OCR is used for recognizing street signs (Google Street View) and searching through photos (Dropbox). If you like to know its working, this document helps.
OCR, or optical character recognition, is one of the earliest addressed computer vision tasks, since in some aspects it does not require deep learning. Below is the data-set of house numbers extracted from google street view.
Below flow talks how an image is processed for extracting characters
Most of today text CAPTCHAs are not very hard to solve, especially if we don’t try to solve all of them at once.
Capturing text from moving object. For example, capturing vehicle number
Capturing texts in street view (Ref Google street view)
Extracting text from PDF
Digitisation of hand written books (Refer Mnist)
Variety of letters: Letter orms in some alphabets are harder to recognize. For example, as even the printed Arabic characters are in the cursive form, character recognition becomes a challenge.
Variety of font types & sizes
Look-alike characters - For example, it is hard to differentiate between the number “0” and the letter “O”
Handwritten text
It uses convolutional neural networks
EAST, or Efficient and Accurate Scene Text Detector, is a deep learning model for detecting text from natural scene images
Refer here for OpenCV python library
https://youtu.be/GA35F3N3i_I
https://mobidev.biz/blog/ocr-machine-learning-implementation
https://towardsdatascience.com/a-gentle-introduction-to-ocr-ee1469a201aa
https://medium.com/syncedreview/stn-ocr-a-single-neural-network-for-text-detection-and-text-recognition-220debe6ded4
https://research.aimultiple.com/ocr-technology/
https://images.app.goo.gl/85ABhFcLgnnxcu9LA
https://images.app.goo.gl/5ex2vHXavJmaRTW58