code: def prepro(I):
      
      I = I[35:195]
      I = I[::2, ::2, 0]
      I[I == 144] = 0
      I[I == 109] = 0
      I[I != 0] = 1
      return I.astype(np.float).ravel()
docs: Prepro 210x160x3 uint8 frame into 6400 (80x80) 1D float vector.