Matplotlib includes the image module for image manipulation

import matplotlib.image as mpimg
import matplotlib.pyplot as plt

Images are read from file (.png only) with the imread function:

img = mpimg.imread('my_image.png')

and they are rendered by the imshow function:

plt.imshow(img)

Let's plot the Stack Overflow logo:

import matplotlib.image as mpimg
import matplotlib.pyplot as plt
img = mpimg.imread('so-logo.png')
plt.imshow(img)
plt.show()

The resulting plot is