SHAPE MODELING WITH FRONT PROPAGATION - A LEVEL SET APPROACH
SHAPE MODELING WITH FRONT PROPAGATION - A LEVEL SET APPROACH
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DOI：
10.1109/34.368173
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发表时间：
1995-02-01
影响因子：
23.6
通讯作者：
VEMURI, BC
中科院分区：
文献类型：
--
作者：
MALLADI, R;SETHIAN, JA;VEMURI, BC
形状建模是计算机视觉以及计算机图形研究的重要组成部分。形状模型有助于对象表示和识别的任务。本文提出了一种塑造建模的新方法，该方法保留了现有方法的一些吸引力，并克服了其一些局限性。我们的技术可以应用于模型任意复杂的形状，其中包括具有重要突出的形状，以及没有对对象拓扑的先验假设的情况。我们的模型的一个实例，当出现具有多个感兴趣对象的图像时，可以自由拆分以表示每个对象。该方法基于Osher和Sethian开发的思想，以模拟以曲率依赖性速度传播固体/液体界面。界面（正面）是一个封闭的，非电向的，超出表面的沿梯度场的流动，以恒定的速度或取决于曲率的速度，它可以通过求解为“ hamilton-jacobi”的“'hamilton-jacobi''类型方程式，为此函数编写的方程接口是特定级别集。从图像中合成的速度项用于停止对象边界的接口。通过采用熵 - 符合方向的有限差异方案来解决所得的运动方程。我们提出了各种计算前面发展的方法，包括狭窄的频段，重新定义和不同的停止标准。通过在某些合成图像和一些低对比度医学图像上进行数值实验，证明了该方案的功效。
Shape modeling is an important constituent of computer vision as well as computer graphics research. Shape models aid the tasks of object representation and recognition. This paper presents a new approach to shape modeling which retains some of the attractive features of existing methods and overcomes some of their limitations. Our techniques can be applied to model arbitrarily complex shapes, which include shapes with significant protrusions, and to situations where no a priori assumption about the object's topology is made. A single instance of our model, when presented with an image having more than one object of interest, has the ability to split freely to represent each object. This method is based on the ideas developed by Osher and Sethian to model propagating solid/liquid interfaces with curvature dependent speeds. The interface (front) is a closed, nonintersecting, hypersurface flowing along its gradient field with constant speed or a speed that depends on the curvature, It is moved by solving a ''Hamilton-Jacobi'' type equation written for a function in which the interface is a particular level set. A speed term synthesized from the image is used to stop the interface in the vicinity-of object boundaries. The resulting equation of motion is solved by employing entropy-satisfying upwind finite difference schemes. We present a variety of ways of computing evolving front, including narrow bands, reinitializations, and different stopping criteria. The efficacy of the scheme is demonstrated with numerical experiments on some synthesized images and some low contrast medical images.