[GRASS-user] How to import as vector?

[Markus Neteler]

On Wed, Jan 11, 2012 at 1:25 PM, Bulent Arikan <bulent.arikan at gmail.com> wrote:
> Dear List,
>
> I found a plan / architectural drawing online. I am not sure about the
> resolution but JPG version is 25 Mb and TIFF version is 410 Kb. I want to
> import the drawing as vector into 'xy location' and then rectify it. I
> already did rectify the image as "raster" but I will need a vector layer.
> Looking at 'v.in.ogr' I am not sure how to bring images of such formats into
> GRASS as vector. Raster to vector transformation does not work.

Since it is a raster map you have (at least) two options:
- use it as background for a digitizer (likely a lot of work)
- try image processing to get out raster lines, then r.thin and
  subsequently r.to.vect with lines. This much depends on the
  JPG quality.
- (there are some autotracer tools, too)

Markus