title: Why does adding Gaussian noise to image give white screen?
body: <p>I added some Gaussian noise to the image(water_coins.jpg) added below, but it returns me a completely white blank screen (for both "noi" and "hoho"). I can't figure out why</p>
  
  <pre><code>import numpy as np
  import cv2
  
  
  def gauss_noise(image):
      row, col, ch = image.shape
      mean = 0
      var = 0.01
      sigma = var ** 0.5
      gauss = np.random.normal(mean, sigma, (row, col, ch))
      gauss = gauss.reshape(row, col, ch)
      print(image)
      cv2.imshow("hoho", gauss + image)
      noisy = image + gauss
      return noisy
  
  
  img = cv2.imread('water_coins.jpg')
  noi = gauss_noise(img)
  cv2.imshow("Noisy Gauss image", noi)
  cv2.imshow("ho", img)
  cv2.waitKey()
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/Ve1Dy.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Ve1Dy.jpg" alt="Water_coins.jpg"></a></p>