import matplotlib.pyplot as plt
from skimage.morphology import convex_hull_image
from skimage import data, img_as_float
from skimage.util import invert
image = invert(data.horse())
chull = convex_hull_image(image)
fig, ax = plt.subplots(1, 3, figsize=(18, 9))
ax[0].imshow(data.horse(),'gray')
ax[0].set_title('data.horse')
ax[1].set_title('Original picture')
ax[1].imshow(image, cmap=plt.cm.gray, interpolation='nearest')
ax[1].set_axis_off()
ax[2].set_title('Transformed picture')
ax[2].imshow(chull, cmap=plt.cm.gray, interpolation='nearest')
ax[2].set_axis_off()
plt.tight_layout()
plt.show()
