@conference {garbe2002c, title = {Thermographic measurements in environmental and bio sciences}, booktitle = {Quantitative Infrared Thermography}, volume = {6}, year = {2002}, pages = {253--259}, url = {http://qirt.gel.ulaval.ca/archives/qirt2002/papers/033.pdf}, author = {Christoph S. Garbe and Uwe Schimpf and Ulrich Schurr and Bernd J{\"a}hne} } @conference {garbe2002d, title = {Thermographic measurements on plant leaves}, booktitle = {ThermoSense}, volume = {4710}, year = {2002}, pages = {407--416}, publisher = {SPIE}, organization = {SPIE}, abstract = {An important process of plant physiology is the transpiration of plant leaves. It is actively controlled by pores (stomata) in the leaf and the governing feature for vital factors such as gas exchange and water transport affixed to which is the nutrient transport from the root to the shoot. Because of its importance, the transpiration and water transport in leaves have been extensively studied. However, current measurement techniques provide poor spatial and temporal resolution. With the use of one single low-NETD infrared camera important parameter of plant physiology such as transpiration rates, heat capacity per unit area of the leaf and the water flow velocity can be measured to high temporal and special resolution by techniques presented in this paper. The latent heat flux of a plant, which is directly proportional to the transpiration rate, can be measured with passive thermography. Here use is made of the linear relationship between the temperature difference between a non transpiring reference body and the transpiring leaf and the latent heat flux. From active thermography the heat capacity per unit area of the leaf can be measured. This method is termed active, because the response of the leaf temperature to an imposed energy flux is measured. Through the use of digital image processing techniques simultaneous measurements of the velocity field and temporal change of heated water parcels traveling through the leaf can be estimated from thermal image sequences.}, doi = {10.1117/12.459590}, author = {Christoph S. Garbe and Ulrich Schurr and Bernd J{\"a}hne}, editor = {Maldague, X. P. and Rozlosnik, A. E.} } @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} } @incollection {jaehne2001b, title = {Thermographie in den Umwelt- und Biowissenschaften}, year = {2001}, publisher = {Deutsche Gesellschaft f{\"u}r zerst{\"o}rungsfreie Pr{\"u}fung e.V.}, author = {Bernd J{\"a}hne and Christoph S. Garbe and Uwe Schimpf 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} } @incollection {schmundt2000, title = {Optical leaf growth analysis}, year = {2000}, pages = {640-641}, publisher = {Academic Press}, chapter = {A16}, author = {Dominik Schmund and Ulrich Schurr and Bernd J{\"a}hne}, editor = {Hau\DFecker, H.} } @incollection {kuemmerlen2000, title = {Thermography to measure water relations of plant leaves}, year = {2000}, pages = {636--637}, publisher = {Academic Press}, chapter = {A14}, author = {Bernd K{\"u}mmerlen and Stefan Dauwe and Dominik Schmund and Ulrich Schurr and Bernd J{\"a}hne and Horst Hau{\ss}ecker} } @incollection {schmundt1999a, title = {Plant-leaf growth studied by image sequence analysis}, volume = {3: Systems and Applications}, year = {1999}, pages = {719-735}, publisher = {Academic Press}, chapter = {33}, author = {Dominik Schmund and Ulrich Schurr and Bernd J{\"a}hne and Horst Hau{\ss}ecker and Peter Gei{\ss}ler} } @incollection {kuemmerlen1999, title = {Thermography to measure water relations of plant leaves}, volume = {3: Systems and Applications}, year = {1999}, pages = {763-781}, publisher = {Academic Press}, chapter = {36}, author = {Bernd K{\"u}mmerlen and Stefan Dauwe and Dominik Schmund and Ulrich Schurr and Bernd J{\"a}hne and Peter Gei{\ss}ler and Horst Hau{\ss}ecker} } @article {schmundt1998, title = {Quantitative analysis of the local rates of growth of dicot leaves at a high temporal and spatial resolution, using image sequence analysis}, journal = {Plant Journal}, volume = {16}, year = {1998}, pages = {505--514}, abstract = {A new technique is presented for quantitative mapping of dicot leaf growth at high spatial and temporal resolution, at a speed making online-mapping feasible. Time lapse video sequences of growing leaves are captured by a personal computer (PC) with a frame-grabber board and a standard CCD camera, and evaluated using algorithms that have been recently developed to analyse motion in dynamic image sequences. Growth can be detected at under 1\% per hour, with a time resolution of minutes and a spatial resolution of a few millimeters. The new technique has been verified by comparing it with classical approaches to map integrated growth. Diurnal courses of leaf growth of Ricinus communis and tobacco are presented to demonstrate the localised character of growth in leaves. Expansion growth is restricted to the base of the leaf and is restricted to a few hours at the end of the night and the start of the day. The high resolution of the method is illustrated by mapping the responses to step-changes in leaf turgor. A 3 bar turgor jump led to a rapid transient expansion over the entire length of the leaf that was partially reversed when the turgor was relaxed.}, doi = {10.1046/j.1365-313x.1998.00314.x}, author = {Dominik Schmund and Mark Stitt and Bernd J{\"a}hne and Ulrich Schurr} } @conference {jaehne1998b, title = {Study of dynamical processes with tensor-based spatiotemporal image processing techniques}, booktitle = {ECCV 1998}, volume = {1407}, year = {1998}, pages = {322--336}, publisher = {Springer}, organization = {Springer}, abstract = {Image sequence processing techniques are used to study exchange, growth, and transport processes and to tackle key questions in environmental physics and biology. These applications require high accuracy for the estimation of the motion field since the most interesting parameters of the dynamical processes studied are contained in first-order derivatives of the motion field or in dynamical changes of the moving objects. Therefore the performance and optimization of low-level motion estimators is discussed. A tensor method tuned with carefully optimized derivative filters yields reliable and dense displacement vector fields (DVF) with an accuracy of up to a few hundredth pixels/frame for real-world images. The accuracy of the tensor method is verified with computer-generated sequences and a calibrated image sequence. With the improvements in accuracy the motion estimation is now rather limited by imperfections in the CCD sensors, especially the spatial nonuniformity in the responsivity. With a simple two-point calibration, these effects can efficiently be suppressed. The application of the techniques to the analysis of plant growth, to ocean surface microturbulence in IR image sequences, and to sediment transport is demonstrated.}, doi = {10.1007/BFb0054750}, author = {Bernd J{\"a}hne and Horst Hau{\ss}ecker and Hanno Scharr and Hagen Spies and Dominik Schmund and Ulrich Schurr} } @conference {jaehne1997j, title = {The research unit (Forschergruppe) Image Sequence Processing to Study Dynamical Processes}, booktitle = {Proc.\ 3D Image Analysis and Synthesis{\textquoteright}97, Erlangen (Germany), November 17--18, 1997}, year = {1997}, pages = {107--114}, publisher = {infix}, organization = {infix}, author = {Bernd J{\"a}hne and Horst Hau{\ss}ecker and Ulrich Platt and Ulrich Schurr and Mark Stitt}, editor = {Hans-Peter Seidel and B. Girod and H. Niemann} } @conference {jaehne1996a, title = {The role of active vision in exploring growth, transport, and exchange processes}, booktitle = {Aktives Sehen in technischen und biologischen Systemen, Workshop der GI-Fachgruppe 1.0.4. Bildverstehen Hamburg, 3--4. December 1996}, volume = {4}, year = {1996}, pages = {194--202}, publisher = {infix}, organization = {infix}, author = {Bernd J{\"a}hne and Horst Hau{\ss}ecker and Frank Hering and G{\"u}nther Balschbach and J. Klinke and Martin Lell and Dominik Schmund and Michael Schultz and Ulrich Schurr and Mark Stitt and Ulrich Platt}, editor = {B Mertsching} } @article {schurr1996, title = {Structural and functional evidence for xylem-mediated water transport and high tranpiration in Agrobacterium tumefaciens-induced tumors of Ricinus communis}, journal = {Botanica Acta}, volume = {109}, year = {1996}, pages = {405--412}, doi = {10.1111/j.1438-8677.1996.tb00590.x}, author = {Ulrich Schurr and B. Schuberth and R. Aloni and K. S. Pradel and Dominik Schmund and Bernd J{\"a}hne and C. I. Ullrich} }