灰度分层

import cv2
import numpy as np
from skimage import data,color
from matplotlib import pyplot as plt
img=cv2.imread('C:/Users/xpp/Desktop/Lena.png')#原始图像
cv2.imshow("original",img)
grayimg=color.rgb2gray(img)#将彩色图片转换为灰度图片
rows,cols=grayimg.shape
labels=np.zeros([rows,cols])
for i in range(rows):
    for j in range(cols):
        if(grayimg[i,j]<0.4):
            labels[i,j]=0
        elif(grayimg[i,j]<0.8):
            labels[i,j]=1
        else:
            labels[i,j]=2
psdimg=color.label2rgb(labels)#灰度分层
cv2.imshow("result",psdimg)        
cv2.waitKey()
cv2.destroyAllWindows()