Head

The Head movement is defined along three directional dimensions: Vertical, Sagittal and Lateral dimension.

Vertical Head Turn is a Left/Right rotation around the vertical axis (around y axis).
Sagittal Head Tilt is an Upward/Downward rotation in the sagittal plan (around x axis).
Lateral Head Tilt is Left/Right rotation in the lateral plan (around z axis).

We distinguish two types of head movement: Head Gesture and Head posture. For each type of head movement we can use one, two or three directional dimensions. For example Head Shake gesture is defined along the vertical dimension starting from the right (or the left) direction to the left (or right) direction. Left upward head posture uses Vertical and Sagittal dimension with Left direction for the first dimension and Upward direction for the second dimension

<head id="ShakeRightLeft" lexeme="SHAKE">
	<KeyPoint type="strokeStart">
		<VerticalTurn direction="Right" min="0.02" max="0.5"/>
	</keypoint>

	<KeyPoint type="strokeEnd">
		<VerticalTurn direction="Left" min="0.02" max="0.5"/>
	</keypoint>
</head>
<head id="ShakeLeftRight" lexeme="SHAKE">
	<KeyPoint type="strokeStart">
		<VerticalTurn direction="Left" min="0.02" max="0.5"/>
	</keypoint>

	<KeyPoint type="strokeEnd">
		<VerticalTurn direction="Right" min="0.02" max="0.5"/>
	</keypoint>
</head>

<headDirectionShift id="LeftTurnUpward">
	<VerticalTurn direction="Left" min="0.0" max="0.5"></verticalturn>
	<SagittalTilt direction="Upward" min="0.0" max="0.5"></sagittaltilt>
</headdirectionshift>

Additional information about head gestures are presented in the XML files HeadGestures and HeadAmount. The former defines the proposed (but not the final) set of head postures and gestures, while the latter defines the real values of maximal head gesture amount (in degree) with respect to the human anatomy.