Save matplotlib no margins

matplotlib-fig-no-margins.py

%matplotlib inline
import matplotlib
import matplotlib.pyplot as plt
import seaborn as sns
import numpy as np
from PIL import Image
fname = '../../test-graf/img1.png'
img = Image.open(fname).convert('RGB')
img = np.array(img)

fig, ax = plt.subplots(1,1,figsize=(12,12),frameon=False)
fig.subplots_adjust(hspace = 0, wspace = 0)
ax.imshow(img), 
ax.plot(100+np.arange(100), 100+np.arange(100), linewidth=10)
ax.grid('off')

ax.xaxis.set_major_locator(plt.NullLocator())
ax.yaxis.set_major_locator(plt.NullLocator())
fig.savefig('graf.pdf', bbox_inches = 'tight',  pad_inches = 0)