Pores in Spherical Radiolarian Skeletons Directly Determined from Three-Dimensional Data

Takashi Yoshino¹*, Naoko Kishimoto², Atsushi Matsuoka³, Naoto Ishida⁴, Toshiyuki Kurihara⁵ and Katsunori Kimoto⁶

¹Department of Mechanical Engineering, Toyo University, Japan
²Department of Mechanical Engineering, Setsunan University, Japan
³Department of Geology, Faculty of Science, Niigata University, Japan
⁴Gas Hydrate Research Laboratory, Meiji University, Japan
⁵Graduate School of Science and Technology, Niigata University, Japan
⁶Research Institute for Global Change (RIGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Japan
*E-mail address: tyoshino@toyo.jp

(Received October 5, 2013; Accepted June 17, 2014)

Abstract. We propose a method that uses three-dimensional data to directly determine the pores (holes) in the skeleton of a spherical radiolarian. Our goal is to automatically determine both the number and the distribution of the pores. We used a set of grid points on a spherical surface to approximate the skeletal structure, which was obtained from a micro X-ray CT scan. Next, we counted the number of pores by using an algorithm for counting clusters on a grid. Finally, we used Voronoi tessellation to determine the distribution of the pores. For noisy data, a smoothing filter was applied before the procedure. We applied our method to three real data sets, and the results showed that our method worked well.

Keywords: Pore Number, Distribution of Pores, Voronoi Tessellation, Radiolarian