检索结果-内蒙古大学图书馆

3D geometric features based real-time American sign language recognition using PointNet and MLP with MediaPipe hand skeleton detection

引用

Measurement: Sensors 2025年 38卷

作者： Zhang, Yan Notni, Gunther Group for Quality Assurance and Industrial Image Processing Technische Universität Ilmenau Ilmenau Germany Fraunhofer Institute for Applied Optics and Precision Engineering IOF Jena Jena Germany

This paper presents a robust and fast hand gesture recognition method. Utilizing the 21 hand key points predicted by MediaPipe developed by Google, we calculate additional 3D geometric features, including the angles of each finger joint. These geometric features are then subjected to deeper feature extraction using a Multilayer Perceptron (MLP). Simultaneously, these hand key points are normalized in 3D spatial space, and the finger and palm regions are interpolated to generate a point cloud representing the hand skeleton. Subsequently, PointNet is employed for feature extraction from this point cloud. The features extracted by MLP and PointNet are fused, and a classifier is employed to output the probability distribution of hand gestures for each frame of a 3D video stream. Furthermore, a probability machine is designed to analyze the probability sequence, providing the overall gesture prediction. In the experimental phase, we trained a model to classify American Sign Language (English letters and numbers 0 to 9). The results demonstrate an overall accuracy of 99.81 %. The entire method operates in less than 10 milliseconds (using an NVIDIA 2080Ti graphics card), showcasing its real-time detection capabilities. © 2024

关键词： Human robot interaction

来源：评论

学校读者我要写书评

暂无评论

Quantum imaging with undetected photons

Quantum imaging with undetected photons

引用

International Conference on Transparent Optical Networks

作者： F. Krajinic J.R. Leon-Tores M. Kumar C. Helgert F. Setzpfandt B. Jelenkovic Institute of Physics University of Belgrade Pregrevica 118 Belgrade Serbia Fraunhofer Institute of Applied Optics and Precision Engineering IOF Albert-Einstein-Straße 7 Jena Germany

ISBN: (数字)9798350377323

ISBN: (纸本)9798350377330

We present principles of quantum imaging with undetected photons (QIUP) and show modifications we made to the nonlinear interferometer for QUIP in order to use off-axes holography for faster image reconstruction. We present images made by off-axes quantum holography (OAQH) and discuss image capabilities of the system. In this work we use a pair of quantum correlated photons, generated by spontaneous parametric down-conversion in a non-linear crystal; one photon form a pair interacts with object, and another is detected. In our system both photons are in near infra-red, but by slight modifications they will be in different spectral regions, interacting photons in mid infra-red, detected photons in visible or near infra-ed. This opens very useful applications of QIUP for imaging and sensing in MIR.

关键词： Spectroscopy Optical diffraction Imaging Phase shifting interferometry Crystals Phonons Holography

来源：评论

学校读者我要写书评

暂无评论

Thermal single-shot 3D shape measurement of transparent objects: optimization of the projected statistical LWIR pattern 13

Thermal single-shot 3D shape measurement of transparent obje...

引用

Optical Measurement Systems for Industrial Inspection XIII 2023

作者： Landmann, Martin Speck, Henri Das, Saikat Chandra Heist, Stefan Kühmstedt, Peter Notni, Gunther Fraunhofer Institute for Applied Optics and Precision Engineering IOF Albert-Einstein-Str. 7 Jena07745 Germany Friedrich Schiller University Institute of Applied Physics Abbe Center of Photonics Albert-Einstein-Str. 6 Jena07745 Germany Ilmenau University of Technology Department of Mechanical Engineering Gustav-Kirchhoff-Platz 2 Ilmenau98693 Germany

ISBN: (数字)9781510664463

ISBN: (纸本)9781510664456

Fast and non-contacting 3D shape measurements of objects for quality assurance, human machine interaction, or robot handling, e.g., in the industrial sector, have become well established. Recently, we have successfully combined thermography and triangulation to tackle the challenge of measuring the 3D shape of uncooperative materials, i.e., materials with optical properties such as being glossy, transparent, absorbent, or translucent. Therefore, we have developed the principle of thermal 3D measurements, a two-step process consisting of (1) the projection and absorption of projection patterns in the thermal infrared and (2) the stereo recording of heat patterns re-emitted by the object surface. We match image points by evaluating the temporal normalized cross correlation between pixels in both camera image stacks. In order to measure dynamic scenes, the previously achieved measurement times of a few seconds must be reduced by at least one order of magnitude to the range © 2023 SPIE.

关键词： Stereophonic recordings

来源：评论

学校读者我要写书评

暂无评论

High-speed 3D shape measurement of transparent objects by sequential thermal fringe projection and image acquisition in the long-wave infrared 45

High-speed 3D shape measurement of transparent objects by se...

引用

Thermosense: Thermal Infrared Applications XLV 2023

作者： Landmann, Martin Speck, Henri Gao, Zengyang Heist, Stefan Kühmstedt, Peter Notni, Gunther Fraunhofer Institute for Applied Optics and Precision Engineering IOF Albert-Einstein-Str. 7 Jena07745 Germany Friedrich Schiller University Institute of Applied Physics Abbe Center of Photonics Albert-Einstein-Str. 6 Jena07745 Germany Ilmenau University of Technology Department of Mechanical Engineering Gustav-Kirchhoff-Platz 2 Ilmenau98693 Germany

ISBN: (纸本)9781510661868

Recently, we have successfully tackled the challenge of measuring the 3D shape of uncooperative materials, i.e., materials with optical properties such as being glossy, transparent, absorbent, or translucent. By projecting sequential thermal fringes in the long-wave infrared (LWIR) combined with a stereo camera setup in the mid-wave infrared (MWIR), we were able to three-dimensionally record object shapes within one second. However, in many applications, e.g., for 100 % quality assurance, even shorter measurement times are required. To achieve camera frame rates higher than 125 fps at room temperature, Max Planck’s law of thermal emission teaches us a change in the camera spectral range from MWIR to LWIR. If irradiation and image acquisition have to run in parallel, the camera chips must therefore be protected against the radiation projected by the CO2 laser at a wavelength of 10.6 µm. Appropriate filters have been available only recently. In this contribution, we present our high-speed LWIR 3D sensor. The work includes a characterization of our setup regarding its measurement accuracy and speed. The results are compared to the performance of previous thermal 3D sensors. We show 3D measurement results of static objects as well as of a dynamic measurement situation of a transparent object. Furthermore, we demonstrate that our setup enables us to extend the measurability of material classes towards objects with high thermal conductivities. © 2023 SPIE.

关键词： Image acquisition

来源：评论

学校读者我要写书评

暂无评论

Polarization-Entangled Photon-Pair Sources Based on 3R-MoS2

Polarization-Entangled Photon-Pair Sources Based on 3R-MoS2

引用

CLEO: Fundamental Science, CLEO:FS 2024 - Part of Conference on Lasers and Electro-optics, CLEO 2024

作者： Weissflog, Maximilian A. Fedotova, Anna Tang, Yilin Santos, Elkin A. Laudert, Benjamin Shinde, Saniya Abtahi, Fatemeh Afsharnia, Mina Pérez, Inmaculada Pérez Ritter, Sebastian Qin, Hao Janousek, Jiri Shradha, Sai Staude, Isabelle Saravi, Sina Pertsch, Thomas Setzpfandt, Frank Lu, Yuerui Eilenberger, Falk Institute of Applied Physics Abbe Center of Photonics Friedrich Schiller University Jena Jena07745 Germany Institute of Solid State Physics Friedrich Schiller University Jena Helmholtzweg 3 Jena07743 Germany School of Engineering College of Science and Computer Science The Australian National University CanberraACT Australia Institute for Condensed Matter Physics Technical University of Darmstadt Darmstadt64289 Germany Fraunhofer Institute for Applied Optics and Precision Engineering IOF Jena07745 Germany

We demonstrate for the first time generation of polarization-entangled photon-pairs in a transition metal dichalcogenide. Using 3R-phase molybdenum disulfide, we experimentally show tunable, high-fidelity generation o... 详细信息

ISBN: (纸本)9781957171395

关键词： Polarization

来源：评论

学校读者我要写书评

暂无评论

Enhancing Nonlinear Effects through Lattice Plasmon Excitation in Plasmonic Metasurfaces

Enhancing Nonlinear Effects through Lattice Plasmon Excitati...

引用

2023 Conference on Lasers and Electro-optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023

作者： Gour, Jeetendra Beer, Sebastian Alberucci, Alessandro David, Christin Nolte, Stefan Zeitner, Uwe D. Friedrich Schiller University Jena Institute of Applied Physics Albert Einstein Str. 15 Jena07745 Germany Friedrich Schiller University Jena Institute of Condensed Matter Theory and Optics Jena07743 Germany Fraunhofer Institute for Applied Optics and Precision Engineering IOF Albert-Einstein-Str. 7 Jena07745 Germany Munich University of Applied Sciences Department of Applied Sciences and Mechatronics Loristr.19 Munich80335 Germany

ISBN: (纸本)9798350345995

Plasmonic metasurfaces have gained significant attention in recent years due to their potential applications in areas such as biosensing, biomedical research, and photonic devices. These metasurfaces possess two main types of resonances: localized surface plasmon resonance (LSPR) from individual metal nanoantennas, and surface lattice resonance (SLR) arising from the periodic arrangement of the plasmonic nanoantennas [1]. The interplay between these two resonances determines the linear optical response of plasmonic metasurfaces. The strong field enhancement associated with the linear resonances has also been widely exploited to boost nonlinear effects [1,2,3]. © 2023 IEEE.

关键词： Nanoantennas

来源：评论

学校读者我要写书评

暂无评论

Simultaneous quantum imaging and spectroscopy with undetected photons

Simultaneous quantum imaging and spectroscopy with undetecte...

引用

Quantum 2.0, QUANTUM 2024 in Quantum 2.0 Conference and Exhibition

作者： Dosan, Vasile-Laurentiu Perna, Adrià Sansa Basset, Marta Gilaberte Töpfer, Sebastian de Vries, Oliver Quantum Optics Jena GmbH Moritz-von-Rohr-Straße 1a Jena07745 Germany Abbe Center of Photonics Friedrich Schiller University Jena Albert-Einstein-Straße 6 Jena07745 Germany Fraunhofer Institute for Applied Optics and Precision Engineering IOF Albert-Einstein-Straße 7 Jena07745 Germany Institute of Applied Physics Technical University of Darmstadt Schloßgartenstraße 7 Darmstadt64289 Germany

We report a scheme for simultaneous quantum imaging and spectroscopy with undetected photons for low-cost IR sensing. Using curved mirrors and SPDC spatial filtering, we improve fiber-coupled visibility and minimize o... 详细信息

ISBN: (纸本)9781557525185

关键词： Aberrations

来源：评论

学校读者我要写书评

暂无评论

Single Shot Phase Shift 3D Scanning with Convolutional Neural Network and Synthetic Fractals

Single Shot Phase Shift 3D Scanning with Convolutional Neura...

引用

2022 Eurographics Workshop on 3D Object Retrieval, EG 3DOR 2022

作者： Li, K. Spehr, M. Höhne, D. Bräuer-Burchardt, C. Tünnermann, A. Kühmstedt, P. Fraunhofer Institute for Applied Optics and Precision Engineering Germany Abbe School of Photonics Friedrich Schiller University Jena Germany

ISBN: (纸本)9783038681748

The phase shift algorithm is an important 3D shape reconstruction method in industrial quality inspection and reverse engineering. To retrieve dense and accurate point clouds, the conventional phase shift methods require at least three fringe projection patterns, limiting its application to statics or semi-statics scenes only. In this paper, we propose a novel and low-cost single-shot phase shift 3D reconstruction framework using convolution neural networks (CNN) trained on 3D synthetic fractals. We first design and optimize a novel projection pattern that compresses the phase period orders and the ambiguous phase information into a single image. Then, we train two different CNNs to predict the ambiguous phase information and the period orders separately. The CNNs were trained on randomly generated 3D shapes whose geometric complexity is modeled by recursive shape generation algorithms which can create an unlimited amount of random 3D shapes on the fly. Initial results demonstrate that our method can produce high-quality point clouds from just a pair of 2D images, thus improving the temporal resolution of a phase-shift 3D scanner to the highest possible. As we also include different real-world lighting and textural conditions in the training data set, experiments also demonstrate that our CNN models which were trained on random synthetic fractals only can perform equally well in the real world. © 2022 The Author(s) Eurographics Proceedings © 2022 The Eurographics Association.

关键词： Fractals

来源：评论

学校读者我要写书评

暂无评论

Entangled two-photon absorption in commercial fluorophores

Entangled two-photon absorption in commercial fluorophores

引用

CLEO: Science and Innovations, CLEO:S and I 2021 - Part of Conference on Lasers and Electro-optics, CLEO 2021

作者： Gäbler, Tobias B. Jain, Nitish León Torres, Josue R. Hendra, Patrick Gräfe, Markus Fraunhofer Institute of Applied Optics and Precision Engineering IOF Albert-Einstein-Straße 7 JenaD-07745 Germany

Our study addresses the applicability of simple and common fluorophores for entangled two-photon fluorescence microscopy. Using CW-pumped SPDC waveguides, we can measure linear absorption rates of entangled photons in... 详细信息

ISBN: (纸本)9781557528209

关键词： Fluorophores

来源：评论

学校读者我要写书评

暂无评论

Structured Illumination EUV Imaging

Structured Illumination EUV Imaging

引用

Computational Optical Sensing and Imaging, COSI 2024 - Part of Optica Imaging Congress

作者： Licht, L. Eschen, W. Liu, C. Penagos Molina, D.S. Steinert, M. Siefke, T. Pertsch, T. Limpert, J. Rothhardt, J. Helmholtz Institute Jena Fröbelstieg 3 Jena07743 Germany GSI Helmholtzzentrum für Schwerionenforschung Planckstraße 1 Darmstadt64291 Germany Institute of Applied Physics Abbe Center of Photonics Friedrich-Schiller-University Jena Albert-Einstein-Straße 15 Jena07745 Germany Fraunhofer Institute for Applied Optics and Precision Engineering IOF Albert-Einstein-Str. 7 Jena07745 Germany

We present table-top EUV imaging at 13.5 nm. Using an EUV phase diffusor for generating a highly structured illumination, improves the image quality and resolution in ptychography and opens new avenues for single-shot...

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：