Three-dimensional Image Analysis Software
Processing a volume data of 1mm diameter glass beads

Case Example
Dr. Kei Teraoka,
Advanced Manufacturing Research Institute,
The National Institute of Advanced Industrial
Science and Technology

In the field of regenerative medicine, porous ceremic is

attracting attention as a promissing candidate material
for artificial bone. Dr. Teraoka has diveloped the "mosaic

Analyzing the network structure of porous media and particles

artificial bone," a cylindrical cell filled with spherical apatite
ABC

A: CT volume data
B: extracting the void space
C: after the thinning processbeads. The three-dimensional structure made up of closepacked spheres does not form closed cavities, whichmeans biologic factors, including osteocyte and blood, caneasily access inside and flow through, thereby promoting

favorable bone formation. As a part of meterial evaluation,

Dr. Teraoka uses ExFact Analysis to conduct quantitative

structural analysis on the 3D images of bone regenerationmaterials obtained with microfocus X-ray CT.

Close packing of spheres

Application Fields
Material engineering in generalincluding petroleum, rubber, plastics, resin, polymer, granules(dosage form), methane hydrate, concrete/gravel, fuel cell, carbon
nanotube, paper, pulp fiber, ceramic, catalyst, bone, dental/medical
material, precision/electronic component, semiconductor.

Input data format
A series of tomographic image obtained through imaging devices
such as X-ray CT, CLSM and TEM tomography

Before conducting 3D image analysis on ExFact Analysis, the image

stack needs to be preprocessed, including the extraction of theregion of interest, on ExFact VR. ExFact VR supports various fileformats including tiff, bmp, dicom and original forms of different
devices.

ExFact® Analysis Product Lineup/ Specification Details
Product Lineup

・ ExFact® Analysis for Porous/Particles
・ ExFact® Analysis for Fiber

Please use either or both, depending on the types of object materials.

Required Software

・ Exfact® VR Windows（64-bit version）		

* for preprocessing and rendering/display of image data.

Software Licensing

・ USB Software Protection Device

System Requirements

・ Operating System : All editions of Microsoft Windows 7/8,
Japanese/English versions supported.
・ At least 4GB of RAM
・ 1280 x 1024, full color screen resolution or higher
・ A USB port (for USB Software Protection Device)

MA (Medial Axes)

4.1um ← pore width → 36.9um

ExFact® Analysis Series

Visualize your imagination

Specification and release time may change without notice.Company and product name are registration of trademark.
Imaging technologies such as X-ray CT, CLSM and TEM tomography provide a seriesof tomographic image of industrial products and materials for the construction of their
3D images. ExFact® Analysis, a software based on the novel concept of "Medial Axis"
to capture the complex structure of various objects, offers a tool to conduct statisticalevaluation/analysis on the properties of those 3D images, including shapes/distributionsof grains/voids, as well as orientations of fibers.

Three-dimensional Image Analysis Software

Basic Concepts

Graphs Plotted Based on Analysis Results

Newly Developed Segmentation Process
A cross sectional (tomographic) image obtained with imaging devices, such as X-ray CT,

ExFact Analysis calculates various statistical values for material evaluation.

basically consists of pixels of various gray values. Each of these pixels represents thecorresponding point of imaged object, with their gray values corresponding to the material
density of the points. On a digital image, whose spatial resolution has a certain limitation,
the intensity values of marginal region become lower than their true values (which is called

Existing Method

Nodal pore volume distribution

Average volume of the nodal poresadjoining to a given pore"partial volume effect"). This effect, along with noises and artifacts, makes it difficult toobtain an ideal image in which material phase and pore space are clearly separated.
Equipped with a newly developped segmentation algorithm, ExFact Analysis carries out

Original Imagebinalization process based on its three-dimentional scanning of highly-intricate material/Binarization

void-space structure. The software sets two thresholds (high and low) on a 3D image

Histogram for pore volume
distribution

histogram, where the voxels with gray values higher than the high threshold are classified
into material phase, while those with lower values than the low threshold into void space.

New Method

Those with in-between gray values are classified into either of the two categories after thesoftware statistically processces the gray values of their neighbouring voxels, providingmore probable contour estimation. The resultant output file after the segmentation can be

1. adjoining pores have smaller volumes
2. adjoining pores have larger volumes

used on ExFact® VR for further image processing.

Medial axis
ExFact Analysis constructs the "Medial Axis" of the object - skelton of void space
represented in a union of one dimentional curves. This lower dimentional representation ofthe object, while preserving important geometric properties, is easier to analyze than a 3D

Medial axis

Effective pore radii distribution(radius of the sphere whose volume is equal to that ofa given pore)

Average effective radius of two poresadjoining to a given throat

image. ExFact Analysis uses the medial axis as the basis for understanding the complicated
3D properties of the original object.

Analyzing the 3D structure of porous media

The void space structure of a porous media has a complicated 3D structure. First step of
the analysis is the thinning (skeltonization) of the void space and the construction of themedial axis. The medial axis represents the continuum of void space. Next step is to identify

r: effective radius of a given throat
R1, R2: effective radii of poresadjoining to a the throat

R: radius of the sphere
whose volume is equal tothat of a given nodal porethroats, the most constricted part on each pathway, which can be likened to a door placed
between two rooms. Throat area size determines the permeability of fluids. Nodal pores aredefined as the void spaces divided by throats. ExFact Analysis analyzes the properties ofporous media based on those pores and throats.

Throat surface area distribution

Coordination number for nodal poresplotting the coordination number for a given nodal pore of a certain effective radius

Flow StepsHistogram showing the area size
distribution of throats (planes
dividing two adjoining voids)

Objects of analysis
granular or porous media

Loading image data, extracting the region ofinterest, and converting the file to a format
readable on ExFact® Analysis

Conducting binarization on a 3D volume data,
separating material phase and void space,and proceeding with analysis process

Effective throat radii distribution(radius of the circle whose area is equal to that ofDistribution of pores-to-throat constrictiona given throat)

Observing the 2D slice
images processed by
ExFact Analysis

3D visualization of themedial axis processed by
ExFact Analysis

Plotting graphs ofvarious indices forstatistical evaluation ofmaterials

r: radius of the circle
whose area is equal tothat of a given throat

degree of constliction defined as theratio of a given throat's effective radiusto those of two adjoining pores.

r = effective throat radius
R = effective pore radiusr/R = degree of constliction