Apparatus, method and system for screening receptacles and persons, having image distortion correction functionality

• US 20070041612A1
• Filed: 05/11/2006
• Published: 02/22/2007
• Est. Priority Date: 05/11/2005
• Status: Active Grant

• Current Assignee: Vanderlande Industries BV (VIVE BV)
• Original Assignee: Optosecurity Inc.
• Inventors: Roy, Sebastien, Perron, Luc, Xu, Chen, Bouchard, Michel, Bergeron, Alain
• Granted Patent: US 7,991,242 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G06V 10/255 Detecting or recognising potential candidate objects based on visual cues, e.g. shapes
• CPC Class Codes: G06V 10/898 combination of filters, e.g. phase-only filters
• CPC Class Codes: G06V 2201/05 Recognition of patterns representing particular kinds of hidden objects, e.g. weapons, explosives, drugs
• CPC Class Codes: G06V 30/144 using a slot moved over the image; using discrete sensing elements at predetermined points; using automatic curve following means

Abstract

An apparatus suitable for screening a receptacle. The apparatus comprises an input for receiving an image signal, the image signal conveying an input image related to contents of the receptacle, the image signal having been produced by a device that is characterized by introducing distortion into the input image. The apparatus also comprises a processing unit operative for: applying a distortion correction process to the image signal to remove at least part of the distortion from the input image, thereby to generate a corrected image signal conveying at least one corrected image; processing the corrected image signal in combination with a plurality of data elements associated with a plurality of target objects in an attempt to detect a presence of at least one of said target objects in the receptacle; and generating a detection signal in response to detection of the presence of at least one of said target objects in the receptacle.

Claims

1. An apparatus suitable for screening a receptacle, said apparatus comprising:

a) an input for receiving an image signal associated with the receptacle, the image signal conveying an input image related to contents of the receptacle, the image signal having been produced by a device that is characterized by introducing distortion into the input image;

b) a processing unit in communication with said input, said processing unit being operative for;

applying a distortion correction process to the image signal to remove at least part of the distortion from the input image, thereby to generate a corrected image signal conveying at least one corrected image related to the contents of the receptacle;

processing the corrected image signal in combination with a plurality of data elements associated with a plurality of target objects in an attempt to detect a presence of at least one of said target objects in the receptacle;

generating a detection signal in response to detection of the presence of at least one of said target objects in the receptacle;

c) an output for releasing the detection signal.

2. The apparatus defined in claim 1, wherein the corrected image signal conveys a plurality of corrected images, each of said corrected images being associated with a respective target object distance to the device.

3. The apparatus defined in claim 1, wherein the corrected image signal conveys a plurality of corrected images, each of said corrected images being associated with a respective target object height within the receptacle.

4. The apparatus defined in claim 1, wherein the input image is defined by intensity data for a set of observed coordinates, wherein each of the at least one corrected image is defined by modified intensity data for a set of new coordinates, and wherein said applying a distortion correction process comprises applying an image transformation to the intensity data for the set of observed coordinates to derive said modified intensity data for the new coordinates.

5. The apparatus defined in claim 4, wherein said image transformation involves processing of a data structure representative of an inferred spatial transformation applied by the device.

6. The apparatus defined in claim 4, wherein the corrected image signal conveys a plurality of corrected images, each of said corrected images being associated with a respective target object distance to the device, and wherein said image transformation involves processing of a data structure representative of an inferred spatial transformation applied by the device for objects at the respective target object distance.

7. The apparatus defined in claim 5, wherein said inferred spatial transformation is two-dimensional.

8. The apparatus defined in claim 5, wherein said data structure is characterized by a set of parameters derived from registration of the observed coordinates with respect to a set of original coordinates.

9. The apparatus defined in claim 1, wherein the receptacle is a luggage item.

10. The apparatus defined in claim 1, wherein the receptacle is a cargo container.

11. The apparatus defined in claim 1, wherein the receptacle is a mail parcel.

12. The apparatus defined in claim 1, wherein said plurality of data elements includes images of the plurality of target objects.

13. The apparatus defined in claim 1, wherein said plurality of data elements includes data elements indicative of Fourier transforms of images of the plurality of target objects.

14. The apparatus defined in claim 13, the data elements being first Fourier transform data elements, wherein said processing unit includes an optical correlator, said optical correlator operative for:

a) processing the corrected image signal to derive a set of at least one second Fourier transform data element, each of the at least one second Fourier transform data element being indicative of a Fourier transform of a respective one of the at least one corrected image; and

b) processing the at least one second Fourier transform data element and at least one of said first Fourier transform data elements to detect a presence of at least one of said target objects in the receptacle.

15. The apparatus defined in claim 1, wherein said image signal is derived on the basis of penetrating radiation.

16. The apparatus defined in claim 15, wherein said image signal is an x-ray image.

17. The apparatus defined in claim 1, wherein said image signal is derived on the basis of emitted radiation.

18. The apparatus defined in claim 1, wherein the detection signal conveys the presence of at least one target object in the receptacle.

19. The apparatus defined in claim 1, wherein the detection signal enables identification of at least one of the at least one target object whose presence in the receptacle was detected.

20. The apparatus defined in claim 1, wherein the detection signal conveys a data element identifying at least one of the at least one target object whose presence in the receptacle was detected.

21. The apparatus defined in claim 1, wherein the detection signal conveys information describing at least one characteristic of at least one of the at least one target object whose presence in the receptacle was detected.

22. The apparatus defined in claim 21, wherein the at least one characteristic comprises position information

23. The apparatus defined in claim 1, wherein said detection signal is operative for causing a display unit to convey information related to at least one of the at least one target object whose presence in the receptacle was detected.

24. The apparatus defined in claim 1, wherein said processing unit is responsive to detection of the presence of at least one target object in the receptacle to:

a) generate log information elements conveying a presence of at least one of the at least one target object whose presence in the receptacle was detected;

b) store said log information data elements on a computer readable storage medium.

25. The apparatus defined in claim 24, wherein said log information elements include a time stamp data element.

26. The apparatus defined in claim 1, wherein said processing the corrected image signal in combination with a plurality of data elements associated with a plurality of target objects comprises said processing unit being operative to effect a correlation operation between data derived from the corrected image signal and data derived from images of the plurality of target objects.

27. The apparatus defined in claim 26, wherein said processing unit comprises an optical correlator for effecting the correlation operation.

28. The apparatus defined in claim 26, wherein said processing unit comprises a digital correlator for effecting the correlation operation.

29. The apparatus defined in claim 1, wherein the input image related to the contents of the receptacle is two-dimensional.

30. The apparatus defined in claim 1, wherein the input image related to the contents of the receptacle is three-dimensional.

31. The apparatus defined in claim 1, wherein said image signal is in a format selected from the set consisting of VGA, SVGA and XGA.

32. The apparatus defined in claim 1, wherein said input image is in a format selected from the set consisting of JPEG, GIF, TIFF and bitmap.

33. The apparatus defined in claim 1, wherein said apparatus further comprises a second input for receiving the plurality of data elements, said second input being in communication with said processing unit.

34. The apparatus defined in claim 33, wherein the plurality of target objects include at least one weapon.

35. An apparatus for detecting the presence of one or more prohibited objects in a receptacle, comprising:

a) an input for receiving an input image conveying graphic information regarding contents of a receptacle, the image having been produced by a device that introduces distortion into the input image;

b) a distortion correction functional unit operable for processing the input image to remove at least part of the distortion from the input image in order to derive at least one corrected image;

c) an optical correlator operable for processing the at least one corrected image in an attempt to detect whether at least one of said one or more prohibited objects is depicted in at least one of the at least one corrected image;

d) an output for releasing a signal in response to detecting that at least one of said one or more prohibited objects is depicted in at least one of the at least one corrected image.

36. The apparatus defined in claim 35, wherein said signal permits identification of said at least one of said one or more prohibited objects detected as having been depicted in at least one of the at least one corrected image.

37. A method for screening a receptacle, comprising:

a) receiving an image signal associated with the receptacle, the image signal conveying an input image related to contents of the receptacle, the image signal having been produced by a device that is characterized by introducing distortion into the input image;

b) applying a distortion correction process to the image signal to remove at least part of the distortion from the input image, thereby to generate a corrected image signal conveying at least one corrected image related to the contents of the receptacle;

c) processing the corrected image signal in combination with a plurality of data elements associated with a plurality of target objects in an attempt to detect a presence of at least one of said target objects in the receptacle;

d) generating a detection signal in response to detection of the presence of at least one of said target objects in the receptacle;

e) releasing the detection signal.

38. The method defined in claim 37, wherein the corrected image signal conveys a plurality of corrected images, each of said corrected images being associated with a respective target object distance to the device.

39. The method defined in claim 37, wherein the corrected image signal conveys a plurality of corrected images, each of said corrected images being associated with a respective target object height within the receptacle.

40. The method defined in claim 37, wherein the input image is defined by intensity data for a set of observed coordinates, wherein each of the at least one corrected image is defined by modified intensity data for a set of new coordinates, and wherein said applying a distortion correction process comprises applying an image transformation to the intensity data for the set of observed coordinates to derive said modified intensity data for the new coordinates.

41. The method defined in claim 40, wherein said image transformation involves processing of a data structure representative of an inferred spatial transformation applied by the device.

42. The method defined in claim 40, wherein the corrected image signal conveys a plurality of corrected images, each of said corrected images being associated with a respective target object distance to the device, and wherein said image transformation involves processing of a data structure representative of an inferred spatial transformation applied by the device for objects at the respective target object distance.

43. The method defined in claim 41, wherein said inferred spatial transformation is two-dimensional.

44. The method defined in claim 41, wherein said data structure is characterized by a set of parameters derived from registration of the observed coordinates with respect to a set of original coordinates.

45. The method defined in claim 37, wherein said plurality of data elements includes images of the plurality of target objects.

46. The method defined in claim 37, wherein said plurality of data elements includes data elements indicative of Fourier transforms of images of the plurality of target objects.

47. The method defined in claim 46, the data elements being first Fourier transform data elements, wherein said processing the corrected image signal in combination with a plurality of data elements associated with a plurality of target objects comprises:

a) processing the corrected image signal to derive a set of at least one second Fourier transform data element, each of the at least one second Fourier transform data element being indicative of a Fourier transform of a respective one of the at least one corrected image; and

b) processing the at least one second Fourier transform data element and at least one of said first Fourier transform data elements to detect a presence of at least one of said target objects in the receptacle.

48. The method defined in claim 37, further comprising deriving said image signal on the basis of penetrating radiation.

49. The method defined in claim 48, wherein said image signal is an x-ray image.

50. The method defined in claim 37, further comprising deriving said image signal on the basis of emitted radiation.

51. The method defined in claim 37, wherein the detection signal conveys the presence of at least one target object in the receptacle.

52. The method defined in claim 37, wherein the detection signal enables identification of at least one of the at least one target object whose presence in the receptacle was detected.

53. The method defined in claim 37, wherein the detection signal conveys a data element identifying at least one of the at least one target object whose presence in the receptacle was detected.

54. The method defined in claim 37, wherein the detection signal conveys information describing at least one characteristic of at least one of the at least one target object whose presence in the receptacle was detected.

55. The method defined in claim 54, wherein the at least one characteristic comprises position information

56. The method defined in claim 37, further comprising causing a display unit to convey information related to at least one of the at least one target object whose presence in the receptacle was detected.

57. The method defined in claim 37, further comprising, in response to detection of the presence of at least one target object in the receptacle:

a) generating log information elements conveying a presence of at least one of the at least one target object whose presence in the receptacle was detected;

b) storing said log information data elements on a computer readable storage medium.

58. The method defined in claim 57, wherein said log information elements include a time stamp data element.

59. The method defined in claim 37, wherein said processing the corrected image signal in combination with a plurality of data elements associated with a plurality of target objects comprises said processing unit being operative to effect a correlation operation between data derived from the corrected image signal and data derived from images of the plurality of target objects.

60. The method defined in claim 59, wherein said correlation operation is effected by an optical correlator.

61. The method defined in claim 59, wherein said correlation operation is effected by a digital correlator.

62. The method defined in claim 37, wherein the input image related to the contents of the receptacle is two-dimensional.

63. The method defined in claim 37, wherein the input image related to the contents of the receptacle is three-dimensional.

64. The method defined in claim 37, wherein said image signal is in a format selected from the set consisting of VGA, SVGA and XGA.

65. The method defined in claim 37, wherein said input image is in a format selected from the set consisting of JPEG, GIF, TIFF and bitmap.

66. The method defined in claim 37, further comprising receiving the plurality of data elements.

67. The method defined in claim 66, wherein the plurality of target objects include at least one weapon.

68. A computer-readable medium comprising computer-readable program code which, when interpreted by a computing apparatus, causes the computing apparatus to execute a method of screening a receptacle, the computer-readable program code comprising:

first computer-readable program code for causing the computing apparatus to be attentive to receipt of an image signal associated with the receptacle, the image signal conveying an input image related to contents of the receptacle, the image signal having been produced by a device that is characterized by introducing distortion into the input image;

second computer-readable program code for causing the computing apparatus to apply a distortion correction process to the image signal to remove at least part of the distortion from the input image, thereby to generate a corrected image signal conveying at least one corrected image related to the contents of the receptacle;

third computer-readable program code for causing the computing apparatus to process the corrected image signal in combination with a plurality of data elements associated with a plurality of target objects in an attempt to detect a presence of at least one of said target objects in the receptacle;

fourth computer-readable program code for causing the computing apparatus to generate a detection signal in response to detection of the presence of at least one of said target objects in the receptacle;

fifth computer-readable program code for causing the computing apparatus to release the detection signal.

69. An apparatus for screening a receptacle, comprising:

a) means for receiving an image signal associated with the receptacle, the image signal conveying an input image related to contents of the receptacle, the image signal having been produced by a device that is characterized by introducing distortion into the input image;

b) means for applying a distortion correction process to the image signal to remove at least part of the distortion from the input image, thereby to generate a corrected image signal conveying at least one corrected image related to the contents of the receptacle;

c) means for processing the corrected image signal in combination with a plurality of data elements associated with a plurality of target objects in an attempt to detect a presence of at least one of said target objects in the receptacle;

d) means for generating a detection signal in response to detection of the presence of at least one of said target objects in the receptacle;

e) means for releasing the detection signal.

70. A system for screening a receptacle, comprising:

a) an image generation device operable to generate an image signal associated with the receptacle, the image signal conveying an input image related to contents of the receptacle, the input image containing distortion introduced by said image generation device;

b) an apparatus in communication with said image generation device, said apparatus operable for

applying a distortion correction process to the image signal to remove at least part of the distortion from the input image, thereby to generate a corrected image signal conveying at least one corrected image related to the contents of the receptacle;

processing the corrected image signal in combination with a plurality of data elements associated with a plurality of target objects in an attempt to detect a presence of at least one of said target objects in the receptacle;

generating a detection signal in response to detection of the presence of at least one of said target objects in the receptacle;

c) an output module for conveying information derived at least in part on the basis of said detection signal to a user of the system.

71. The apparatus defined in claim 70, wherein the image generation device uses penetrating radiation to generate said image signal.

72. The system defined in claim 71, wherein the penetrating radiation is selected from the set consisting of x-ray, gamma-ray, computed tomography (CT scans) and millimeter wave.

73. The apparatus defined in claim 70, wherein the image generation device uses penetrating radiation to generate said image signal.