Values.LandmarkSourceIndicates the location of the landmark on the face.
type nonrec t = {type_ : LandmarkType.t option;Type of landmark.
*)x : Float_.t option;The x-coordinate of the landmark expressed as a ratio of the width of the image. The x-coordinate is measured from the left-side of the image. For example, if the image is 700 pixels wide and the x-coordinate of the landmark is at 350 pixels, this value is 0.5.
*)y : Float_.t option;The y-coordinate of the landmark expressed as a ratio of the height of the image. The y-coordinate is measured from the top of the image. For example, if the image height is 200 pixels and the y-coordinate of the landmark is at 50 pixels, this value is 0.25.
*)}