@conference {spies2002e,
	title = {Estimating expansion rates from range data sequences},
	booktitle = {15th International Conference on Vision Interface},
	year = {2002},
	pages = {339 - 346},
	author = {Hagen Spies and John L. Barron}
}
@conference {spies2002,
	title = {Evaluating the range flow motion constraint.},
	booktitle = {ICPR},
	year = {2002},
	pages = {517--},
	author = {Hagen Spies and John L. Barron}
}
@article {spies2002d,
	title = {Range flow estimation.},
	journal = {Computer Vision and Image Understanding},
	volume = {85},
	number = {3},
	year = {2002},
	pages = {209--231},
	abstract = {We discuss the computation of the instantaneous 3D displacement vector fields of deformable surfaces from sequences of range data. We give a novel version of the basic motion constraint equation that can be evaluated directly on the sensor grid. The various forms of the aperture problem encountered are investigated and the derived constraint solutions are solved in a total least squares (TLS) framework. We propose a regularization scheme to compute dense full flow fields from the sparse TLS solutions. The performance of the algorithm is analyzed quantitatively for both synthetic and real data. Finally we apply the method to compute the 3D motion field of living plant leaves.},
	doi = {10.1006/cviu.2002.0970},
	author = {Hagen Spies and Bernd J{\"a}hne and John L. Barron}
}
@incollection {barron2001,
	title = {The fusion of image and range flow},
	year = {2001},
	pages = {174--192},
	publisher = {Springer},
	doi = {10.1007/3-540-45134-X_13},
	author = {John L. Barron and Hagen Spies},
	editor = {R. Klette and Huang, T. and Gimel{\textquoteright}farb, G.}
}
@conference {spies2001c,
	title = {Surface expansion from range data sequences},
	booktitle = {Proceedings of the 23th DAGM Symposium on Pattern Recognition},
	year = {2001},
	pages = {163--169},
	publisher = {Springer},
	organization = {Springer},
	abstract = {We compute the range flow field, i.e. the 3D velocity field, of a moving deformable surface from a sequence of range data. This is done in a differential framework for which we derive a new constraint equation that can be evaluated directly on the sensor data grid. It is shown how 3D structure and intensity information can be used together in the estimation process. We then introduce a method to compute surface expansion rates from the now available velocity field. The accuracy of the proposed scheme is assessed on a synthetic data set. Finally we apply the algorithm to study 3D leaf motion and growth on a real range sequence.},
	doi = {10.1007/3-540-45404-7_22},
	author = {Hagen Spies and Bernd J{\"a}hne and John L. Barron}
}
@conference {spies2000b,
	title = {Dense range flow from depth and intensity data},
	booktitle = {ICPR},
	year = {2000},
	pages = {131--134},
	doi = {10.1109/ICPR.2000.905290},
	author = {Hagen Spies and Bernd J{\"a}hne and John L. Barron}
}
@conference {barron2000,
	title = {Optical and range flow to measure 3D plant growth and motion},
	booktitle = {Image Vision Computing New Zealand},
	year = {2000},
	pages = {68--77},
	author = {John L. Barron and Liptay, A. and Hagen Spies}
}
@conference {barron2000a,
	title = {Quantitative regularized range flow},
	booktitle = {Vision Interface},
	year = {2000},
	pages = {203--210},
	author = {John L. Barron and Hagen Spies}
}
@conference {spies2000a,
	title = {Regularised range flow},
	booktitle = {European Conference on Computer Vision (ECCV)},
	volume = {2},
	year = {2000},
	pages = {785--799},
	publisher = {Springer},
	organization = {Springer},
	abstract = {Extending a differential total least squares method for range flow estimation we present an iterative regularisation approach to compute dense range flow fields. We demonstrate how this algorithm can be used to detect motion discontinuities. This can can be used to segment the data into independently moving regions. The different types of aperture problem encountered are discussed. Our regularisation scheme then takes the various types of flow vectors and combines them into a smooth flow field within the previously segmented regions. A quantitative performance analysis is presented on both synthetic and real data. The proposed algorithm is also applied to range data from castor oil plants obtained with the Biris laser range sensor to study the 3-D motion of plant leaves.},
	doi = {10.1007/3-540-45053-X_50},
	author = {Hagen Spies and Bernd J{\"a}hne and John L. Barron},
	editor = {Vernon, D.}
}
@conference {spies1999a,
	title = {Differential range flow estimation},
	booktitle = {Proceedings of the 21th DAGM Symposium on Pattern Recognition},
	year = {1999},
	note = {DAGM award},
	pages = {309--316},
	doi = {10.1007/978-3-642-60243-6_36},
	author = {Hagen Spies and Horst Hau{\ss}ecker and Bernd J{\"a}hne and John L. Barron}
}
