title: How to count the number of objects detected with Template Matching?
body: <p>I was reading the docs about template matching with opencv and python and in the last part about template matching with multiple objects, the code detect the 19 coins on the mario image but, is it possible to count the number of objects detected with some function on python like len() or any opencv method?</p>
  
  <p>Here is the code showed on the tutorial:
  <a href="http://docs.opencv.org/3.1.0/d4/dc6/tutorial_py_template_matching.html" rel="nofollow noreferrer">http://docs.opencv.org/3.1.0/d4/dc6/tutorial_py_template_matching.html</a></p>
  
  <p>Template Matching Code:</p>
  
  <pre><code>import cv2
  import numpy as np
  from matplotlib import pyplot as plt
  
  img_rgb = cv2.imread('mario.png')
  img_gray = cv2.cvtColor(img_rgb, cv2.COLOR_BGR2GRAY)
  template = cv2.imread('mario_coin.png',0)
  w, h = template.shape[::-1]
  
  res = cv2.matchTemplate(img_gray,template,cv2.TM_CCOEFF_NORMED)
  threshold = 0.8
  loc = np.where( res &gt;= threshold)
  for pt in zip(*loc[::-1]):
      cv2.rectangle(img_rgb, pt, (pt[0] + w, pt[1] + h), (0,0,255), 2)
  
  cv2.imwrite('res.png',img_rgb)
  </code></pre>
  
  <p>And the result is:
  <a href="https://i.stack.imgur.com/bC0Gh.jpg" rel="nofollow noreferrer">Mario Bros &amp; Coins</a></p>
  
  <p>So, is there any way to count the coins detected on the image and print the number on the terminal?
  Something like:</p>
  
  <pre><code>The Template Matching code showed before...
  
  print "Function that detect number of coins with template matching"
  &gt;&gt;&gt; 19
  </code></pre>