APPARATUS AND METHOD FOR ERODING OBJECTS IN COMPUTED TOMOGRAPHY DATA

A method and apparatus for detecting objects in computed tomography (CT) data, including sheet-shaped objects such as sheet explosives, analyze a neighborhood of voxels surrounding a test voxel. 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 be performed on the eroded object to replace surface voxels removed by erosion.