import pnm_image


color_im = pnm_image.load_ppm("ar.ppm")

print "image size: %dx%d" % (color_im.width, color_im.height)

red_channel = pnm_image.color_image_channel(color_im, pnm_image.CHANNEL_R)

if hasattr(pnm_image, "image_to_numpy_array"):
  print "converting red channel to numpy array"

  table = pnm_image.image_to_numpy_array(red_channel)

  from matplotlib import pyplot
  pyplot.gray()
  pyplot.imshow(table)
  pyplot.show()


# explicit deletion...
pnm_image.color_image_delete(color_im)
pnm_image.image_delete(red_channel)