Scanning maps into GRASS

[R.A.Sanderson]

Does anyone have experience of using a flatbed scanner (e.g. HP ScanJet) to
scan colour maps from paper, and convert them into GRASS raster maps
(running GRASS on SunOS).  I have managed to get a simple test map,
containing only 2 colours, into GRASS, via r.in.sunrast, but it has proved
very difficult to clean up the image, to remove speckles without changing
the total areas of each scanned colour.  I've tried using r.buffer and
r.neighbours, together with r.mapcalc.  The main problems are associated
with text on the map resulting in a "noisy" image, and editing out these
points using d.rast.edit is too slow to be practical.

Thanks
Roy

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Roy Sanderson
Centre for Land Use and Water Resources Research
Porter Building
University of Newcastle
Newcastle upon Tyne
NE1 7RU
United Kingdom

Tel: +44 191 222 7789
Fax: +44 191 222 6563
URL: http://www.cluwrr.ncl.ac.uk
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