{"id":"https://data.mapsnap.org/runs/v1.3/iiif/chronoscope/sanborn03684_006.keymap.iiif.json","type":"AnnotationPage","@context":["http://www.w3.org/ns/anno.jsonld"],"label":"Ayer, Massachusetts | 1921 | key map | mapsnap generated fit (2026-09-23)","creator":{"type":"Software","name":"mapsnap","homepage":"https://mapsnap.org"},"rights":"https://opendatacommons.org/licenses/odbl/1-0/","metadata":[{"label":"generated","value":"2026-09-23"},{"label":"run","value":"corpus-v1"}],"items":[{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd376m:g3764m:g3764am:g036841921:03684_1921-0001__1/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Ayer, Massachusetts | 1921 | sanborn03684_006 p1 [1]","metadata":[{"label":"streets","value":"32"},{"label":"intersections","value":"44"},{"label":"split_canvas_x","value":"0.0"},{"label":"split_canvas_y","value":"0.0"},{"label":"split_canvas_w","value":"6878.4"},{"label":"split_canvas_h","value":"8074.1"}],"created":"2026-09-23T06:16:40Z","modified":"2026-09-23T06:16:40Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd376m:g3764m:g3764am:g036841921:03684_1921-0001__1/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd376m:g3764m:g3764am:g036841921:03684_1921-0001","type":"ImageService3","width":1613,"height":1913},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"0.0,1036.2 844.9,1036.2 839.9,1913 849.5,1913 849.5,1406.2 1613,1407.2 1613,0.0 0.0,0.0 0.0,1036.2\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd376m:g3764m:g3764am:g036841921:03684_1921-0001__1/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[474.8,527.5],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-71.5858881,42.5605929]}},{"type":"Feature","properties":{"resourceCoords":[410.1,495.8],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-71.5871073,42.5617059]}}]}}]}