Directional analysis of digitized three-dimensional images by configuration counts

A method for estimating the orientated rose of normal directions of a three-dimensional (3D) set Z from a digitization of Z, i.e. a voxel image, is presented. It is based on counts of informative configurations in nxnxn voxel cubes. An algorithm for finding all informative configurations is proposed and an estimation procedure is described in detail for the case n = 2. The presented method is a 3D version of a method of estimating the orientated rose of binary planar images using nxn configurations. A new feature is the design-based approach, being more appropriate for biomedical image analysis than the formerly applied model-based approach.