new_contents: # Hough Transform Example:
  #
  # This example demonstrates using the Hough transform to find lines in an image.
  import sensor, image, time
  
  kernel_size = 1 # kernel width = (size*2)+1, kernel height = (size*2)+1
  kernel = [-1, -1, -1,\
            -1, +8, -1,\
            -1, -1, -1]
            
  # This is a high pass filter kernel. see here for more kernels:
  # http://www.fmwconcepts.com/imagemagick/digital_image_filtering.pdf
  thresholds = [(200, 255)] # grayscale thresholds
  
  sensor.reset() # Initialize the camera sensor.
  sensor.set_pixformat(sensor.GRAYSCALE) # or sensor.RGB565
  sensor.set_framesize(sensor.QQVGA) # or sensor.QVGA (or others)
  sensor.skip_frames(30) # Let new settings take affect.
  clock = time.clock() # Tracks FPS.
  
  # On the OV7725 sensor, edge detection can be enhanced
  # significantly by setting the sharpness/edge registers.
  # Note: This will be implemented as a function later.
  if (sensor.get_id() == sensor.OV7725):
      sensor.__write_reg(0xAC, 0xDF)
      sensor.__write_reg(0x8F, 0xFF)
  
  while(True):
      clock.tick() # Track elapsed milliseconds between snapshots().
      sensor.set_pixformat(sensor.GRAYSCALE)
      img = sensor.snapshot() # Take a picture and return the image.
  
      img.morph(kernel_size, kernel)
      img.binary(thresholds)
  
      # Erode pixels with less than 2 neighbors using a 3x3 image kernel
      img.erode(1, threshold = 2)
      img.draw_rectangle((0, 0, 160, 120), color=0x00)
      
      # Find lines.
      lines = img.find_lines(threshold=40)
      # Switch back to RGB to draw red lines.
      sensor.set_pixformat(sensor.RGB565) # or sensor.RGB565
      img = sensor.snapshot()
      for l in lines:
          img.draw_line(l, color=(0xFF, 0x00, 0x00))
  
      print(clock.fps()) # Note: Your OpenMV Cam runs about half as fast while
      img = sensor.snapshot() # Take a picture and return the image.
  
subject: Add Hough Transform example script.