Contour vectorization (SUMMARY)

[Bruce_Byars at baylor.edu]

David,

I'm not exactly clear on your question.  You can scan
and import raster images into GRASS (tiff, sun raster,etc)
Using GRASS, you can then use the r.poly tool to extract
vectors from your raster map.  It will take the category
seperations and trace the vector contours for you.  We
use it a lot with good results.

Bruce

--
Bruce Byars
GRASS Dev. Team
CAGSR - Baylor Univ.



David Osborne wrote:

> I asked on this list about software to do raster to vector conversion
> of contours:
>
> > I would like to be able to take a colour scanned image of a map and
> > extract the contours as vectors, to be able to prepare a DEM of the
> > scanned area.
>
> The replies I had recommended the following software:
>
> Mapscan
>
> URL: http://www.undp.org/popin/softproj/software/mapscan.htm
> Platforms: DOS, Windows
> Cost: free
> Input formats: Paintbrush (PCX), GEM (IMG) and TIFF uncompressed; black
> and white images only, not colour.
> Output formats: AutoCAD (DXF) and PopMap
> Recommended by: Dieter Lehmann
>
> R2V
>
> URL: http://www.ablesw.com/r2v/
> Platforms: Windows 9X/NT
> Cost: $1495 ($960 educational); demo version limited to 256x256 raster
> available for download
> Input formats: many, incl. BMP, TIFF, GeoTIFF
> Output formats: many, incl. ARC/INFO, DXF, MapInfo
> Recommended by: Johnny Duke
>
> WinTopo
>
> URL: http://www.softsoft.net/wintopo/
> Platforms: Windows; Linux version under development
> Cost: free version available for download; Professional version to be
> released soon
> Input formats: BMP (free version); TIFF, GIF, BMP (Pro version)
> Output formats: BMP (free version); TIFF, BMP (Pro version)
> Recommended by: Bong Khin Fah
>
> My thanks to those who replied.
>
> David
>
> --
> David Osborne                         david.osborne at nottingham.ac.uk
> School of Geography             phone/voicemail: +44 (0)115 951 3397
> University of Nottingham                    fax: +44 (0)115 951 3358
> Nottingham NG7 2RD, UK     http://www.geog.nottingham.ac.uk/~osborne