Tagged Questions

3
votes
0answers
159 views

Polygonize vegetation area from Landsat7 RGB using QGis / Bilko?

I'm trying to extract the areas with vegetation as a polygon-shape from a landsat7-image, 30m resolution, RGB, using QGis 1.8 or Bilko or (hopefully in the near future) ArcGIS. The area is in Northern ...
0
votes
0answers
82 views

Regional statistics from a dataset (point inside a polygon aka region)

I am relatively new to GIS and I am trying to do some geographical analysis on same data I've collected. The dataset I have consists essentially in a file with the following format: ...
1
vote
1answer
131 views

gdal_rasterize -at function still won't capture covered pixels properly

I'm currently using the gdal_rasterize tool in bash. My code looks like this: gdal_rasterize -l $(basename $file .shp) -burn 1 -a_nodata 0 -te -180 -90 180 90 -tr 0.1 0.01 -at -ot Byte $file ...
3
votes
1answer
424 views

How do I split polygons that cross the dateline?

I have a dataset of country borders which I obtained from: http://thematicmapping.org/downloads/world_borders.php/ I have that dataset in both shp and SQL, but I'll put out there that I don't feel ...
3
votes
1answer
277 views

how do I get the “outer mantle” of a polygon shape file? (without joining all the polygons)

I am interested in finding all the vertices of all polygons which are not on the inside the most outer polygoin that can be formed in a shape file: Here is how I get all the vertices: def ...
4
votes
1answer
941 views

GDAL - creating vector from raster

[SOLVED] Good day! I'm looking at either gdal_contour or gdal_polygonize.py to create a vector layer file from a raster file. I can create the vector file using either method, but it's upside down ...
3
votes
1answer
242 views

Polygon Shared Boundaries in GML

Last week I was told on a phone conference that GML supports shared boundaries in Polygon's. I have been unable to find any documenatation to substantiate the claim. Here is the situation: I have a ...