https://github.com/Calamari-OCR/calamari
https://builtin.com/data-science/python-ocr
https://www.geeksforgeeks.org/python-reading-contents-of-pdf-using-ocr-optical-character-recognition/#
https://github.com/usnistgov/ocr-pipeline
https://github.com/Calamari-OCR/calamari
https://builtin.com/data-science/python-ocr
https://www.geeksforgeeks.org/python-reading-contents-of-pdf-using-ocr-optical-character-recognition/#
https://github.com/usnistgov/ocr-pipeline