The world of Machine Learning is vast and mostly unexplored, and ANNs are but one of the many concepts related to Machine Learning, which is one of the many subdisciplines of Artificial Intelligence. For the purpose of this chapter, we will only be exploring the concept of ANNs in the context of OpenCV. It is by no means an exhaustive treatise on the subject of Artificial Intelligence.
Ultimately, we're interested in seeing ANNs work in the real world. So let's go ahead and make it happen.
One of the most popular resources on the Web for the training of classifiers dealing with OCR and handwritten character recognition is the MNIST database, publicly available at http://yann.lecun.com/exdb/mnist/.
This particular database is a freely available resource to kick-start the creation of a program that utilizes ANNs to recognize handwritten digits.