Method and system for identifying a containment vessel

1. A method for identifying an object in an acquired image, said method comprising:

detecting an object within the acquired image;

detecting a low-density material within the acquired image;

determining whether the detected object is a containment vessel;

determining whether the low-density material is within the containment vessel;

applying a first set of rules for classifying the object if the object is not the containment vessel using a first CT number threshold; and

applying a second set of rules for classifying the object if the object is the containment vessel.

2. A method in accordance with claim 1 , further comprising:

applying the first set of rules to classify the low-density material if the low-density material is not within the containment vessel; and

applying the second set of rules to classify the low-density material if the low-density material is within the containment vessel.

3. A method in accordance with claim 1 , further comprising determining whether a material of the object is one of a dense material and a non-dense material.

4. A method in accordance with claim 3 , further comprising:

when the material is the non-dense material, determining whether the non-dense material is contraband; and

when the material is the dense material, adjusting a threshold in the first set of rules to account for an effect of the containment vessel on the acquired image.

5. A method in accordance with claim 4 , wherein adjusting a threshold further comprises raising a CT number threshold of the first set of rules to account for higher computed tomography numbers within the containment vessel.

6. A method in accordance with claim 1 , wherein determining whether the detected object is a containment vessel further comprises:

detecting a region of connected pixels;

labeling each pixel within the detected region as one of a region pixel, an exterior pixel, and an interior pixel; and

determining whether a field of interior pixels is a contained area.

7. A method in accordance with claim 6 , when the field of interior pixels is determined to be the contained area, said method further comprising:

determining an area of the field of interior pixels;

comparing the determined area to a threshold area; and

when the determined area is at least equal to the threshold area:

labeling the field of interior pixels as the contained area; and

labeling a field of region pixels as the containment vessel.

8. A method in accordance with claim 1 , wherein determining whether the detected object is a containment vessel further comprises:

detecting a region of connected voxels;

labeling each voxel within the detected region as one of a region voxel, an exterior voxel, and an interior voxel; and

determining whether a field of interior voxels is a contained volume.

9. A method in accordance with claim 8 , when the field of interior voxels is determined to be the contained volume, said method further comprising:

determining a volume of the field of interior voxels;

comparing the determined volume to a threshold volume; and

when the determined volume is at least equal to the threshold volume:

labeling the field of interior voxels as the contained volume; and

labeling a field of region voxels as the containment vessel.

10. A system for identifying an object, said system comprising:

a radiation source;

a detector for detecting radiation generated by said radiation source; and

a control system coupled in communication with said radiation source and said detector, said control system configured to:

acquire an image:

detect an object within the acquired image;

detect a low-density material within the acquired image;

determine whether the detected object is a containment vessel;

determine whether the low-density material is within the containment vessel;

apply a first set of rules for classifying the object if the object is not the containment vessel using a first CT number threshold;

apply a second set of rules for classifying the object if the object is the containment vessel; and

output information relating to the object.

11. A system in accordance with claim 10 , wherein said control system is further configured to:

apply the first set of rules to classify the low-density material when the low-density material is not within the containment vessel; and

apply the second set of rules to classify the low-density material when the low-density material is within the containment vessel.

12. A system in accordance with claim 10 , wherein said control system is further configured to:

determine whether a material from which the containment vessel is formed is one of a dense material and a non-dense material;

when the material is the non-dense material, determine whether the non-dense material is contraband; and

when the material is the dense material, adjust a threshold in the first set of rules to account for an effect of the containment vessel on the acquired image by raising a CT number threshold of the first set of rules to account for higher computed tomography numbers within the containment vessel.

13. A system in accordance with claim 10 , wherein said control system is further configured to:

detect a region of connected pixels;

label each pixel within the detected region as one of a region pixel, an exterior pixel, and an interior pixel;

determine an area of the field of interior pixels;

compare the determined area to a threshold area; and

when the determined area is at least equal to the threshold area:

label the field of interior pixels as a contained area; and

label a field of region pixels as the containment vessel.

14. A system in accordance with claim 10 , wherein said control system is further configured to:

detect a region of connected voxels;

label each voxel within the detected region as one of a region voxel, an exterior voxel, and an interior voxel;

determine a volume of a field of interior voxels;

compare the determined volume to a threshold volume; and

when the determined volume is at least equal to the threshold volume:

label the field of interior voxels as a contained volume; and

label a field of region voxels as the containment vessel.

15. A computer program embodied on a computer-readable medium, said computer program comprising a code segment that configures a processor to:

detect an object within an acquired image;

detect a low-density material within the acquired image;

determine whether the detected object is a containment vessel;

determine whether the low-density material is within the containment vessel;

apply a first set of rules for classifying the object if the object is not the containment vessel using a first CT number threshold;

apply a second set of rules for classifying the object if the object is the containment vessel; and

output information relating to the object.

16. A computer program in accordance with claim 15 , wherein the code segment further configures the processor to:

apply the first set of rules to classify the low-density material when the low-density material is not within the containment vessel; and

apply the second set of rules to classify the low-density material when the low-density material is within the containment vessel.

17. A computer program in accordance with claim 15 , wherein the code segment further configures the processor to:

determine whether a material from which the containment vessel is formed is one of a dense material and a non-dense material;

when the material is the non-dense material, determine whether the non-dense material is contraband; and

when the material is the dense material, adjust a threshold in the first set of rules to account for an effect of the containment vessel on the acquired image by raising a CT number threshold of the first set of rules to account for higher computed tomography numbers within the containment vessel.

18. A computer program in accordance with claim 15 , wherein the code segment further configures the processor to:

detect a region of connected image elements;

label each image element within the detected region as one of a region image element, an exterior image element, and an interior image element;

determine a quantity of a field of interior image elements;

compare the determined quantity to a threshold quantity; and

when the determined quantity is at least equal to the threshold quantity:

label the field of interior image elements as a contained quantity; and

label a field of region image elements as the containment vessel.