You're right to ask. Some of the methods like Eigenfaces are antiquated when compared to today, existing, stand-alone methods. Sadly, the context of the listed

You're right to ask. Some of the methods like Eigenfaces are antiquated when compared to today, existing, stand-alone methods. Sadly, the context of the listed papers and implementations is lacking. It's not because it's outdated that it's worthless given the right outlook.