title: How do I rotate an image manually without using cv2.getRotationMatrix2D
body: <p>I want to rotate an image without using built-in cv2 library. So I have seen this equation</p>
  
  <p><img src="https://i.stack.imgur.com/NBWON.png" alt=""> </p>
  
  <p>but I dont know how do I apply it in my code.</p>
  
  <p>//edit  </p>