title: tesseract not able to read all digits accurately
body: <p>I'm using Tesseract to recognize numbers from images of a screen taken with a phone camera. I've done some preprocessing of the image: <a href="https://i.stack.imgur.com/P1zma.jpg" rel="nofollow noreferrer">processed image</a>, and using Tesseract, I'm able to get some mixed results. Using the following code on the above images, I get the following output: "EOE". However, with this image, <a href="https://i.stack.imgur.com/R5q4E.jpg" rel="nofollow noreferrer">processed image</a>, I get an exact match: "39:45.8"</p>
  
  <pre><code>import cv2
  import pytesseract
  from PIL import Image, ImageEnhance
  from matplotlib import pyplot as plt
  
  orig_name  = "time3.jpg";
  image_name = "time3_.jpg";
  
  img = cv2.imread(orig_name, 0)
  img = cv2.medianBlur(img, 5)
  
  img_th = cv2.adaptiveThreshold(img, 255,\
      cv2.ADAPTIVE_THRESH_MEAN_C,cv2.THRESH_BINARY, 11, 2)
  
  cv2.imshow('image', img_th)
  cv2.waitKey(0)
  cv2.imwrite(image_name, img_th)
  
  im = Image.open(image_name)
  
  time = pytesseract.image_to_string(im, config = "-psm 7")
  print(time)
  </code></pre>
  
  <p>Is there anything I can do to get more consistent results?</p>