Multi-step differential approaches for the localization of 3D point landmarks in medical images
Sönke Frantz, Karl Rohr, H. Siegfried Stiehl · 2015
In this contribution, we are concerned with the detection and re#ned subvoxel localization of 3D point landmarks. We propose multi-step differential approaches which are generalizations of an existing two-step approach for subpixel localization of 2D point landmarks. This two-step approach combines landmark detection by applying a di#erential operator with re#ned localization through a di#erential edge intersection approach. In this paper, weinvestigate the localization performance of this two-step approach for an analytical model of a Gaussian blurred L-corner as well as a Gaussian blurred ellipse. By varying the model parameters, di#erently tapered and curved structures are represented. The results motivate the use of an analogous approachto3Dpoint landmark localization. We generalize the edge intersection approach to 3D and, by combining it with 3D di#erential operators for landmark detection, we propose multi-step approaches for subvoxel localization of 3D point landma...