2.6.8.11. Image denoising

This example demoes image denoising on a Raccoon face.

import numpy as np
import scipy as sp
import matplotlib.pyplot as plt

rng = np.random.default_rng(27446968)

f = sp.datasets.face(gray=True)
f = f[230:290, 220:320]

noisy = f + 0.4 * f.std() * rng.random(f.shape)

gauss_denoised = sp.ndimage.gaussian_filter(noisy, 2)
med_denoised = sp.ndimage.median_filter(noisy, 3)


plt.figure(figsize=(12, 2.8))

plt.subplot(131)
plt.imshow(noisy, cmap="gray", vmin=40, vmax=220)
plt.axis("off")
plt.title("noisy", fontsize=20)
plt.subplot(132)
plt.imshow(gauss_denoised, cmap="gray", vmin=40, vmax=220)
plt.axis("off")
plt.title("Gaussian filter", fontsize=20)
plt.subplot(133)
plt.imshow(med_denoised, cmap="gray", vmin=40, vmax=220)
plt.axis("off")
plt.title("Median filter", fontsize=20)

plt.subplots_adjust(wspace=0.02, hspace=0.02, top=0.9, bottom=0, left=0, right=1)
plt.show()