Pattern recognition in an image using python?

Question

How can I use Python to find similar simple patterns in a black and white image? For example: find all figures with a horizontal pattern and all figures with vertical lines and mark them as separate groups. I guess I'll end up using the OpenCV library but haven´t quite found the way.

To make myself clear, I include images of what I would expect the program to do.

Answer 1

I assume that the patterns you are looking for are already known.
Template Matching should then do the trick for you:

Template Matching is a method for searching and finding the location of a template image in a larger image.

Things will get more complicated, if the patterns your are looking for are scaled or rotated in the bigger image, but from the example you provided this shouldn't be the case