How are these nodal points determined by a face recognition software?

Nodal points in face recognition software, often referred to as "landmarks," are determined through algorithms that analyze key facial features like the eyes, nose, mouth, and the contours of the face. Techniques such as facial landmark detection use machine learning models trained on large datasets of facial images to identify these points with high accuracy. Once established, these nodal points help in creating a unique facial signature that can be used for recognition and comparison against other images. The process typically involves detecting and aligning the face, followed by extracting features based on the identified landmarks.