@proceedings {diebold-etal-2015-SPIE,
	title = {Light-field camera design for high-accuracy depth estimation},
	year = {2015},
	month = {06/2015},
	abstract = {Light-field imaging is a research field with applicability in a variety of imaging areas including 3D cinema, entertainment, robotics, and any task requiring range estimation. In contrast to binocular or multi-view stereo approaches, capturing light fields means densely observing a target scene through a window of viewing directions. A principal benefit in light-field imaging for range computation is that one can eliminate the error-prone and computationally expensive process of establishing correspondence. The nearly continuous space of observation allows to compute highly accurate and dense depth maps free of matching. Here, we discuss how to structure the imaging system for optimal ranging over a defined volume - what we term a bounded frustum. We detail the process of designing the light-field setup, including practical issues such as camera footprint and component size influence the depth of field, lateral and range resolution. Both synthetic and real captured scenes are used to analyze the depth precision resulting from a design, and to show how unavoidable inaccuracies such as camera position and focal length variation limit depth precision. Finally, inaccuracies may be sufficiently well compensated through calibration and must be eliminated at the outset.},
	doi = {http://dx.doi.org/10.1117/12.2184845},
	author = {Maximilian Diebold and Oliver Blum and Marcel Gutsche and Sven Wanner and Christoph S. Garbe and Harlyn Baker and Bernd J{\"a}hne}
}
@conference {gottfried2014,
	title = {Time of flight motion compensation revisited},
	booktitle = {International Conference on Image Processing, ICIP 2014},
	year = {2014},
	author = {Gottfried, Jens-Malte and Nair, Rahul and Stephan Meister and Christoph S. Garbe and Daniel Kondermann}
}
@incollection {Lenzen2013stategies,
	title = {Denoising Strategies for Time-of-Flight Data},
	volume = {8200},
	year = {2013},
	pages = {25-45},
	publisher = {Springer},
	author = {Frank Lenzen and Kim, Kwang In and Sch{\"a}fer, Henrik and Nair, Rahul and Stephan Meister and Florian Becker and Christoph S. Garbe},
	editor = {Grzegorzek, Marcin and Theobalt, Christian and Andreas Kolb and Theobalt, Christian and Reinhard Koch}
}
@conference {lenzen_13_denoising,
	title = {Denoising Strategies for Time-of-Flight Data},
	booktitle = {Time-of-Flight Imaging: Algorithms, Sensors and Applications},
	volume = {8200},
	year = {2013},
	note = {1},
	pages = {24-25},
	publisher = {Springer},
	organization = {Springer},
	doi = {10.1007/978-3-642-44964-2_2},
	author = {Frank Lenzen and Kim, K. I. and Sch{\"a}fer, H. and Nair, R. and Stephan Meister and Florian Becker and Christoph S. Garbe},
	editor = {Grzegorzek, M. and Theobalt, C. and Andreas Kolb and Theobalt, C. and Reinhard Koch}
}
@conference {schaefer_13_depth,
	title = {Depth and Intensity Based Edge Detection in Time-of-Flight Images},
	booktitle = {3D Imaging, Modeling, Processing, Visualization and Transmission
(3DIMPVT), 2013 International Conference on},
	year = {2013},
	note = {1},
	pages = {111-118},
	publisher = {IEEE},
	organization = {IEEE},
	doi = {10.1109/3DV.2013.23},
	author = {Sch{\"a}fer, H. and Frank Lenzen and Christoph S. Garbe}
}
@conference {Schaefer2013depth,
	title = {Depth and Intensity Based Edge Detection in Time-of-Flight Images},
	booktitle = {3DV-Conference, 2013 International Conference on},
	year = {2013},
	pages = {111-118},
	doi = {10.1109/3DV.2013.23},
	author = {Sch{\"a}fer, Henrik and Frank Lenzen and Christoph S. Garbe}
}
@inbook {garbe:MBPE:2013,
	title = {Parameter Estimation in Image Processing and Computer Vision},
	booktitle = {Model Based Parameter Estimation: Theory and Applications},
	year = {2013},
	pages = {311--334},
	publisher = {Springer},
	organization = {Springer},
	isbn = {978-3-642-30366-1},
	author = {Christoph S. Garbe and Bj{\"o}rn Ommer}
}
@incollection {Nair2013survey,
	title = {A Survey on Time-of-Flight Stereo Fusion},
	volume = {8200},
	year = {2013},
	pages = {105-127},
	publisher = {Springer},
	author = {Nair, Rahul and Ruhl, Kai and Frank Lenzen and Stephan Meister and Sch{\"a}fer, Henrik and Christoph S. Garbe and Eisemann, Martin and Magnor, Marcus and Daniel Kondermann},
	editor = {Grzegorzek, Marcin and Theobalt, Christian and Andreas Kolb and Reinhard Koch}
}
@conference {nair_13_survey,
	title = {A Survey on Time-of-Flight Stereo Fusion},
	booktitle = {Time-of-Flight Imaging: Algorithms, Sensors and Applications},
	volume = {8022},
	year = {2013},
	pages = {105-127},
	publisher = {Springer},
	organization = {Springer},
	doi = {10.1007/978-3-642-44964-2_6},
	author = {Nair, R. and Ruhl, K. and Frank Lenzen and Stephan Meister and Sch{\"a}fer, H. and Christoph S. Garbe and Eisemann, M. and Daniel Kondermann},
	editor = {Grzegorzek, M. and Theobalt, C. and Andreas Kolb and Reinhard Koch}
}
@article {voss2012exp,
	title = {Bichromatic Particle Streak Velocimetry bPSV -- Interfacial, v3C3D velocimetry using a single camera},
	journal = {Exp. Fluids},
	year = {2012},
	note = {Submitted},
	author = {Bj{\"o}rn Voss and Julian Stapf and A. Berthe and Christoph S. Garbe}
}
@conference {schaefer_12_edge,
	title = {Edge Detection in Time-of-Flight Images},
	booktitle = {submitted to ECCV, 2nd Workshop on Consumer Depth Cameras for Computer
Vision},
	year = {2012},
	note = {1},
	author = {Sch{\"a}fer, H. and Frank Lenzen and Stephan Meister and Christoph S. Garbe}
}
@conference {nair_12_high,
	title = {High Accuracy TOF and Stereo Sensor Fusion at Interactive Rates},
	booktitle = {submitted to ECCV 2012},
	volume = {7584},
	year = {2012},
	note = {1},
	pages = {1-11},
	publisher = {Springer},
	organization = {Springer},
	doi = {10.1007/978-3-642-33868-7_1},
	author = {Nair, R. and Frank Lenzen and Sch{\"a}fer, H. and Stephan Meister and Christoph S. Garbe and Daniel Kondermann}
}
@conference {Nair2012highaccuracy,
	title = {High accuracy TOF and stereo sensor fusion at interactive rates},
	booktitle = {Computer Vision--ECCV 2012. Workshops and Demonstrations},
	year = {2012},
	pages = {1--11},
	publisher = {Springer Berlin Heidelberg},
	organization = {Springer Berlin Heidelberg},
	author = {Nair, Rahul and Frank Lenzen and Stephan Meister and Sch{\"a}fer, Henrik and Christoph S. Garbe and Daniel Kondermann}
}
@incollection {garbe2012,
	title = {Plenoptic Particle Streak Velocimetry (pPSV): 3D3C fluid flow measurement from light fields with a single plenoptic camera},
	year = {2012},
	pages = {1-12},
	publisher = {Instituto Superior T{\'e}cnico},
	author = {Christoph S. Garbe and Bj{\"o}rn Voss and Julian Stapf}
}
@conference {lenzen_11_denoising,
	title = {Denoising Time-Of-Flight Data with Adaptive Total Variation},
	booktitle = {Proceedings ISVC},
	year = {2011},
	note = {1},
	pages = {337-346},
	publisher = {Springer},
	organization = {Springer},
	doi = {10.1007/978-3-642-24028-7_31},
	author = {Frank Lenzen and Sch{\"a}fer, H. and Christoph S. Garbe}
}
@conference {voss2010,
	title = {A new approach for 3C3D measurements of aqueous boundary layer flows relative to the wind-wave undulated interface},
	booktitle = {6th Int. Symp. Gas Transfer at Water Surfaces, Kyoto, May 17--21, 2010},
	year = {2010},
	note = {poster},
	doi = {10.5281/zenodo.14930},
	author = {Bj{\"o}rn Voss and Alexander Heinlein and Bernd J{\"a}hne and Christoph S. Garbe}
}
@conference {voss2010a,
	title = {Novel strategy for water sided interfacial 3D3Cflow-visualization using a single camera},
	booktitle = {14th International Symposium on Flow Visualization},
	year = {2010},
	pages = {D1-018},
	author = {Bj{\"o}rn Voss and Christoph S. Garbe}
}
@article {berthe2010,
	title = {Three-dimensional, three-component wall-PIV},
	journal = {Exp. Fluids},
	volume = {48},
	year = {2010},
	pages = {online},
	doi = {10.1007/s00348-009-0777-4},
	author = {A. Berthe and Daniel Kondermann and Christensen, C. and Goubergrits, L. and Christoph S. Garbe and Affeld, K. and U. Kertzscher}
}
@incollection {beushausen2009,
	title = {2D-measurement technique for simultaneous quantitative determination of mixing ratio and velocity field in microfluidic applications},
	volume = {106},
	year = {2009},
	pages = {155--164},
	publisher = {Springer},
	abstract = {Two-dimensional Molecular-Tagging-Velocimetry (2D-MTV) has been used to investigate velocity fields of liquid flow in a micro mixer. Optical tagging was realized by using caged dye. For the first time patterns were generated by structured laser illumination using optical masks. This allows the generation of nearly any imaginable pattern. The flow induced deformation of the optically written pattern is tracked by imaging of laser induced fluorescence. Quantitative analysis of raw image series is carried out by novel optical flow based techniques. A comparison to the standard technique of uPIV has also been conducted. Additionally Planar Spontaneous Raman Scattering (PSRS) was applied in order to determine concentration fields for mixtures of ethanol and water.},
	doi = {10.1007/978-3-642-01106-1_16},
	author = {Volker Beushausen and Karsten Roetmann and Waldemar Schmunk and Mike Wellhausen and Christoph S. Garbe and Bernd J{\"a}hne},
	editor = {W. Nitsche and C. Dobriloff}
}
@incollection {garbe2009,
	title = {Spatiotemporal image analysis for flow measurements},
	volume = {106},
	year = {2009},
	pages = {289--305},
	publisher = {Springer},
	abstract = {In this chapter, a framework will be presented for measuring and modeling transport processes using novel visualization techniques and extended optical flow techniques for digital image sequence analysis. In this way, parameters besides the 2-D xy velocity components can be extracted concurrently from the acquired 2-D image sequences, such as wall shear rates and momentum transport close to boundaries, diffusion coefficients, and depth z in addition to the z velocity components. Depending on the application, particularly the temporal regularization can be enhanced, leading to stabilization of results and reduction of spatial regularization. This is frequently of high importance for flows close to boundaries. Results from applications will be presented from the fields of environmental and life sciences as well as from engineering.},
	doi = {10.1007/978-3-642-01106-1_29},
	author = {Christoph S. Garbe and Daniel Kondermann and Markus Jehle and Bernd J{\"a}hne},
	editor = {W. Nitsche and C. Dobriloff}
}
@conference {garbe2009b,
	title = {Thermographic measurements of the temperature difference across the air- water interface: results from experimental and numerical studies},
	booktitle = {Poster abstracts SOLAS Open Science Conference, Barcelona, 16--19 Sep. 2009},
	year = {2009},
	abstract = {Thermography is a powerful tool for analyzing spatially and temporally resolved the transport of heat across the air-water interface. In this contribution, measurements of the temperature difference across the aqueous boundary layer will be presented. These measurements are based on a statistical analysis of the temperature distribution directly at the water surface. This technique will be presented together with results of measurements conducted in the laboratory and in the field. These thermographic measurements are compared to measurements with standard techniques. Also, the same statistical analysis is performed on data from direct numerical simulation of a wind-driven, aqueous turbulent boundary-layer flow. The agreement between thermography and simulation is very good. Moreover, the full 3D simulations are used for a thorough analysis and validation of the thermographic technique and help to discuss the results.},
	author = {Christoph S. Garbe and Leila Nagel and Hung, L. -P. and Tsai, W. -T.}
}
@conference {garbe2009a,
	title = {Transport of dust across the Sahara from satellite image sequence analysis},
	booktitle = {Eos Transactions},
	volume = {90},
	year = {2009},
	note = {Fall Meet. Suppl.},
	pages = {EP21A-0565},
	author = {Christoph S. Garbe and Flatow, F. and Klinger, M. and Schepanski, K. and Tegen, I. and Rannacher, R.}
}
@conference {garbe2009c,
	title = {Transport of Sahara dust into the Atlantic Ocean from satellite image sequence analysis},
	booktitle = {SOLAS Open Science Conference},
	year = {2009},
	pages = {27},
	abstract = {In this contribution, image processing techniques in conjunction with efficient numerical solvers will be used for measuring the transport of atmospheric dust originating in the Sahara to the Atlantic Ocean. Mineral dust aerosols are an important component of the Earth{\textquoteright}s climate system through a number of direct and indirect influences, and have a strong effect on terrestrial and oceanic biogeochemical cycles. We use Meteosat Second Generation (MSG) infra-red (IR) difference dust index images for visualizing dust plumes in the atmosphere. For every 15-minute scan the dust index is computed basing on the difference of the brightness temperatures measured by the Spinning enhanced Visible and Infra-Red Imager (SEVIRI) at the wavelengths centred at 8.7 m, 10.8 m and 12.0 m. Sinks and sources of the plumes are detected and trajectories computed. Newly developed techniques for computing optical flows and transport parameters are employed. Through the estimation of these transport parameters, dust deposition in the ocean can be quantified. We will present results for a wide range of events, highlighting the capabilities of our approach.},
	author = {Christoph S. Garbe and Flatow, F. and Klinger, M. and Schepanski, K. and Tegen, I. and Rannacher, R.}
}
@article {banerjee2008,
	title = {An active thermographic technique for highly resolved heat transport measurements in paper drying},
	journal = {APPITA Journal},
	volume = {61},
	number = {3},
	year = {2008},
	pages = {244--249},
	abstract = {A novel measurement technique, based on infrared thermography, has been applied for characterizing the thermal properties of paper with high spatial resolution. The technique is referred to as {\textquoteright}active thermography{\textquoteright} since the temperature response of a paper sheet is observed and analysed with respect to an external periodic heating. Through the analysis of the temperature response of the paper surface in the Fourier domain for different modulation frequencies of incident heat flux, heat transfer velocities across the solid-gas interface can be estimated. This in turn results in estimation of the heat capacity of paper by solving the heat balance equations of the system. The thermal heating is applied spatially homogeneously. Therefore all these calculations are performed for all pixels in the image sequence. The spatial distribution and temporal development of all these parameters were visualized. The technique shows high potential for non-invasive dynamic measurements in paper drying.},
	url = {http://search.informit.com.au/documentSummary;dn=113990239180698;res=IELHSS},
	author = {D. Banerjee and Christoph S. Garbe and Uwe Schimpf and Bernd J{\"a}hne and S. Schabel}
}
@article {scholz2008,
	title = {Double-pulse planar-LIF investigations using fluorescence motion analysis for mixture formation investigation},
	journal = {Exp. Fluids},
	volume = {45},
	number = {4},
	year = {2008},
	pages = {583--593},
	abstract = {A concept for dynamic mixture formation investigations of fuel/air mixtures is presented which can equally be applied to several other laser induced fluorescence (LIF) applications. Double-pulse LIF imaging was used to gain insight into dynamic mixture formation processes. The setup consists of a modified standard PIV setup. The "fuel/air ratio measurement by laser induced fluorescence (FARLIF)" approach is used for a quantification of the LIF images in order to obtain pairs of 2D fuel/air ratio maps. Two different evaluation concepts for LIF double pulse images are discussed. The first is based on the calculation of the temporal derivative field of the fuel/air ratio distribution. The result gives insight into the dynamic mixing process, showing where and how the mixture is changing locally. The second concept uses optical flow methods in order to estimate the motion of fluorescence (i.e., mixture) structures to gain insight into the dynamics, showing the distortion and the motion of the inhomogeneous mixture field. For this "fluorescence motion analysis" (FMA) two different evaluation approaches the "variational gradient based approach" and the "variational cross correlation based approach" are presented. For the validation of both, synthetic LIF image pairs with predefined motion fields were generated. Both methods were applied and the results compared with the known original motion field. This validation shows that FMA yields reliable results even for image pairs with low signal/noise ratio. Here, the "variational gradient based approach" turned out to be the better choice so far. Finally, the experimental combination of double-pulse FARLIF imaging with FMA and simultaneous PIV measurement is demonstrated. The comparison of the FMA motion field and the flow velocity field captured by PIV shows that both results basically reflect complementary information of the flow field. It is shown that the motion field of the fluorescence structures does not (necessarily) need to represent the actual flow velocity and that the flow velocity field alone can not illustrate the structure motion in any case. Therefore, the simultaneous measurement of both gives the deepest insight into the dynamic mixture formation process. The examined concepts and evaluation approaches of this paper can easily be adapted to various other planar LIF methods (with the LIF signal representing, e.g., species concentration, temperature, density etc.) broadening the insight for a wide range of different dynamic processes.},
	doi = {10.1007/s00348-008-0537-x},
	author = {J. Scholz and T. Wiersbinski and Paul Ruhnau and Daniel Kondermann and Christoph S. Garbe and R. Hain and Volker Beushausen}
}
@conference {andres2008,
	title = {On errors-in-variables regression with arbitrary covariance and its application to optical flow estimation},
	booktitle = {IEEE Conference on Computer Vision and Pattern Recognition, CVPR 2008},
	year = {2008},
	pages = {1--6},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {Linear inverse problems in computer vision, including motion estimation, shape fitting and image reconstruction, give rise to parameter estimation problems with highly correlated errors in variables. Established total least squares methods estimate the most likely corrections Acirc and bcirc to a given data matrix [A, b] perturbed by additive Gaussian noise, such that there exists a solution y with [A + Acirc, b +bcirc]y = 0. In practice, regression imposes a more restrictive constraint namely the existence of a solution x with [A + Acirc]x = [b + bcirc]. In addition, more complicated correlations arise canonically from the use of linear filters. We, therefore, propose a maximum likelihood estimator for regression in the general case of arbitrary positive definite covariance matrices. We show that Acirc, bcirc and x can be found simultaneously by the unconstrained minimization of a multivariate polynomial which can, in principle, be carried out by means of a Grobner basis. Results for plane fitting and optical flow computation indicate the superiority of the proposed method.},
	doi = {10.1109/CVPR.2008.4587571},
	author = {Bj{\"o}rn Andres and Claudia Kondermann and Daniel Kondermann and Fred A. Hamprecht and Christoph S. Garbe}
}
@article {andres_08_errors-in-variables,
	title = {On errors-in-variables regression with arbitrary covariance and its application to optical flow estimation},
	journal = {Computer Vision and Pattern Recognition, 2008. CVPR 2008. IEEE Conference on},
	year = {2008},
	note = {1},
	pages = {1-6},
	doi = {10.1109/CVPR.2008.4587571},
	author = {Bj{\"o}rn Andres and Claudia Kondermann and Daniel Kondermann and Ullrich K{\"o}the and Fred A. Hamprecht and Christoph S. Garbe}
}
@incollection {acker2008,
	title = {Inverse Problems and Parameter Identification in Image Processing},
	year = {2008},
	pages = {111--151},
	publisher = {Springer},
	abstract = {Many problems in imaging are actually inverse problems. One reason for this is that conditions and parameters of the physical processes underlying the actual image acquisition are usually not known. Examples for this are the inhomogeneities of the magnetic field in magnetic resonance imaging (MRI) leading to nonlinear deformations of the anatomic structures in the recorded images, material parameters in geological structures as unknown parameters for the simulation of seismic wave propagation with sparse measurement on the surface, or temporal changes in movie sequences given by intensity changes or moving image edges and resulting from deformation, growth and transport processes with unknown fluxes. The underlying physics is mathematically described in terms of variational problems or evolution processes. Hence, solutions of the forward problem are naturally described by partial differential equations. These forward models are reflected by the corresponding inverse problems as well. Beyond these concrete, direct modeling links to continuum mechanics abstract concepts from physical modeling are successfully picked up to solve general perceptual problems in imaging. Examples are visually intuitive methods to blend between images showing multiscale structures at different resolution or methods for the analysis of flow fields.},
	doi = {10.1007/978-3-540-75632-3_4},
	author = {Jens F. Acker and Benjamin Berkels and Kristian Bredies and Mamadou S. Diallo and Marc Droske and Christoph S. Garbe and Matthias Holschneider and Jaroslav Hron and Claudia Kondermann and Michail Kulesh and Peter Maass and Nadine Olischl{\"a}ger and Heinz-Otto Peitgen},
	editor = {R. Dahlhaus and J. Kurths and Timmer, J. and Peter Maass}
}
@conference {garbe2008c,
	title = {Measuring momentum transport directly at the air water interface from active infrared thermography},
	booktitle = {Geophysical Research Abstracts},
	year = {2008},
	author = {Christoph S. Garbe and Uwe Schimpf and Bernd J{\"a}hne}
}
@article {roetmann2007,
	title = {Micro-flow analysis by molecular tagging velocimetry and planar raman-scattering},
	journal = {Exp. Fluids},
	volume = {44},
	year = {2008},
	pages = {419--430},
	abstract = {The two dimensional Molecular Tagging Velocimetry (2D-MTV) was used to measure velocity fields of the flow in a micro mixer. Instead of commonly used micro particles an optical tagging of the flow was performed by using a caged dye. The flow induces a deformation of the optically written pattern that can be tracked by laser induced fluorescence. The series of raw images gained this way were analyzed quantitatively with a novel optical flow based technique. Reference measurements have been carried out allowing to draw conclusions about the accuracy of this procedure. A comparison to the standard technique of uPIV was also conducted. Apart from measuring flow velocities in microfluidic mixing processes, the spatial distribution of concentration fields for different species were also measured. To this end, a new technique has been developed that allows spatial measurements from Planar Spontaneous Raman Scattering (PSRS). The Raman stray light of the relevant species was spectrally selected by a narrow bandpass filter and thus detected unaffectedly by the Raman stray light of other species. The successful operation of this measurement procedure in micro flows will be demonstrated exemplary for a mixing process of water and ethanol.},
	doi = {10.1007/s00348-007-0420-1},
	author = {Karsten Roetmann and Waldemar Schmunk and Christoph S. Garbe and Volker Beushausen}
}
@conference {kondermann2008b,
	title = {Motion Estimation Based on a Temporal Model of Fluid Flows},
	booktitle = {13th International Symposium on Flow Visualization},
	year = {2008},
	pages = {1-10},
	author = {Daniel Kondermann and Claudia Kondermann and A. Berthe and U. Kertzscher and Christoph S. Garbe}
}
@incollection {garbe_08_nonlinear,
	title = {Nonlinear Analysis of Multi-Dimensional Signals},
	year = {2008},
	note = {1},
	pages = {231-288},
	publisher = {Springer},
	doi = {10.1007/978-3-540-75632-3_7},
	author = {Christoph S. Garbe and Kai Krajsek and Pavel Pavlov and Bj{\"o}rn Andres and Matthias M{\"u}hlich and Ingo Stuke and Cicero Mota and Martin B{\"o}hme and Martin Haker and Schuchert, T. and Hanno Scharr and Til Aach and Erhardt Barth},
	editor = {R. Dahlhaus and J. Kurths and Timmer, J. and Peter Maass}
}
@incollection {garbe2008,
	title = {Nonlinear analysis of multi-dimensional signals: local adaptive estimation of complex motion and orientation patterns},
	year = {2008},
	pages = {231-288},
	publisher = {Springer},
	abstract = {We consider the general task of accurately detecting and quantifying orientations in n-dimensional signals s. The main emphasis will be placed on the estimation of motion, which can be thought of as orientation in spatiotemporal signals. Associated problems such as the optimization of matched kernels for deriving isotropic and highly accurate gradients from the signals, optimal integration of local models, and local model selection will also be addressed.},
	doi = {10.1007/978-3-540-75632-3_7},
	author = {Christoph S. Garbe and Kai Krajsek and Pavel Pavlov and Bj{\"o}rn Andres and Matthias M{\"u}hlich and Ingo Stuke and Cicero Mota and Martin B{\"o}hme and Martin Haker and Tobias Schucher and Hanno Scharr and Til Aach and Erhardt Barth},
	editor = {R. Dahlhaus and J. Kurths and Timmer, J. and Peter Maass}
}
@article {garbe2008b,
	title = {An optical flow MTV based technique for measuring microfluidic flow in the presence of diffusion and Taylor dispersion},
	journal = {Exp. Fluids},
	volume = {44},
	year = {2008},
	pages = {439--450},
	abstract = {A novel technique is presented for accurately measuring flow fields in microfluidic flows from molecular tagging velocimetry (MTV). Limited optical access is frequently encountered in microfluidic systems. Therefore, in this contribution we analyze the special case of tagging a line across the thin dimension of a microchannel and subsequent imaging along this line. This represents a set-up that is applicable to a wide range of microfluidic applications. A volume illumination has to be used, resulting in an integration of the visualized dye across the flow profile. This leads to the well-known effect of Taylor dispersion. Our novel technique consists of measuring motion from digital image sequences in a gradient-based approach. A motion model is developed which explicitly deals with brightness changes due to Taylor dispersion and additional molecular diffusion of dyes. The presented approach is specific to the case of a parabolic velocity profile. In the presence of these effects, an accurate computation of motion is only possible by applying this novel motion model. Our technique is tested on simulated sequences corrupted with varying levels of noise and on actual measurements. Measurements were conducted in a microfluidic mixer of precisely known flow properties. In the same mixer, a comparative study of our MTV technique to uPIV was performed. Also, the results were compared to bulk measurements of the fluid flow velocity. The novel algorithm compared favorably and also, measurements were conducted on inhomogeneous flow configurations.},
	doi = {10.1007/s00348-007-0435-7},
	author = {Christoph S. Garbe and Karsten Roetmann and Volker Beushausen and Bernd J{\"a}hne}
}
@conference {kondermann2008,
	title = {Postprocessing of optical flows via surface measures and motion inpainting},
	booktitle = {Pattern Recognition},
	volume = {5096},
	year = {2008},
	pages = {355--364},
	abstract = {Dense optical flow fields are required for many applications. They can be obtained by means of various global methods which employ regularization techniques for propagating estimates to regions with insufficient information. However, incorrect flow estimates are propagated as well. We, therefore, propose surface measures for the detection of locations where the full flow can be estimated reliably, that is in the absence of occlusions, intensity changes, severe noise, transparent structures, aperture problems and homogeneous regions. In this way we obtain sparse, but reliable motion fields with lower angular errors. By subsequent application of a basic motion inpainting technique to such sparsified flow fields we obtain dense fields with smaller angular errors than obtained by the original combined local global (CLG) method and the structure tensor method in all test sequences. Experiments show that this postprocessing method makes error improvements of up to 38\% feasible.},
	doi = {10.1007/978-3-540-69321-5_36},
	author = {Claudia Kondermann and Daniel Kondermann and Christoph S. Garbe}
}
@conference {friedrich2008,
	title = {Sarcomere Structure and Motor-Protein Function in an Animal Model of Duchenne Muscular Dystrophy (mdx mouse)},
	booktitle = {87th Annual Meeting of the German Physiological Society},
	year = {2008},
	author = {O. Friedrich and C. Weber and M. Both and Wegner, F. von and J. S. Chamberlain and Christoph S. Garbe and Rainer H. A. Fink}
}
@conference {kondermann2008a,
	title = {A statistical confidence measure for optical flows},
	booktitle = {Proceedings of the ECCV},
	volume = {5304},
	year = {2008},
	pages = {290--301},
	abstract = {Confidence measures are crucial to the interpretation of any optical flow measurement. Even though numerous methods for estimating optical flow have been proposed over the last three decades, a sound, universal, and statistically motivated confidence measure for optical flow measurements is still missing. We aim at filling this gap with this contribution, where such a confidence measure is derived, using statistical test theory and measurable statistics of flow fields from the regarded domain. The new confidence measure is computed from merely the results of the optical flow estimator and hence can be applied to any optical flow estimation method, covering the range from local parametric to global variational approaches. Experimental results using state-of-the-art optical flow estimators and various test sequences demonstrate the superiority of the proposed technique compared to existing confidence measures.},
	doi = {10.1007/978-3-540-88690-7_22},
	author = {Claudia Kondermann and Mester, R. and Christoph S. Garbe}
}
@conference {banerjee2007b,
	title = {An active thermographic technique for highly resolved heat transport measurements in paper drying},
	booktitle = {61st Appita Annual Conference Proceedings},
	year = {2007},
	pages = {161-167},
	publisher = {APPITA},
	organization = {APPITA},
	author = {D. Banerjee and Christoph S. Garbe and Uwe Schimpf and Bernd J{\"a}hne and S. Schabel}
}
@conference {kondermann2007,
	title = {An adaptive confidence measure for optical flows based on linear subspace projections},
	booktitle = {Proceedings of the 29th DAGM Symposium on Pattern Recognition},
	volume = {4713},
	year = {2007},
	pages = {132--141},
	publisher = {Springer},
	organization = {Springer},
	abstract = {Confidence measures are important for the validation of optical flow fields by estimating the correctness of each displacement vector. There are several frequently used confidence measures, which have been found of at best intermediate quality. Hence, we propose a new confidence measure based on linear subspace projections. The results are compared to the best previously proposed confidence measures with respect to an optimal confidence. Using the proposed measure we are able to improve previous results by up to 31\%.},
	doi = {10.1007/978-3-540-74936-3_14},
	author = {Claudia Kondermann and Daniel Kondermann and Bernd J{\"a}hne and Christoph S. Garbe and Christoph Schn{\"o}rr and Bernd J{\"a}hne},
	editor = {Fred A. Hamprecht}
}
@conference {garbe2007b,
	title = {Aktive Thermografie f{\"u}r die Untersuchung von Transportprozessen},
	booktitle = {Thermografie-Kolloquium},
	year = {2007},
	pages = {1--8},
	publisher = {Deutsche Gesellschaft f{\"u}r Zerst{\"o}rungsfreie Pr{\"u}fung e.V.},
	organization = {Deutsche Gesellschaft f{\"u}r Zerst{\"o}rungsfreie Pr{\"u}fung e.V.},
	author = {Christoph S. Garbe and D. Banerjee and Uwe Schimpf and Bernd J{\"a}hne}
}
@conference {scholz2007,
	title = {Double-pulse planar-LIF investigations using fluorescence motion analysis for mixture formation investigation},
	booktitle = {7th International Symposium on Particle Image Velocimetry Rome, 11. - 14.Sept.},
	year = {2007},
	author = {J. Scholz and T. Wiersbinski and Paul Ruhnau and Daniel Kondermann and Christoph S. Garbe and R. Hain and Volker Beushausen}
}
@incollection {garbe2007c,
	title = {Estimating the viscous shear stress at the water surface from active thermography},
	year = {2007},
	pages = {223--239},
	publisher = {Springer-Verlag},
	abstract = {A novel technique is presented that makes it possible to measure the viscous shear stress from active thermography. With a CO2 laser, patterns are written to the sea surface. This temperature structure is distorted by the linear velocity profile in the viscous boundary layer. Due to the non-zero penetration depth of both the laser and the infrared camera, this vertical velocity profile can be resolved. By resolving the velocity profile, the viscous shear stress can be extracted from the recorded image sequences. At the same time, the flow field at the water surface can be measured accurately. Estimating both quantities is only possible by modeling the imaging process as well as the velocity profile in the boundary layer. The model parameters can then be computed in a standard parameter estimation framework. This novel technique was tested both on simulated data and on measurements conducted in a small annular wind-wave flume. The friction velocity computed in this fashion compared favorably to independent measurements. Although not tested yet, this technique should be equally applicable to field measurements.},
	doi = {10.1007/978-3-540-36906-6_16},
	author = {Kai Degreif and Bernd J{\"a}hne and Bernd J{\"a}hne},
	editor = {Christoph S. Garbe and Christoph S. Garbe and Handler, R. A.}
}
@incollection {hara2007,
	title = {Estimation of air-sea gas and heat fluxes from infrared imagery based on near surface turbulence models},
	year = {2007},
	publisher = {Springer-Verlag},
	abstract = {Water surface infrared images were obtained during the GASEX2001 experiment in the South Equatorial Pacific waters and during the laboratory experiment in the AEOLOTRON wind wave tank at University of Heidelberg in October 2004. The infrared imagery during these experiments reveals coexistence of roller type turbulence and intermittent breaking events. Previous interpretations of the infrared images relied on the surface renewal model, in which the water surface is assumed to be occasionally renewed by bursts of turbulent eddies reaching the water surface. A new complementary model (eddy renewal model) based on stationary and spatially periodic turbulent eddies is developed to reinterpret the infrared images of near surface turbulence. The model predicts warm elongated patches bounded by cold streaks aligned with mean wind, being consistent with field and laboratory infrared images. The model yields bulk temperature estimates and mean heat flux estimates that are very close to those based on the surface renewal model.},
	doi = {10.1007/978-3-540-36906-6_17},
	author = {T. Hara and VanInwegen, E. and J. Wendelbo and Uwe Schimpf and Bernd J{\"a}hne and Nelson M. Frew and Bernd J{\"a}hne},
	editor = {Christoph S. Garbe and Christoph S. Garbe and Handler, R. A.}
}
@conference {garbe2007,
	title = {Fluid flow estimation through integration of physical flow configurations},
	booktitle = {Proceedings of the 29th DAGM Symposium on Pattern Recognition},
	year = {2007},
	pages = {92--101},
	publisher = {Springer},
	organization = {Springer},
	abstract = {The measurement of fluid flows is an emerging field for optical flow computation. In a number of such applications, a tracer is visualized with modern digital cameras. Due to the projective nature of the imaging process, the tracer is integrated across a velocity profile. In this contribution, a novel technique is presented that explicitly models brightness changes due to this integration. Only through this modeling is an accurate estimation of the flow velocities feasible. Apart from an accurate measurement of the fluid flow, also the underlying velocity profile can be reconstructed. Applications from shear flow, microfluidics and a biological applications are presented.},
	doi = {10.1007/978-3-540-74936-3_10},
	author = {Christoph S. Garbe and Christoph Schn{\"o}rr and Bernd J{\"a}hne},
	editor = {Fred A. Hamprecht}
}
@incollection {jaehne2007f,
	title = {The influence of intermittency on air/water gas transfer measurements},
	year = {2007},
	publisher = {Springer-Verlag},
	abstract = {This paper theoretically investigates the influence of intermittency on determining average transfer velocities using different measuring techniques. It is shown that all measuring techniques can significantly be biased by intermittency. Mass balance and eddy correlation measurements are only biased when the concentration difference between the air and the water is spatially or temporally inhomogeneous over the measurement interval. Mean transfer velocities calculated either from mean boundary layer thicknesses or from thermographic techniques, which compute the mean transfer velocity either from concentration differences of from time constants, are biased toward lower values. The effects can be large and a simple stochastic bimodal model is used to estimate the effect.},
	doi = {10.1007/978-3-540-36906-6_18},
	author = {Bernd J{\"a}hne and Christopher Popp and Uwe Schimpf and Christoph S. Garbe and Bernd J{\"a}hne},
	editor = {Christoph S. Garbe and Handler, R. A.}
}
@phdthesis {garbe2007a,
	title = {Measuring and Modeling Fluid Dynamic Processes using Digital Image Sequence Analysis},
	year = {2007},
	publisher = {IWR, Fakult{\"a}t f{\"u}r Physik und Astronomie, Univ.\ Heidelberg},
	author = {Christoph S. Garbe}
}
@article {preusser2007,
	title = {A phase field method for joint denoising, edge detection, and motion estimation in image sequence processing.},
	journal = {SIAM Journal of Applied Mathematics},
	volume = {68},
	year = {2007},
	pages = {599-618},
	abstract = {The estimation of optical flow fields from image sequences is incorporated in a Mumford/Shah approach for image denoising and edge detection. Possibly noisy image sequences are considered as input and a piecewise smooth image intensity, a piecewise smooth motion field, and a joint discontinuity set are obtained as minimizers of the functional. The method simultaneously detects image edges and motion field discontinuities in a rigorous and robust way. It is able to handle information on motion that is concentrated on edges. Inherent to it is a natural multiscale approximation that is closely related to the phase field approximation for edge detection by Ambrosio and Tortorelli. We present an implementation for two-dimensional image sequences with finite elements in space and time. This leads to three linear systems of equations, which have to be solved in a suitable iterative minimization procedure. Numerical results and different applications underline the robustness of the approach presented.},
	doi = {10.1137/060677409},
	author = {Preusser, T. and Marc Droske and Christoph S. Garbe and Martin Rumpf and Alexandru Telea}
}
@conference {andres_07_selection,
	title = {Selection of Local Optical Flow Models by Means of Residual Analysis},
	booktitle = {Pattern Recognition},
	volume = {4713},
	year = {2007},
	note = {1},
	pages = {72-81},
	publisher = {Springer},
	organization = {Springer},
	doi = {10.1007/978-3-540-74936-3_8},
	author = {Bj{\"o}rn Andres and Fred A. Hamprecht and Christoph S. Garbe},
	editor = {Christoph Schn{\"o}rr and Bernd J{\"a}hne and Fred A. Hamprecht}
}
@conference {andres2007,
	title = {Selection of local optical flow models by means of residual analysis},
	booktitle = {Proceedings of the 29th DAGM Symposium on Pattern Recognition},
	year = {2007},
	pages = {72--81},
	publisher = {Springer},
	organization = {Springer},
	abstract = {This contribution presents a novel approach to the challenging problem of model selection in motion estimation from sequences of images. New light is cast on parametric models of local optical flow. These models give rise to parameter estimation problems with highly correlated errors in variables (EIV). Regression is hence performed by equilibrated total least squares. The authors suggest to adaptively select motion models by testing local empirical regression residuals to be in accordance with the probability distribution that is theoretically predicted by the EIV model. Motion estimation with residual-based model selection is examined on artificial sequences designed to test specifically for the properties of the model selection process. These simulations indicate a good performance in the exclusion of inappropriate models and yield promising results in model complexity control.},
	doi = {10.1007/978-3-540-74936-3_8},
	author = {Bj{\"o}rn Andres and Christoph S. Garbe and Christoph Schn{\"o}rr and Bernd J{\"a}hne},
	editor = {Fred A. Hamprecht and Fred A. Hamprecht}
}
@book {garbe2007d,
	title = {Transport at the Air Sea Interface --- Measurements, Models and Parameterizations},
	year = {2007},
	publisher = {Springer},
	organization = {Springer},
	doi = {10.1007/978-3-540-36906-6},
	url = {http://hci.iwr.uni-heidelberg.de/publications/dip/2007/TASI/index.html},
	author = {Bernd J{\"a}hne},
	editor = {Christoph S. Garbe and Handler, R. A.}
}
@incollection {falkenroth2007a,
	title = {Visualisation of oxygen concentration fields in the mass boundary layer by fluorescence quenching},
	year = {2007},
	publisher = {Springer Verlag},
	abstract = {Laser-Induced Fluorescence (LIF) is applied to observe directly the mechanism of gas exchange in the aqueous viscous boundary layer at a free water surface. In order to make dissolved oxygen visible, a new class of fluorescent dyes is used with a life time in the order of microseconds so that the quenching constant for dissolved oxygen is sufficiently high for sensitive measurements. Depth profiles of the O2 concentration near the water surface are obtained by a vertical laser sheet at a rate of 185 frames per second. This technique is capable of a measurement sector up to several centimetres down from the water surface with a resolution in the order of 50-100 um. For a small circular wind/wave facility a correlation between wind speed and gas-exchange rates calculated from the extrapolated mean boundary-layer thickness are presented as well as the results of parallel measurements with a budget method for other gases with known Schmidt numbers.},
	doi = {10.1007/978-3-540-36906-6_4},
	author = {A. Falkenroth and Kai Degreif and Bernd J{\"a}hne and Bernd J{\"a}hne},
	editor = {Christoph S. Garbe and Handler, R. A.}
}
@conference {roetmann2006,
	title = {Analyse Mikrofluidischer Str{\"o}mungen mit Molecular Tagging Velocimetry und Planarer Ramanstreuung},
	booktitle = {Tagungsband Lasermethoden in der Str{\"o}mungsmesstechnik},
	year = {2006},
	author = {Karsten Roetmann and Waldemar Schmunk and Christoph S. Garbe and Volker Beushausen}
}
@conference {roetmann2006a,
	title = {Micro-flow analysis by molecular tagging velocimetry and planar Raman-scattering},
	booktitle = {Proc.\ of 12th International Symposium on Flow Visualization},
	year = {2006},
	author = {Karsten Roetmann and Christoph S. Garbe and Waldemar Schmunk and Volker Beushausen}
}
@conference {garbe2006b,
	title = {An optical flow based technique for the non-invasive measurement of microfluidic flows},
	booktitle = {12th Intern. Symp. on Flow Visualization, G{\"o}ttingen, 10--14. September 2006},
	year = {2006},
	doi = {10.5281/zenodo.14846},
	author = {Christoph S. Garbe and Karsten Roetmann and Bernd J{\"a}hne}
}
@conference {telea2006,
	title = {A variational approach to joint denoising, edge detection and motion estimation},
	booktitle = {Proceedings of the 28th DAGM Symposium on Pattern Recognition},
	year = {2006},
	pages = {525--535},
	url = {http://numod.ins.uni-bonn.de/research/papers/public/PrDrGa06.pdf},
	author = {Alexandru Telea and Tobias Preu{\ss}er and Christoph S. Garbe and Marc Droske and Martin Rumpf}
}
@conference {roetmann2005,
	title = {2D-Molecular Tagging Velocimetry zur Analyse Mikrofluidischer Str{\"o}mungen},
	booktitle = {Tagungsband Lasermethoden in der Str{\"o}mungsmesstechnik (GALA)},
	year = {2005},
	pages = {26/1--26/10},
	author = {Karsten Roetmann and Christoph S. Garbe and Volker Beushausen}
}
@conference {jaehne2005,
	title = {Air-Sea Gas Transfer; Schmidt Number dependency and intermittency},
	booktitle = {Presented at: International Liege Colloquium on Ocean Dynamics, Gas Transfer at Water Surfaces},
	year = {2005},
	author = {Bernd J{\"a}hne and Nielsen, R. and Christopher Popp and Uwe Schimpf and Christoph S. Garbe}
}
@conference {hara2005,
	title = {Estimation of air-sea gas and heat fluxes from infrared imagery and surface wave measurements},
	booktitle = {Presented at: International Li{\`e}ge Colloquium on Ocean Dynamics, Gas Transfer at Water Surfaces},
	year = {2005},
	author = {T. Hara and J. Wendelbo and Christoph S. Garbe and Uwe Schimpf and Nelson M. Frew}
}
@conference {jaehne2005f,
	title = {The Heidelberg Aeolotron: new perspectives for laboratory investigations of small-scale air-sea interaction},
	booktitle = {Poster presented at: International Liege Colloquium on Ocean Dynamics, Gas Transfer at Water Surfaces},
	year = {2005},
	doi = {10.5281/zenodo.15417},
	author = {Bernd J{\"a}hne and Uwe Schimpf and Christoph S. Garbe and Kai Degreif}
}
@incollection {banerjee2005,
	title = {High resolution optical measurement techniques in paper drying},
	volume = {4},
	year = {2005},
	pages = {16--22},
	author = {D. Banerjee and S. Schabel and Christoph S. Garbe and Uwe Schimpf and Bernd J{\"a}hne and Spiegel, W. von}
}
@conference {garbe2004,
	title = {Estimation of motion and parameters of heat transport from thermography},
	booktitle = {Quantitative Infrared Thermography},
	year = {2004},
	author = {Christoph S. Garbe and Bernd J{\"a}hne}
}
@conference {jaehne2004e,
	title = {Exchange processes at the ocean surface: their role in coupling atmosphere and ocean, a contribution to the SOLAS project},
	booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Spring Conference, Munich, 22.-26.03.2004},
	year = {2004},
	publisher = {Deutsche Physikalische Gesellschaft},
	organization = {Deutsche Physikalische Gesellschaft},
	abstract = {Der Stoffaustausch zwischen Atmosph{\"a}re und Ozean ist trotz seiner Bedeutung f{\"u}r die globalen Stoffkreisl{\"a}ufe immer noch wenig verstanden und experimentell schwer zug{\"a}nglich. In den letzten Jahre wurde eine neue Technik entwickelt, die es mittels aktiver Thermographie erlaubt, die Antwortfunktion des Transports durch die wasserseitige viskose Grenzschicht sowohl im Labor als auch im Feld zu messen. Damit ist es nicht nur m{\"o}glich, innerhalb weniger Minuten die Transfergeschwindigkeit f{\"u}r Gase zu messen, sondern auch verschiedene Modelle zu unterscheiden und die Schmidtzahlabh{\"a}ngigkeit zu bestimmen. Dies bedeutet f{\"u}r zuk{\"u}nftige Messungen im Feld, dass Messungen der Konzentrationen von beliebigen Tracern im Wasser und der Atmosph{\"a}re ausreichend sind, um Flussraten relevanter Tracer zwischen Atmosph{\"a}re und Ozean zu bestimmen. Es sind keine aufwendigen und unsicheren direkten Flussraten (z.B. durch Eddykorrelations- oder -akkumulationsmessungen) mehr notwendig. Die neue Technik soll ein wesentliches Bindeglied zwischen den atmosph{\"a}rischen und ozeanographischen Untersuchungen des internationalen SOLAS-Projekt werden.},
	url = {http://old.dpg-tagungen.de/archive/2004/up_1.html},
	author = {Bernd J{\"a}hne and Uwe Schimpf and Christopher Popp and Christoph S. Garbe}
}
@article {schimpf2004,
	title = {Investigation of transport processes across the sea surface microlayer by infrared imagery},
	journal = {J. Geophys. Res.},
	volume = {109},
	number = {C8},
	year = {2004},
	pages = {C08S13},
	abstract = {Heat is used as a proxy tracer for gases to study the transport processes across the sea surface microlayer. Infrared imaging techniques permit fast measurements of heat transfer velocities and give an insight into the transport mechanisms across the thermal sublayer. The observed fluctuations of the sea surface temperature suggest that surface renewal is the major turbulent transport mechanism at medium and high wind speeds. The scale space analysis of the temperature patterns at the sea surface with respect to their contribution to the skin-bulk temperature difference shows the turbulent nature of the transport process. Large-scale turbulence dominates the transport at low friction velocities, whereas small-scale turbulence is more dominant at higher wind friction. The skin-bulk temperature difference is estimated by fitting the measured sea surface temperature distribution with a PDF function based on a surface renewal model. Periodic heat flux switching in the wind-wave flume delivers independent estimates of surface and bulk temperature and verifies the statistical approach, whereas at very low wind speeds and film-covered surfaces the statistical method underestimates the skin-bulk temperature difference across the thermal sublayer. The large scatter of the transfer velocities when plotted versus wind speed indicates that not only the wind shear but also other processes such as the wave field and surfactants influences near-surface turbulence and thus air-water gas transfer.},
	issn = {0148-0227},
	doi = {10.1029/2003JC001803},
	author = {Uwe Schimpf and Christoph S. Garbe and Bernd J{\"a}hne}
}
@conference {strzodka2004,
	title = {Real-time motion estimation and visualization on graphics cards},
	booktitle = {Proceedings IEEE Visualization 2004},
	year = {2004},
	pages = {545--552},
	abstract = {We present a tool for real-time visualization of motion features in 2D image sequences. The motion is estimated through an eigenvector analysis of the spatio-temporal structure tensor at every pixel location. This approach is computationally demanding but allows reliable velocity estimates as well as quality indicators for the obtained results. We use a 2D color map and a region of interest selector for the visualization of the velocities. On the selected velocities we apply a hierarchical smoothing scheme which allows the choice of the desired scale of the motion field. We demonstrate several examples of test sequences in which some persons are moving with different velocities than others. These persons are visually marked in the real-time display of the image sequence. The tool is also applied to angiography sequences to emphasize the blood flow and its distribution. An efficient processing of the data streams is achieved by mapping the operations onto the stream architecture of standard graphics cards. The card receives the images and performs both the motion estimation and visualization, taking advantage of the parallelism in the graphics processor and the superior memory bandwidth. The integration of data processing and visualization also saves on unnecessary data transfers and thus allows the real-time analysis of 320{\texttimes}240 images. We expect that on the newest generation of graphics hardware our tool could run in real time for the standard VGA format.},
	doi = {10.1109/VISUAL.2004.88},
	author = {Strzodka, R. and Christoph S. Garbe}
}
@article {zhang2004,
	title = {Studying dynamical processes of air-sea exchanges with air-water interface image techniques},
	journal = {Recent Research Developments in Fluid Dynamics},
	volume = {5},
	year = {2004},
	pages = {57--87},
	url = {www-pord.ucsd.edu/~xzhang/publication/fd1.pdf},
	author = {Zhang, X. and Christoph S. Garbe}
}
@article {garbe2004a,
	title = {A surface renewal model to analyze infrared image sequences of the ocean surface for the study of air-sea heat and gas exchange},
	journal = {J. Geophys. Res.},
	volume = {109},
	number = {C8},
	year = {2004},
	pages = {1-18},
	abstract = {Thermographic techniques are presented that directly measure the temperature difference across the thermal boundary layer at the sea surface, the probability density function of surface renewal, the net heat flux, and the heat transfer velocity during nighttime. The techniques are based on a model of surface renewal. Through the use of digital image processing techniques, temporally and spatially highly resolved measurements are feasible, limited only by the thermal imager. We present laboratory measurements from the Heidelberg Aeolotron and field measurements from the GasExII cruise taken at a spatial resolution of 3 mm and temporal resolution of 10 ms. The net heat flux estimates of the thermographic techniques and micrometeorological methods agree with an error less than 5\% for conditions in which the surface renewal model is applicable. Experimental evidence is presented for the probability density function of surface renewal to be best described by a logarithmic normal distribution. At moderate and high wind speeds when the influence of surface films is not significant, surface renewal seems to be an adequate model for air-water heat exchange.},
	issn = {0148-0227},
	doi = {10.1029/2003JC001802},
	author = {Christoph S. Garbe and Uwe Schimpf and Bernd J{\"a}hne}
}
@article {garbe2003c,
	title = {Estimation of complex motion from thermographic image sequences},
	journal = {SPIE Proc.},
	volume = {5073},
	year = {2003},
	pages = {303--317},
	abstract = {In this contribution a novel technique for computing complexmotion involving heat transport processes will be presented. Theproposed technique is a local gradient based approach, combiningtransport models with motion analysis. It allows for thesimultaneous estimation of both motion and parameter of anunderlying transport model. Since the analysis is based on thermalimage sequences, estimates are computed to a high temporal andspatial resolution, limited only by the resolution and frame rateof the employed IR camera. This novel technique was utilized onexchange processes at the atmosphere/ocean boundary, wheresignificant parameters of heat transfer could be measured and atransport model verified. Using the presented algorithms, surfaceflows as well as convergences and divergences on air-waterinterfaces can be measured accurately. Apart from applications inoceanography and botany, relevant benefits of the proposedtechnique to NDT will be presented. It is possible to compensatefor motion to reach accuracies much better than 1/10th of a pixel.Through the direct estimation of locally resolved diffusivities inmaterials, insights can be gained about defects present. Byestimating not only isotropic diffusion but also the whole matrixof anisotropic diffusion, the technique is highly relevant tomeasurements of composite materials.},
	doi = {10.1117/12.501121},
	author = {Christoph S. Garbe and Hagen Spies and Bernd J{\"a}hne}
}
@article {garbe2003b,
	title = {Estimation of surface flow and net heat flux from infrared image sequences},
	journal = {Journal of Mathematical Imaging and Vision},
	volume = {19},
	number = {3},
	year = {2003},
	pages = {159--174},
	abstract = {The study of dynamical processes at the sea surface interface using infrared image sequence analysis has gained tremendous popularity in recent years. Heat is transferred by similar transport mechanisms as gases relevant to global climatic changes. These similarities lead to the use of infrared cameras to remotely visualize and quantitatively estimate parameters of the underlying processes. Relevant parameters that provide important evidence about the models of air-sea gas transfer are the temperature difference across the thermal sub layer, the probability density function of surface renewal and the flow field at the surface. Being a driving force in air sea interactions, it is of equal importance to measure heat fluxes. In this paper we will present algorithms to measure the above parameters of air-sea gas transfer during night-time and show how to combine physical modeling and quantitative digital image processing algorithms to identify transport models. The image processing routines rely on an extension of optical flow computations to incorporate brightness changes in a total least squares (TLS) framework. Statistical methods are employed to support a model of gas transfer and estimate its parameters. Measurements in a laboratory environment were conducted and results verified with ground truth data gained from traditional measurement techniques.},
	doi = {10.1023/A:1026233919766},
	author = {Christoph S. Garbe and Hagen Spies and Bernd J{\"a}hne}
}
@conference {schimpf2003a,
	title = {Observational studies of parameters influencing air--sea gas exchange},
	booktitle = {Geophysical Research Abstracts},
	volume = {5},
	year = {2003},
	pages = {09328},
	author = {Uwe Schimpf and Nelson M. Frew and Kalkenings, R. and Christoph S. Garbe and Bernd J{\"a}hne}
}
@conference {garbe2003a,
	title = {A surface renewal model to analyze infrared image sequences for the study of air-sea heat and gas exchange},
	booktitle = {Geophysical Research Abstracts},
	year = {2003},
	pages = {11893},
	author = {Christoph S. Garbe and Uwe Schimpf and Bernd J{\"a}hne}
}
@conference {jaehne2003b,
	title = {Towards objective performance analysis for estimation of complex motion: analytic motion modeling, filter optimization, and test sequences},
	booktitle = {In Proceedings of IEEE International Conference on Image Processing},
	year = {2003},
	doi = {10.1109/ICIP.2003.1247184},
	url = {./pdf/2003/barth_ICIP2003.pdf:PDF},
	author = {Bernd J{\"a}hne and Christoph S. Garbe}
}
@conference {spies2002b,
	title = {Dense parameter fields from total least squares},
	booktitle = {Proceedings of the 24th DAGM Symposium on Pattern Recognition},
	volume = {LNCS 2449},
	year = {2002},
	pages = {379--386},
	publisher = {Springer},
	organization = {Springer},
	abstract = {A method for the interpolation of parameter fields estimated by total least squares is presented. This is applied to the study of dynamic processes where the motion and further values such as divergence or brightness changes are parameterised in a partial differential equation. For the regularisation we introduce a constraint that restricts the solution only in the subspace determined by the total least squares procedure. The performance is illustrated on both synthetic and real test data.},
	doi = {10.1007/3-540-45783-6_46},
	author = {Hagen Spies and Christoph S. Garbe},
	editor = {Luc Van Gool}
}
@conference {spies2002a,
	title = {Local models for dynamic processes in image sequences},
	booktitle = {Dynamic Perception},
	year = {2002},
	pages = {59--64},
	publisher = {Aka GmbH},
	organization = {Aka GmbH},
	author = {Hagen Spies and Tobias Dierig and Christoph S. Garbe and W{\"u}rtz, R. P.},
	editor = {Lappe, M.}
}
@conference {garbe2002b,
	title = {Measuring important parameters for air-sea heat exchange},
	booktitle = {ThermoSense},
	volume = {4710},
	year = {2002},
	pages = {171--182},
	publisher = {SPIE},
	organization = {SPIE},
	doi = {10.1117/12.459564},
	author = {Christoph S. Garbe and Uwe Schimpf and Bernd J{\"a}hne},
	editor = {Maldague, X. P. and Rozlosnik, A. E.}
}
@conference {garbe2002a,
	title = {Measuring the sea surface heat flux and probability distribution of surface renewal events},
	booktitle = {Gas Transfer at Water Surfaces},
	volume = {127},
	year = {2002},
	pages = {109-114},
	publisher = {American Geophysical Union},
	organization = {American Geophysical Union},
	doi = {10.1029/GM127p0109},
	author = {Christoph S. Garbe and Horst Hau{\ss}ecker and Bernd J{\"a}hne},
	editor = {E. S. Saltzman and M. A. Donelan and R. Wanninkhof and W. M. Drennan}
}
@conference {garbe2002e,
	title = {Mixed OLS-TLS for the estimation of dynamic processes with a linear source term},
	booktitle = {Proceedings of the 24th DAGM Symposium on Pattern Recognition},
	volume = {2449},
	year = {2002},
	pages = {463--471},
	publisher = {Springer-Verlag},
	organization = {Springer-Verlag},
	abstract = {We present a novel technique to eliminate strong biases in parameter estimation were part of the data matrix is not corrupted by errors. Problems of this type occur in the simultaneous estimation of optical flow and the parameter of linear brightness change as well as in range flow estimation. For attaining highly accurate optical flow estimations under real world situations as required by a number of scientific applications, the standard brightness change constraint equation is violated. Very often the brightness change has to be modelled by a linear source term. In this problem as well as in range flow estimation, part of the data term consists of an exactly known constant. Total least squares (TLS) assumes the error in the data terms to be identically distributed, thus leading to strong biases in the equations at hand. The approach presented in this paper is based on a mixture of ordinary least squares (OLS) and total least squares, thus resolving the bias encountered in TLS alone. Apart from a thorough performance analysis of the novel estimator, a number of applications are presented.},
	doi = {10.1007/3-540-45783-6_56},
	author = {Christoph S. Garbe and Hagen Spies and Bernd J{\"a}hne},
	editor = {Luc Van Gool}
}
@conference {schimpf2002,
	title = {Novel insights into heat transfer across the aqueous boundary layer by infrared imagery and its application to air-sea exchange processes},
	booktitle = {Proceedings of Eurotherm 71 on Visualization, Imaging and Data Analysis In Convective Heat and Mass Transfer},
	year = {2002},
	author = {Uwe Schimpf and Christoph S. Garbe and Bernd J{\"a}hne}
}
@conference {haussecker2002,
	title = {Physics from IR image sequences: Quantitative analysis of transport models and parameters of air-sea gas transfer},
	booktitle = {Gas Transfer at Water Surfaces},
	volume = {127},
	year = {2002},
	note = {invited},
	pages = {103--108},
	publisher = {American Geophysical Union},
	organization = {American Geophysical Union},
	doi = {10.1029/GM127p0103},
	author = {Horst Hau{\ss}ecker and Uwe Schimpf and Christoph S. Garbe and Bernd J{\"a}hne},
	editor = {E. S. Saltzman and M. A. Donelan and R. Wanninkhof and W. M. Drennan}
}
@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.}
}
@phdthesis {garbe2001,
	title = {Measuring Heat Exchange Processes at the Air--Water Interface from Thermographic Image Sequence Analysis},
	year = {2001},
	publisher = {IWR, Fakult{\"a}t f{\"u}r Physik und Astronomie, Univ.\ Heidelberg},
	abstract = {In this thesis a novel technique for estimating heat transfer at the free air water interface is presented. For the first time spatially resolved heat flux and transfer velocity measurements are available with a high temporal resolution. The statistical properties of the transfer processes are deduced and the parameters characterizing them established. Based on this analysis a second way to estimate the heat flux is presented. These techniques are based on thermal image sequences on which a motion analysis is performed. The motion is modelled in a general parameterization and physically motivated intensity changes can be incorporated by means of linear partial differential equations. In the presented framework the parameters of physical processes described by such differential equations can be estimated in multidimensional data. These general equations of motion are solved simultaneously by a method of least squares. To do so algorithms are developed that allow for unbiased estimates taking the structure of the noise into account. Methods from robust statistics are employed to correctly solve the estimation problem regardless if the data is corrupted by outliers. The relevance of the developed techniques to other scientific applications is shown. In an accuracy analysis confidence bounds of the proposed algorithms are established and limitations revealed. Following an examination under controlled laboratory conditions in the Heidelberg Aeolotron, the techniques are successfully applied at an international field campaign.},
	url = {http://www.ub.uni-heidelberg.de/archiv/1875},
	author = {Christoph S. Garbe}
}
@conference {garbe2001b,
	title = {Reliable estimates of the sea surface heat flux from image sequences},
	booktitle = {Proceedings of the 23th DAGM Symposium on Pattern Recognition, M{\"u}nchen},
	number = {2191},
	year = {2001},
	pages = {194--201},
	publisher = {Springer},
	organization = {Springer},
	abstract = {We present a new technique for estimating the sea surface heat flux from infrared image sequences. Based on solving an extension to the standard brightness change constraint equation in a total least squares (TLS) sense, the total derivative of the sea surface temperature with respect to time is obtained. Due to inevitable reflexes in field data the TLS framework was further extended to a robust estimation based on a Least Median of Squares Orthogonal Distances (LMSOD) scheme. From this it is possible for the first time to compute accurate heat flux densities to a high temporal and spatial resolution. Results obtained at the Heidelberg Aeolotron showed excellent agreement to ground truth and field data was obtained on the GasExII experiment.},
	doi = {10.1007/3-540-45404-7_26},
	author = {Christoph S. Garbe and Bernd J{\"a}hne},
	editor = {B. Radig}
}
@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}
}
@incollection {engelmann2000b,
	title = {Particle-tracking velocimetry},
	year = {2000},
	pages = {646-647},
	publisher = {Academic Press},
	chapter = {A19},
	author = {D. Engelmann and M. St{\"o}hr and Christoph S. Garbe and Frank Hering and Bernd J{\"a}hne},
	editor = {Hau\DFecker, H.}
}
@inbook {stoehr1999,
	title = {4D particle tracking velocimetry applied to gas-liquid reactors},
	booktitle = {In Scientific Computing in Chemical Engineering II - Simulation, Image Processing, Optimization and Control.},
	year = {1999},
	pages = {270--279},
	publisher = {Springer Verlag},
	organization = {Springer Verlag},
	author = {M. St{\"o}hr and Christoph S. Garbe and D. Engelmann and Peter Gei{\ss}ler and Gomes, S. and Frank Hering and Bernd J{\"a}hne and F. Keil and W. Mackens and H. Vo{\ss} and Wagner, H.-G..},
	editor = {J. Werther}
}
@incollection {engelmann1999a,
	title = {Particle-tracking velocimetry},
	volume = {3: Systems and Applications},
	year = {1999},
	pages = {663-697},
	publisher = {Academic Press},
	chapter = {31},
	author = {D. Engelmann and M. St{\"o}hr and Christoph S. Garbe and Frank Hering and Bernd J{\"a}hne and Horst Hau{\ss}ecker and Peter Gei{\ss}ler}
}
@conference {engelmann1999,
	title = {Three dimensional flow dynamics beneath the air-water interface},
	booktitle = {The Wind-Driven Air-Sea Interface, Electromagnetic and Acoustic Sensing, Wave Dynamics and Turbulent Fluxes},
	year = {1999},
	pages = {181--184},
	doi = {10.5281/zenodo.14910},
	author = {D. Engelmann and Christoph S. Garbe and M. St{\"o}hr and Bernd J{\"a}hne}
}
@conference {haussecker1999a,
	title = {A total least squares framework for low-level analysis of dynamic scenes and processes},
	booktitle = {Proceedings of the 21th DAGM Symposium on Pattern Recognition},
	year = {1999},
	note = {DAGM award},
	pages = {240--249},
	publisher = {Springer},
	organization = {Springer},
	doi = {10.1007/978-3-642-60243-6_28},
	author = {Horst Hau{\ss}ecker and Christoph S. Garbe and Hagen Spies and Bernd J{\"a}hne}
}
@mastersthesis {garbe1998,
	title = {Entwicklung eines Systems zur dreidimensionalen Particle Tracking Velocimetry mit Genauigkeitsuntersuchungen und Anwendung bei Messungen in einem Wind-Wellen Kanal},
	year = {1998},
	school = {IWR, Fakult{\"a}t f{\"u}r Physik und Astronomie, Univ.\ Heidelberg},
	author = {Christoph S. Garbe}
}
@conference {engelmann1998,
	title = {Stereo particle tracking},
	booktitle = {Proc. of the 8th International Symposium on Flow Visualization},
	year = {1998},
	pages = {240--249},
	doi = {10.5281/zenodo.14906},
	author = {D. Engelmann and Christoph S. Garbe and M. St{\"o}hr and Peter Gei{\ss}ler and Frank Hering and Bernd J{\"a}hne}
}
