Machine Learning for Cybersecurity Cookbook

How to do it...

In the following steps, we'll process a CAPTCHA dataset to make it amenable to training a machine learning model:

1. Collect a large corpus of CAPTCHAs.
2. Our next goal is to process the CAPTCHAs, specify where the CAPTCHA images are stored and then enumerate all CAPTCHAs in the specified folder:

import oscaptcha_images_folder = "captcha_images"captchas = [    os.path.join(captcha_images_folder, f) for f in os.listdir(captcha_images_folder)]

3.  Define a function that will take the image of a CAPTCHA and produce a grayscale version, as well as a thresholded (that is, black and white) version of the CAPTCHA's image:

import cv2def preprocess_CAPTCHA(img):    """Takes a CAPTCHA image and thresholds it.""" gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) ...