old_contents: # Object tracking with keypoints example.
  # Show the camera an object and then run the script. A set of keypoints will be extracted
  # once and then tracked in the following frames. If you want a new set of keypoints re-run
  # the script. NOTE: see the docs for arguments to tune find_keypoints and match_keypoints.
  import sensor, time, image
  
  # Reset sensor
  sensor.reset()
  
  # Sensor settings
  sensor.set_contrast(3)
  sensor.set_gainceiling(16)
  sensor.set_framesize(sensor.VGA)
  sensor.set_windowing((320, 240))
  sensor.set_pixformat(sensor.GRAYSCALE)
  
  sensor.skip_frames(30)
  sensor.set_auto_gain(False, value=100)
  
  def draw_keypoints(img, kpts):
      print(kpts)
      img.draw_keypoints(kpts)
      img = sensor.snapshot()
      time.sleep(1000)
  
  kpts1 = None
  # NOTE: uncomment to load a keypoints descriptor from file
  #kpts1 = image.load_descriptor("/desc.orb")
  #img = sensor.snapshot()
  #draw_keypoints(img, kpts1)
  
  clock = time.clock()
  while (True):
      clock.tick()
      img = sensor.snapshot()
      if (kpts1 == None):
          # NOTE: By default find_keypoints returns multi-scale keypoints extracted from an image pyramid.
          kpts1 = img.find_keypoints(max_keypoints=150, threshold=10, scale_factor=1.2)
          draw_keypoints(img, kpts1)
      else:
          # NOTE: When extracting keypoints to match the first descriptor, we use normalized=True to extract
          # keypoints from the first scale only, which will match one of the scales in the first descriptor.
          kpts2 = img.find_keypoints(max_keypoints=150, threshold=10, normalized=True)
          if (kpts2):
              c = image.match_descriptor(kpts1, kpts2, threshold=85)
              match = c[6] # C[6] contains the number of matches.
              if (match>10):
                  img.draw_rectangle(c[2:6])
                  img.draw_cross(c[0], c[1], size=10)
  
              print(kpts2, "matched:%d dt:%d"%(match, c[7]))
              # NOTE: uncomment if you want to draw the keypoints
              #img.draw_keypoints(kpts2, size=KEYPOINTS_SIZE, matched=True)
  
      # Draw FPS
      img.draw_string(0, 0, "FPS:%.2f"%(clock.fps()))
  
new_contents: # Object tracking with keypoints example.
  # Show the camera an object and then run the script. A set of keypoints will be extracted
  # once and then tracked in the following frames. If you want a new set of keypoints re-run
  # the script. NOTE: see the docs for arguments to tune find_keypoints and match_keypoints.
  import sensor, time, image
  
  # Reset sensor
  sensor.reset()
  
  # Sensor settings
  sensor.set_contrast(3)
  sensor.set_gainceiling(16)
  sensor.set_framesize(sensor.VGA)
  sensor.set_windowing((320, 240))
  sensor.set_pixformat(sensor.GRAYSCALE)
  
  sensor.skip_frames(30)
  sensor.set_auto_gain(False, value=100)
  
  def draw_keypoints(img, kpts):
      print(kpts)
      img.draw_keypoints(kpts)
      img = sensor.snapshot()
      time.sleep(1000)
  
  kpts1 = None
  # NOTE: uncomment to load a keypoints descriptor from file
  #kpts1 = image.load_descriptor("/desc.orb")
  #img = sensor.snapshot()
  #draw_keypoints(img, kpts1)
  
  clock = time.clock()
  while (True):
      clock.tick()
      img = sensor.snapshot()
      if (kpts1 == None):
          # NOTE: By default find_keypoints returns multi-scale keypoints extracted from an image pyramid.
          kpts1 = img.find_keypoints(max_keypoints=150, threshold=10, scale_factor=1.2)
          draw_keypoints(img, kpts1)
      else:
          # NOTE: When extracting keypoints to match the first descriptor, we use normalized=True to extract
          # keypoints from the first scale only, which will match one of the scales in the first descriptor.
          kpts2 = img.find_keypoints(max_keypoints=150, threshold=10, normalized=True)
          if (kpts2):
              match = image.match_descriptor(kpts1, kpts2, threshold=85)
              if (match.count()>10):
                  # If we have at least n "good matches"
                  # Draw bounding rectangle and cross.
                  img.draw_rectangle(match.rect())
                  img.draw_cross(match.cx(), match.cy(), size=10)
  
              print(kpts2, "matched:%d dt:%d"%(match.count(), match.theta()))
              # NOTE: uncomment if you want to draw the keypoints
              #img.draw_keypoints(kpts2, size=KEYPOINTS_SIZE, matched=True)
  
      # Draw FPS
      img.draw_string(0, 0, "FPS:%.2f"%(clock.fps()))
  
subject: Update keypoints example script.