{"id":"https://data.mapsnap.org/runs/v1.3/iiif/loc/sanborn01790_089.keymap.iiif.json","type":"AnnotationPage","@context":["http://www.w3.org/ns/anno.jsonld"],"label":"Chicago, Illinois | 1950 | 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:g01790195003:01790_03_1950-0000a/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Chicago, Illinois | 1950 | sanborn01790_089 p0a","metadata":[{"label":"streets","value":"34"},{"label":"intersections","value":"56"}],"created":"2026-09-21T05:01:23Z","modified":"2026-09-21T05:01:23Z","motivation":"georeferencing","target":{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790195003:01790_03_1950-0000a/selector","type":"SpecificResource","source":{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790195003:01790_03_1950-0000a/info.json","type":"ImageService2","height":7324,"width":5844},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"5844.0,7324.0 -0.0,7324.0 0.0,-0.0 5799.5,0.0 5797.7,127.1 5819.6,127.7 5819.5,147.0 5812.3,572.7 5790.4,573.4 5789.9,594.3 5811.8,593.9 5790.3,1046.4 5754.5,3211.4 5844.0,3213.2 5844.0,3391.9 5750.2,3463.8 5748.5,3554.1 5844.0,3558.0 5844.0,3703.0 5826.2,3856.8 5742.5,3854.3 5735.1,4351.9 5704.5,4905.3 5687.8,5621.8 5844.0,5625.8 5844.0,6484.5 5827.3,7302.5 5844.0,7302.9 5844.0,7324.0\" /></svg>"}},"body":{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790195003:01790_03_1950-0000a/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[3764.9,5819.8],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-87.6599658,41.8421341]}},{"type":"Feature","properties":{"resourceCoords":[4629.4,6108.8],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-87.6537271,41.8407948]}}]}},{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790195003:01790_03_1950-0000b/georef","type":"Annotation","@context":["http://iiif.io/api/extension/georef/1/context.json","http://iiif.io/api/presentation/3/context.json"],"label":"Chicago, Illinois | 1950 | sanborn01790_089 p0b","metadata":[{"label":"streets","value":"49"},{"label":"intersections","value":"249"}],"created":"2026-09-21T05:01:23Z","modified":"2026-09-21T05:01:23Z","motivation":"georeferencing","target":{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790195003:01790_03_1950-0000b/selector","type":"SpecificResource","source":{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790195003:01790_03_1950-0000b/info.json","type":"ImageService2","height":7324,"width":5740},"selector":{"type":"SvgSelector","value":"<svg><polygon points=\"260.9,7324.0 260.9,5671.7 87.9,5670.7 89.9,4964.5 109.1,4418.6 106.3,3928.2 189.7,3929.1 204.4,3776.9 201.3,3634.4 106.1,3632.3 106.0,3543.3 198.0,3470.7 194.3,3294.6 105.2,3294.6 96.7,1160.8 108.9,714.6 87.2,715.3 87.2,694.8 109.0,693.6 107.2,255.0 85.4,254.9 84.6,129.6 -0.0,131.2 -0.0,-0.0 5740.0,0.0 5740.0,7324.0 260.9,7324.0\" /></svg>"}},"body":{"id":"https://tile.loc.gov/image-services/iiif/service:gmd:gmd410m:g4104m:g4104cm:g01790195003:01790_03_1950-0000b/gcps","type":"FeatureCollection","transformation":{"type":"helmert"},"features":[{"type":"Feature","properties":{"resourceCoords":[1640.9,5896.8],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-87.6354426,41.8425658]}},{"type":"Feature","properties":{"resourceCoords":[2639.4,2555.3],"type":"gcp"},"geometry":{"type":"Point","coordinates":[-87.628788,41.8601461]}}]}}]}