Contour detection in Wireless Sensor Networks (WSNs) is crucial for tasks like energy saving and network optimization, especially in security and surveillance applications. Coverage holes, where data transmission is not achievable, are a significant issue caused by factors such as energy depletion and physical damage. Traditional methods for detecting these holes often suffer from inaccuracy, low processing speed, and high energy consumption, relying heavily on physical information like node coordinates and sensing range. To address these challenges, we propose a novel, coordinate-free coverage hole detection method using Connected Component Labeling (CCL) and Force-Directed (FD) algorithms, termed FD-CCL. This method does not require node coordinates or sensing range information. We also investigate Suzuki's Contour Tracing (CT) algorithm and compare its performance with CCL on various FD graphs. Our experiments demonstrate the effectiveness of FD-CCL in terms of processing time and accuracy. Simulation results confirm the superiority of FD-CCL in detecting and locating coverage holes in WSNs.

翻译：无线传感器网络（WSNs）中的轮廓检测对于节能和网络优化等任务至关重要，尤其在安防监控应用中。覆盖空洞是指无法实现数据传输的区域，通常由能量耗尽或物理损坏等因素引起，是网络中的关键问题。传统的空洞检测方法常依赖节点坐标和感知范围等物理信息，存在精度低、处理速度慢及能耗高等缺陷。为应对这些挑战，本文提出一种无需坐标的覆盖空洞检测新方法，结合连通域标记（CCL）与力导向（FD）算法，称为FD-CCL。该方法无需节点坐标或感知范围信息。我们还研究了Suzuki轮廓追踪（CT）算法，并在多种FD图上比较了其与CCL的性能。实验结果表明，FD-CCL在处理时间和准确性方面均表现优异。仿真结果证实了FD-CCL在检测和定位WSNs覆盖空洞方面的优越性。