Apparatus and method for detecting concealed objects in computed tomography data
US6195444A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 1999 |
| Grant date | Feb 27, 2001 |
| Priority date | — |
| Expiry date | Jan 12, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V2201/05
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for detecting concealed objects in computed tomography data are disclosed. Sheet-shaped objects such as sheet explosives can be detected by a CT scanning system, in particular, a CT baggage scanning system. The invention analyzes CT voxels in a subregion in proximity to the sheet object to determine if the sheet object is concealed in an electronic device or is "sandwiched" within an item such as a book or magazine. To detect electronic concealment, the number of voxels in a subregion that contains the object having a density above a predetermined threshold is counted and the ratio of that number of voxels to the number of object voxels is computed. If the ratio exceeds a threshold, then it is concluded that the object is concealed in electronics. In response, the CT scanning system can alter discrimination parameters to allow the object to be classified as a threat. For "sandwich" concealment, layers on opposite sides of a sheet object are examined. The mean and standard deviation of density values for the voxels are computed. Where the mean density exceeds a predetermined threshold and the standard deviation is below a different threshold, for at least one …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.