为了提取人眼的高精度亚像素特征参数，利用亮瞳现象，提出了一种基于多通道图像的高精度亚像素特征参数提取方法。该方法首先通过差分图像滤波获得瞳孔区域，进而检测瞳孔区域的边缘，并在眼睛区域附近基于灰度，搜索角膜反射区域； 然后求取其质心用于定位角膜反射区域中心，并对瞳孔边缘做滤波，以消除角膜反射对瞳孔边缘轮廓的影响,进而利用椭圆拟合来定位瞳孔中心；最后提取包括人眼特征和人脸位置的多个参数，另外，还建立了一个多特征参数提取的流程,为下一步的视线估计提供了参数依据。 实验结果及视线追踪系统最终的视线估计结果证明，该方法是有效的。

In order to extract the high-precision sub-pixel feature parameters，this paper presents a high-precision sub-pixel feature extraction method based on the multichannel image by use of the phenomenon of the bright pupil. Firstly, the pupil area is obtained by filter on a difference image. Then the edge of the pupil area is detected and cornea reflection area is searched nearby the eye area based on gray level. Then corneal reflex center is located by centroid and the edge of the pupil is filtered to eliminate the impact of corneal reflex to the contour of the pupil. Ellipse fitting is used to locate the pupil center. Finally, multiple parameters of facial features and face position are extracted.We establish a multi-feature extraction process, which provides parameter basis for gaze estimation which is in the next step. The results of feature extraction and the ultimate gaze estimation results made by gaze tracking system verify the effectiveness of the method.