This project is used to recognize the postal code on the envelope along with Optical Character Recognition.
Run ip.py to get the number image on the envelope.
Run knn.py to recognize the number in the image with knn classifier.
http://arbu00.blogspot.tw/2016/11/1-opencv-knn.html
https://mehmethanoglu.com.tr/blog/6-opencv-ile-dikdortgen-algilama-python.html
https://www.quora.com/How-do-I-extract-a-particular-object-from-images-using-OpenCV
https://stackoverflow.com/questions/30331944/finding-red-color-using-python-opencv