Author/Editor		Pret, Dimitri; Sardini, Paul
Title		An original method for thresholding of clasts into clay-rich fault gouge
Type		članek
Source		Image Anal Stereol
Vol. and No.		Letnik 20, št. Suppl 1
Publication year		2001
Volume		str. 544-9
Language		eng
Abstract		The ultimate goal of this work is to provide a tool for the characterisation of a clay-rich fault gouge microstructure. The visualisation of clasts into the gouge is not possible using current techniques for observations at the centimetric scale with a micrometric resolution. This paper purposes a new method for clast visualisation using autoradiographs. These images display the 2D spatial heterogeneities of porosity. The clasts become observable because they are less porous than the matrix. An automatic thresholding algorithm for clasts on autoradiograph has been computed using mathematical morphology tools. The algorithm is based on watershed lines segmentation of gradient image of autoradiographs. The results are well validate by SEM observations. Besides, it is purposed some exploitations of thresholded images in order to characterise in a quantitative way the microstructure heterogeneities. An estimation of the clast relative surface area, a clast granulometry analyse, a quantitative porosity measurement for each gouge component and a porosity map can be obtained.
Descriptors		POROSITY IMAGE PROCESSING, COMPUTER-ASSISTED AUTORADIOGRAPHY MATERIALS TESTING PARTICLE SIZE MICROSCOPY, ELECTRON, SCANNING