{"id":"https://data.mapsnap.org/runs/v2.0/iiif/chronoscope/sanborn04159_006.keymap.iiif.json","type":"AnnotationPage","@context":["http://www.w3.org/ns/anno.jsonld"],"label":"Port Huron, Michigan | 1950 | key map | mapsnap generated fit (2026-10-18)","creator":{"type":"Software","name":"mapsnap","homepage":"https://mapsnap.org"},"rights":"https://opendatacommons.org/licenses/odbl/1-0/","metadata":[{"label":"generated","value":"2026-10-18"},{"label":"run","value":"corpus-v2"}],"items":[{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd411m:g4114m:g4114pm:g041591950:04159_1950-0000__1/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Port Huron, Michigan | 1950 | sanborn04159_006 p0 [1]","metadata":[{"label":"streets","value":"110"},{"label":"intersections","value":"482"},{"label":"split_canvas_x","value":"0.0"},{"label":"split_canvas_y","value":"0.0"},{"label":"split_canvas_w","value":"6914.3"},{"label":"split_canvas_h","value":"8217.6"}],"created":"2026-10-18T04:51:14Z","modified":"2026-10-18T04:51:14Z","motivation":"georeferencing","target":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd411m:g4114m:g4114pm:g041591950:04159_1950-0000__1/selector","type":"SpecificResource","source":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd411m:g4114m:g4114pm:g041591950:04159_1950-0000","type":"ImageService3","width":1622,"height":1949},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"1622,0.0 291.7,0.0 287.9,701.5 0.0,701.5 0.0,1949 1622,1949 1622,1600.1 1622,1494.7 1622,0.0\" /></svg>"}},"body":{"id":"https://cdn.chronoscope.io/mapsnap/service:gmd:gmd411m:g4114m:g4114pm:g041591950:04159_1950-0000__1/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[922.9,480.1],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-82.4284574,43.0015877]}},{"type":"Feature","properties":{"resourceCoords":[572.5,1419.3],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-82.4448535,42.9650408]}}]}}]}