A New Image Analysis Technique for Aggregate Morphology Analysis using Two-dimensional Fourier Transform Method

摘要

This paper presents some results of the NCHRP 4-34 Laser Detection and Ranging (LADAR)project. A high-resolution Fourier Transform Interferometry (FTI) system is developed foraggregate morphology characterization by using a fiber optic coupler to form a Young’s doublepinhole interferometer. The FTI system uses a charge-coupled device (CCD) camera to capturefringe images of aggregates with the size ranging from 3/4’’ to #50 and reconstruct three7dimensional (3D) surfaces of aggregates based on fringe distortions from the captured digitalimages. A program is developed in MATLAB to quantify morphological characteristics ofaggregates from a variety of sources. The output results include sphericity, flatness ratio,elongation ratio, angularity and texture for each individual aggregate particle. In this paper, onlythe morphological characteristics of seven types of coarse aggregate with the size ranging from3/4’’ to #4 is presented. These aggregates are also analyzed using the Aggregate ImageMeasurement System (AIMS) II and the University of Illinois Aggregate Image Analyzer(UIAIA) for further comparison. It is found that the FTI system is easy to operate and that it isable to rapidly quantify morphological characteristics of aggregates. The FTI results of theseaggregates are generally consistent with the results of AIMS II and UIAIA with regard toroughness rankings despite minor differences for several aggregates.