# -*- coding: utf-8 -*-  
from PIL import Image  
from pylab import *  
from PCV.tools import imtools  
import numpy
 
  
im = array(Image.open('C:/pic/train2/1.jpg').convert('L'))  # 開啟影象，並轉成灰度影象  
img11=Image.fromarray(uint8(im))
img11.save("C:/pic/train2/10.jpg")# 儲存灰度影象
 

補充用opencv開啟和儲存影象：

#coding=utf-8  
import cv2  
   
  
img = cv2.imread("C:/pic/train1/2.jpg", 0)   
cv2.imwrite('C:/pic/1/5.jpg',img)