Pressure Based Segmentation in Volumetric Images

Analysing Roman coins found in archaeology sites has been traditionally done manually by an operator using volumetric image slices provided by a computed tomography scanner. In order to automate the counting process, a good segmentation for the coins has to be achieved to separate the touching surfaces of the coins. Separating touching surfaces in volumetric images has not yet attracted much attention. In this paper we propose a new method based on using a form of pressure to separate the intersecting surfaces. We analogise the background of the image to be filled with an ideal gas. The pressure at a point has an inverse relationship with the volume of homogeneous material surrounding it. By studying the pressure space, the locations of intersecting surfaces are highlighted and encouraging segmentation results are achieved. Our analysis concerns a selection of images, naturally demonstrating success, together with an analysis of the new technique’s sensitivity to noise.