title: Photoshop like brush with OpenCV
body: <p>I am trying to add some blur brush stroke with OpenCV</p>
  
  <p>If I use cv.add or cv.addweighted, I only got half of the red color (look pink), </p>
  
  <p>but I want the red to cover the underlying picture, not blend.</p>
  
  <p>If I use copyto or clone, I can't get the blur edge, so how should I do it ??</p>
  
  <p><a href="https://i.stack.imgur.com/876pU.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/876pU.jpg" alt="Paint Brush"></a></p>
  
  <p><a href="https://i.stack.imgur.com/MDGhv.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/MDGhv.jpg" alt="enter image description here"></a></p>