Method, apparatus and system for determining if a piece of luggage contains a liquid product

• US 8,879,791 B2
• Filed: 07/30/2010
• Issued: 11/04/2014
• Est. Priority Date: 07/31/2009
• Status: Expired due to Fees

• Current Assignee: Vanderlande Industries BV (VIVE BV)
• Original Assignee: Optosecurity Inc.
• Inventors: Perron, Luc, Gudmundson, Dan, Drouin, Stphane, Poulin, Rgis
• Primary Examiner(s): Tabatabai, Abolfazl
• Application Number:
  US13/387,578
• Publication Number:
  US 20120275646A1
• Time in Patent Office: 1,558 Days
• Field of Search: 382/103, 382/236, 348/169, 348/170, 348/171, 348/172, 378/46, 378/57, 378/66, 378/87, 378/90, 378/92, 378/98.6, 378/207, 726/14, 345/424
• US Class Current: 382/103
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 2223/637 liquid
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: G01V 5/22 Active interrogation, i.e. by irradiating objects or goods using external radiation sources, e.g. using gamma rays or cosmic rays
• CPC Class Codes: G01V 5/228 using stereoscopic means
• CPC Class Codes: G06T 2207/10116 X-ray image
• CPC Class Codes: G06T 2207/30232 Surveillance
• CPC Class Codes: G06T 7/62 of area, perimeter, diameter or volume
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69

Abstract

A method, an apparatus and a system are provided for determining if a piece of luggage contains a liquid product comprised of a container holding a body of liquid. The piece of luggage is scanned with an X-ray scanner to generate X-ray image data conveying an image of the piece of luggage and contents thereof. The X-ray image data is processed with a computer to detect a liquid product signature in the X-ray image data and determine if a liquid product is present in the piece of luggage. A detection signal is released at an output of the computer conveying whether a liquid product was identified in the piece of luggage. The detection signal may, for example, be used in rendering a visual representation of the piece of luggage on a display device to convey information to an operator as to the presence of a liquid product in the piece of luggage.

Claims

1. A method for performing security screening on luggage, the method comprising:

a) receiving X-ray image data conveying an image of a piece of luggage and contents thereof, the X-ray image data being generated by scanning the piece of luggage with an X-ray scanner;

b) processing the X-ray image data using program code executed by a computer to detect if a liquid product is present in the piece of luggage, the liquid product being comprised of a container holding a body of liquid, wherein processing the X-ray image data includes using the program code executed by the computer to detect a liquid product signature in the X-ray image data;

c) releasing at an output of the computer detection results obtained by processing the X-ray image data.

2. A method as defined in claim 1, wherein processing the X-ray image data includes identifying in the image conveyed by the X-ray image data an area of interest.

3. A method as defined in claim 2, comprising:

a) processing the X-ray image data to estimate a thickness of the identified area of interest;

b) selectively disqualifying the identified area of interest as being unlikely to be associated with the liquid product at least in part by processing the estimated thickness of the identified area of interest in combination with attenuation information derived from the X-ray image data.

4. A method as defined in claim 2, comprising:

i. processing the X-ray image data to derive geometric information associated with the identified area of interest;

ii. selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on the derived geometric information.

5. A method as defined in claim 4, comprising selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on:

a) the derived geometric information; and

b) a threshold aspect ratio.

6. A method as defined in claim 4, comprising selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on:

a) the derived geometric information; and

b) a reference solidity threshold.

7. A method as defined in claim 2, comprising selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on symmetrical properties of the identified area of interest.

8. A method as defined in claim 2, comprising:

i. processing the identified area of interest to derive density information associated with the identified area of interest;

ii. selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on the derived density information.

9. A method as defined in claim 2, comprising:

(1) processing the identified area of interest to determine whether it is likely to be associated with at least one object in a set of imposter objects;

(2) selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on results obtained in (1).

10. A method as defined in claim 9, wherein the set of imposter objects includes at least one object selected from the set consisting of CDs, Shoes, books and binders.

11. A method as defined in claim 2, wherein identifying the area of interest includes:

a) deriving compensated X-ray image data at least in part by compensating the X-ray image data for an amount of object induced X-ray attenuation resulting from X-rays travelling through an object in the piece of luggage, the object being unlikely to be part of the liquid product;

b) using the compensated X-ray image data when identifying the area of interest in the image.

12. A method as defined in claim 2, wherein identifying the area of interest includes identifying in the image conveyed by the X-ray image data a set of areas of interest.

13. A method as defined in claim 12, comprising processing at least some of the identified areas of interest according to a set of merging criterion to determine whether two or more areas of interest can be combined to form a merged area of interest.

14. A method as defined in claim 1 wherein the detection results convey a location in the piece of luggage corresponding to the liquid product.

15. A method as defined in claim 1, said method comprising rendering a visual representation of the piece of luggage, the visual representation of the piece of luggage being derived at least in part based on the X-ray image data and the detection results and conveying to an operator a location in the piece of luggage corresponding to the liquid product.

16. A method as defined in claim 15, wherein the location in the piece of luggage corresponding to the liquid product is conveyed by highlighting a portion of the visual representation of the piece of luggage.

17. A method as defined in claim 1, wherein the X-ray image data is obtained using a multi-view X-ray scanner and wherein said image of the piece of luggage and contents thereof is a first X-ray image obtained by subjecting the piece of luggage to X-rays in a first orientation, said X-ray image data conveying a second X-ray image of the piece of luggage, the second image being obtained by subjecting the piece of luggage item to X-rays in a second orientation.

18. A method as defined in claim 17, comprising processing the first X-ray image and the second X-ray image to derive the detection results.

19. A non-transitory computer readable storage medium storing a program element suitable for execution by a computing apparatus for use in performing security screening on luggage, said computing apparatus comprising:

a) a memory unit;

b) a processor operatively connected to said memory unit, said program element when executing on said processor being configured for;

i. receiving X-ray image data conveying an image of a piece of luggage and contents thereof, the X-ray image data being generated by scanning the piece of luggage with an X-ray scanner;

ii. processing the X-ray image data to detect if a liquid product is present in the piece of luggage, the liquid product being comprised of a container holding a body of liquid, wherein processing the X-ray image data includes detecting a liquid product signature in the X-ray image data;

iii. releasing detection results obtained by processing the X-ray image data.

20. A non-transitory computer readable storage medium as defined in claim 19, wherein processing the X-ray image data includes identifying in the image conveyed by the X-ray image data an area of interest.

21. A non-transitory computer readable storage medium as defined in claim 20, wherein said program element when executing on said processor is configured for:

a) processing the X-ray image data to estimate a thickness of the identified area of interest;

b) selectively disqualifying the identified area of interest as being unlikely to be associated with the liquid product at least in part by processing the estimated thickness of the identified area of interest in combination with attenuation information derived from the X-ray image data.

22. A non-transitory computer readable storage medium as defined in claim 20, wherein said program element when executing on said processor is configured for:

i. processing the X-ray image data to derive geometric information associated with the identified area of interest;

ii. selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on the derived geometric information.

23. A non-transitory computer readable storage medium as defined in claim 20, wherein said program element when executing on said processor is configured for:

i. processing the identified area of interest to derive density information associated with the identified area of interest;

ii. selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on the derived density information.

24. A non-transitory computer readable storage medium as defined in claim 20, wherein said program element when executing on said processor is configured for:

(1) processing the identified area of interest to determine whether it is likely to be associated with at least one object in a set of imposter objects;

(2) selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on results obtained in (1).

25. A non-transitory computer readable storage medium as defined in claim 24, wherein the set of imposter objects includes at least one object selected from the set consisting of CDs, Shoes, books and binders.

26. A non-transitory computer readable storage medium as defined in claim 20, wherein identifying the area of interest includes:

a) deriving compensated X-ray image data at least in part by compensating the X-ray image data for an amount of object induced X-ray attenuation resulting from X-rays travelling through an object in the piece of luggage, the object being unlikely to be part of the liquid product;

b) using the compensated X-ray image data when identifying the area of interest in the image.

27. A non-transitory computer readable storage medium as defined in claim 19, wherein said program element when executing on said processor is configured for rendering a visual representation of the piece of luggage, the visual representation of the piece of luggage being derived at least in part based on the X-ray image data and the detection results and conveying to an operator a location in the piece of luggage corresponding to the liquid product.

28. A non-transitory computer readable storage medium as defined in claim 27, wherein the location in the piece of luggage corresponding to the liquid product is conveyed by highlighting a portion of the visual representation of the piece of luggage.

29. An apparatus for use in performing security screening on luggage, said apparatus comprising:

a) an input for receiving X-ray image data conveying an image of a piece of luggage and contents thereof, the X-ray image data being generated by scanning the piece of luggage with an X-ray scanner;

b) a processing unit programmed for processing the X-ray image data received at the input to detect if a liquid product is present in the piece of luggage, the liquid product being comprised of a container holding a body of liquid, wherein processing the X-ray image data includes detecting a liquid product signature in the X-ray image data;

c) an output for releasing detection results obtained by the processing unit.

30. An apparatus as defined in claim 29, wherein processing the X-ray image data includes identifying in the image conveyed by the X-ray image data an area of interest.

31. An apparatus as defined in claim 30, wherein said processing unit is further programmed for:

a) processing the X-ray image data to estimate a thickness of the identified area of interest;

b) selectively disqualifying the identified area of interest as being unlikely to be associated with the liquid product at least in part by processing the estimated thickness of the identified area of interest in combination with attenuation information derived from the X-ray image data.

32. An apparatus as defined in claim 30, wherein said processing unit is further programmed for:

i. processing the X-ray image data to derive geometric information associated with the identified area of interest;

ii. selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on the derived geometric information.

33. An apparatus as defined in claim 30, wherein said processing unit is further programmed for:

i. processing the identified area of interest to derive density information associated with the identified area of interest;

ii. selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on the derived density information.

34. An apparatus as defined in claim 30, wherein said processing unit is further programmed for:

(1) processing the identified area of interest to determine whether it is likely to be associated with at least one object in a set of imposter objects;

(2) selectively disqualifying the identified area of interest for being unlikely to be associated with the liquid product at least in part based on results obtained in (1).

35. An apparatus as defined in claim 34, wherein the set of imposter objects includes at least one object selected from the set consisting of CDs, Shoes, books and binders.

36. An apparatus as defined in claim 30, wherein identifying the area of interest includes:

a) deriving compensated X-ray image data at least in part by compensating the X-ray image data for an amount of object induced X-ray attenuation resulting from X-rays travelling through an object in the piece of luggage, the object being unlikely to be part of the liquid product;

b) using the compensated X-ray image data when identifying the area of interest in the image.

37. An apparatus as defined in claim 29, wherein said processing unit is further programmed for rendering a visual representation of the piece of luggage, the visual representation of the piece of luggage being derived at least in part based on the X-ray image data and the detection results and conveying to an operator a location in the piece of luggage corresponding to the liquid product.

38. An apparatus as defined in claim 37, wherein the location in the piece of luggage corresponding to the liquid product is conveyed by highlighting a portion of the visual representation of the piece of luggage.

39. A system suitable for performing security screening on luggage, said system comprising:

a) an inspection device for performing an X-ray inspection on a piece of luggage using penetrating radiation to generate X-ray image data associated with the piece of luggage under inspection;

b) an apparatus comprising;

i. an input for receiving X-ray image data conveying an image of the piece of luggage and contents thereof, the X-ray image data being generated by scanning the piece of luggage with an X-ray scanner;

ii. a processing unit programmed for processing the X-ray image data received at the input to detect if a liquid product is present in the piece of luggage, the liquid product being comprised of a container holding a body of liquid, wherein processing the X-ray image data includes detecting a liquid product signature in the X-ray image data;

iii. an output for releasing detection results obtained by the processing unit;

c) a display screen in communication with the output of said apparatus for visually conveying to an operator information derived at least in part based on the detection results released by the apparatus.

40. A system as defined in claim 39, wherein the inspection device is a multi-view X-ray machine.