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Try using rasterio, which uses GDALFPolygonize on float arrays. import numpy as np import rasterio.features from affine import Affine from shapely.geometry import shape # triangular array ar = np.tri(5, dtype='f') print(ar) for shp, val in rasterio.features.shapes(ar, transform=Affine(1, 0, 0, 0, -1, 5)): print('%s: %s' % (val, shape(shp))) ...


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As mentioned by Mapperz historical paper maps/drawings still get digitized. Three examples include the digitizing of old coal mine plans, the digitizing of land parcels, and digitizing building plans. With the parcel data we were using Esri's parcel fabric so rather than digitize we used the survey measurements on the plan and then used least squares ...


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For work related projects, where GIS data and layers are seldom available, I extract the data from maps and official documents that were published. As gyoung1986 mentioned, these data usually comprise of infrastructure, but I also found myself digitizing borders and other political boundaries, as well as the incorporated areas of interest, from PDF maps.


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Following the request "Gene, Can you expand a little" for geological maps,here are the explanations using Aprèn a interpretar un mapa geològic of the Institut Geològic de Catalunya: 1) First, geological field work : Field work figures from Field work 2) Laboratory work: geological map construction, cross sections, etc. (paper, GIS,look at 4)): Cabinet ...


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I use this method when I am trying to draw existing gathering systems and transmission pipeline routes that are given to us by clients when they do not or are not willing to give us their .shp files. I can get maps of these lines on the internet of the pipeline is large enough then use the georeferencing tool to lay them into Arc.


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I have a side project at the moment that looks at the historical routes of horse-driven and electric trams in New Zealand cities. I have some old maps of these that I have scanned and georeferenced. I will have to heads-up digitise these, as no autovectorisation proceedure seems to work—the pictures are all monochrome, labels and text overlap, routes I want ...


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You can't use GDALFPolygonize with the GDAL python bindings without modifying the source code and recompiling as it isn't exposed in the GDAL swig interface. To polygonize your raster, you will need to convert from float to integer. If you want to retain some decimal places multiply your raster by 10^N where N is the number of decimal places you want to ...



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