title: Explanation for ddepth parameter in cv2.filter2d() opencv?
body: <pre><code>import cv2
  import numpy as np
  from matplotlib import pyplot as plt
  
  img = cv2.imread('logo.png')
  
  kernel = np.ones((5, 5), np.float32) / 25
  dst = cv2.filter2D(img, -1, kernel)
  plt.subplot(121), plt.imshow(img), plt.title('Original')
  plt.xticks([]), plt.yticks([])
  plt.subplot(122), plt.imshow(dst), plt.title('Averaging')
  plt.xticks([]), plt.yticks([])
  plt.show()
  </code></pre>
  
  <p>I was trying smoothing a picture and i didnt understand the ddepth parameter of cv2.filter2d() where the value is -1. So what does -1 do and also what does ddpeth mean ? </p>