Zhu Zhiwei, Ji Qiang
Department of Electrical, Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180-3590, USA.
IEEE Trans Biomed Eng. 2007 Dec;54(12):2246-60. doi: 10.1109/tbme.2007.895750.
Most available remote eye gaze trackers have two characteristics that hinder them being widely used as the important computer input devices for human computer interaction. First, they have to be calibrated for each user individually; second, they have low tolerance for head movement and require the users to hold their heads unnaturally still. In this paper, by exploiting the eye anatomy, we propose two novel solutions to allow natural head movement and minimize the calibration procedure to only one time for a new individual. The first technique is proposed to estimate the 3-D eye gaze directly. In this technique, the cornea of the eyeball is modeled as a convex mirror. Via the properties of convex mirror, a simple method is proposed to estimate the 3-D optic axis of the eye. The visual axis, which is the true 3-D gaze direction of the user, can be determined subsequently after knowing the angle deviation between the visual axis and optic axis by a simple calibration procedure. Therefore, the gaze point on an object in the scene can be obtained by simply intersecting the estimated 3-D gaze direction with the object. Different from the first technique, our second technique does not need to estimate the 3-D eye gaze directly, and the gaze point on an object is estimated from a gaze mapping function implicitly. In addition, a dynamic computational head compensation model is developed to automatically update the gaze mapping function whenever the head moves. Hence, the eye gaze can be estimated under natural head movement. Furthermore, it minimizes the calibration procedure to only one time for a new individual. The advantage of the proposed techniques over the current state of the art eye gaze trackers is that it can estimate the eye gaze of the user accurately under natural head movement, without need to perform the gaze calibration every time before using it. Our proposed methods will improve the usability of the eye gaze tracking technology, and we believe that it represents an important step for the eye tracker to be accepted as a natural computer input device.
大多数现有的远程视线追踪器有两个特点，这阻碍了它们被广泛用作人机交互的重要计算机输入设备。第一，它们必须针对每个用户单独进行校准；第二，它们对头部运动的容忍度较低，要求用户不自然地保持头部静止。在本文中，通过利用眼睛解剖结构，我们提出了两种新颖的解决方案，以允许自然的头部运动，并将校准过程最小化到针对新个体仅需一次。第一种技术被提出用于直接估计三维视线。在这项技术中，眼球的角膜被建模为一个凸面镜。通过凸面镜的特性，提出了一种简单的方法来估计眼睛的三维光轴。在通过一个简单的校准过程知道视轴和光轴之间的角度偏差后，随后可以确定作为用户真实三维注视方向的视轴。因此，通过简单地将估计的三维注视方向与场景中的物体相交，就可以获得场景中物体上的注视点。与第一种技术不同，我们的第二种技术不需要直接估计三维视线，而是从一个注视映射函数隐式地估计物体上的注视点。此外，还开发了一个动态计算头部补偿模型，以便在头部移动时自动更新注视映射函数。因此，可以在自然头部运动下估计视线。此外，它将针对新个体的校准过程最小化到仅需一次。所提出的技术相对于当前最先进的视线追踪器的优势在于，它可以在自然头部运动下准确估计用户的视线，而无需在每次使用前进行注视校准。我们提出的方法将提高视线追踪技术的可用性，并且我们相信这代表了视线追踪器被接受为自然计算机输入设备的重要一步。
