Zheng Pan, Belaton Bahari, Liao Iman Yi, Rajion Zainul Ahmad
Faculty of Engineering, Computing and Science, Swinburne University of Technology Sarawak Campus, Kuching, Malaysia.
School of Computer Sciences, Universiti Sains Malaysia, Penang, Malaysia.
PLoS One. 2017 Nov 9;12(11):e0187558. doi: 10.1371/journal.pone.0187558. eCollection 2017.
Landmarks, also known as feature points, are one of the important geometry primitives that describe the predominant characteristics of a surface. In this study we proposed a self-contained framework to generate landmarks on surfaces extracted from volumetric data. The framework is designed to be a three-fold pipeline structure. The pipeline comprises three phases which are surface construction, crest line extraction and landmark identification. With input as a volumetric data and output as landmarks, the pipeline takes in 3D raw data and produces a 0D geometry feature. In each phase we investigate existing methods, extend and tailor the methods to fit the pipeline design. The pipeline is designed to be functional as it is modularised to have a dedicated function in each phase. We extended the implicit surface polygonizer for surface construction in first phase, developed an alternative way to compute the gradient of maximal curvature for crest line extraction in second phase and finally we combine curvature information and K-means clustering method to identify the landmarks in the third phase. The implementations are firstly carried on a controlled environment, i.e. synthetic data, for proof of concept. Then the method is tested on a small scale data set and subsequently on huge data set. Issues and justifications are addressed accordingly for each phase.
地标,也称为特征点,是描述曲面主要特征的重要几何基元之一。在本研究中,我们提出了一个独立的框架,用于在从体数据中提取的曲面上生成地标。该框架设计为具有三个步骤的流水线结构。该流水线包括三个阶段,即曲面构建、脊线提取和地标识别。以体数据作为输入,地标作为输出,该流水线接收三维原始数据并生成零维几何特征。在每个阶段,我们研究现有方法,对方法进行扩展和调整以适应流水线设计。该流水线设计得具有功能性,因为它被模块化以在每个阶段具有特定功能。在第一阶段,我们扩展了隐式曲面多边形化方法用于曲面构建;在第二阶段,开发了一种计算最大曲率梯度的替代方法用于脊线提取;最后在第三阶段,我们结合曲率信息和K均值聚类方法来识别地标。首先在可控环境即合成数据上进行实现,以验证概念。然后在小规模数据集上进行测试,随后在大数据集上进行测试。针对每个阶段相应地讨论了问题和理由。