Computed tomography apparatus and method for classifying objects
US6317509A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 1998 |
| Grant date | Nov 13, 2001 |
| Priority date | — |
| Expiry date | Feb 11, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V2201/05
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus detects sheet explosives in computed tomography (CT) data. In particular, sheet-shaped objects such as sheet explosives can be discriminated from other object shapes and detected. The detection includes analyzing a neighborhood of voxels surrounding a test voxel. If the density of the test voxel is sufficiently different from the mean density of the neighboring voxels, then it is concluded that the test voxel is associated with a sheet object. Sheet objects can also be detected by eroding the CT data so as to eliminate voxels associated with thin objects. Remaining objects are then subtracted from the original data, leaving only thin sheet-shaped objects. Erosion of the data can be performed by identifying a neighborhood of voxels surrounding a voxel of interest. If the number of voxels having densities below a predetermined threshold exceeds a predetermined number, then it is assumed that the test voxel is a surface voxel and is removed from the object. A connectivity process can be applied to voxels to combine them into objects after sheets are detected to prevent sheets from being inadvertently removed from the data by erosion. A dilation function can then…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.