code: def visualize():
      
  
      session['settings'] = {}
      image_uid = request.args.get('image')
      vis_name = request.args.get('visualizer')
      vis = get_visualizations()[vis_name]
      if vis.ALLOWED_SETTINGS:
          for key in vis.ALLOWED_SETTINGS.keys():
              if request.args.get(key) is not None:
                  session['settings'][key] = request.args.get(key)
              else:
                  session['settings'][key] = vis.ALLOWED_SETTINGS[key][0]
      else:
          logger.debug('Selected Visualizer {0} has no settings.'.format(vis_name))
      inputs = []
      for image in session['image_list']:
          if image['uid'] == int(image_uid):
              full_path = os.path.join(session['img_input_dir'],
                                       image['filename'])
              entry = dict()
              entry['filename'] = image['filename']
              entry['data'] = Image.open(full_path)
              inputs.append(entry)
  
      vis.update_settings(session['settings'])
      output = vis.make_visualization(
          inputs, output_dir=session['img_output_dir'])
      return jsonify(output[0])
docs: Trigger a visualization via the REST API
  
      Takes a single image and generates the visualization data, returning the
      output exactly as given by the target visualization.