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
    )