import cv2
img_opencv = cv2.imread('C:/Users/20752/Desktop/GraduationProject/DogFace/DogFace/OpenSourceCrop_align/0/0.0.png')# BGR
plt.figure()
plt.imshow(img_opencv)
plt.show()

gray_img = cv2.cvtColor(img_opencv, cv2.COLOR_BGR2GRAY)##彩色图像转为灰度图像
plt.figure()
plt.imshow(gray_img)
plt.show()

img_opencv = cv2.cvtColor(img_opencv, cv2.COLOR_BGR2RGB)