charlie wrote: > In response to your questions, I am trying to convert a raster > map (a scanned & georeferenced map with only XY data) > with a shoreline and some wetland islands into a vector map > so I can compare gains/losses over time. > > A preview of the map is here: > http://historicalcharts.noaa.gov/tiled_jpgs_done/zoomifyURLDrivenWebPage.htm?zoomifyImagePath=579-12-1929
if I am getting that right, the area is Hempsted Bay? if so fyi NY DEC (DECRP/NYS GIS Clearinghouse) maintains vectors of the wetland areas already, e.g. these are loaded into OpenStreetMap, metadata in the data layer there. http://www.openstreetmap.org/?lat=40.59313&lon=-73.60279&zoom=15&layers=M hmmm, but maybe only protected/listed/named areas are covered? also the ENC version of the nautical chart can be imported with v.in.ogr's S-57 driver, and you can extract the features that way (but s57 is a bit ugly to work with in this context) Hamish _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
