2
votes
1answer
125 views

How to find the projection of an image?

Instead of georeferencing the image and deforming it, I'm trying to find the projection used by the author of the image. I've got tens of these distribution maps to digitize. The idea is to avoid ...
1
vote
1answer
28 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
784 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
3k 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
929 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. ...