EXTRACTION OF CONTOUR PART ONLY FACE IMAGE AND IMAGING METHOD

As shown in the figure above (for example, I don't want to do it in the same way as this), how can I extract only the outline that does not include hair from the face image and make it into an image?
The language is Python or C++.The image is from http://www.intechopen.com/books/new-approaches-to-characterization-and-recognition-of-faces/real-time-video-face-recognition-for-embedded-devices.Its purpose is to automatically process large amounts of images.

I thought about using Opencv's facial recognition to cut the outline from the feature points, but I would appreciate it if you could tell me specifically how to implement it