All Questions
Tagged with vectorization gdal
15
questions
1
vote
1
answer
119
views
Fastest way to clip millions of small polygons and storing results as JSON [closed]
I have a dataset with couple million farm polygons (around 2.5 million and only expected to grow in the future), and I need to calculate the NDVI for these farm polygons, with some basic stats (...
- 3,346
3
votes
1
answer
148
views
Chain the output of gdal_polygonize to ogr2ogr
I am doing a two step process:
Polygonize a PNG raster via gdal_polygonize.py
Add a custom field named id
Upload the resulting vector to PostGIS via ogr2ogr
I am currently doing it in two steps, ...
- 91
8
votes
1
answer
614
views
Creating a seamless vector dataset from raster with gdal, R or Python
I'm trying to create a seamless vector dataset from an integer raster. "Seamless" as in: not gaps between features and no overlapping features.
The tools gdal_polygonize, pkpolygonize, terra:...
- 1,003
0
votes
2
answers
601
views
How to polygonize NDVI raster using GDAL?
I have raster with NDVI values. I would like to polygonize the raster to get vector where each polygon is a pixel.
I have tried gdal.Polygonize as described in the documentation and that runs without ...
- 2,169
2
votes
1
answer
473
views
Runtime problem gdal:polygonize processing algorithm
I have a c. 60 MB file containing the GTOPO30 30-arc second (c. 1 km) digital elevation model of Africa. The dataset is described here: https://databasin.org/datasets/2965da954b114ff3b47621e99e3b29ba.
...
- 73
6
votes
0
answers
211
views
Telling gdal_polygonize.py how to interpret colors / what does the `DN` field mean
I have lots of raster files I am converting to polys with gdal_polygonize.py. All these images have a consistent palette which I'd like to map to an attribute in the resulting polygons.
On most ...
- 161
3
votes
1
answer
3k
views
Converting large raster to vector?
I have a shapefile which contains 10.000 polygons and I want to know how many of them falls on a specific land use. Unfortunately, the land use map that I have to use is a raster map and not a vector ...
- 81
2
votes
1
answer
458
views
Vectorize raster
I'd like to vectorise the Natural Earth II raster in order to be able to change its colours and display it with as a vector map. Using gdal_polygonize.py won't help as it will create 1 polygon per ...
- 594
2
votes
0
answers
337
views
Error while converting raster into vector in QGIS
I am using QGIS 2.18.23 and trying to convert a raster file (.tif) into a vector file (.shp). But I am getting an unusual error:
2018-08-28T12:41:38 1 Traceback (most recent call last):
...
1
vote
2
answers
941
views
Batch convert ESRI Ascii Grid files to MapInfo TAB
I’m looking for a ‘quick’ (in terms of my time, not computer time) solution to converting a whole bunch of ESRI Ascii Grid files into MapInfo TAB files consisting of a grid of points with XYZ fields. ...
- 2,203
1
vote
2
answers
1k
views
Raster to CSV with x y cell center coordinates, the original raster cell value, and values from another raster avoiding shapefile
I am looking for FOSS (maybe GDAL/OGR) solutions to a problem.
I need to go from raster (200 million records) to CSV. It is easy enough to do via point but the point file breaks the allowable 2GB “...
3
votes
2
answers
4k
views
Creating point shapefile from GeoTIFF using GDAL/OGR?
I have a 0.05 deg global maps (~8000 files) in GeoTiff format. It's a kind of a mask containig "1" and "0". I need to create a point shapefile for each raster with points located over "1" values of ...
- 41
6
votes
1
answer
2k
views
Extracting the pixelwise proportion of classes of a finer raster in a coarser one
I have two rasters, one has a 1 km resolution. The other has a spatial resolution of 30 m. This latter pixelwise is a classification. I want to overlay the 1 km raster on the classification raster and ...
- 1,087
11
votes
3
answers
16k
views
How to convert float raster to vector with python GDAL
I have float raster and now I want to convert it to vector. How is it possible with the Python GDAL library?
I have tried with gdal_polygonize.py of GDAL utilities on the command line and it worked ...
- 399
6
votes
2
answers
6k
views
Converting points to lines with Python GDAL
I have a dictionary with points. The points are derived from a raster (see image below). The points are not sorted and are not in order. The dictionary looks for example like this:
pointDict = {0: (...
- 8,024