Control Point Extraction

The Final Control Points:

Control Points were extracted in this order:

The order is important because the accuracy of points 3-5 is dependent on point 2.  All points are dependent of point 1.

1. Nose Tip
2. Nose Width Points (Left & Right)
3. Inner Eye Corner (Left & Right)
4. Outer Eye Corner (Left & Right)
5. Mouth Corners (Left & Right)

The Control Points were extracted using different methods:

Nose Tip - The greatest z-axis value

Nose Width - A search area is defined where the Control Point is expected to be.  The Control Point is determined by finding the steepest curve.

InnerEye - A search area is defined directly above the Nose Width Point.  The point with the lowest Z-Coordinate is determined to be the Control Point

OuterEye - The distance between the two InnerEye points is added to each control Point to determine the OuterEye point.

MouthCorner - Half the distance between from the InnerEye to the OuterEye is added to the InnerEye.  A straight line is drawn downward in the y-direction to define a new search area.  Within this region, the point with the lowest z-value is estimated to be the final control point.