Segmentation and recognition of fission tracks in photomicrographs from different materials using the wavelet transform

• Grant number: 14/22922-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: March 01, 2015
• End date: February 28, 2019
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geophysics
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Sandro Guedes de Oliveira
• Grantee: Alexandre Fioravante de Siqueira
• Host Institution: Instituto de Física Gleb Wataghin (IFGW). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated scholarship(s): 15/24582-4 - RECOGNITION OF FISSION TRACKS ON MINERAL PHOTOMICROGRAPHS USING THE DUAL-TREE COMPLEX WAVELET TRANSFORM, BE.EP.PD

Abstract

Obtaining the age of natural minerals using the Method of Fission Tracks requires that tracks from the fission of Uranium-238 formed on polished surfaces of minerals such as apatite and zircon be counted in a optical microscope or in photomicrographs. When these tracks are entirely contained in the mineral (confined), they could have their length measured if attacked by another track of fracture from the mineral. The distribution of frequencies of the length of confined tracks allows the inference of the geological thermal history that the mineral was submitted. Besides of time expensive, the measure and mainly counting procedures could bring to practical problems, as the variation of the observing efficience. An automatic method of fission-track identification could solve such issues and increase the speed of track counting. In the particular case of fission tracks in a photomicrograph, it is necessary to develop a methodology able to perform such automation satisfactorily. This research project proposes the creation of a methodology for segmentation of photomicrographs from different materials, in order to quantify and measure the contained fission-tracks. For this purpose, we propose the use of two different wavelet transforms: the complex dual-tree wavelets (DT-CWT) and the undecimated wavelets.The proposed methodology also aims at possible three-dimensional reconstruction by layers to identify deeper tracks, that will allow the analysis of not only the two-dimensional projection presented in optical microscopy images, but also the total length of the tracks. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE SIQUEIRA, ALEXANDRE FIORAVANTE; NAKASUGA, WAGNER MASSAYUKI; GUEDES, SANDRO; RATSCHBACHER, LOTHAR. Segmentation of nearly isotropic overlapped tracks in photomicrographs using successive erosions as watershed markers. MICROSCOPY RESEARCH AND TECHNIQUE, v. 82, n. 10, JULY 2019. (15/24582-4, 14/22922-0)