Reading and saving raster data#

For reading raster data (DEMs) from files (GeoTIFFs) to a numpy array we suggest using the rvt.default module (which uses gdal). You can also use rasterio, gdal or any other module for reading and saving geo rasters.

Reading raster data#

Example

To read a raster with rvt.default:

# import the module
import rvt.default

# change this to the path to your GeoTIFF
dem_path = r"C:/data/dem.tif"

# call the function rvt.default.get_raster_arr() to return a dictionary with keys:
#   array (contains numpy array of raster),
#   resolution (contains the tuple(x resolution, y resolution)),
#   no_data (contains the value of no_data)
dem_dict = rvt.default.get_raster_arr(dem_path)

# numpy array
dem_arr = dem_dict["array"]

# resolution tuple (x-direction resolution, y-direction resolution)
dem_resolution_tuple = dem_dict["resolution"]

# first element of the resolution tuple (the x-direction resolution)
dem_x_resolution = dem_resolution_tuple[0]

# second element of resolution tuple (the y-direction resolution)
dem_y_resolution = dem_resolution_tuple[1]

# the value of no_data stored in DEM
dem_no_data = dem_dict["no_data"]

Saving raster data#

Example

Let’s say we wanted to use a DEM stored in dem_path to compute a hillshade (using rvt.vis) stored in hillshade_arr, and then save this hillshade visualization to hillshade_path:

# import the required modules
import rvt.default
import numpy as np

# call the function rvt.default.save_raster() and define the function parameters:
#   src_raster_path: source raster path (dem_path) to copy metadata,
#   out_raster_path: path to new file (visualization tif),
#   out_raster_arr: vizualization numpy array,
#   no_data: value of no_data (visualizations return no data as np.nan)
rvt.default.save_raster(
    src_raster_path=dem_path,
    out_raster_path=hillshade_path,
    out_raster_arr=hillshade_arr,
    no_data=np.nan
    )