Hi,
I am new to the list and still learning to use GRASS. I am running it on Darwin on an OS X 10.2.4 operating system on an Apple Macintosh. I also use several Adobe programs like Illustrator. I have a map I would like to digitize, but do not have a digitizing tablet. Would it be possible to scan the section of the map I need and use it as a template to trace the contours in Illustrator, and from that file create the contour map with the various elevations? I eventually want to create a 3D map with this.
Any help or suggestions would be greatly appreciated.
Kurt D. Springs
Archaeology post-grad at NUI Galway
Yes, you can scan your map and trace the contours in Illustrator, and then export that as a dxf file and import it into GRASS. You might need to convert the dxf file (which is a text file) from Macintosh line breaks to Unix line breaks before importing it into GRASS. Then you'd want to rectify the vector file in GRASS, and attach values to the contour lines using v.digit. V.digit has good facilities for labelling contour lines.
You could also do it all in GRASS. You could scan your map, bring it into GRASS as a raster (r.in.tif, for instance), rectify it (i.rectify); then convert to a vector map within GRASS using r.thin, r.line. Or you could trace it by hand within GRASS using v.digit; this works well too. Illustrator has more editing tools and if you're comfortable with it, that might be the better way to create the vectors (I think i'd be more comfortable with it); but the GRASS tools are good too.
Good luck,
Nick Cahill
On Sunday, February 23, 2003, at 04:17 PM, Kurt Springs wrote:
Hi,
I am new to the list and still learning to use GRASS. I am running it on Darwin on an OS X 10.2.4 operating system on an Apple Macintosh. I also use several Adobe programs like Illustrator. I have a map I would like to digitize, but do not have a digitizing tablet. Would it be possible to scan the section of the map I need and use it as a template to trace the contours in Illustrator, and from that file create the contour map with the various elevations? I eventually want to create a 3D map with this.
Any help or suggestions would be greatly appreciated.
Kurt D. Springs
Archaeology post-grad at NUI Galway