Methods of extracting summary statistics alike to OS Building Height Attribute of surface or image values by polygon. Example usage:
python heightStats.py --footprints "test_data/osm_university_park_polygons_27700.shp" --dsmSlopeImg "test_data/DSM_slope.tif" --dsmImg "test_data/DSM.tif" --dtmImg "test_data/DTM.tif"