Raphael Grasset

Raphael Grasset
PTC · Vuforia

PhD, MSc

About

95
Publications
73,907
Reads
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2,346
Citations
Introduction
Technical Fellow at PTC (Parametric Technology Corporation) working on AR/VR Technologies. Previously Staff Engineer at Qualcomm Austria Research Center (November 2013-November 2015), Senior Researcher at the Institute for Computer Graphics and Vision (ICG), Graz University of Technology (2011-2013) and Senior Researcher at HIT Lab NZ, University of Canterbury (2004-2010).

Publications

Publications (95)
Conference Paper
Full-text available
In this paper, we introduce a novel view management technique for placing labels in Augmented Reality systems. A common issue in many Augmented Reality applications is the absence of knowledge of the real environment, limiting the efficient representation and optimal layout of the digital information augmented onto the real world. To overcome this...
Conference Paper
The development of new Simultaneous Localization and Mapping (SLAM) techniques is quickly advancing in research communities and rapidly transitioning into commercial products. Creating accurate and high-quality SLAM maps relies on a robust initialization process. However, the robustness and usability of SLAM initialization for end-users has often b...
Article
Full-text available
This document summarizes the major milestones in mobile Augmented Reality between 1968 and 2014. Major parts of the list were compiled by the member of the Christian Doppler Laboratory for Handheld Augmented Reality in 2010 (author list in alphabetical order) for the ISMAR society. Later in 2013 it was updated, and more recent work was added during...
Article
Full-text available
In recent years, the development of Augmented Reality (AR) frameworks made AR application development widely accessible to developers without AR expert background. With this development, new application fields for AR are on the rise. This comes with an increased need for visualization techniques that are suitable for a wide range of application are...
Patent
Techniques are presented for constructing a digital representation of a physical environment. In some embodiments, a method includes obtaining image data indicative of the physical environment; receiving gesture input data from a user corresponding to at least one location in the physical environment, based on the obtained image data; detecting at...
Patent
Methods, systems, computer-readable media, and apparatuses for generating an Augmented Reality (AR) object are presented. The method may include capturing an image of one or more target objects, wherein the one or more target objects are positioned on a predefined background. The method may also include segmenting the image into one or more areas c...
Article
Full-text available
Sketching leverages human skills for various purposes, such as content authoring. This paper explores the different aspects of sketch-based interaction in augmented reality. We explore the design space of sketching in in-place augmented reality with particular attention to AR games. We propose a contextual model that offers a framework for the expl...
Conference Paper
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This paper evaluates different state-of-the-art approaches for implementing an X-ray view in Augmented Reality (AR). Our focus is on approaches supporting a better scene understanding and in particular a better sense of depth order between physical objects and digital objects. One of the main goals of this work is to provide effective X-ray visuali...
Article
Augmented reality (AR) enables users to retrieve additional information about real world objects and locations. Exploring such location-based information in AR requires physical movement to different viewpoints, which may be tiring and even infeasible when viewpoints are out of reach. In this paper, we present object-centric exploration techniques...
Article
This paper investigates the utility of the Magic Lens metaphor on small screen handheld devices for map navigation given state of the art computer vision tracking. We investigate both performance and user experience aspects. In contrast to previous studies a semi-controlled field experiment (n=18)(n=18) in a ski resort indicated significant longer...
Conference Paper
Full-text available
Augmented Reality (AR) applications require knowledge about the real world environment in which they are used. This knowledge is often gathered while developing the AR application and stored for future uses of the application. Consequently, changes to the real world lead to a mismatch between the previously recorded data and the real world. New cap...
Conference Paper
Full-text available
Annotations of objects in 3D environments are commonly controlled using view management techniques. State-of-the-art view management strategies for external labels operate in 2D image space. This creates problems, because the 2D view of a 3D scene changes over time, and temporal behavior of elements in a 3D scene is not obvious in 2D image space. W...
Conference Paper
Full-text available
Augmented reality (AR) enables users to retrieve additional information about the real world objects and locations. Exploring such location-based information in AR requires physical movement to different viewpoints, which may be tiring and even infeasible when viewpoints are out of reach. In this paper, we present object-centric exploration techniq...
Article
Full-text available
*Download the updated version of this paper using the DOI* This paper discusses methods for reducing beam hardening effects using spectral data for biomaterial applications. A small-animal spectral scanner operating in the diagnostic energy range was used. We investigate the use of photon-processing features of the Medipix3RX ASIC in reducing beam...
Article
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Spectral molecular imaging is a new imaging technique able to discriminate and quantify different components of tissue simultaneously at high spatial and high energy resolution. Our MARS scanner is an x-ray based small animal CT system designed to be used in the diagnostic energy range (20 to 140 keV). In this paper, we demonstrate the use of the M...
Article
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While mobile Augmented Reality (AR) browsers have become one of the major commercial AR application, real-world usage behaviour with this technology is still a widely unexplored area. We report on our findings from an online survey that we conducted on the topic and an analysis of mobile distribution platforms for popular Augmented Reality browsers...
Article
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How lessons learned from the evolution of the Web and Web browsers can influence the development of AR browsers.
Conference Paper
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In-situ 3D Modeling becomes increasingly prominent in current Augmented Reality research, particularly for mobile scenarios. However, real-time performance and qualitative modeling remain highly challenging. In this work, we propose a new interactive 3D modeling approach for indoor environments, combining an assistive user interface and constrained...
Conference Paper
Full-text available
Real-time three-dimensional acquisition of real-world scenes has many important applications in computer graphics, computer vision and human-computer interaction. Inexpensive depth sensors such as the Microsoft Kinect allow to leverage the development of such applications. However, this technology is still relatively recent, and no detailed studies...
Conference Paper
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In this paper we present a novel approach to record and replay video content composited in-situ with a live view of the real environment. Our real-time technique works on mobile phones, and uses an panorama-based tracker to create visually seamless and spatially registered overlay of video content. We apply a temporal foreground-background segmenta...
Conference Paper
Full-text available
The use of Augmented Reality for overlaying visual information on print media like street posters has become widespread over the last few years. While this user interface metaphor represents an instance of cross-media information spaces the specific context of its use has not yet been carefully studied, resulting in productions generally relying on...
Article
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In response to dramatic changes in the environment, and supported by advances in wireless networking, pervasive sensor networks have become a common tool for environmental monitoring. However, tools for on-site visualization and interactive exploration of environmental data are still inadequate for domain experts. Current solutions are generally li...
Article
Full-text available
In this paper, we explore techniques that aim to improve site understanding for outdoor Augmented Reality (AR) applications. While the first person perspective in AR is a direct way of filtering and zooming on a portion of the data set, it severely narrows overview of the situation, particularly over large areas. We present two interactive techniqu...
Article
Full-text available
In this paper, we discuss the impact of tracking technology on user studies of mobile augmented reality applications. We present findings from several of our previous publications in the field, discussing how tracking technology can impact, influence and compromise experimental results. Lessons learned from our experience show that suitable trackin...
Conference Paper
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Creating entertaining and educational books not only requires providing visually stimulating content but also means for students to interact, create, and express themselves. In this paper we present a new type of mixed-reality book experience, which augments an educational coloring book with user-generated three dimensional content. We explore a “p...
Conference Paper
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Current projectors can easily be combined to create an everywhere display, using all suitable surfaces in offices or meeting rooms for the presentation of information. However, the resulting irregular display is not well supported by traditional desktop window managers, which are optimized for rectangular screens. In this paper, we present novel di...
Conference Paper
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In this paper, we present virtual embedded views used for turn-based pedestrian navigation in Augmented Reality (AR). Embedded views allow users to see around occluding structures and at the same time seamlessly integrate the augmented navigation aid into the otherwise occluded view. Users get a preview on upcoming route changes, without the need t...
Conference Paper
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This paper offers a contribution to an emerging culturally orientated discourse regarding mixed reality interaction. It seeks to analyse syncretic, hybridized agency, particularly in mixed reality data transfer systems. Recent developments in bridging autonomous relationships with digital representation through mixed reality interfacing, have broug...
Conference Paper
Full-text available
This paper offers a contribution to an emerging culturally orientated discourse regarding mixed reality interaction. It seeks to define syncretic, or hybridized agency, particularly in social mixed reality data transfer artworks. Recent developments in bridging relationships with digital representation of identity through mixed reality interfacing,...
Chapter
Exploring and surveying the world has been an important goal of humankind for thousands of years. Entering the twenty-first century, the Earth has almost been fully digitally mapped. Widespread deployment of GIS (Geographic Information Systems) technology and a tremendous increase of both satellite and street-level mapping over the last decade enab...
Conference Paper
Full-text available
In this paper we present importance-driven compositing window management, which considers windows not only as basic rectangular shapes but also integrates the importance of the windows' content using a bottom-up visual attention model. Based on this information, importance-driven compositing optimizes the spatial window layout for maximum visibilit...
Conference Paper
Full-text available
Nowadays, mobile devices provide new possibilities for gesture interaction due to the large range of embedded sensors they have and their physical form factor. In addition, auditory interfaces can now be more easily supported through advanced mobile computing capabilities. Although different types of gesture techniques have been proposed for handhe...
Article
Full-text available
In this paper we introduce a novel augmented reality based exposure therapy system for phobia treatment. This allows patients to see virtual fear stimuli overlaid onto the real world and to fully interact with them in real time. Extending on previous work, we focus on creating a controllable and interactive system (through gesture recognition and p...
Article
Full-text available
Ambient intelligence (AmI) has the goal of embedding context sensitive technology in the user's surroundings. AmI is defined as "digital environments that are sensitive and responsive to the presence of people". Thus, AmI research involves the convergence of several earlier research ideas, including ubiquitous or pervasive computing, intelligent sy...
Article
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AMH is a very unique program of the ISMAR. This program suggests new possibilities of reinterpreting the technical issues in Mixed Reality and AR from a humanity perspective.
Conference Paper
Full-text available
Sketching leverages human skills for various purposes. In-Place Augmented Reality Sketching experiences build on the intuitiveness and flexibility of hand sketching for tasks like content creation. In this paper we explore the design space of In-Place Augmented Reality Sketching, with particular attention to content authoring in games. We propose a...
Article
Full-text available
Spectral CT differs from dual-energy CT by using a conventional X-ray tube and a photon-counting detector. We wished to produce 3D spectroscopic images of mice that distinguished calcium, iodine and barium. We developed a desktop spectral CT, dubbed MARS, based around the Medipix2 photon-counting energy-discriminating detector. The single conventio...
Article
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Python is a popular language widely adopted by the sci-entific community due to its clear syntax and an extensive number of specialized packages. For image processing or computer vision development, two libraries are prominently used: NumPy/SciPy and OpenCV with a Python wrapper. In this paper, we present a comparative evaluation of both libraries,...
Article
Full-text available
In this work we evaluated the usability of tangible user interaction for traditional desktop augmented reality environments. More specifically, we compared physical sliders and tracked paddles, and traditional mouse input for a system control task. While task accuracy was the same for all interfaces, mouse input performed the fastest and input with...
Conference Paper
Spectral computed tomography (CT) is a new approach for medical diagnosis. Where traditional methods deliver a unique 3D volumetric dataset, spectral CT supplies multiple 3D volumetric datasets (energy bins). The novelty of this technique creates new opportunities and new challenges regarding visualization of the acquired data. In this paper we des...
Article
A system for patient set-up in external beam radiotherapy was developed using Augmented Reality (AR). Live images of the linac treatment couch and patient were obtained with video cameras and displayed on a nearby monitor. A 3D model of the patient's external contour was obtained from planning CT data, and AR tracking software was used to superimpo...
Conference Paper
Over the last year Mixed and Augmented Reality has reached a growing audience, going far beyond the interests of the technical scholar community. The emergence of more accessible software tools, and simple hardware solutions have made it easy for artists, designers, media companies and others to develop augmented reality applications for the masses...
Conference Paper
Full-text available
We introduce a novel touch-based interaction technique for tangible user interfaces (TUIs) in Augmented Reality (AR) applications. The technique allows for direct access and manipulation of virtual content on a registered tracking target, is robust and lightweight, and can be applied in numerous tracking and interaction scenarios.
Conference Paper
Full-text available
We present a novel algorithm for improving the accuracy of structure from motion on video sequences. Its goal is to eciently re- cover scene structure and camera pose by using dynamic programming to maximize the lengths of putative keypoint tracks. By eciently dis- carding poor correspondences while maintaining the largest possible set of inliers,...
Conference Paper
Full-text available
Ambient Interface research has the goal of embedding technology that disappears into the user’s surroundings. In many ways Augmented Reality (AR) technology is complimentary to this in that AR interfaces seamlessly enhances the real environment with virtual information overlay. The two merge together in context aware Ambient AR applications, which...
Article
The goal of the work was to develop a general method for processing spectral x-ray image data. Principle component analysis (PCA) is a well understood technique for multivariate data analysis and so was investigated. To assess this method, spectral (multi-energy) computed tomography (CT) data was obtained using a Medipix2 detector in a MARS-CT (Med...
Article
A system for visual image guidance in patient set-up for external-beam radiotherapy procedures was developed using augmented reality. The system uses video cameras to obtain views of the linear accelerator, and the live images are displayed on a monitor in the treatment room. 3D models of the patient’s external surface, obtained from planning CT da...
Conference Paper
With the increased precision in dose delivery provided by highly conformal radiotherapy techniques such as intensity modulated radiotherapy (IMRT), the requirement for accuracy in patient positioning for treatment is emphasised. This system uses augmented reality (AR) to allow the radiation therapist to visually guide the patient during positioning...
Conference Paper
Full-text available
ABSTRACT In this paper we present the results of our long term development,of a mixed reality book. Most previous work in the area has focused on the technology of augmented reality books, such as providing registration using fiducial markers. In this work, however, we fo- cused on exploring the design and development,process of this type of applic...