Skip to content
WebODM

Quickstart

How To Process Images

Section titled “How To Process Images”

In this tutorial we’ll explore how to process an orthophoto from a set of aerial images using Python. To do that we’ll need to:

  • Authenticate
  • Create a Project. Projects are a way to group together related Task items
  • Upload some images to create a Task
  • Check for Task progress. Photogrammetry can take a long time, so results could take a few minutes to a few hours to be processed.
  • Download the resulting orthophoto.
import requests
res = requests.post('http://localhost:8000/api/token-auth/',
          data={'username': 'admin',
              'password': 'admin'}).json()
token = res['token']

First, we authenticate with WebODM. A token is returned when authentication is successful.

res = requests.post('http://localhost:8000/api/projects/',
          headers={'Authorization': 'JWT {}'.format(token)},
          data={'name': 'Hello WebODM!'}).json()
project_id = res['id']

Then we need to create a Project. We pass our token via the Authorization header. If we forget to pass this header, the system will not authenticate us and will refuse to process the request. We also assign a name to our project.

images = [
  ('images', ('image1.jpg', open('image1.jpg', 'rb'), 'image/jpg')),
  ('images', ('image2.jpg', open('image2.jpg', 'rb'), 'image/jpg')),
  # ...
]
options = json.dumps([
  {'name': "orthophoto-resolution", 'value': 24}
])


res = requests.post('http://localhost:8000/api/projects/{}/tasks/'.format(project_id),
      headers={'Authorization': 'JWT {}'.format(token)},
      files=images,
      data={
        'options': options
      }).json()


task_id = res['id']

We can then create a Task. The only required parameter is a list of multiple, multipart-encoded images. Processing will start automatically as soon as a Processing Node is available. It is possible to specify additional options by passing an options value, which is a JSON-encoded list of name/value pairs. Several other options are available. See the Processing Node - Processing Options reference for more information.

while True:
  res = requests.get('http://localhost:8000/api/projects/{}/tasks/{}/'.format(project_id, task_id),
        headers={'Authorization': 'JWT {}'.format(token)}).json()


  if res['status'] == status_codes.COMPLETED:
    print("Task has completed!")
    break
  elif res['status'] == status_codes.FAILED:
    print("Task failed: {}".format(res))
    sys.exit(1)
  else:
    print("Processing, hold on...")
    time.sleep(3)

We periodically check for the Task status using a loop.

res = requests.get("http://localhost:8000/api/projects/{}/tasks/{}/download/orthophoto.tif".format(project_id, task_id),
            headers={'Authorization': 'JWT {}'.format(token)},
            stream=True)
with open("orthophoto.tif", 'wb') as f:
    for chunk in res.iter_content(chunk_size=1024):
        if chunk:
            f.write(chunk)
print("Saved ./orthophoto.tif")

Our orthophoto is ready to be downloaded. A variety of other assets, including a dense 3D point cloud and a textured model are also available.

Congratulations! You just processed some images.

Success