Srikrishnan V, Chaudhuri Subhasis
Department of Electrical Engineering, Indian Institute of Technology, Bombay, Mumbai, PIN 400076, India.
IEEE Trans Image Process. 2009 Aug;18(8):1859-72. doi: 10.1109/TIP.2009.2021310. Epub 2009 Apr 21.
Depending on implementation, active contours have been classified as geometric or parametric active contours. Parametric contours, irrespective of representation, are known to suffer from the problem of irregular bunching and spacing out of curve points during the curve evolution. In a spline-based implementation of active contours, this leads to occasional formation of loops locally, and subsequently the curve blows up due to instabilities. In this paper, we analyze the reason for this problem and propose a solution to alleviate the same. We propose an ordinary differential equation (ODE) for controlling the curve parametrization during evolution by including a tangential force. We show that the solution of the proposed ODE is bounded. We demonstrate the effectiveness of the proposed method for segmentation and tracking tasks on closed as well as open contours.
根据实现方式的不同，活动轮廓已被分为几何活动轮廓或参数活动轮廓。参数轮廓，无论其表示形式如何，在曲线演化过程中都存在曲线点不规则聚集和间隔的问题。在基于样条的活动轮廓实现中，这会导致局部偶尔形成环路，随后曲线因不稳定而爆炸。在本文中，我们分析了这个问题的原因，并提出了一种解决方案来缓解该问题。我们提出了一个常微分方程（ODE），通过引入切向力来在演化过程中控制曲线参数化。我们证明了所提出的ODE的解是有界的。我们展示了所提出的方法在封闭轮廓和开放轮廓的分割与跟踪任务中的有效性。
