This work presents a way to estimate the matching probabilities for histogrammed intensity patches [41] by approximating the robustness and distinctiveness of a feature with beta distributions. We propose a simplified analytical approach to calculate the distinctiveness and show that it produces at least as good results as a specifically trained neural network. The matching probability correlates stronger with the inlier ratio than the dissimilarity score does. We then evaluate a basic tracking by detection pipeline where no longer the closest but the most probable match is chosen. Our tests show, that this improves the average performance of the system in terms of tracking rate.

Wiedmer, Martin (Ed.) et al.: 10th IEEE International Symposium on Mixed and Augmented Reality 2011 : ISMAR. Science & Technology Proceedings, pp. 15-18

With "House of Olbrich" we present an iPhone Augmented Reality (AR) app that visualizes the compelling history of Darmstadt's unique Jugendstil (Art Nouveau) quarter with video-see through Augmented Reality. We propose methods for enabling high performance computer vision algorithms to deploy sophisticated AR visuals on current generation Smartphones by outsourcing resource intensive tasks to the cloud. This allows us to apply methods on 3D feature recognition for even complex tracking situations outdoors, where lightning conditions change and tracked objects are often occluded. By taking a snapshot of the building, the user learns about the architect, design and history of the building. Historical media, like old photographs and blueprints are superimposed on the building's front, depicting the moved history of the famous House of Olbrich, which was destroyed during World War II and has been only rudimentary restored. Augmented Reality technology allows tourists to jump back in time visually by using their Smartphones: Mixing Realities emphasizes the user's experience and leads his attention to the impressive historical architecture of the Art Nouveau. In addition, we ease interaction means by superimposing snapshots. Tourists may view and read information also in a relaxed position without the need to front-up their mobiles all the time.

Richard, Paul (Ed.) et al.: GRAPP 2011 : Proceedings of the International Conference on Computer Graphics Theory and Applications. Portugal: SciTePress, 2011, pp. 286-295

Multi-projector systems are widely used in many application areas. Such systems are for instance employed to increase the brightness or the resolution of projected images. Intrinsic to multi-projector systems are problems like geometric misalignment, especially when projecting onto complex arbitrarily formed projection surfaces, and photometric deviations. Therefore, several difficult calibration tasks (geometry, brightness, color) have to be performed. A high-quality and easy-to-use calibration process is the key to good usability for untrained or unexperienced users. Due to the fact that manual calibration is time-consuming and imprecise, automatic approaches were developed in recent years. This paper analyzes the most popular state-of-the-art algorithms and setups with respect to their advantages and disadvantages. We summarize the general working principles of calibration algorithms and provide an outlook into the fields in which the described algorithms are most useful.

Alem, Leila (Ed.) et al.: Recent Trends of Mobile Collaborative Augmented Reality Systems. Berlin, Heidelberg, New York: Springer, 2011, pp. 21-38

This chapter discusses the current state, issues, and direction of the development and use of international standards for use in Augmented Reality (AR) applications and services. More specifically, the paper focuses on AR and mobile devices. Enterprise AR applications are not discussed in this chapter. There are many existing international standards that can be used in AR applications but there may not be defined best practices or profiles of those standards that effectively meet AR development requirements. This chapter provides information on a number of standards that can be used for AR applications but may need further international agreements on best practice use.

Alem, Leila (Ed.) et al.: Recent Trends of Mobile Collaborative Augmented Reality Systems. Berlin, Heidelberg, New York: Springer, 2011, pp. 69-82

Training for service technicians inmaintenance tasks is a classical application field of Augmented Reality explored by different research groups. Mostly technical aspects (tracking, visualization etc.) have been in focus of this research field. In this chapter we present results of interdisciplinary research based on the fusion of cognitive science, psychology and computer science. We focus on analyzing the improvement of Augmented Reality based training of skills which are relevant for maintenance and assembly tasks. The skills considered in this work comprise sensorimotor skills as well as cognitive skills. Different experiments have been conducted in order to find recommendations for the design of Augmented Reality training systems which overcome problems of existing approaches. The suggestions concern the fields of content visualization and multimodal feedback.

BIO Web of Conferences, Vol.1 (2011), 4 p.

Augmented Reality (AR) points out to be a good technology for training in the field of maintenance and assembly, as instructions or rather location-dependent information can be directly linked and/or attached to physical objects. Since objects to maintain usually contain a large number of similar components (e.g. screws, plugs, etc.) the provision of location-dependent information is vitally important. Another advantage is that AR-based training takes place with the real physical devices of the training scenario. Thus, the trainee also practices the real use of the tools whereby the corresponding sensorimotor skills are trained.

Avizzano, Carlo Alberto (Ed.) et al.: IEEE RO-MAN 2010 : 19th IEEE International Symposium on Robot and Human Interactive Communication. Proceedings [online]. New York: The Institute of Electrical and Electronics Engineers (IEEE), 2010, pp. 434-439

Augmented Reality (AR) is a technology which has become very popular in the last years. In this context also the idea of using of AR for training applications has become very important. AR offers a large potential for training only if the training is well focused to the skills that have to be trained and if the training protocol is well designed. On the other hand, the generation of the training content to be transferred via AR is a comprehensive problem that is addressed in this paper. Thus, this paper tries to describe the whole chain of implementations and general aspects involved in the creation of AR training applications, including examples for used multimodal devices. This chain starts with the capturing of expert actions to be hold in "digital representation of skill". The digital representation of skill is transferred to the training protocol that specifies the storyboard of the AR training session. The paper includes two different implementations of AR training systems and describes the general idea of informational abstraction from low level data up to interaction and from design to application.

Höllerer, Tobias (Ed.) et al.: 9th IEEE International Symposium on Mixed and Augmented Reality 2010 : ISMAR. Science & Technology Proceedings. Los Alamitos, Calif.: IEEE Computer Society, 2010, pp. 223-224

The creation of training applications using Augmented Reality (AR) is still a new field of research. In order to get good training results therefore evaluation should be performed. For the creation of such systems the questions arising are related to the general process of generation, visualization, evaluation and its psychological background. An important aspect of vision based AR is also the robust tracking and initialization of objects for correct augmentation. In this work we present a concept of an entire processing chain, which allows for efficient and automatic generation of such training systems that can also be used for evaluation. We do this in the context of a Lego training system. While explaining the whole process of application generation and usage, we also present a novel approach for robust marker free initialization of colored partly occluded plates and their tracking using one off the shelf monocular camera.

Latoschik, Marc Erich (Ed.) et al.: 2nd Workshop on Software Engineering and Architectures for Realtime Interactive Systems (SEARIS@VR2009) : IEEE Virtual Reality 2009 Workshop. Aachen: Shaker, 2009, pp. 51-54

In this paper we introduce an architecture for rapid development and assessment of advanced 3D visual track ing algorithms. We claim, that no universal tracking approach exists, that fulfills the requirements of all possible application seenarios at the same time. On the contrary, very specific and working solutions can be developed for given situations and uses. Therefore, software for visual tracking must be designed as a highly flexible system that can be quickly re-configured in order to enable the development of optimized solutions in terms of robustness, accuracy, frame rate and delay. To this purpose we designed an architecture that offers many functionalities, which can be combined together to build a new processing chain. The overall system offers numerous advantages, such as interactive programming, run-time access to data and parameters and easy interfacing with other libraries or applications.

Latoschik, Marc Erich (Ed.) et al.: 2nd Workshop on Software Engineering and Architectures for Realtime Interactive Systems (SEARIS@VR2009) : IEEE Virtual Reality 2009 Workshop. Aachen: Shaker, 2009, pp. 51-54

In this paper we introduce an architecture for rapid development and assessment of advanced 3D visual track ing algorithms. We claim, that no universal tracking approach exists, that fulfills the requirements of all possible application seenarios at the same time. On the contrary, very specific and working solutions can be developed for given situations and uses. Therefore, software for visual tracking must be designed as a highly flexible system that can be quickly re-configured in order to enable the development of optimized solutions in terms of robustness, accuracy, frame rate and delay. To this purpose we designed an architecture that offers many functionalities, which can be combined together to build a new processing chain. The overall system offers numerous advantages, such as interactive programming, run-time access to data and parameters and easy interfacing with other libraries or applications.

Gutiérrez, Teresa (Ed.) et al.: SKILLS 09 : Enaction on SKILLS. Donostia - San Sebastián: SKILLS Consortium, 2009, pp. 39-45

Within the European project SKILLS Virtual and Augmented Reality platforms have been developed that are used for the realization of different training simulators in the field of sports (training of rowing and juggling), surgery (training of maxillofacial and telerobotic surgery), rehabilitation (rehabilitation of upper limp), maintenance (training of assembly procedures) and robotics (training of robot programming). These platforms are integrating capturing and rendering technologies. The capturing technologies are used to register specific criteria of skills to be hold in a digital representation. Thus, parameters relevant for specific skills are qualified and used as evaluation factors within the training simulators. The training simulators not only can simulate the virtual environment of the training situation, but this environment can be enhanced via multimodal renderings, fostering the training process and accelerating the training effect. The integrative platforms from scalable and adaptable frameworks that can be used to realize different training protocols and that can be adapted to the trainee's degree of skill. Therefore the training protocol can be specified via standardized application scripts.

Gutiérrez, Teresa (Ed.) et al.: SKILLS 09 : Enaction on SKILLS. Donostia - San Sebastián: SKILLS Consortium, 2009, pp. 129-134

The present paper describes a multimodal training system to be used in the context of Industrial Maintenance and assembly. The system is being developed by the SKILLS consortium members as a dedicated platform to conduct controlled skill transfer exercises as well as the technological platform to develop a dedicated training program. The paper provides an introduction to the current state of the demonstrator, which is now at the first stage of an iterative process that will see the final demonstrator delivered in 2011.

Gutiérrez, Teresa (Ed.) et al.: SKILLS 09 : Enaction on SKILLS. Donostia - San Sebastián: SKILLS Consortium, 2009, pp. 189-190

When a learner of a new procedural skill is provided with elaborated knowledge: "how-it-works" knowledge or "context procedures", in addition to the "how-to-do-it" knowledge or "list procedures", his performance becomes more accurate, faster, and more flexible. It is hypnotized that a display of the device which is assembled during the assembly task has the potential to support the trainee's mental model building.

Institute for Systems and Technologies of Information, Control and Communication (INSTICC): VISIGRAPP 2009. Proceedings : International Joint Conference on Computer Vision and Computer Graphics Theory and Applications [CD-ROM]. INSTICC Press, 2009, GRAPP, pp. 387-392

This paper introduces novel techniques of interacting and controlling 3D content using multi-touch interaction principles for navigation and virtual camera control. Based on applications from GIS and for the architectural design review process, implementation and usage of these interaction techniques are illustrated. A comprehensive hardware and software setup is used, which not only includes tracking, but also an X3D based layer to simplify application development. Therefore it allows designers and other non-programmers to develop multi-touch applications very efficiently, while allowing to focus on user interaction and content.

Latoschik, Marc Erich (Ed.) et al.: 2nd Workshop on Software Engineering and Architectures for Realtime Interactive Systems (SEARIS@VR2009) : IEEE Virtual Reality 2009 Workshop. Aachen: Shaker, 2009, pp. 37-40

This paper describes the implementation od a deviceless interaction 'device' using hand gesture recognition within a calibrated stereo system. Video-based interaction is one of the most intuitive kinds of Human Computer Interaction with Virtual Reality applications due to the fact that users are not wired to a computer. If interaction with three-dimensional environments is considered, pointing, grabbing and releasing are the most intuitive gestures used by humans. This paper describes a video-based gesture recognition that observes the user in front of a large displaying screen, indentifying three different hand gestures in real time using 2D feature classification and determines 3D information like the 3D position of the user's hand or the pointing direction if performed. Different scenario applications like a virtual chess game against the computer or an industrial scenario have been deployed and tested.

Spencer, Stephen N. (Ed.): Proceedings WEB3D 2008 : 13th International Symposium on 3D Web Technology. New York: ACM Press, 2008, pp. 27-30

Multi-touch interaction on tabletop displays is a very active field of todays HCI research. However, most publications still focus on tracking techniques or develop a gesture configuration for a specific application setup. Very few explore generic high level interfaces for multi-touch applications. In this paper we present a comprehensive hardware and software setup, which includes an X3D based layer to simplify the application development process. We present a robust FTIR based optical tracking system, examine in how far current sensor and navigation abstractions in the X3D standard are useful and finally present extensions to the standard, which enable designers and other non-programmers to develop multi-touch applications very efficiently.