一种高精度头部受限式眼动仪

摘要

探讨了一种基于视频图像的高精度头部受限式眼动仪。在测量凝视点的过程中，被测对象将下颌放在支架上并保持头部不动，同时用摄像机拍摄其某一只眼睛的图像。根据瞳孔和普尔钦亮斑在眼部图像中的相对位置，确定被测对象在计算机显示器上的凝视点坐标。文中不仅给出了凝视点测量数学模型，还给出了瞳孔和普尔钦亮斑的识别方法。为了识别瞳孔和普尔钦亮斑，首先将眼部图像转换为二值图像，然后采用F．Chang等人提出的方法标记二值图像中的每个团块。在此基础上，根据各团块的面积和形状分别识别眼部图像中的瞳孔和普尔钦亮斑。文中也给出了部分实验结果，实验结果表明：实验装置的最大平均测量误差为0．62°。%It discusses a video -based head-fixed eye tracker with high precision .While measuring the coordi-nates associated with eye -gaze, a subject places his mandibular on a support and keeps his head fixed .Mean-while, a camera is used to capture images of the subject's left or right eye .The subject's gaze point fallen on a computer screen can be determined according to the relative position of the pupil and Purkinje reflex in an eye image .This paper presents not only the mathematical model used to measure the coordinates associated with eye gaze , but also the methods used to recognize the pupil and Purkinje reflex in an eye image .To recognize the pupil and Purkinje reflex in an eye image , the eye image is firstly converted into a binary image , and then the method proposed by F .Chang et al is used to label the components in the binary image .On this basis, the pu-pil and Purkinje reflex in an eye image are recognized based on the area and shape of the components .This pa-per also presents some experimental results , and the experimental results show that the maximal average error of the experimental apparatus is 0.62 degree.