PROCEEDINGS ARTICLE | September 13, 2011
Proc. SPIE. 8135, Applications of Digital Image Processing XXXIV
KEYWORDS: Image processing algorithms and systems, Image segmentation, Image processing, Digital filtering, X-rays, 3D modeling, Solids, Image filtering, Filtering (signal processing), 3D image processing
High-resolution x-ray micro-tomography is used for imaging of solid materials at micrometer scale in 3D. Our
goal is to implement nondestructive techniques to quantify properties in the interior of solid objects, including
information on their 3D geometries, which supports modeling of the fluid dynamics into the pore space of the
host object. The micro-tomography data acquisition process generates large data sets that are often difficult to
handle with adequate performance when using current standard computing and image processing algorithms.
We propose an efficient set of algorithms to filter, segment and extract features from stacks of image slices of
porous media. The first step tunes scale parameters to the filtering algorithm, then it reduces artifacts using a
fast anisotropic filter applied to the image stack, which smoothes homogeneous regions while preserving borders.
Next, the volume is partitioned using statistical region merging, exploiting the intensity similarities of each
segment. Finally, we calculate the porosity of the material based on the solid-void ratio. Our contribution is to
design a pipeline tailored to deal with large data-files, including a scheme for the user to input image patches
for tuning parameters to the datasets. We illustrate our methodology using more than 2,000 micro-tomography
image slices from 4 different porous materials, acquired using high-resolution X-ray. Also, we compare our
results with standard, yet fast algorithms often used for image segmentation, which includes median filtering
and thresholding.
