The Enhancement of 3D Scans Depth Resolution Obtained by Confocal Scanning of Porous Materials

Abstract

The 3D reconstruction of simple structured materials using a confocal microscope is widely used in many different areas including civil engineering. Nonetheless, scans of porous materials such as concrete or cement paste are highly problematic. The well-known problem of these scans is low depth resolution in comparison to the horizontal and vertical resolution. The degradation of the image depth resolution is caused by systematic errors and especially by different random events. Our method is focused on the elimination of such random events, mainly the additive noise. We use an averaging method based on the Lindeberg-Lévy theorem that improves the final depth resolution to a level comparable with horizontal and vertical resolution. Moreover, using the least square method, we also precisely determine the limit value of a depth resolution. Therefore, we can continuously evaluate the difference between current resolution and the optimal one. This substantially simplifies the scanning process because the operator can easily determine the required number of scans.

The Analysis of Rock Surface Asperities

“…See [21] for more information about SfF method. The other possible reconstruction methods are presented e. g. in [24,25,28].…”

“…2.1. from non-confocal data (40 images). Due to the porous property of the material, there was the obvious noise in the data, so that this noise was decreased by usage of Lindeberg-Levi Central Limit theorem [25].…”

“…2) is very subjective and unjustifiable reductive. We propose the method based on cosine Fourier series [25] that can increase the exactness and objectivity of the evaluation. Let This part shows the application of the proposed 3D reconstruction method SfF and following analysis on real sample of limestone.…”

Finite Element Modeling of Porous Microstructures With Random Holes of Different-Shapes and -Sizes to Predict Their Effective Elastic Behavior

“…Pores of different shapes and sizes are inevitable constituents of practical engineering materials, such as composites, metals and synthetic materials. They significantly affect the overall elastic properties and the failure mechanism of the material [1][2][3][4][5]. Specifically, they render porous materials more suitable for medical applications [6][7][8][9] because of the high controllability, lightweight, biocompatibility and easy of design.…”

“…The finite element method (FEM) is a possible approach to quantitatively evaluate the material properties influenced by defects, like holes, cracks and many other imperfections, in the materials and the large structures in view of its low cost and relatively high efficiency [11,12]. Many pioneering studies concerning this topic [1][2][3][4][5][13][14][15][16][17][18] have been conducted by now, and one critical step is to reconstruct a proper microstructure model of the porous materials. A straightforward way is adopting a commercial package, say Minics or others, to reproduce the true microstructures of porous materials at a specific scale by using the tomographic images generated by the atom-probe tomography [19], electron microscopy [20], X-ray tomography [21], or focused-ion-beam-nonatomography [22].…”