Computerized assembly of neurocranial fragments based on surface extrapolation

Takeo Kikuchi, Naomichi Ogihara

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Fossil crania are often fractured and fragmented due to compaction and diagenesis. To restore the antemortem appearance of a fossil cranium, it is necessary to correctly assemble the fragments into their original anatomical positions. In this study, we propose a concept for computerized reconstruction that employs surface extrapolation to aid the assembly of fossil neurocranial fragments. Specifically, we approximate the surface of each neurocranial fragment using a bicubic Bézier surface to extrapolate the surface and mathematically predict the shape of adjacent fragments. The positions and orientations of adjacent fragments were calculated by minimizing the fitting errors. To evaluate the usefulness of this concept, we virtually divided modern human and chimpanzee neurocrania into pieces and used the proposed method to reassemble the generated virtual fragments. The neurocranial fragments were smoothly and correctly assembled. Comparison of the results obtained using the proposed method and conventional manual assembly revealed that the proposed method delivered similar performance in terms of differences between the original and reassembled shapes. However, the accuracy of the reassembly was found to be worse in the chimpanzee case because the fragments were more curved than those for the human cranium. Although there are some methodological limitations, the proposed concept may be useful for development of digital reassembly of fossil neurocranial fragments.

Original languageEnglish
Pages (from-to)115-122
Number of pages8
JournalAnthropological Science
Volume121
Issue number2
DOIs
Publication statusPublished - 2013

Fingerprint

reconstruction
performance

Keywords

  • Assemblage
  • Bézier surface
  • Computed tomography
  • Fossil
  • Virtual reconstruction

ASJC Scopus subject areas

  • Anthropology

Cite this

Computerized assembly of neurocranial fragments based on surface extrapolation. / Kikuchi, Takeo; Ogihara, Naomichi.

In: Anthropological Science, Vol. 121, No. 2, 2013, p. 115-122.

Research output: Contribution to journalArticle

Kikuchi, Takeo ; Ogihara, Naomichi. / Computerized assembly of neurocranial fragments based on surface extrapolation. In: Anthropological Science. 2013 ; Vol. 121, No. 2. pp. 115-122.
@article{fd7d62593ae04031946ee0b330c1e9d5,
title = "Computerized assembly of neurocranial fragments based on surface extrapolation",
abstract = "Fossil crania are often fractured and fragmented due to compaction and diagenesis. To restore the antemortem appearance of a fossil cranium, it is necessary to correctly assemble the fragments into their original anatomical positions. In this study, we propose a concept for computerized reconstruction that employs surface extrapolation to aid the assembly of fossil neurocranial fragments. Specifically, we approximate the surface of each neurocranial fragment using a bicubic B{\'e}zier surface to extrapolate the surface and mathematically predict the shape of adjacent fragments. The positions and orientations of adjacent fragments were calculated by minimizing the fitting errors. To evaluate the usefulness of this concept, we virtually divided modern human and chimpanzee neurocrania into pieces and used the proposed method to reassemble the generated virtual fragments. The neurocranial fragments were smoothly and correctly assembled. Comparison of the results obtained using the proposed method and conventional manual assembly revealed that the proposed method delivered similar performance in terms of differences between the original and reassembled shapes. However, the accuracy of the reassembly was found to be worse in the chimpanzee case because the fragments were more curved than those for the human cranium. Although there are some methodological limitations, the proposed concept may be useful for development of digital reassembly of fossil neurocranial fragments.",
keywords = "Assemblage, B{\'e}zier surface, Computed tomography, Fossil, Virtual reconstruction",
author = "Takeo Kikuchi and Naomichi Ogihara",
year = "2013",
doi = "10.1537/ase.130618",
language = "English",
volume = "121",
pages = "115--122",
journal = "Anthropological Science",
issn = "0918-7960",
publisher = "Anthropological Society of Nippon",
number = "2",

}

TY - JOUR

T1 - Computerized assembly of neurocranial fragments based on surface extrapolation

AU - Kikuchi, Takeo

AU - Ogihara, Naomichi

PY - 2013

Y1 - 2013

N2 - Fossil crania are often fractured and fragmented due to compaction and diagenesis. To restore the antemortem appearance of a fossil cranium, it is necessary to correctly assemble the fragments into their original anatomical positions. In this study, we propose a concept for computerized reconstruction that employs surface extrapolation to aid the assembly of fossil neurocranial fragments. Specifically, we approximate the surface of each neurocranial fragment using a bicubic Bézier surface to extrapolate the surface and mathematically predict the shape of adjacent fragments. The positions and orientations of adjacent fragments were calculated by minimizing the fitting errors. To evaluate the usefulness of this concept, we virtually divided modern human and chimpanzee neurocrania into pieces and used the proposed method to reassemble the generated virtual fragments. The neurocranial fragments were smoothly and correctly assembled. Comparison of the results obtained using the proposed method and conventional manual assembly revealed that the proposed method delivered similar performance in terms of differences between the original and reassembled shapes. However, the accuracy of the reassembly was found to be worse in the chimpanzee case because the fragments were more curved than those for the human cranium. Although there are some methodological limitations, the proposed concept may be useful for development of digital reassembly of fossil neurocranial fragments.

AB - Fossil crania are often fractured and fragmented due to compaction and diagenesis. To restore the antemortem appearance of a fossil cranium, it is necessary to correctly assemble the fragments into their original anatomical positions. In this study, we propose a concept for computerized reconstruction that employs surface extrapolation to aid the assembly of fossil neurocranial fragments. Specifically, we approximate the surface of each neurocranial fragment using a bicubic Bézier surface to extrapolate the surface and mathematically predict the shape of adjacent fragments. The positions and orientations of adjacent fragments were calculated by minimizing the fitting errors. To evaluate the usefulness of this concept, we virtually divided modern human and chimpanzee neurocrania into pieces and used the proposed method to reassemble the generated virtual fragments. The neurocranial fragments were smoothly and correctly assembled. Comparison of the results obtained using the proposed method and conventional manual assembly revealed that the proposed method delivered similar performance in terms of differences between the original and reassembled shapes. However, the accuracy of the reassembly was found to be worse in the chimpanzee case because the fragments were more curved than those for the human cranium. Although there are some methodological limitations, the proposed concept may be useful for development of digital reassembly of fossil neurocranial fragments.

KW - Assemblage

KW - Bézier surface

KW - Computed tomography

KW - Fossil

KW - Virtual reconstruction

UR - http://www.scopus.com/inward/record.url?scp=84883243277&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84883243277&partnerID=8YFLogxK

U2 - 10.1537/ase.130618

DO - 10.1537/ase.130618

M3 - Article

AN - SCOPUS:84883243277

VL - 121

SP - 115

EP - 122

JO - Anthropological Science

JF - Anthropological Science

SN - 0918-7960

IS - 2

ER -