Represent a face landmark. A landmark is a point on a detected face, such as an eye, nose, or mouth.
When 'left' and 'right' are used, they are relative to the subject in the image. For example, the
is the subject's left eye, not the eye that is on the left when viewing the image.
Gets a 2D point for landmark position, where (0, 0) is the upper-left corner of the image.