Draping an orthophoto over a DEM

This time around, we are going to take our previous recipe to the next level by draping satellite imagery over our DEM to create a truly impressive 3D interactive web map.

You can take a look at other orthophotos from geogratis.ca at http://geogratis.gc.ca/api/en/nrcan-rncan/ess-sst/77618678-421b-4a28-a0a5-b074e5f072ff.html.

Getting ready

To drape an orthophoto directly over our DEM, we need to make sure that the input DEM and the orthophoto have the same extent and pixel size. For this exercise, you need to complete the previous section and have data available in the /ch10/geodata/092j02_1_1.tif folder. This is the orthophoto that we are going to drape over the DEM.

How to do it...

1. Let's dive into some code that's full of comments for your enlightenment:

   #!/usr/bin/env python
   # -*- coding: utf-8 -*-
   
   import subprocess
   from PIL import Image
   from jinja2 import Environment, FileSystemLoader
   
   
   # convert from Canada UTM http://epsg.io/3157/map   to 3857...