{"id":"https://data.mapsnap.org/runs/v1.3/iiif/loc/sanborn01790_037.keymap.iiif.json","type":"AnnotationPage","@context":["http://www.w3.org/ns/anno.jsonld"],"label":"Chicago, Illinois | 1908 | key map | mapsnap generated fit (2026-09-21)","creator":{"type":"Software","name":"mapsnap","homepage":"https://mapsnap.org"},"rights":"https://opendatacommons.org/licenses/odbl/1-0/","metadata":[{"label":"generated","value":"2026-09-21"},{"label":"run","value":"corpus-v1"}],"items":[{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790190818:01790_18_1908-0000__2/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Chicago, Illinois | 1908 | sanborn01790_037 p0 [2]","metadata":[{"label":"streets","value":"30"},{"label":"intersections","value":"47"},{"label":"split_canvas_x","value":"0.0"},{"label":"split_canvas_y","value":"0.0"},{"label":"split_canvas_w","value":"6289.3"},{"label":"split_canvas_h","value":"8927.7"}],"created":"2026-09-21T03:45:56Z","modified":"2026-09-21T03:45:56Z","motivation":"georeferencing","target":{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790190818:01790_18_1908-0000__2/selector","type":"SpecificResource","source":{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790190818:01790_18_1908-0000/info.json","type":"ImageService2","height":8508,"width":5860},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"6289.3,8927.7 6289.3,0.0 -0.0,0.0 0.0,4866.3 954.8,4866.3 1013.9,6545.3 1055.9,8927.7 6289.3,8927.7\" /></svg>"}},"body":{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790190818:01790_18_1908-0000__2/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[1432.5,5117.3],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-87.7654559,41.8966766]}},{"type":"Feature","properties":{"resourceCoords":[1642.9,4697.4],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-87.7637191,41.8994254]}}]}}]}