Simple and Accurate Iris Center Localization Method based on Geometric Relationship of Eyeball Model

Precise iris localization plays a significant role on accurate gaze estimation. In this paper, a novel iris center localization method is proposed to deal with the iris contour change caused by the rotation of eyeball using the geometric relationship among iris center, eyeball center and iris contour. First, a face alignment method is employed to detect the face feature points that are used to initialize the iris center and eyeball locations. The three-dimensional rotation information of the eyeball is then described by the positional relationship between the centers of the eyeball and iris at the image level. The new obtained iris contour after the rotation is used to update the location of the iris center iteratively. To reduce the effect of illumination on image binarization, the cumulative histogram is introduced to adaptively get the threshold for binarization. Finally, experiments conducted on the BioID Face dataset and GI4E dataset as well as eight subjects demonstrate the superior performance of the proposed method.