Detection of explosives using image analysis Dr Charles A Bouman, Eri Haneda, Aarthi Balachander, Krithika Chandrasekar, Govind Manian, Charvaka Mattaparthy, Aziza Satkhozhina School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana. Overview.
Dr Charles A Bouman, Eri Haneda, Aarthi Balachander, Krithika Chandrasekar, Govind Manian, Charvaka Mattaparthy, Aziza Satkhozhina
School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana
Review of Background
Flowchart of Algorithm
Input: CT slices of scanned baggage
Step 2: Connected Component analysis to group together pixel regions of interest
(OUTPUT: connected regions of pixels for each CT slice)
Step 1: Otsu Thresholding
(OUTPUT: image with two distinct classes of pixels)
Step 5: K means clustering to determine regions of change in linear attenuation co-efficient
Step 3: Region Growing across multiple slices to obtain the 3D object
Step 4: Feature vector determination for K-means clustering
Step 6: Comparison with attenuation co-efficient of known explosives
Output: Location of explosive in baggage
Fig 2 Flow Diagram of Algorithm
Fig 5. Pixel intensity histogram of slice 20 (graphical verification of Otsu threshold). The threshold value found to minimize intra-class variance for this slice is 0.1255.
Methods and Approach
1Committee on the Review of Existing and Potential Standoff Explosives Detection Techniques, National Research Council, (2004). Existing and Potential Standoff Explosives Detection Techniques. National Academies Press.
2FDA. (2009, June 18). What is Computed tomography?. Retrieved from http://www.fda.gov/Radiation- Herman, G.T. (2009).
3Hu, Y., Huang, P., Guo, L., Wang, X., & Zhang, C. (2006). Terahertz spectroscopic investigations of explosives. Physics Letters A, 359, 728-32.
4Singh, S., & Singh, M. (2003). Explosives detection systems (EDS) for aviation security. Signal Processing, 83, 31-55.
5UTCT. (2009). About High-resolution x-ray ct. Retrieved from http://www.ctlab.geo.utexas.edu/overview/index.php
6Computed tomography for airport security. (2010.).
Fig 3. CT Slice 20 of Pan Am data set (Input)
School of Electrical and Computer Engineering
West Lafayette, Indiana
All questions or correspondence related to this document should be addressed to
Dr Charles A Bouman – email@example.com
Ms Eri Haneda – firstname.lastname@example.org
Aarthi Balachander – email@example.com
Krithika Chandrasekar – firstname.lastname@example.org
Govind Manian – email@example.com
Charvaka Mattaparthy – firstname.lastname@example.org
Aziza Satkhozhina - email@example.com
Fig 1. Absorption of explosives3
Fig 4. CT Slice after applying Otsu’s Method (Step 1 of algorithm)