System and Method for Detecting the Presence of a Threat in a Package

• US 20080063140A1
• Filed: 07/20/2005
• Published: 03/13/2008
• Est. Priority Date: 07/20/2004
• Status: Abandoned Application

• Current Assignee: VOTI Inc. (VOTI Detection, Inc.)
• Original Assignee: VOTI Inc. (VOTI Detection, Inc.)
• Inventors: Awad, William
• Application Number:
  US11/632,836
• Publication Number:
  US 20080063140A1
• Time in Patent Office: Days
• US Class Current: 378/57
• CPC Class Codes: G01N 23/04 and forming images of the material

Abstract

A method for scanning an object for potential threats. The method includes steps obtaining a plurality of stereographic colored X-ray images of the object, combining the plurality of stereographic images to produce a tridimensional model of the object, classifying each voxel from the tridimensional model into a predetermined material class indicative of a type of material included at a physical location modeled by the voxel, segmenting the tridimensional model using the intensity values and material classes associated with the voxels, thereby producing a segmented model including a plurality of object sub-components classifying each of the object sub-components included in the segmented model into a threat class, and issuing an alert signal upon a detection of an object subcomponent classified into a threatening class.

Claims

1. A method for detecting the presence of a threatening object in a package, said method comprising:

obtaining a multi-energy x-ray image of the package, the multi-energy x-ray image being obtained using x-rays having at least two substantially distinct image energies;

selecting a region of interest within the multi-energy x-ray image;

computing a region of interest signature, the region of interest signature being indicative of the absorption of x-rays within the region of interest at all image energies;

determining if the region of interest signature satisfies a specific threat detection criterion; and

taking a predetermined action upon the specific threat detection criterion being satisfied.

2. A method as defined in claim 1, further comprising obtaining a database of predetermined threat signatures, each predetermined threat signature being indicative of the absorption of x-rays by a threat at all image energies, wherein satisfying the specific threat detection criterion includes identifying a specific threat signature within the database of predetermined threat signatures that matches the region of interest signature.

3. A method as defined in claim 2, wherein the specific threat signature matches the region of interest signature upon the absorption of x-rays in the region of interest being substantially equivalent to the absorption of x-rays indicated by the specific threat signature for all image energies.

4. A method as defined in claim 2, wherein the region of interest is identified as containing a safe item upon the region of interest signature satisfying a specific safety detection criterion.

5. A method as defined in claim 4, wherein:

the database of predetermined threat signatures further includes at least one predetermined safe signature, each predetermined safe signature being indicative of the absorption of x-rays by a safe material at all image energies; and

satisfying the specific safety detection criterion includes identifying a specific safe signature within the database of predetermined threat signatures that matches the region of interest signature.

6. A method as defined in claim 5, wherein the specific safe signature matches the region of interest signature upon the absorption of x-rays in the region of interest being substantially equivalent to the absorption of x-rays indicated by the specific safe signature for all image energies.

7. A method as defined in claim 1, wherein the region of interest signature is indicative of an absorption of x-rays averaged over the region of interest at all image energies.

8. A method as defined in claim 7, wherein computing the region of interest signature includes computing an average density of the region of interest and computing an average effective atomic number of the region of interest.

9. A method as defined in claim 1, wherein computing the region of interest signature further includes computing a geometric parameter indicative of the geometry of the region of interest, the region of interest signature being thereby indicative of the geometry of the region of interest.

10. A method as defined in claim 1, wherein the region of interest is automatically selected by:

segmenting the multi-energy x-ray image to obtain segmented regions of substantially uniform region signature indicative of the absorption of x-rays at all image energies;

selecting as a region of interest at least one of the segmented regions.

11. A method as defined in claim 1, further comprising obtaining a complementary image of the package, wherein the region of interest signature is further indicative of a parameter of the complementary image for the region of interest.

12. A method as defined in claim 1, further comprising:

selecting another region of interest within the multi-energy x-ray image;

computing another region of interest signature, the other region of interest signature being indicative of the absorption of x-rays within the other region of interest at all image energies;

determining if the other region of interest signature satisfies another specific threat detection criterion; and

taking another predetermined action upon the specific threat detection criterion and the other specific threat detection criterion being both satisfied.

13. A method as defined in claim 1, further comprising:

obtaining another multi-energy x-ray image of another package;

selecting another region of interest within the other multi-energy x-ray image;

computing another region of interest signature, the other region of interest signature being indicative of the absorption of x-rays within the other region of interest at all image energies;

determining if the other region of interest signature satisfies another specific threat detection criterion;

determining if the two regions of interest satisfy a region of interest combination criterion, the region of interest combination criterion indicating that the combined satisfaction of the specific threat detection criterion and the other specific threat detection criterion poses a threat; and

taking another predetermined action upon;

the specific threat detection criterion and the other specific threat detection criterion being both satisfied; and

the two region of interests satisfying the region of interest combination criterion.

14. A method as defined in claim 13, wherein the region of interest combination criterion includes having obtained the two multi-energy x-ray images within a predetermined time interval.

15. A method as defined in claim 13, wherein the region of interest combination criterion includes having obtained the two multi-energy x-ray images obtained from two packages scheduled for transportation in a common shipment.

16. A method as defined in claim 1, wherein the multi-energy x-ray image is a tridimensional image.

17. A threat detection system for detecting the presence of a threatening object in a package, said threat detection system comprising:

an image acquisition system for obtaining a multi-energy x-ray image of the package, the multi-energy x-ray image being obtained using x-rays having at least two substantially distinct image energies;

an image processor for processing the multi-energy x-ray image, said image processor being linked to said image acquisition system, said image processor being operative for;

selecting a region of interest within the multi-energy x-ray image;

computing a region of interest signature, the region of interest signature being indicative of the absorption of x-rays within the region of interest at all image energies;

determining if the region of interest signature satisfies a specific threat detection criterion; and

taking a predetermined action upon the specific threat detection criterion being satisfied; and

a communication link for linking said image acquisition system to said image processor.

18. A threat detection system as defined in claim 17, wherein said image processor includes a database of predetermined threat signatures, each predetermined threat signature being indicative of the absorption of x-rays by a threat at all image energies, wherein satisfying the specific threat detection criterion includes identifying a specific threat signature within said database of predetermined threat signatures that matches the region of interest signature.

19. A threat detection system as defined in claim 17, wherein the region of interest signature is indicative of an absorption of x-rays averaged over the region of interest at all image energies.

20. A threat detection system as defined in claim 17, wherein computing the region of interest signature further includes computing a geometric parameter indicative of the geometry of the region of interest, the region of interest signature being thereby indicative of the geometry of the region of interest.

21. A threat detection system as defined in claim 17, wherein:

said image acquisition system is operative for obtaining a complementary image of the package; and

the region of interest signature is further indicative of a parameter of the complementary image for the region of interest.

22. A threat detection system as defined in claim 17, wherein said image processor is operative for:

selecting another region of interest within the multi-energy x-ray image;

computing another region of interest signature, the other region of interest signature being indicative of the absorption of x-rays within the other region of interest at all image energies;

determining if the other region of interest signature satisfies another specific threat detection criterion; and

taking another predetermined action upon the specific threat detection criterion and the other specific threat detection criterion being both satisfied.

23. A threat detection system as defined in claim 17, wherein:

wherein said image acquisition system is further operative for obtaining another multi-energy x-ray image of another package; and

said image processor is operative for

selecting another region of interest within the other multi-energy x-ray image;

computing another region of interest signature, the other region of interest signature being indicative of the absorption of x-rays within the other region of interest at all image energies;

determining if the other region of interest signature satisfies another specific threat detection criterion;

determining if the two region of interests satisfy a region of interest combination criterion, the region of interest combination criterion indicating that the combined satisfaction of the specific threat detection criterion and the other specific threat detection criterion poses a threat; and

taking another predetermined action upon;

the specific threat detection criterion and the other specific threat detection criterion being both satisfied; and

the two region of interests satisfying the region of interest combination criterion.

24. A threat detection system as defined in claim 17, wherein the region of interest combination criterion includes having obtained the two multi-energy x-ray images within a predetermined time interval.

25. A threat detection system as defined in claim 17, wherein the region of interest combination criterion includes having obtained the two multi-energy x-ray images obtained from two packages scheduled for transportation in a common shipment.

26. A machine readable storage medium containing a program element for execution by a computing device, said program element being provided for detecting the presence of a threatening object in a package using a multi-energy x-ray image of the package, the multi-energy x-ray image being obtained using x-rays having at least two substantially distinct image energies, said program element comprising:

an input module provide for receiving the multi-energy x-ray image,

a region of interest selection module provided for selecting a region of interest within the multi-energy x-ray image;

a signature computing module provided for computing a region of interest signature, the region of interest signature being indicative of the absorption of x-rays within the region of interest at all image energies; and

an output module provided for;

determining if the region of interest signature satisfies a specific threat detection criterion; and

issuing a predetermined threat signal upon the specific threat detection criterion being satisfied.

27. A method for remotely detecting the presence of a substance in an object, said method comprising:

obtaining a multi-energy x-ray image of the object, the multi-energy x-ray image being obtained using x-rays having at least two substantially distinct image energies;

selecting a region of interest within the multi-energy x-ray image;

computing a region of interest signature, the region of interest signature being indicative of the absorption of x-rays within the region of interest at all image energies;

determining if the region of interest signature satisfies a specific detection criterion, the satisfaction of the specific detection criterion indicating the presence of the substance in the package; and

taking a predetermined action upon the specific detection criterion being satisfied.