[GRASS-user] OCR

[Rich Shepard]

On Thu, 5 May 2011, Markus Neteler wrote:

> You could try with this software:
> http://www.gnu.org/software/ocrad/ocrad.html

   Nah, that won't work. OCR, as the name implies, recognizes text
characters: letters and digits. I've used gocr/jocr for years with varying
degrees of success. Unless the typeface is simple (monospaced, for example)
the software cannot make any sense of it.

   A map is not made up of characters, so OCR is inappropriate.

   What might work is to open the scanned image in The GIMP, open a
transparent layer on top of it, and trace the lines of interest. Then run
the file (you can try this on the original scanned map, too) through
ImageMagick's 'convert' program to produce a .pdf version. This converts the
image from bit-mapped to vector. Heck, convert might alao produce a .svg
output that one could clean and tweak with Inkscape.

   I have a large digitizing tablet with 4-button cursor I'm looking to sell
because it's been years since I've needed to digitize a paper map. Won't
help in this case because shipping this 2'x3' digitizer would be quite
expensive.

Rich