tobler.dasymetric.raster_tools¶
tools for working with rasters.
Module Contents¶
Functions¶
Generate a geodataframe from raster data by polygonizing contiguous pixels with the same value using rasterio’s features module. |
API¶
- tobler.dasymetric.raster_tools.extract_raster_features(gdf, raster_path, pixel_values=None, nodata=255, n_jobs=-1, collapse_values=False)[source]¶
Generate a geodataframe from raster data by polygonizing contiguous pixels with the same value using rasterio’s features module.
Parameters
gdf : geopandas.GeoDataFrame geodataframe defining the area of interest. The input raster will be clipped to the extent of the geodataframe raster_path : str path to raster file, such as downloaded from https://lcviewer.vito.be/download pixel_values : list-like, optional subset of pixel values to extract, by default None. If None, this function may generate a very large geodataframe nodata : int, optional pixel value denoting “no data” in input raster n_jobs : int [Optional. Default=-1] Number of processes to run in parallel. If -1, this is set to the number of CPUs available collapse_values : bool, optional If True, multiple values passed to the pixel_values argument are treated as a single type. I.e. polygons will be generated from any contiguous collection of values from pixel_types, instead of unique polygons generated for each value This can dramatically reduce the complexity of the resulting geodataframe a fewer polygons are required to represent the study area.
Returns
geopandas.GeoDataFrame geodataframe whose rows are the zones extracted by the rasterio.features module. The geometry of each zone is the boundary of a contiguous group of pixels with the same value; the
valuecolumn contains the pixel value of each zone.