python opencv 使用GrabCut算法分割前景

import numpy as np
import cv2
from matplotlib import pyplot as plt
%matplotlib inline
img = cv2.imread('meixi.jpg')
mask = np.zeros(img.shape[:2],np.uint8)


bgdModel = np.zeros((1,65),np.float64)
fgdModel = np.zeros((1,65),np.float64)

rect = (50,50,450,290)
cv2.grabCut(img,mask,rect,bgdModel,fgdModel,5,cv2.GC_INIT_WITH_RECT)

mask2 = np.where((mask==2)|(mask==0),0,1).astype('uint8')
img = img*mask2[:,:,np.newaxis]

plt.imshow(img),plt.colorbar(),plt.show()

[[0 0 0 ... 0 0 0]
 [0 0 0 ... 0 0 0]
 [0 0 0 ... 0 0 0]
 ...
 [0 0 0 ... 3 3 3]
 [0 0 0 ... 3 3 3]
 [0 0 0 ... 3 3 3]]

(<matplotlib.image.AxesImage at 0x22eaeb454a8>,
 <matplotlib.colorbar.Colorbar at 0x22eaeb7a860>,
 None)