DMS-REQ-0074 specifies that the data management system should store the identify of the input exposures and related metadata. At present this reconstruction is not simple: While the input calexp can be reconstructed by matching dataIds from the processed image
repository, determining the template applied requires a new call to getCoaddAsTemplateTask, with concomitant restrictions on stack versioning, template repository association, etc.

This ticket is to design an improved provenance system for image differences.