@phdthesis {kirchgessner2003, title = {Extraktion physiologischer Koordinatensysteme von Pflanzenwurzeln und -bl{\"a}ttern aus Bildsequenzen}, year = {2003}, publisher = {IWR, Fakult{\"a}t f{\"u}r Physik und Astronomie, Univ.\ Heidelberg}, abstract = {The present work develops a method for analyzing the growth of plant leaves and roots in natural object coordinates using image processing techniques. The method is based on the structure tensor method that has already been used for the acquisition of growth charts in image coordinates. The main advantages of growth measurements in physiological coordinates is the possibility to compare the results of different measurements and the direct interpretation of the results. A method for extracting the coordinate axes is developed both for leaves and for roots. The center line of a root is identified as the physiological coordinate axis by means of a method based on active contours. In the case of leaves, the physiological coordinate axes are represented by their veins. The latter are searched for by use of a tracking algorithm which relies on matching methods. All physiological coordinate axes are represented in the form of B-splines. The growth charts are sampled from the B-spline positions, thus providing a coordinate transformation into the corresponding physiological coordinate system. The transformation has subpixel accuracy. Thus, it significantly stays behind the spatial resolution of the growth charts. The accomplishment of the present method provides a powerful tool for growth analysis of plant leaves and roots.}, url = {http://www.ub.uni-heidelberg.de/archiv/3482}, author = {Norbert Kirchge{\ss}ner} } @conference {raisch2002, title = {Velocity and feature estimation of actin filaments using active contours in noisy fluorescence image sequences}, booktitle = {Proc. 2nd IASTED Int. Conf. Visualization, Imaging and Image Processing}, year = {2002}, pages = {645--650}, abstract = {We present a new approach for determining particle fea tures such as length, curvature and hence flexibility in addition to the velocity of moving single actin filaments in noisy fluorescence image sequences. The reliable deter mination of these features is essential for the analysis of the elementary force generation process of single motor molecules including heart and skeletal muscle myosins. First, the image sequence is preprocessed with the 3D structure tensor - where the third dimension is the time t in the image sequence - in order to eliminate noise and to obtain a measure for extracting coherently moving par ticles. Secondly, we determine the contour of the actin filaments with subpixel accuracy using active contours. Thereafter, we readjust a local coordinate system to elim inate inner movements of the active contour. In the fourth step, we estimate the initial position of the active contour in the next frame from the displacement vector field cal culated by the 3D structure tensor. The accuracy of the method is verified on synthetic test data, a prerequisite for the quantitative use of this method on experimentally obtained data. Finally this is demonstrated for fluorescence image sequences of actin filament movement in the in vitro motility assay.}, author = {Florian Raisch and Hanno Scharr and Norbert Kirchge{\ss}ner and Bernd J{\"a}hne and Rainer H. A. Fink and D. Uttenweiler} } @conference {kirchgessner2001, title = {Root Growth Analysis in Physiological Coordinates}, booktitle = {International Conference on Image Analysis and Processing (ICIAP{\textquoteright}01)}, year = {2001}, author = {Norbert Kirchge{\ss}ner and Hagen Spies and Hanno Scharr and Ulrich Schurr} } @conference {kirchgessner2001a, title = {Root Growth Measurements in Object Coordinates}, booktitle = {Proceedings of the 23th DAGM Symposium on Pattern Recognition}, year = {2001}, publisher = {Springer}, organization = {Springer}, doi = {10.1007/3-540-45404-7_31}, author = {Norbert Kirchge{\ss}ner and Hagen Spies and Hanno Scharr and Ulrich Schurr} } @conference {kirchgessner2000, title = {3D-Modellierung von Pflan-zen-bl{\"a}t-tern mittels eines Depth-from-Motion Verfahrens}, booktitle = {Proceedings of the 22th DAGM Symposium on Pattern Recognition}, year = {2000}, pages = {381--388}, doi = {10.1007/978-3-642-59802-9_48}, author = {Norbert Kirchge{\ss}ner and Hanno Scharr and Ulrich Schurr} } @conference {spies2000c, title = {Dense structure estimation via regularised optical flow}, booktitle = {VMV 2000}, year = {2000}, pages = {57--64}, publisher = {Aka GmbH, Berlin}, organization = {Aka GmbH, Berlin}, author = {Hagen Spies and Norbert Kirchge{\ss}ner and Hanno Scharr and Bernd J{\"a}hne}, editor = {Girod, G. and Greiner, G. and Hans-Peter Seidel and H. Niemann} } @mastersthesis {kirchgessner1999, title = {Voruntersuchungen zur 3D-Wuchsanalyse von Pflanzenbl{\"a}ttern und die Modellierung der Blattadern}, year = {1999}, school = {IWR, Fakult{\"a}t f{\"u}r Physik und Astronomie, Univ.\ Heidelberg}, author = {Norbert Kirchge{\ss}ner} }