Wir freuen uns sehr über die Presseberichte zu unserem Projekt “KI-Rebschnitt”. Viel Spaß beim Lesen der Artikel:
https://www.rlp-international.de/blog/innovation-im-weinbau-durch-kuenstliche-intelligenz/
https://www.dwm-aktuell.de/foerderbescheid-projekt-ki-rebschnitt
The recent advancements in Deep learning has lead to new interesting applications such as analyzing human motion and activities in recorded videos. The analysis covers from simple motion of humans walking, performing exercises to complex motions such as playing sports.
The athlete’s performance can be easily captured with a fixed camera for sports like tennis, badminton, diving, etc. The large availability of low cost cameras in handheld devices has further led to common place solution to record videos and analyze an athletes performance. Although the sports trainers can provide visual feedback by playing recorded videos, it is still hard to measure and monitor the performance improvement of the athlete. Also, the manual analysis of the obtained footage is a time-consuming task which involves isolating actions of interest and categorizing them using domain-specific knowledge. Thus, the automatic interpretation of performance parameters in sports has gained a keen interest.
Competitive diving is one of the well recognized aquatic sport in Olympics in which a person dives from a platform or a springboard and performs different classes of acrobatics before descending into the water. These classes are standardized by international organization Fédération Internationale de Natation (FINA). The differences in the acrobatics performed in various classes of diving are very subtle. The difference arises in the duration which starts with the diver standing on a diving platform or a springboard and ends at the moment he/she dives into the water. This is a challenging task to model especially due to involvement of rapid changes and requires understanding of long-term human dynamics. Further, the model must be sensitive to subtle changes in body pose over a large number of frames to determine the correct classification.
In order to automate this kind of task, three challenging sub-problems are often encountered: 1) temporally cropping events/actions of interest from continuous video; 2) tracking the person of interest even though other divers and bystanders may be in view; and 3) classifying the events/actions of interest.
We are developing a solution in co-operation with Institut für Angewandte Trainingswissenshaft in Leipzig (IAT) to tackle the three subproblems. We work towards a complete parameter tracking solution based on monocular markerless human body motion tracking using only a mobile device (tablet or mobile phone) as training support tool to the overall diving action analysis. The techniques proposed, can be generalized to video footage recorded from other sports.
Contact person: Dr. Bertram Taetz, Pramod Murthy
We are happy to announce that three papers with respect to our structured light 3D reconstruction pipeline have been accepted for publication at the CAIP 2021. The International Conference on Computer Analysis of Images and Patterns will take place from September 28th to 30th, 2021 as a virtual conference.
The three accepted papers are entitled ”Fast Projector-Driven Structured Light Matching in Sub-Pixel Accuracy using Bilinear Interpolation Assumption”, ”Simultaneous Bi-Directional Structured Light Encoding for Practical Uncalibrated Profilometry” and ”Joint Global ICP for Improved Automatic Alignment of Full Turn Object Scans” and will be available right after the conference.
Authors: Torben Fetzer, Gerd Reis and Didier Stricker
DFKI participates in the VIZTA project, coordinated by ST Micrelectronics, aiming at developing innovative technologies in the field of optical sensors and laser sources for short to long-range 3D-imaging and to demonstrate their value in several key applications including automotive, security, smart buildings, mobile robotics for smart cities, and industry 4.0. The 24-month review by the EU-commission was completed and a public summary of the project was released, including updates from DFKI Augmented Vision on time-of-flight camera dataset recording and deep learning algorithm development for car in-cabin monitoring and smart building person counting and anomaly detection applications.
Please click here to check out the complete summary: https://www.vizta-ecsel.eu/newsletter-april-2021/
Contact: Dr. Jason Rambach, Dr. Bruno Mirbach
We are happy to announce that our paper “SEMANTIC SEGMENTATION IN DEPTH DATA : A COMPARATIVE EVALUATION OF IMAGE AND POINT CLOUD BASED METHODS” has been accepted for publication at the ICIP 2021 IEEE International Conference on Image Processing which will take place from September 19th to 22nd, 2021 at Anchorage, Alaska, USA.
Abstract: The
problem of semantic segmentation from depth images can be addressed by segmenting
directly in the image domain or at 3D point cloud level. In this paper, we
attempt for the first time to provide a study and experimental comparison of the
two approaches. Through experiments on three datasets, namely SUN RGB-D, NYUdV2
and TICaM, we extensively compare various semantic segmentation algorithms, the
input to which includes images and point clouds derived from them. Based on
this, we offer analysis of the performance and computational cost of these
algorithms that can provide guidelines on when each method should be preferred.
Authors: Jigyasa Katrolia,
Lars Krämer, Jason Rambach, Bruno Mirbach, Didier Stricker
Contact: Jigyasa_Singh.Katrolia@dfki.de, Jason.Rambach@dfki.de
We are proud that our paper “RPSRNet: End-to-End Trainable Rigid Point Set Registration Network using Barnes-Hut 2^D-Tree Representation” has been accepted for publication at the Computer Vision Pattern Recognition (CVPR) 2021 Conference, which will take place virtually online from June 19th to 25th. CVPR is the premier annual computer vision conference. Our paper was accepted from ~12000 submissions as one of 23.4% (acceptance rate: 23.4%).
Abstract: We propose RPSRNet – a novel end-to-end trainable deep neural network for rigid point set registration. For this task, we use a novel 2^D-tree representation for the input point sets and a hierarchical deep feature embedding in the neural network. An iterative transformation refinement module of our network boosts the feature matching accuracy in the intermediate stages. We achieve an inference speed of ~12-15$\,$ms to register a pair of input point clouds as large as ~250K. Extensive evaluations on (i) KITTI LiDAR-odometry and (ii) ModelNet-40 datasets show that our method outperforms prior state-of-the-art methods – e.g., on the KITTI dataset, DCP-v2 by 1.3 and 1.5 times, and PointNetLK by 1.8 and 1.9 times better rotational and translational accuracy respectively. Evaluation on ModelNet40 shows that RPSRNet is more robust than other benchmark methods when the samples contain a significant amount of noise and disturbance. RPSRNet accurately registers point clouds with non-uniform sampling densities, e.g., LiDAR data, which cannot be processed by many existing deep-learning-based registration methods.
Authors: Sk Aziz Ali, Kerem Kahraman, Gerd Reis, Didier Stricker
To view the paper, please click here.
We are happy to announce that our paper “Fast Gravitational Approach for Rigid Point Set Registration With Ordinary Differential Equations” has been accepted for publication in the IEEE Access Journal (Impact Factor: 3.745).
Abstract: This article introduces a new physics-based method for rigid point set alignment called Fast Gravitational Approach (FGA). In FGA, the source and target point sets are interpreted as rigid particle swarms with masses interacting in a globally multiply-linked manner while moving in a simulated gravitational force field. The optimal alignment is obtained by explicit modeling of forces acting on the particles as well as their velocities and displacements with second-order ordinary differential equations of n-body motion. Additional alignment cues can be integrated into FGA through particle masses. We propose a smooth-particle mass function for point mass initialization, which improves robustness to noise and structural discontinuities. To avoid the quadratic complexity of all-to-all point interactions, we adapt a Barnes-Hut tree for accelerated force computation and achieve quasilinear complexity. We show that the new method class has characteristics not found in previous alignment methods such as efficient handling of partial overlaps, inhomogeneous sampling densities, and coping with large point clouds with reduced runtime compared to the state of the art. Experiments show that our method performs on par with or outperforms all compared competing deep-learning-based and general-purpose techniques (which do not take training data) in resolving transformations for LiDAR data and gains state-of-the-art accuracy and speed when coping with different data.
Authors: Sk Aziz Ali, Kerem Kahraman, Christian Theobalt, Didier Stricker, Vladislav Golyanik
Link to the paper: https://ieeexplore.ieee.org/document/9442679
In the frame of a research cooperation, DFKI’s Augmented Vision Department and BMW are working jointly on Augmented Reality for In-Car applications. Ahmet Firintepe, a BMW research PhD under the supervision of Dr. Alain Pagani and Prof. Didier Stricker has recently published two papers on outside-in head and glass pose estimation:
Ahmet Firintepe, Alain Pagani and Didier Stricker:
“A Comparison of Single and Multi-View IR image-based AR Glasses Pose Estimation Approaches”
Proc. of the IEEE Virtual Reality conference – Posters. IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VRW) (IEEEVR-2021)
In this paper, we present a study on single and multi-view image-based AR glasses pose estimation with two novel methods. The first approach is named GlassPose and is a VGG-based network. The second approach GlassPoseRN is based on ResNet18. We train and evaluate the two custom developed glasses pose estimation networks with one, two and three input images on the HMDPose dataset. We achieve errors as low as 0.10 degrees and 0.90 mm on average on all axes for orientation and translation. For both networks, we observe minimal improvements in position estimation with more input views.
Ahmet Firintepe, Carolin Vey, Stylianos Asteriadis, Alain Pagani, Didier Stricker:
“From IR Images to Point Clouds to Pose: Point Cloud-Based AR Glasses Pose Estimation”
In: Journal of Imaging 7 80 Seiten 1-18 MDPI 4/2021.
In this paper, we propose two novel AR glasses pose estimation algorithms from single infrared images by using 3D point clouds as an intermediate representation. Our first approach “PointsToRotation” is based on a Deep Neural Network alone, whereas our second approach “PointsToPose” is a hybrid model combining Deep Learning and a voting-based mechanism. Our methods utilize a point cloud estimator, which we trained on multi-view infrared images in a semisupervised manner, generating point clouds based on one image only. We generate a point cloud dataset with our point cloud estimator using the HMDPose dataset, consisting of multi-view infrared images of various AR glasses with the corresponding 6-DoF poses. In comparison to another point cloud-based 6-DoF pose estimation named CloudPose, we achieve an error reduction of around 50%. Compared to a state-of-the-art image-based method, we reduce the pose estimation error by around 96%.
Our paper “Controlling Teleportation-Based Locomotion in Virtual Reality with Hand Gestures: A Comparative Evaluation of Two-Handed and One-Handed Techniques” got accepted at MDPI Electronics for a Special Issue on Recent Advances in Virtual Reality and Augmented Reality.
Paper: https://www.mdpi.com/2079-9292/10/6/715 (available as Open Access)
Authors: Alexander Schäfer, Gerd Reis, Didier Stricker
Abstract: Virtual Reality (VR) technology offers users the possibility to immerse and freely navigate through virtual worlds. An important component for achieving a high degree of immersion in VR is locomotion. Often discussed in the literature, a natural and effective way of controlling locomotion is still a general problem which needs to be solved. Recently, VR headset manufacturers have been integrating more sensors, allowing hand or eye tracking without any additional required equipment. This enables a wide range of application scenarios with natural freehand interaction techniques where no additional hardware is required. This paper focuses on techniques to control teleportation-based locomotion with hand gestures, where users are able to move around in VR using their hands only. With the help of a comprehensive study involving 21 participants, four different techniques are evaluated. The effectiveness and efficiency as well as user preferences of the presented techniques are determined. Two two-handed and two one-handed techniques are evaluated, revealing that it is possible to move comfortable and effectively through virtual worlds with a single hand only.
As part of the research activities of DFKI Augmented Vision in the VIZTA project (https://www.vizta-ecsel.eu/), we have published the open-source dataset for automotive in-cabin monitoring with a wide-angle time-of-flight depth sensor. The TiCAM dataset represents a variety of in-car person behavior scenarios and is annotated with 2D/3D bounding boxes, segmentation masks and person activity labels. The dataset is available here https://vizta-tof.kl.dfki.de/. The publication describing the dataset in detail is available as a preprint here: https://arxiv.org/pdf/2103.11719.pdf
Contacts: Jason Rambach, Jigyasa Katrolia
