text: # Edge Detection Example:
  #
  # This example demonstrates using the morph function on an image to do edge
  # detection and then thresholding and filtering that image afterwards.
  
  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 = [(100, 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(10) # 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().
      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)
  
      print(clock.fps()) # Note: Your OpenMV Cam runs about half as fast while
      # connected to your computer. The FPS should increase once disconnected.
  