TY - CHAP A1 - Mueller, Patrick A1 - Lehmann, Matthias A1 - Braun, Alexander T1 - Simulating tests to test simulation T2 - IS&T International Symposium on Electronic Imaging 2020: Autonomous Vehicles and Machines, 26 January 2020 — 30 January 2020, Burlingame, CA, USA Y1 - 2020 U6 - https://doi.org/10.2352/ISSN.2470-1173.2020.16.AVM-149 VL - 2020 IS - 16 PB - Society for Imaging Science and Technology ER - TY - CHAP A1 - Müller, Patrick A1 - Braun, Alexander T1 - Simulating optical properties to access novel metrological parameter ranges and the impact of different model approximations T2 - 2022 IEEE International Workshop on Metrology for Automotive (MetroAutomotive), 4-6 July 2022 Y1 - 2022 SN - 978-1-6654-6689-9 U6 - https://doi.org/10.1109/MetroAutomotive54295.2022.9855079 SP - 133 EP - 138 PB - IEEE ER - TY - CHAP A1 - Lehmann, Matthias A1 - Wittpahl, Christian A1 - Zakour, Hatem Ben A1 - Braun, Alexander ED - Haverkamp, Nils ED - Youngworth, Richard N. T1 - Resolution and accuracy of non-linear regression of PSF with artificial neural networks T2 - SPIE Optical Systems Design: Optical Instrument Science, Technology, and Applications, 2018, Frankfurt, Germany N2 - In a previous work we have demonstrated a novel numerical model for the point spread function (PSF) of an optical system that can efficiently model both experimental measurements and lens design simulations of the PSF. The novelty lies in the portability and the parameterization of this model, which allows for completely new ways to validate optical systems, which is especially interesting for mass production optics like in the automotive industry, but also for ophtalmology. The numerical basis for this model is a non-linear regression of the PSF with an artificial neural network (ANN). In this work we examine two important aspects of this model: the spatial resolution and the accuracy of the model. Measurement and simulation of a PSF can have a much higher resolution then the typical pixel size used in current camera sensors, especially those for the automotive industry. We discuss the influence this has on on the topology of the ANN and the final application where the modeled PSF is actually used. Another important influence on the accuracy of the trained ANN is the error metric which is used during training. The PSF is a distinctly non-linear function, which varies strongly over field and defocus, but nonetheless exhibits strong symmetries and spatial relations. Therefore we examine different distance and similarity measures and discuss its influence on the modeling performance of the ANN. Y1 - 2018 U6 - https://doi.org/10.1117/12.2313144 N1 - Preprint bei ArXiv verfügbar. VL - Proc. SPIE, Vol. 10695 IS - 106950C SP - 52 EP - 63 PB - International Society for Optics and Photonics CY - Frankfurt ER - TY - CHAP A1 - Müller, Patrick A1 - Lehmann, Matthias A1 - Braun, Alexander ED - Kress, Bernard C. ED - Schelkens, Peter T1 - Optical quality metrics for image restoration T2 - Digital Optical Technologies 2019 N2 - Image restoration is a process used to remove blur (from different sources like object motion or aberrations) from images by either non-blind or blind-deconvolution. The metrics commonly used to quantify the restoration process are peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM). Often only a small sample of test images are used (like Lena or the camera guy). In optical design research PSNR and SSIM are not normally used, here image quality metrics based on linear system theory (e.g. modulation transfer function, MTF) are used to quantify optical errors like spherical or chromatic aberration. In this article we investigate how different image restoration algorithms can be quantified by applying image quality metrics. We start with synthetic image data that is used in camera test stands (e.g. Siemens star etc.), apply two different spatially variant degradation algorithms, and restore the original image by a direct method (Wiener filtering within sub-images), and by an iterative method (alternating direction method of multipliers, ADMM). Afterwards we compare the quality metrics (like MTF curves) for the original, the degraded and the restored image. As a first result we show that restoration algorithms sometimes fail in dealing with non-natural scenes, e.g. slanted-edge targets. Further, these first results indicate a correlation between degradation and restoration, i.e. the restoration algorithms are not capable of removing the optically relevant errors introduced by the degradation, a fact neither visible nor available from the PSNR values. We discuss the relevance in the context of the automotive industry, where image restoration may yield distinct advantages for camera-based applications, but testing methods rely on the used image quality metrics. Y1 - 2019 U6 - https://doi.org/10.1117/12.2528100 VL - Proceedings, Vol. 11062 CY - Munich ER - TY - CHAP A1 - Johanning, M. A1 - Braun, Alexander A1 - Elman, V. A1 - Wunderlich, Chr. A1 - Neuhauser, W. T1 - Individual Addressing with Trapped Yb+ Ions T2 - 2007 European Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference, 17.06.2007 - 22.06.2007, Munich, Germany Y1 - 2007 UR - http://ieeexplore.ieee.org/document/4386787/ SN - 978-1-4244-0930-3 U6 - https://doi.org/10.1109/CLEOE-IQEC.2007.4386787 PB - IEEE CY - München ER - TY - CHAP A1 - Müller, Patrick A1 - Braun, Alexander A1 - Keuper, Margret T1 - Impact of realistic properties of the point spread function on classification tasks to reveal a possible distribution shift T2 - NeurIPS 2022: Workshop on Distribution Shifts: Connecting Methods and Applications, December 3rd, 2022, New Orleans, USA KW - chromatic aberration KW - corruption KW - Deep Neural Networks KW - Distribution Shift KW - MTF Y1 - 2022 UR - https://openreview.net/forum?id=r7WJpE3oy0 CY - New Orleans ER - TY - CHAP A1 - Balzer, Chr. A1 - Hannemann, Th. A1 - Wunderlich, Chr. A1 - Braun, Alexander A1 - Ettler, M. A1 - Paape, Chr. A1 - Neuhauser, W. T1 - Efficient photoionisation, preparation and coherent manipulation of trapped /sup 171/Yb/sup +/-ions T2 - EQEC '05. European Quantum Electronics Conference, 12-17 June 2005, Munich Y1 - 2005 UR - http://ieeexplore.ieee.org/document/1567474/ SN - 0-7803-8973-5 U6 - https://doi.org/10.1109/EQEC.2005.1567474 SP - 308 PB - IEEE ER - TY - CHAP A1 - Kornmesser, Christoph A1 - Braun, Alexander A1 - Beushausen, Volker T1 - Applicability of different fluorescent dyes for 2D temperature measurements in dense sprays using planar laser induced fluorescence T2 - Proceedings of the 17th Annual Conference on Liquid Atomization and Spray Systems, 02.06.2001, Zürich KW - Deconvolution Y1 - 2001 UR - https://www.ilasseurope.org/ICLASS/ilass2001/ILASS2001.pdf SN - 3952224413 SP - 554 EP - 559 PB - ETH Zürich CY - Zürich ER -