This repository is forked from Node.js implementation and has the Python equivalent server implementation. The functionalityy remains the same and allows users to upload images and add a C2PA manifest to each image.

Install and build

Follow these steps:

1. Clone this repo by entering this command in a terminal window:

   git clone https://github.com/snrism/c2pa_service_example.git
   

2. Download the latest version of c2patool for your platform from https://github.com/contentauth/c2patool/releases.
3. Extract the zip file and put a copy of the c2patool executable in the root of this repo (c2pa_service_example directory). NOTE: Depending on your operating system, you may need to take some extra steps to be able to run this file; for example on MacOS you have to follow the instructions to open a Mac app from an unidentified developer.
4. Open a terminal window and install the required packages. Enter these commands

   cd <path_where_you_cloned_repo>/c2pa_service_example
   npm install
   

5. Start the service by entering this command:

   python3 server.py
   

   You'll see this in your terminal:

   * Serving Flask app 'server'
   * Debug mode: on
   WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
   * Running on http://127.0.0.1:8000
   Press CTRL+C to quit
   * Restarting with stat
   * Debugger is active!
   

Add C2PA manifest to any PNG or JPEG files.

1. Open a browser to http://localhost:8000.
2. Click the Choose Files button and select one or more JPEG or PNG images in the native file chooser dialog.
   The service uploads the selected images, stores them in the uploads folder, and then calls the c2patool to add a C2PA manifest to each image.
3. Hover over the badge for information about the associated manifest.
4. The service returns the full-sized image, not thumbnails.
5. Right-click and download an image to view the credentials on https://verify.contentauthenticity.org/.

Overview of the app

The code in server.py (re-write of server.js) contains all the server-side logic. It defines three routes:

• GET /version displays the version of c2patool being used
• POST /upload uploads a file, adds a C2PA manifest, and returns a URL.
• GET /, the default route, serves client/index.html, which is a simple page with a user interface you can use to upload one or more files. The associated client JavaScript is in client/index.js. Selecting files triggers a client JavaScript event listener that calls the /upload route for each file and then calls the addGalleryItem function to display the returned image on the page.

Customizing

The data added to the manifest is determined by the manifest.json file in the root folder. To modify the information added to the file, modify manifest.json.

For more information about c2patool and manifests, see the documentation.