On Mon, 27 Jun 2011 22:29:56 +0200 Andreas Neumann <[email protected]> wrote:
> Hi, > > What is the purpose of converting these maps to vector files? > I doubt that it makes a lot of sense to convert scanned historic maps > to a vector format (unless it is clearly a clean black and white line > graphic). Included in the historic rasters is parts of features, eg canals, turnpikes, etc, that have been omitted from the OS OpenData set I am using for base layers. > > You will get all sorts of ugly artefacts and the filesize would > probably be bigger than the original rasters. Also, you would get > vectors without attribute data (except maybe color/gray values), > which is also not ideal. Artifacts I can fix and attributes I can add, it just takes time. File size isn't an issue at this stage. > > Probably you just want to geo-reference those scanned maps and use > them as background layers? > > Andreas > As an Invalid Pensioner I am time-rich - money-poor so the time involved is not a serious concern. The goal of my project is to produce a set of map layers depicting the world my ancestors lived in (1600 - 1840) that I can share with other family historians. The desired results are a set of maps that can be shared as either ESRI shape files, MapInfo tables or Google Earth overlays. mick _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
