title: cv.imshow() is not working - cv2 method - pycharm
body: <p>im new to python and coding. i wanted to play around with cv2 and learn the module but came across a problem my first go. Im sure its a simple fix however the tutorial video im watching has the same code.</p>
  <pre><code>import cv2 as cv
  img = cv.imread(&quot;dog.png&quot;)
  cv.imshow(&quot;Output&quot;, img)
  cv.waitKey(0)
  </code></pre>
  <p>#angrey red error message</p>
  <pre><code>Traceback (most recent call last):
    File &quot;C:/Users/jaski/PycharmProjects/opencvpython1/main.py&quot;, line 3, in &lt;module&gt;
      cv.imshow(&quot;Output&quot;, img)
  cv2.error: OpenCV(4.3.0) C:\projects\opencv-python\opencv\modules\highgui\src\window.cpp:376: error: (-215:Assertion failed) size.width&gt;0 &amp;&amp; size.height&gt;0 in function 'cv::imshow'
  </code></pre>