How to extract numbers or digits using OCR in Python

Question

I try to extract numbers using OCR.

The development environment is run by pycharm (Python version 3).

My problem is how to extract numbers using OCR.

The image looks like this:

In the picture above I want to get the following numeric text:

1 2   3
4 5 6 7
8 9   0

How can I get the results I want?

Answer 1

There a range of libraries to achieve this here is an example of one from: https://pypi.org/project/pytesseract/ https://github.com/madmaze/pytesseract

try:
    from PIL import Image
except ImportError:
    import Image
import pytesseract

# If you don't have tesseract executable in your PATH, include the following:
pytesseract.pytesseract.tesseract_cmd = r'<full_path_to_your_tesseract_executable>'
# Example tesseract_cmd = r'C:\Program Files (x86)\Tesseract-OCR\tesseract'

# Simple image to string
print(pytesseract.image_to_string(Image.open('test.png')))

Answer 2

You can Otsu's threshold to obtain a binary image then extract each number. After thresholding we get this

Now we iterate through the contours and extract/save each ROI

Now you can apply your desired OCR tool to read the text on each ROI

import cv2

image = cv2.imread('1.jpg', 0)
thresh = cv2.threshold(image, 0, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)[1]

cnts = cv2.findContours(thresh, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
cnts = cnts[0] if len(cnts) == 2 else cnts[1]
for c, num in zip(cnts, range(len(cnts))):
    x,y,w,h = cv2.boundingRect(c)
    ROI = 255 - thresh[y:y+h, x:x+w]
    cv2.imwrite('ROI_{}.png'.format(num), ROI)

cv2.imshow('thresh', 255 - thresh)
cv2.waitKey()