2010/11/9 Micha Silver <[email protected]> > > On 11/09/2010 06:21 PM, charlie wrote: > > Micha and Achim, thank you for the replies. 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 you succeed to separate the boundaries, then run the resulting raster thru > r.thin, and finally convert to vector.
In order to remove the JPEG/whatever data compression artifacts, you can preprocess with r.seg from GRASS Addons (see Wiki). It does a great job. Then go on as Micha describes. Cheers Markus _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
