1
vote
1answer
27 views

Searching 'select by color' for raster or map data

I'm planing to create an online map component with which the user can create/draw polygons based on underlying raster data. Is there some library / tool / procedure existing which enables the ...
0
votes
2answers
602 views

Digitizing from OpenLayers Plugin in QGIS, or create raster?

Is there an easy method for digitizing from a layer added from the OpenLayers pluggin. As i cannot snap to it or use it as raster so the entire map does not load? two separate issues there.
6
votes
2answers
2k views

How to extract road and building features from raster data?

I work with raster data and my task is to digitize a big image. This consumes much time just for digitizing roads and buildings! I'm looking for tools to simplify working on raster data to digitize ...
7
votes
1answer
858 views

GRASS - Will r.to.vect work on this scanned map?

Total GRASS noob here. I have several very large hand contoured maps to digitize, and this thread intrigues me. In the past I have spent hours upon hours digitizing these maps and revisions in ArcMap. ...