There are lots of commercial packages. (e.g. The ArcScan extension to ArcGIS: http://resources.arcgis.com/en/help/main/10.1/index.html#//000w00000001000000 htt

There are lots of commercial packages. (e.g. The ArcScan extension to ArcGIS: http://resources.arcgis.com/en/help/main/10.1/index.html#//000w00000001000000 http://resources.arcgis.com/en/help/main/10.1/index.html#//0... ) A naive version is also fairly easy to build up from existing tools (e.g. OpenCV), but getting it to work reliably is often a pain. Even with the best tools, this sort of thing requires a lot of manual QC. It still greatly speeds things up, though!