Maphub is a web portal for georeferencing and annotating digitized historic maps. Georeferencing transforms the map image to align with real world geographic coordinates, while the annotations are overlaps plus notes. Maphub suggests possible tags for the annotation based on its text and location; tags link to related Wikipedia articles. Once created, user-contributed annotations are shared via the Maphub Open Annotation API.

A first prototype of Maphub, using digitized maps from the Library of Congress’ Map Division, can be found at http://maphub.herokuapp.com/.

This is an open source platform for georectifying scanned images of maps, so that they can be displayed in web maps or used in GIS applications. It could be particularly useful for creating map overlays for Google Earth or similar applications, without using specialized desktop software. Map images must first be uploaded and made publicly available, and then by aligning with Open Street Map reference data, the maps are warped into georeferenced images. Georectified images are downloadable as GeoTIFF, PNG, or KML files, along with map tiles or WMS capabilities.

The same platform was used for NYPL Map Warper and WorldMap Warp.