Development and Preliminary Application of Image Filters for

Quantitative XCT Damage Analyses

Orlando, Florida, USA

March 10 - 14, 2003

12th Annual Research Symposium of the American Society for Nondestructive Testing

Outline

• Abstract

• TIFF Binaries

• 3D Reconstructions

• Creating Image Filters

• Using AutoCAD layers as image filters

• Interpreting Data

• Summary

Abstract

• Segmented binarized XCT images were analyzed using a method developed using a number of software applications to graphically interrogate the physical amount of ballistic meso-damage (>250 m) in impacted titanium alloy (Ti-6Al-4V) disk samples.

TIFF image Binaries• A threshold is used to create the binary TIFF

images– These images are exported as a stack of binary 16

bit TIFF images!

3D Reconstructions

• 16 Bit Tiff Images– ACTIS software puts these together and makes a 3D solid– Analysis of images using the ACTIS software produces

qualitative results

• Using AutoCAD, a filter was developed– First:

• A cylinder is created within another cylinder with radius plus ¼ millimeter

– Second• The smaller cylinder is subtracted from the larger one,

creating a ring

– Third• The ¼ millimeter ring is subtracted from a

rectangular solid, creating a hollow rectangular solid

– Finally• Hollow rectangular solids are created from subtracting

rings with three to twenty millimeter radii and each one becomes an individual layer within AutoCAD

Combined Layers

TIFF Image is 70 X 70; it is aligned within the Tiff Image Bounding BoxLayer Bounding Box – 100mm X 100mm X 1mmTIFF Image Bounding Box – 70mm X 70mm

Using AutoCAD Layers as Image Filters

TIFF Image Stays in Original Position

(0.334, 1.476)

• Layers move to a calculated offset.

• TIFF image is placed on alignment lines which lie beneath the hollow rectangular solid

• The current ring is zoomed in on

• The Scene is Rendered, creating a ring with a ¼ millimeter radius.– This shows damaged and undamaged pixels– The rendered scene is then exported as a Bitmap

image

• For all ¼ millimeter layers, this process is executed

Using The Exported Images• The exported bitmap images created in

AutoCAD are multiple colors; the solids color is magenta, the damaged pixels are black, and the undamaged pixels are white

• AutoCAD averages the color of the pixels from the inner and outer radial ring causing more than three colors to be present in the export

• Exported images from AutoCAD are imported to Paint Shop Pro and reduced to three colors

ImageJ and the Excel Standard Table• Using Image J, the three color images made

with Paint Shop Pro are analyzed and the number of pixels for each color are reported.

• An excel table calculates values for Axi-Symmetric Damage Fraction, Cumulative Damage, and Cumulative Unit Damage.

Axi-Symmetric Damage Fraction• A measure of the percent damage in each

quarter millimeter ring out to the edge of the object. %d

Axi-Symmetric Unit Damage Fraction

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Ti64 Sample 4

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Ti64 Sample 2

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Summary• The data from this work and work to come will

allow more accurate damage modeling to take place

• Predicting failure in materials is essential in improving the survivability and lethality of military units

Current Goals

• Submit 2 Abstracts to NDIA conference ’24th International Symposium on Ballistics’– Abstracts Due - December 1, 2007– Paper Selection - January 15, 2008– Authors Notified - February 15, 2008– Papers Due - April 1, 2008– Final Program - June 1, 2008– Symposium - September 22-26, 2008

Abstract 1

• Perspectives on the Requirements, Development, and Outputs of an X-Ray Computed Tomography Image Processing Application for Ballistic Impact Analysis In Armor Samples

Abstract 2

• Advances in the Automated Analysis and Visualization of X-Ray Computed Tomography Image Data