Forma, Vol. 29 (No. 1), pp. 21-27, 2014

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:

(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

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