Context and Terms

[thehabes]

"@context": [
   "http://www.w3.org/ns/anno.jsonld",
   "http://geojson.org/geojson-ld/geojson-context.jsonld",
   "http://iiif.io/api/presentation/3/context.json"
]

in your JSON example will need to become

"@context": [
   "http://allmaps.org/georef/context.json",
   "http://iiif.io/api/presentation/3/context.json"
]

You will have to make a context file of your own to describe the terms and syntax you are using. Plan to do a Scoped Context which scopes in GeoJSON, Presentaiton API 3 already scopes in Web Annotation. See below for an example georef/context.json

{
   "@context": {
      "@version": 1.1,
      "georef_vocab": "https://allmaps.org/georef/vocab.md#",
      "georeferencing": "georef_vocab: georeferencing",
      "gcp-georeferencing": "georef_vocab: gcp-georeferencing",
      "pixelCoords": "georef_vocab:pixelCoords",
      "body" : {
         "@context": "https://geojson.org/geojson-ld/geojson-context.jsonld"
      }
   }
}

You will also have to have a terms file to go with that context file, like the vocab.md in the example above. It will need to contain your terms as seen in https://github.com/allmaps/iiif-api/blob/georef/source/extension/georef/vocab/new-terms.md