new_contents: #!/usr/bin/env python
  
  import sys, warnings
  from skimage import io, color, img_as_ubyte
  
  if len(sys.argv) != 4:
      print 'Usage: %s <cfam.png> <fam.png> <outfile.png>' % sys.argv[0]
      sys.exit(1)
  
  fam = io.imread(sys.argv[2])
  fam_norm = fam.astype(float) / 255
  cfam = io.imread(sys.argv[1])[:, :, 0:3]
  cfam_lab = color.rgb2lab(cfam)
  cfam_lightness = cfam_lab[:, :, 0].astype(float) / 100
  lcfam_lab = cfam_lab
  lcfam_lightness = fam_norm * 100
  lcfam_lab[:, :, 0] = lcfam_lightness
  lcfam = color.lab2rgb(lcfam_lab)
  warnings.simplefilter("ignore")
  io.imsave(sys.argv[3], lcfam);
subject: Add command line tool