TY - JOUR A1 - Götzelmann, Timo T1 - Visually Augmented Audio-Tactile Graphics for Visually Impaired People JF - ACM Transactions on Accessible Computing (TACCESS) N2 - Tactile graphics play an essential role in knowledge transfer for blind people. The tactile exploration of these graphics is often challenging because of the cognitive load caused by physiological constraints and their complexity. The coupling of physical tactile graphics with electronic devices offers to support the tactile exploration by auditory feedback. Often, these systems have strict constraints regarding their mobility or the process of coupling both components. Additionally, visually impaired people cannot appropriately benefit from their residual vision. This article presents a concept for 3D printed tactile graphics, which offers to use audio-tactile graphics with usual smartphones or tablet-computers. By using capacitive markers, the coupling of the tactile graphics with the mobile device is simplified. These tactile graphics integrating these markers can be printed in one turn by off-the-shelf 3D printers without any post-processing and allows us to use multiple elevation levels for graphical elements. Based on the developed generic concept on visually augmented audio-tactile graphics, we presented a case study for maps. A prototypical implementation was tested by a user study with visually impaired people. All the participants were able to interact with the 3D printed tactile maps using a standard tablet computer. To study the effect of visual augmentation of graphical elements, we conducted another comprehensive user study. We tested multiple types of graphics and obtained evidence that visual augmentation may offer clear advantages for the exploration of tactile graphics. Even participants with a minor residual vision could solve the tasks with visual augmentation more quickly and accurately. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:92-opus4-5571 VL - 2018 IS - Volume 11, Issue 2, Article No. 8 PB - ACM ER - TY - JOUR A1 - Götzelmann, Timo T1 - Autonomous Selection and Printing of 3D Models for People Who Are Blind JF - ACM Transactions on Accessible Computing (TACCESS) N2 - 3D models are an important means for understanding spatial contexts. Today these models can be materialized by 3D printing, which is increasingly used at schools for people with visual impairments. In contrast to sighted people, people with visual impairments have so far, however, neither been able to search nor to print 3D models without assistance. This article describes our work to develop an aid for people with visual impairments that would facilitate autonomous searching for and printing of 3D models. In our initial study, we determined the requirements to accomplish this task by means of a questionnaire and developed a first approach that allowed personal computer-based 3D printing. An extended approach allowed searching and printing using common smartphones. In our architecture, technical details of 3D printers are abstracted by a separate component that can be accessed via Wi-Fi independently of the actual 3D printer used. It comprises a search of the models in an annotated database and 3D model retrieval from the internet. The whole process can be controlled by voice interaction. The feasibility of autonomous 3D printing for people with visual impairments is shown with a first user study. Our second user study examines the usability of the user interface when searching for 3D models on the internet and preparing them for the materialization. The participants were able to define important printing settings, whereas other printing parameters could be determined algorithmically. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:92-opus4-5587 VL - 11 IS - 3 SP - 1 EP - 25 PB - ACM ER - TY - JOUR A1 - Götzelmann, Timo A1 - Karg, Pascal A1 - Müller, Mareike T1 - Augminded: Ambient Mirror Display Notifications JF - Multimodal Technologies and Interaction N2 - This paper presents a new approach for providing contextual information in real-world environments. Our approach is consciously designed to be low-threshold; by using mirrors as augmented reality surfaces, no devices such as AR glasses or smartphones have to be worn or held by the user. It enables technical and non-technical objects in the environment to be visually highlighted and thus subtly draw the attention of people passing by. The presented technology enables the provision of information that can be viewed in more detail by the user if required by slowing down their movement. Users can decide whether this is relevant to them or not. A prototype system was implemented and evaluated through a user study. The results show a high level of acceptance and intuitive usability of the system, with participants being able to reliably perceive and process the information displayed. The technology thus offers promising potential for the unobtrusive and context-sensitive provision of information in various application areas. The paper discusses limitations of the system and outlines future research directions to further optimize the technology and extend its applicability. Y1 - 2025 U6 - https://doi.org/10.3390/mti9090093 SN - 2414-4088 VL - 9 IS - 9 PB - MDPI CY - Basel, Switzerland ER - TY - JOUR A1 - Kreimeier, Julian A1 - Bielmeier, Thomas A1 - Götzelmann, Timo T1 - Evaluation of Capacitive Markers Fabricated by 3D Printing, Laser Cutting and Prototyping JF - Inventions: Special Issue Innovations in 3-D Printing N2 - With Tangible User Interfaces, the computer user is able to interact in a fundamentally different and more intuitive way than with usual 2D displays. By grasping real physical objects, information can also be conveyed haptically, i.e., the user not only sees information on a 2D display, but can also grasp physical representations. To recognize such objects (“tangibles”) it is skillful to use capacitive sensing, as it happens in most touch screens. Thus, real objects can be located and identified by the touch screen display automatically. Recent work already addressed such capacitive markers, but focused on their coding scheme and automated fabrication by 3D printing. This paper goes beyond the fabrication by 3D printers and, for the first time, applies the concept of capacitive codes to laser cutting and another immediate prototyping approach using modeling clay. Beside the evaluation of additional properties, we adapt recent research results regarding the optimized detection of tangible objects on capacitive screens. As a result of our comprehensive study, the detection performance is affected by the type of capacitive signal processing (respectively the device) and the geometry of the marker. 3D printing revealed to be the most reliable technique, though laser cutting and immediate prototyping of markers showed promising results. Based on our findings, we discuss individual strengths of each capacitive marker type. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:92-opus4-5603 VL - 2018 IS - Volume 3, Issue 1, Article 9 PB - MDPI ER - TY - JOUR A1 - Kreimeier, Julian A1 - Götzelmann, Timo T1 - Two Decades of Touchable and Walkable Virtual Reality for Blind and Visually Impaired People: A High-Level Taxonomy JF - Multimodal Technologies and Interaction N2 - Although most readers associate the term virtual reality (VR) with visually appealing entertainment content, this technology also promises to be helpful to disadvantaged people like blind or visually impaired people. While overcoming physical objects’ and spaces’ limitations, virtual objects and environments that can be spatially explored have a particular benefit. To give readers a complete, clear and concise overview of current and past publications on touchable and walkable audio supplemented VR applications for blind and visually impaired users, this survey paper presents a high-level taxonomy to cluster the work done up to now from the perspective of technology, interaction and application. In this respect, we introduced a classification into small-, medium- and large-scale virtual environments to cluster and characterize related work. Our comprehensive table shows that especially grounded force feedback devices for haptic feedback (‘small scale’) were strongly researched in different applications scenarios and mainly from an exocentric perspective, but there are also increasingly physically (‘medium scale’) or avatar-walkable (‘large scale’) egocentric audio-haptic virtual environments. In this respect, novel and widespread interfaces such as smartphones or nowadays consumer grade VR components represent a promising potential for further improvements. Our survey paper provides a database on related work to foster the creation process of new ideas and approaches for both technical and methodological aspects. Y1 - 2020 U6 - https://doi.org/10.3390/mti4040079 SN - 2414-4088 VL - 4 IS - 4 PB - MDPI AG ER - TY - JOUR A1 - Wolf, Philipp A1 - Götzelmann, Timo T1 - VEPdgets: Towards Richer Interaction Elements Based on Visually Evoked Potentials JF - Sensors N2 - For brain–computer interfaces, a variety of technologies and applications already exist. However, current approaches use visual evoked potentials (VEP) only as action triggers or in combination with other input technologies. This paper shows that the losing visually evoked potentials after looking away from a stimulus is a reliable temporal parameter. The associated latency can be used to control time-varying variables using the VEP. In this context, we introduced VEP interaction elements (VEP widgets) for a value input of numbers, which can be applied in various ways and is purely based on VEP technology. We carried out a user study in a desktop as well as in a virtual reality setting. The results for both settings showed that the temporal control approach using latency correction could be applied to the input of values using the proposed VEP widgets. Even though value input is not very accurate under untrained conditions, users could input numerical values. Our concept of applying latency correction to VEP widgets is not limited to the input of numbers. KW - brain–computer interface; BCI; VEP; interaction; HCI; interaction elements; control elements; controls; widgets; VEP-widget Y1 - 2023 U6 - https://doi.org/10.3390/s23229127 SN - 1424-8220 VL - 23 IS - 22 PB - MDPI AG ER -