title: Why pytesseract does not recognise single digits?
body: <p>I am performing ocr on a site and specifically on these two images:
  <img src="https://i.stack.imgur.com/lNKH4.png" alt="image1.png"></p>
  
  <p><img src="https://i.stack.imgur.com/FX2in.png" alt="image2.png"></p>
  
  <p>I am fairly new to OCR, I use the following:</p>
  
  <pre><code>from PIL import Image
  import pytesseract
  
  my_image = '....png'
  text = pytesseract.image_to_string(Image.open(my_image))
  </code></pre>
  
  <p>In the second image it recognises everything except the single digits 3, 4, 5, 6.</p>
  
  <p>In the first image it does not recognises the single digits too.</p>
  
  <p>I preprocess the images by resizing them, inverting them and using threshold.</p>
  
  <p>It's a standard font so I know there are other ways to do this, but until a certain degree it works for me, so I want to keep it simple before going to something more advanced.</p>