import cv2
import matplotlib.pyplot as plt

image=cv2.imread('photo.jpeg',0)
img=cv2.cvtColor(image,cv2.COLOR_BGR2RGB)
negative=255-img

plt.figure(figsize=(8,4))
plt.subplot(1,2,1)
plt.title("Original Image")
plt.imshow(img)
plt.axis('off')
plt.subplot(1,2,2)
plt.title("Negative Image")
plt.imshow(negative)
plt.axis('off')
plt.show()