Extracting Egomotion from Optic Flow: Limits of Accuracy and Neural Matched Filters
Extracting Egomotion from Optic Flow: Limits of Accuracy and Neural Matched Filters
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从光流中提取自我运动：精度和神经匹配滤波器的限制
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发表时间：
2001
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通讯作者：
H. Krapp
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作者：
H. Dahmen;Mattihas O. Franz;H. Krapp
在这一章中，我们回顾了两项旨在理解从光学流场中提取运动参数的主要限制的工作(Dahmen等人)。以及苍蝇视觉系统中运动敏感神经元的感受野组织的功能意义(Franz和KRapp 1999)。在第一个研究中，我们模拟了观察者在随机分布的物体环境中同时旋转R和平移T的不同大小和方向时所经历的噪声图像流。估计R的大小和方向以及T方向的t‘是从这种扰动图像流的样本中得到的，并使用Koenderink和van Doom(1987)提出的迭代程序与原始向量进行了比较。采样被限制在视野的一个或两个锥形区域，这些区域具有不同的角度大小和相对于运动矢量R和T平行或垂直的观察方向。我们还研究了环境结构的影响，如物体的不同深度分布以及平面或球面的作用。从我们的结果中，我们得出了两条优化运动估计的一般规则：(I)通过扩大视场来最小化误差。(Ii)从相反方向采样图像运动提高了精度，特别是在小视场情况下。
In this chapter we review two pieces of work aimed at understanding the principal limits of extracting egomotion parameters from optic flow fields (Dahmen et al. 1997) and the functional significance of the receptive field organization of motion sensitive neurones in the fly’s visual system (Franz and Krapp 1999). In the first study, we simulated noisy image flow as it is experienced by an observer moving through an environment of randomly distributed objects for different magnitudes and directions of simultaneous rotation R and translation T. Estimates R’ of the magnitude and direction of R and t’ of the direction of T were derived from samples of this perturbed image flow and were compared with the original vectors using an iterative procedure proposed by Koenderink and van Doom (1987). The sampling was restricted to one or two cone-shaped subregions of the visual field, which had variable angular size and viewing directions oriented either parallel or orthogonal with respect to the egomotion vectors R and T. We also investigated the influence of environmental structure, such as various depth distributions of objects and the role of planar or spherical surfaces. From our results we derive two general rules how to optimize egomotion estimates: (i) Errors are minimized by expanding the field of view. (ii) Sampling image motion from opposite directions improves the accuracy, particularly for small fields of view.