Classification of radiolarian images with hand-crafted and deep features


KEÇELİ A. S., KAYA A., KECELI S. U.

COMPUTERS & GEOSCIENCES, vol.109, pp.67-74, 2017 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 109
  • Publication Date: 2017
  • Doi Number: 10.1016/j.cageo.2017.08.011
  • Journal Name: COMPUTERS & GEOSCIENCES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.67-74
  • Keywords: Deep learning, Image features, Radiolarian image, Pattern classification, TRIASSIC RADIOLARIANS, TAXONOMIC CLASSIFICATION, RHAETIAN RADIOLARIANS, NONLINEAR CORRELATION, PATTERN-RECOGNITION, ANTALYA NAPPES, SE TURKEY, MIDDLE, EVOLUTION, PART
  • Hacettepe University Affiliated: Yes

Abstract

Radiolarians are planktonic protozoa and are important biostratigraphic and paleoenvironmental indicators for paleogeographic reconstructions. Radiolarian paleontology still remains as a low cost and the one of the most convenient way to obtain dating of deep ocean sediments. Traditional methods for identifying radiolarians are time-consuming and cannot scale to the granularity or scope necessary for large-scale studies. Automated image classification will allow making these analyses promptly. In this study, a method for automatic radiolarian image classification is proposed on Scanning Electron Microscope (SEM) images of radiolarians to ease species identification of fossilized radiolarians. The proposed method uses both hand-crafted features like invariant moments, wavelet moments, Gabor features, basic morphological features and deep features obtained from a pre-trained Convolutional Neural Network (CNN). Feature selection is applied over deep features to reduce high dimensionality. Classification outcomes are analyzed to compare hand-crafted features, deep features, and their combinations. Results show that the deep features obtained from a pre-trained CNN are more discriminative comparing to hand-crafted ones. Additionally, feature selection utilizes to the computational cost of classification algorithms and have no negative effect on classification accuracy.