This article explains the purpose of the Events and attached files that are part of the C2PA sample that can be found on the DataTrails UI. For an overview of CAI, C2PA and how DataTrails adds provenance to your images please go here.
What is the C2PA sample?
The C2PA sample is one of the samples that can be found in the "Getting Started" section of the DataTrails UI. It is only visible to administrators of a tenancy.
The sample was created using c2pa-tool to produce the info report, ingredients, manifest, details report and parent external manifest files. The base image is taken from the samples that are available from the C2PA Github repository.
It shows how the C2PA image lifecycle is compatible with DataTrails.
What am I seeing here?
You can see how DataTrails can be used to record the provenance of a CAI/C2PA image that has been associated with an external manifest.
What the sample does not provide is an image and manifest that can be checked using CAI Verify.
What is happening in the Events?
Open the Asset Overview for the sample and click on the Event History tab to see all the events.
- The initial image taken from the C2PA samples. There is no manifest associated with this image version. The file image.jpg is in the Overview of Event 1.
- The info file is generated using c2pa-tool. The info report info.txt will be used to create the manifest. It is found in the Event attributes of Event 2.
- The ingredients file is generated. The ingredients are also used to create the manifest, ingredient.json is found in the Event attributes of Event 3.
- The manifest file for the initial image. The image manifest file signed_image.c2pa and the signed image file signed_image.jpg are found in Event 4. The .c2pa file is a binary file.
- The version of the image that has been signed by the manifest is published in Event 5, signed_image.jpg is found in the Event Overview.
- The Details Report is represented by Event 6. There are two json files, one contains the manifest information and the other describes the internal C2PA format of the manifest.
The files detailed.json and manifest_store.json are found in the Event attributes.
- The Parent file. This is an external manifest file for an image that has been derived from another image. In this scenario the initial image in Event 1 would be a child or derivative of the parent image. This manifest parent_signed_image.c2pa and the parent image signed_image.jpg are located in the Event attributes.
- The manifest file parent_signed_image.c2pa is published in Event 8 and is found in the Overview.
- A manifest is edited and this is recorded in Event 9. The manifest file edited_signed_image.c2pa is found in the Event attributes.
- Publishes the external manifest that has been modified, it is found in the Overview. Note: this has not been used to sign an image.