IIIF Curation Platform (ICP) has a number of open source software, and we also have tools that are available as services.
This service convert all canvases in an IIIF manifest into an IIIF curation. IIIF Curation Viewer can give metadata only to curation, but not to manifest. If you are planning to give metadata for each canvas, first convert a manifest to a curation and read it from IIIF Curation Viewer.