Publications

FXPAL publishes in top scientific conferences and journals.

2002
Publication Details
  • SPIE ITCOM 2002
  • Jul 31, 2002

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We present a framework, motivated by rate-distortion theory and the human visual system, for optimally representing the real world given limited video resolution. To provide users with high fidelity views, we built a hybrid video camera system that combines a fixed wide-field panoramic camera with a controllable pan/tilt/zoom (PTZ) camera. In our framework, a video frame is viewed as a limited-frequency representation of some "true" image function. Our system combines outputs from both cameras to construct the highest fidelity views possible, and controls the PTZ camera to maximize information gain available from higher spatial frequencies. In operation, each remote viewer is presented with a small panoramic view of the entire scene, and a larger close-up view of a selected region. Users may select a region by marking the panoramic view. The system operates the PTZ camera to best satisfy requests from multiple users. When no regions are selected, the system automatically operates the PTZ camera to minimize predicted video distortion. High-resolution images are cached and sent if a previously recorded region has not changed and the PTZ camera is pointed elsewhere. We present experiments demonstrating that the panoramic image can effectively predict where to gain the most information, and also that the system provides better images to multiple users than conventional camera systems.

Communication and Understanding for Decision Support

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  • Proceedings of the IFIP International Conference on Decision Making and Decision Support in the Internet Age
  • Jul 4, 2002

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As the technology for communication changes, the role of communication in the conduct of business changes with it. Communication is no longer just a technical matter of separating signal from noise and managing bandwidth but also a social matter in which negotiating differences in understanding among and between communicators is a primary business priority. Addressing this priority requires an understanding of how individuals interact in the course of their decision making activities. Using the work of Anthony Giddens as a point of departure, this paper views interaction in communication as consisting of three dimensions - meaning, authority, and trust. These three dimensions are used to identify new opportunities for advances in decision making technology which help deal with potential breakdowns in social interaction.

The Elusive Ubiquitous Information System and m-Links

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  • Fuji Xerox Technical Report, No. 14, 2002
  • Jun 25, 2002

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A basic objective of Weiser's Ubiquitous Computing vision is ubiquitous information access: being able to utilize any content or service (e.g., all the rich media content and services on the WWW), using devices that are always "at hand" (embedded in environments or portable), over a network with universal coverage and adequate bandwidth. Although much progress has been made, the ideal remains elusive. This paper examines the inter-relations among three dimensions of ubiquitous information systems: (1) ubiquitous content; (2) ubiquitous devices; and (3) ubiquitous networking. We use the space defined by these dimensions to reflect on the tradeoffs designers make and to chart some past and current information systems. Given this background, we present m-Links (mobile links), a new system that takes aim at the elusive ideal of ubiquitous information. Our approach builds on wireless web phone technologies because of their trend towards ubiquitous devices and networking (the second and third dimensions). Yet such very small devices sacrifice usability as rich media Internet terminals (the first dimension). To offset this limitation, we propose a new information access model for very small devices that supports a much wider range of content and services than previously possible. We have built this system with an emphasis on open systems extensibility and describe its design and implementation.

Going Back in Hypertext

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  • Proceedings of ACM Hypertext 2002
  • Jun 11, 2002

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Hypertext interfaces typically involve navigation, the act (and interaction) of moving from one piece of information to another. Navigation can be exploratory, or it may involve backtracking to some previously-visited node. While backtracking interfaces are common, they may not reflect differences in readers' purposes and mental models. This paper draws on some empirical evidence regarding navigation between and within documents to suggest improvements on traditional hypertext navigation, and proposes a time-based view of backtracking.
Publication Details
  • Journal of Library Administration, 35:1-2, 99-123, Haworth
  • Jun 7, 2002

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In the emerging world of electronic publishing how we create, distribute, and read books will be in a large part determined by an underlying framework of content standards that establishes the range of technological opportunities and constraints for publishing and reading systems. But efforts to develop content standards based on sound engineering models must skillfully negotiate competing and sometimes apparently irreconcilable objectives if they are to produce results relevant to the rapidly changing course of technology. The Open eBook Forum's Publication Structure, an XML-based specification for electronic books, is an example of the sort of timely and innovative problem solving required for successful real-world standards development. As a result of this effort, the electronic book industry will not only happen sooner and on a larger scale than it would have otherwise, but the electronic books it produces will be more functional, more interoperable, and more accessible to all readers. Public interest participants have a critical role in this process.
Publication Details
  • CHI 2002
  • Apr 22, 2002

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Shared text input is a technique we implemented into a note taking system for facilitating text entry on small devices. Instead of writing out words on the tedious text entry interfaces found on handheld computers, users can quickly reuse words and phrases already entered by others. Sharing notes during a meeting also increases awareness among note takers. We found that filtering the text to share was appropriate to deal with a variety of design issues such as screen real estate, scalability, privacy, reciprocity, and predictability of text location
Publication Details
  • CHI 2002
  • Apr 22, 2002

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In this paper, we describe an evaluation of the Palette, a presentation tool that was reported at CHI '99. The Palette allows presenters to quickly access digital presentations using physical cards that have unique barcodes printed on them. The Palette has been in use in our lab for over three years, and has been released as a product in Japan. Our evaluation consists of an analysis of usage logs, an expert walkthrough review, and observations and interviews with users, non-users and the system administrator. The findings reveal benefits and drawbacks of the technology, and offers design ideas for further work on tangible tools of this kind.
Publication Details
  • International Journal of Human-Computer Studies, 56, pp. 75-107
  • Feb 1, 2002

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We describe our experiences with the design, implementation, deployment, and evaluation of a Portholes tool which provides group and collaboration awareness through the Web. The research objective was to explore how such a system would improve communication and facilitate a shared understanding among distributed development groups. During the deployment of our Portholes system, we conducted a naturalistic study by soliciting user feedback and evolving the system in response. Many of the initial reactions of potential users indicated that our system projected the wrong image so that we designed a new version that provided explicit cues about being in public and who is looking back to suggest a social rather than information interface. We implemented the new design as a Java applet and evaluated design choices with a preference study. Our experiences with different Portholes versions and user reactions to them provide insights for designing awareness tools beyond Portholes systems. Our approach is for the studies to guide and to provide feedback for the design and technical development of our system.
2001

Signature Random Fields for Accommodating Illumination Variability

Publication Details
  • In Workshop on Identifying Objects Across Variations in Lighting: Psychophysics & Computation, Proc. IEEE Intl. Conf. on Computer Vision & Pattern Recognition 2001.
  • Dec 12, 2001

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In this paper, we document an extension to traditional pattern-theoretic object templates to jointly accommodate variations in object pose and in the radiant appearance of the object surface. We first review classical object templates accommodating pose variation. We then develop an efficient subspace representation for the object radiance indexed on the surface of the three dimensional object template. We integrate the low-dimensional representation for the object radiance, or signature, into the pattern-theoretic template, and present the results of orientation estimation experiments. The experiments demonstrate both estimation performance fluctuations under varying illumination conditions and performance degradations associated with unknown scene illumination. We also present a Bayesian approach for estimation accommodating illumination variability.

Work/place: mobile technologies and arenas of activity

Publication Details
  • ACM SIGGROUP Bulletin, Volume 22, Issue 3, Pp3-9, Publisher ACM Press, New York, NY, USA
  • Dec 8, 2001

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The increasing number of wireless, portable devices has led inevitably to lyrical rhetorics of business cost-cutting and increased efficiency as workers can be productive while on the and offices become streamlined areas of efficient activity. In this short paper, we raise a number if issues that have been appearing in common discourses the (most) modern office, and the impact of wireless technologies thereupon. We also present an overview of a workshop held at ECSCW in Bonn in September of 2001 on this topic, giving an overview of the comments and discussions that took place at the workshop.

Framing Mobile Collaborations and Mobile Technologies.

Publication Details
  • In B. Brown, N. Green, R. Harper (Eds.) Wireless World: Social and Interactional Aspects of Wireless Technology, London, UK: Springer-Verlag.
  • Dec 1, 2001

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Recent years have seen a marked increase in the production and promotion of portable, wireless communication devices: mobile phones with internet access, wireless PDAs such as the Palm VII and smart pagers such as RIM's 850 and 950. Some claim the presence of such devices in the hands, bags and pockets of so many people heralds a new world of work in which people can be reached and information accessed "anywhere, anytime". Whether or not access to information in itself can promote new working practices, individuals whose lives revolve around movement between work sites have been singled out as an obvious market for such portable wireless communication devices. Using these devices such “mobile workers” can be in touch with colleagues, collaborators and clients "24/7", and still sustain non-work social relationships due, apparently, to their constant connectedness whilst mobile. In this chapter we have two goals. The first is to address the design of mobile technologies. This second is to illustrate our design approach, wherein we consider local practices of technology use, but also the broader cultural context in which technologies are designed, produced, bought, sold, used and redesigned. Our ultimate design aim is to build upon existing practices, but also to consider possibilities for the development of innovative technologies that enable new, complementary, practices.
Publication Details
  • In Proceedings of the International Conference on Image Processing, Thessaloniki, Greece. October 7-10, 2001.
  • Oct 7, 2001

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In this paper, we present a novel framework for analyzing video using self-similarity. Video scenes are located by analyzing inter-frame similarity matrices. The approach is flexible to the choice of similarity measure and is robust and data-independent because the data is used to model itself. We present the approach and its application to scene boundary detection. This is shown to dramatically outperform a conventional scene-boundary detector that uses a histogram-based measure of frame difference.
Publication Details
  • Proceedings of ACM Multimedia 2001, Ottawa, Canada, Oct. 5, 2001.
  • Oct 5, 2001

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Given rapid improvements in storage devices, network infrastructure and streaming-media technologies, a large number of corporations and universities are recording lectures and making them available online for anytime, anywhere access. However, producing high-quality lecture videos is still labor intensive and expensive. Fortunately, recent technology advances are making it feasible to build automated camera management systems to capture lectures. In this paper we report our design of such a system, including system configuration, audio-visual tracking techniques, software architecture, and user study. Motivated by different roles in a professional video production team, we have developed a multi-cinematographer single-director camera management system. The system performs lecturer tracking, audience tracking, and video editing all fully automatically, and offers quality close to that of human-operated systems.
Publication Details
  • Proc. ACM Multimedia 2001, Ottawa,CA, Oct. 2001.
  • Sep 30, 2001

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We describe a system called FlyAbout which uses spatially indexed panoramic video for virtual reality applications. Panoramic video is captured by moving a 360° camera along continuous paths. Users can interactively replay the video with the ability to view any interesting object or choose a particular direction. Spatially indexed video gives the ability to travel along paths or roads with a map-like interface. At junctions, or intersection points, users can chose which path to follow as well as which direction to look, allowing interaction not available with conventional video. Combining the spatial index with a spatial database of maps or objects allows users to navigate to specific locations or interactively inspect particular objects.
Publication Details
  • Proc. International Conference on Computer Music (ICMC), Habana, Cuba, September 2001.
  • Sep 12, 2001

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This paper presents a novel approach to visualizing the time structure of musical waveforms. The acoustic similarity between any two instants of an audio recording is displayed in a static 2D representation, which makes structural and rhythmic characteristics visible. Unlike practically all prior work, this method characterizes self-similarity rather than specific audio attributes such as pitch or spectral features. Examples are presented for classical and popular music.
Publication Details
  • IEEE Computer, 34(9), pp. 61-67
  • Sep 1, 2001

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To meet the diverse needs of business, education, and personal video users, the authors developed three visual interfaces that help identify potentially useful or relevant video segments. In such interfaces, keyframes-still images automatically extracted from video footage-can distinguish videos, summarize them, and provide access points. Well-chosen keyframes enhance a listing's visual appeal and help users select videos. Keyframe selection can vary depending on the application's requirements: A visual summary of a video-captured meeting may require only a few highlight keyframes, a video editing system might need a keyframe for every clip, while a browsing interface requires an even distribution of keyframes over the video's full length. The authors conducted user studies for each of their three interfaces, gathering input for subsequent interface improvements. The studies revealed that finding a similarity measure for collecting video clips into groups that more closely match human perception poses a challenge. Another challenge is to further improve the video-segmentation algorithm used for selecting keyframes. A new version will provide users with more information and control without sacrificing the interface's ease of use.