Scanning maps into GRASS

[Angus Carr]

I also do this, with topo maps. A 256 color scan is usually enough, then a
bit of playing with pallettes if I have multiple tiles, to make sure the
pallettes are the same.
A bitmap editor on the PC with the scanner help me take off the text, but
I usually use these maps only as backdrops for reference, not as an
information source.

I can't think of a better way, really. The color and area accuracy I
demand of this process is relatively low, as long as they end up in the
right place.

Angus. 

On Tue, 23 Jul 1996, R.A.Sanderson wrote:

> 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
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> NE1 7RU
> United Kingdom
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> Tel: +44 191 222 7789
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