Extraction of relevant physical parameters from 3D images of foams obtained by X-ray tomography

3D liquid foams are investigated for the first time through X-ray tomography. This method enables to observe large number of bubbles (several thousands), and hence, to extract significant statistical characteristics of the foam structure. This article presents the successive steps we followed to achieve this purpose: image acquisition, image processing and data extraction. This global procedure can be automatised, but we emphasize the importance of the choice of two parameters which can be arbitrarily set by users. The first one is the cut-off value for the size of the smallest bubbles, the second deals with the definition of the neighbors of a bubble which is ambiguous for wet foams. We discuss here the consequences of these two choices on characteristics such as the average number of faces of bubbles.