title: Python OpenCV: Image Denoising for Text Recognition
body: <p>I have this set of images I want to de-noise in order to run OCR on it:</p>
  
  <p><a href="https://i.stack.imgur.com/Y6bW06.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Y6bW06.jpg" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/3IP0Hg.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3IP0Hg.jpg" alt="enter image description here"></a></p>
  
  <p>I am trying to read the 7810 from the image.</p>
  
  <p>I have tried </p>
  
  <pre><code>cv2.threshold(img, 128, 255,cv2.THRESH_BINARY_INV | cv2.THRESH_OTSU)
  cv2.fastNlMeansDenoising(img,None,60,10,20)
  </code></pre>
  
  <p>and some morphological expressions but none seem to work to clear this image sufficiently.</p>
  
  <p>Any recommendations on how to filter this image sufficiently that I could run OCR or some ML detection scripts on this like pytesseract?</p>