基于脸部骨骼位置信息的唇凸度计算方法
Lip protrusion measurement based on facial skeleton data

该文主要讨论了唇凸度的定义和提取方法。根据上、下唇的运动规律不同，该文把上唇和下唇凸度分别定义为上唇或下唇外沿到上或下门齿的Euclid距离。使用运动捕获器获取发音过程中脸部标志点运动的三维坐标信息，运用奇异值分解法消除头部刚体运动和下颌的开口运动，利用置于脸部骨骼的参考点分别推算出上下门齿的空间位置，使用上唇和下唇外沿的坐标位置计算上唇或下唇凸度。结果表明：该计算方法不但在三维唇形数据上测试效果良好，同时也适用于二维唇形数据。
Abstract：The paper presents a method to measure lip protrusion. The upper and low lip movement patterns differ, so the lip protrusion is defined for the upper or lower lips as the Euclidean distance between the lip edge and the incisor. Three-dimensional lip coordinates were obtained by observing the trajectories of reference markers on human faces. The singular value decomposition (SVD) method was used to eliminate the head rigid-body movement and mouth opening movement. Then, the coordinates for the upper and lower incisors were obtained by calculating the coordinates of the reference markers pasted on the facial bony structure. Finally, lip edge coordinates were introduced to calculate the lip protrusion. The method gives good results with three-dimensional lip data and is also applicable for analyzing two-dimensional lip data.