Publications

FXPAL publishes in top scientific conferences and journals.

2005
Publication Details
  • World Conference on E-Learning in Corporate, Government, Healthcare, & Higher Education (E-Learn 2005)
  • Oct 24, 2005

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Automatic lecture capture can help students, instructors, and educational institutions. Students can focus less on note-taking and more on what the instructor is saying. Instructors can provide access to lecture archives to help students study for exams and make-up missed classes. And online lecture recordings can be used to support distance learning. For these and other reasons, there has been great interest in automatically capturing classroom presentations. However, there is no simple solution that is completely automatic. ProjectorBox is our attempt to create a "zero user interaction" appliance that automatically captures, indexes, and manages presentation multimedia. It operates continuously to record the RGB information sent from presentation devices, such as an instructor's laptop, to display devices such as a projector. It seamlessly captures high-resolution slide images, text, and audio. A web-based user interface allows students to browse, search, replay, and export captured presentations.
Publication Details
  • In Proceedings of International Conference on Computer Vision, 2005, page 1026-1033
  • Oct 17, 2005

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Recent years have witnessed the rise of many effective text information retrieval systems. By treating local visual features as terms, training images as documents and input images as queries, we formulate the problem of object recognition into that of text retrieval. Our formulation opens up the opportunity to integrate some powerful text retrieval tools with computer vision techniques. In this paper, we propose to improve the efficiency of articulated object recognition by an Okapi-Chamfer matching algorithm. The algorithm is based on the inverted index technique. The inverted index is a widely used way to effectively organize a collection of text documents. With the inverted index, only documents that contain query terms are accessed and used for matching. To enable inverted indexing in an image database, we build a lexicon of local visual features by clustering the features extracted from the training images. Given a query image, we extract visual features and quantize them based on the lexicon, and then look up the inverted index to identify the subset of training images with non-zero matching score. To evaluate the matching scores in the subset, we combined the modified Okapi weighting formula with the Chamfer distance. The performance of the Okapi-Chamfer matching algorithm is evaluated on a hand posture recognition system. We test the system with both synthesized and real world images. Quantitative results demonstrate the accuracy and efficiency our system.
Publication Details
  • IEEE Trans. Multimedia, Vol. 7 No. 5, pp. 981-990
  • Oct 11, 2005

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Abstract-We present a system for automatically extracting the region of interest and controlling virtual cameras control based on panoramic video. It targets applications such as classroom lectures and video conferencing. For capturing panoramic video, we use the FlyCam system that produces high resolution, wide-angle video by stitching video images from multiple stationary cameras. To generate conventional video, a region of interest (ROI) can be cropped from the panoramic video. We propose methods for ROI detection, tracking, and virtual camera control that work in both the uncompressed and compressed domains. The ROI is located from motion and color information in the uncompressed domain and macroblock information in the compressed domain, and tracked using a Kalman filter. This results in virtual camera control that simulates human controlled video recording. The system has no physical camera motion and the virtual camera parameters are readily available for video indexing.
Publication Details
  • http://www.strata.com/gallery_detail.asp?id=1480&page=1&category=48
  • Oct 1, 2005

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I produced these Illustrations for two multimedia applications that were developed by FX Palo Alto Laboratory and California State University at Sacramento's Department of Psychology. The applications were part of a study to see how primary school age children learn with certain multimedia tools. Each illustration was viewed as part of a fairly complex screen of information as well as on its own.
Publication Details
  • We organized and ran a full-day workshop at the UbiComp 2005 Conference in Tokyo, Japan, September 11, 2005.
  • Sep 29, 2005

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Designing the technologies, applications, and physical spaces for next-generation conference rooms (This is a day-long workshop in Tokyo.) Next-generation conference rooms are often designed to anticipate the onslaught of new rich media presentation and ideation systems. Throughout the past couple of decades, many researchers have attempted to reinvent the conference room, aiming at shared online or visual/virtual spaces, smart tables or walls, media support and tele-conferencing systems of varying complexity. Current research in high-end room systems often features a multiplicity of thin, bright display screens (both large and small), along with interactive whiteboards, robotic cameras, and smart remote conferencing systems. Added into the mix one can find a variety of meeting capture and metadata management systems, automatic or not, focused on capturing different aspects of meetings in different media: to the Web, to one's PDA or phone, or to a company database. Smart spaces and interactive furniture design projects have shown systems embedded in tables, podiums, walls, chairs and even floors and lighting. Exploiting the capabilities of all these technologies in one room, however, is a daunting task. For example, faced with three or more display screens, all but a few presenters are likely to opt for simply replicating the same image on all of them. Even more daunting is the design challenge: how to choose which capabilities are vital to particular tasks, or for a particular room, or are well suited to a particular culture. In this workshop we'll explore how the design of next-generation conference rooms can be informed by the most recent research in rich media, context-aware mobile systems, ubiquitous displays, and interactive physical environments. How should conference room systems reflect the rapidly changing expectations around personal devices and smart spaces? What kinds of systems are needed to support meetings in technologically complex environments? How can design of conference room spaces and technologies account for differing social and cultural practices around meetings? What requirements are imposed by security and privacy issues in public spaces? What aspects of meeting capture and access technologies have proven to be useful, and how should a smart environment enable them? What intersections exist with other research areas such as digital libraries? Conference room research has been and remains a focal point for some of the most interesting and applied work in ubiquitous computing. What lessons can we take from the research to date as we move forward? We are confident that a lively and useful discussion will be engendered by bringing directions from recent ubicomp research in games, multimedia applications, and social software to ongoing research in conference rooms systems: integrating architecture and tangible media, information design and display, and mobile and computer-mediated communications.
Publication Details
  • Paper presented at SIGGRAPH 2005, Los Angeles.
  • Sep 29, 2005

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The Convertible Podium is a central control station for rich media in next-generation classrooms. It integrates flexible control systems for multimedia software and hardware, and is designed for use in classrooms with multiple screens, multiple media sources and multiple distribution channels. The built-in custom electronics and unique convertible podium frame allows intuitive conversion between use modes (either manual or automatic). The at-a-touch sound and light control system gives control over the classroom environment. Presentations can be pre-authored for effective performance, and quickly altered on the fly. The counter-weighted and motorized conversion system allows one person to change modes simply by lifting the top of the Podium to the correct position for each mode. The Podium is lightweight, mobile, and wireless, and features an onboard 21" LCD display, document cameras and other capture devices, tangible controls for hardware and software, and also possesses embedded RFID sensing for automatic data retrieval and file management. It is designed to ease the tasks involved in authoring and presenting in a rich media classroom, as well as supporting remote telepresence and integration with other mobile devices.
Publication Details
  • INTERACT '05 short paper
  • Sep 12, 2005

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Indexes such as bookmarks and recommendations are helpful for accessing multimedia documents. This paper describes the 3D Syllabus system, which is designed to visualize indexes to multimedia training content along with the information structures. A double-sided landscape with balloons and cubes represents the personal and group indexes, respectively. The 2D ground plane organizes the indexes as a table and the third dimension of height indicates their importance scores. Additional visual properties of the balloons and cubes provide other information about the indexes and their content. Paths are represented by pipes connecting the balloons. A reliminary evaluation of the 3D Syllabus prototype suggests that it is more efficient than a typical training CD-ROM and is more enjoyable to use.
Publication Details
  • INTERACT 2005, LNCS 3585, pp. 781-794
  • Sep 12, 2005

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A video database can contain a large number of videos ranging from several minutes to several hours in length. Typically, it is not sufficient to search just for relevant videos, because the task still remains to find the relevant clip, typically less than one minute of length, within the video. This makes it important to direct the users attention to the most promising material and to indicate what material they already investigated. Based on this premise, we created a video search system with a powerful and flexible user interface that incorporates dynamic visualizations of the underlying multimedia objects. The system employes an automatic story segmentation, combines text and visual search, and displays search results in ranked sets of story keyframe collages. By adapting the keyframe collages based on query relevance and indicating which portions of the video have already been explored, we enable users to quickly find relevant sections. We tested our system as part of the NIST TRECVID interactive search evaluation, and found that our user interface enabled users to find more relevant results within the allotted time than other systems employing more sophisticated analysis techniques but less helpful user interfaces.
Publication Details
  • M.F. Costabile and F. Paternò (Eds.): INTERACT 2005, LNCS 3585
  • Sep 12, 2005

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We developed and studied an experimental system, RealTourist, which lets a user to plan a conference trip with the help of a remote tourist consultant who could view the tourist's eye-gaze superimposed onto a shared map. Data collected from the experiment were analyzed in conjunction with literature review on speech and eye-gaze patterns. This inspective, exploratory research identified various functions of gaze-overlay on shared spatial material including: accurate and direct display of partner's eye-gaze, implicit deictic referencing, interest detection, common focus and topic switching, increased redundancy and ambiguity reduction, and an increase of assurance, confidence, and understanding. This study serves two purposes. The first is to identify patterns that can serve as a basis for designing multimodal human-computer dialogue systems with eye-gaze locus as a contributing channel. The second is to investigate how computer-mediated communication can be supported by the display of the partner's eye-gaze.
Publication Details
  • Short presentation in UbiComp 2005 workshop in Tokyo, Japan.
  • Sep 11, 2005

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As the use of rich media in mobile devices and smart environments becomes more sophisticated, so must the design of the everyday objects used as containers or controllers. Rather than simply tacking electronics onto existing furniture or other objects, the design of a smart object can enhance existing ap-plications in unexpected ways. The Convertible Podium is an experiment in the design of a smart object with complex integrated systems, combining the highly designed look and feel of a modern lectern with systems that allow it to serve as a central control station for rich media manipulation in next-generation confer-ence rooms. It enables easy control of multiple independent screens, multiple media sources (including mobile devices) and multiple distribution channels. The Podium is designed to ease the tasks involved in authoring and presenting in a rich media meeting room, as well as supporting remote telepresence and in-tegration with mobile devices.
Publication Details
  • Demo and presentation in UbiComp 2005 workshop in Tokyo, Japan.
  • Sep 11, 2005

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A Post-Bit is a prototype of a small ePaper device for handling multimedia content, combining interaction control and display into one package. Post-Bits are modeled after paper Post-Its™; the functions of each Post-Bit combine the affordances of physical tiny sticky memos and digital handling of information. Post-Bits enable us to arrange multimedia contents in our embodied physical spaces. Tangible properties of paper such as flipping, flexing, scattering and rubbing are mapped to controlling aspects of the content. In this paper, we introduce the integrated design and functionality of the Post-Bit system, including four main components: the ePaper sticky memo/player, with integrated sensors and connectors; a small container/binder that a few Post-Bits can fit into, for ordering and multiple connections; the data and power port that allows communication with the host com-puter; and finally the software and GUI interface that reside on the host PC and manage multimedia transfer.
Publication Details
  • Sixteenth ACM Conference on Hypertext and Hypermedia
  • Sep 6, 2005

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Hyper-Hitchcock is a hypervideo editor enabling the direct manipulation authoring of a particular form of hypervideo called "detail-on-demand video." This form of hypervideo allows a single link out of the currently playing video to provide more details on the content currently being presented. The editor includes a workspace to select, group, and arrange video clips into several linear sequences. Navigational links placed between the video elements are assigned labels and return behaviors appropriate to the goals of the hypervideo and the role of the destination video. Hyper-Hitchcock was used by students in a Computers and New Media class to author hypervideos on a variety of topics. The produced hypervideos provide examples of hypervideo structures and the link properties and behaviors needed to support them. Feedback from students identified additional link behaviors and features required to support new hypervideo genres. This feedback is valuable for the redesign of Hyper-Hitchcock and the design of hypervideo editors in general.

DoKumobility: Web services for the mobile worker

Publication Details
  • IEEE International Conference on Next Generation Web Services Practices (NWeSP'05), Seoul, Korea
  • Aug 22, 2005

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Mobile users often require access to their documents while away from the office. While pre-loading documents in a repository can make those documents available remotely, people need to know in advance which documents they might need. Furthermore, it may be difficult to view, print, or share the document through a portable device such as cell phone. We implemented DoKumobility, a network of web services for mobile users for managing, printing, and sharing documents. In this paper, we describe the infrastructure and illustrate its use with several applications
Publication Details
  • ACM Transactions on Multimedia Computing, Communications, and Applications
  • Aug 8, 2005

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Organizing digital photograph collections according to events such as holiday gatherings or vacations is a common practice among photographers. To support photographers in this task, we present similarity-based methods to cluster digital photos by time and image content. The approach is general, unsupervised, and makes minimal assumptions regarding the structure or statistics of the photo collection. We present several variants of an automatic unsupervised algorithm to partition a collection of digital photographs based either on temporal similarity alone, or on temporal and content-based similarity. First, inter-photo similarity is quantified at multiple temporal scales to identify likely event clusters. Second, the final clusters are determined according to one of three clustering goodness criteria. The clustering criteria trade off computational complexity and performance. We also describe a supervised clustering method based on learning vector quantization. Finally, we review the results of an experimental evaluation of the proposed algorithms and existing approaches on two test collections.

Parallel Changes: Detecting Semantic Interferences

Publication Details
  • The 29th Annual International Computer Software and Applications Conference (COMPSAC 2005), Edinburgh, Scotland
  • Jul 26, 2005

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Parallel changes are a basic fact of modern software development. Where previously we looked at prima facie interference, here we investigate a less direct form that we call semantic interference. We reduce the forms of semantic interference that we are interested in to overlapping def-use pairs. Using program slicing and data flow analysis, we present algorithms for detecting semantic interference for both concurrent changes (allowed in optimistic version management systems) and sequential parallel changes (supported in pessimistic version management systems), and for changes that are both immediate and distant in time. We provide these algorithms for changes that are additions, showing that interference caused by deletions can be detected by considering the two sets of changes in reverse-time order.
Publication Details
  • International Conference on Image and Video Retrieval 2005
  • Jul 21, 2005

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Large video collections present a unique set of challenges to the search system designer. Text transcripts do not always provide an accurate index to the visual content, and the performance of visually based semantic extraction techniques is often inadequate for search tasks. The searcher must be relied upon to provide detailed judgment of the relevance of specific video segments. We describe a video search system that facilitates this user task by efficiently presenting search results in semantically meaningful units to simplify exploration of query results and query reformulation. We employ a story segmentation system and supporting user interface elements to effectively present query results at the story level. The system was tested in the 2004 TRECVID interactive search evaluations with very positive results.
Publication Details
  • ICME 2005
  • Jul 20, 2005

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A common problem with teleconferences is awkward turn-taking - particularly 'collisions,' whereby multiple parties inadvertently speak over each other due to communication delays. We propose a model for teleconference discussions including the effects of delays, and describe tools that can improve the quality of those interactions. We describe an interface to gently provide latency awareness, and to give advanced notice of 'incoming speech' to help participants avoid collisions. This is possible when codec latencies are significant, or when a low bandwidth side channel or out-of-band signaling is available with lower latency than the primary video channel. We report on results of simulations, and of experiments carried out with transpacific meetings, that demonstrate these tools can improve the quality of teleconference discussions.
Publication Details
  • 2005 IEEE International Conference on Multimedia & Expo
  • Jul 6, 2005

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A convenient representation of a video segment is a single keyframe. Keyframes are widely used in applications such as non-linear browsing and video editing. With existing methods of keyframe selection, similar video segments result in very similar keyframes, with the drawback that actual differences between the segments may be obscured. We present methods for keyframe selection based on two criteria: capturing the similarity to the represented segment, and preserving the differences from other segment keyframes, so that different segments will have visually distinct representations. We present two discriminative keyframe selection methods, and an example of experimental results.

AN ONLINE VIDEO COMPOSITION SYSTEM

Publication Details
  • IEEE International Conference on Multimedia & Expo July 6-8, 2005, Amsterdam, The Netherlands
  • Jul 6, 2005

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This paper presents an information-driven online video composition system. The composition work handled by the system includes dynamically setting multiple pan/tilt/zoom (PTZ) cameras to proper poses and selecting the best close-up view for passive viewers. The main idea of the composition system is to maximize captured video information with limited cameras. Unlike video composition based on heuristic rules, our video composition is formulated as a process of minimizing distortions between ideal signals (i.e. signals with infinite spatial-temporal resolution) and displayed signals. The formulation is consistent with many well-known empirical approaches widely used in previous systems and may provide analytical explanations to those approaches. Moreover, it provides a novel approach for studying video composition tasks systematically. The composition system allows each user to select a personal close-up view. It manages PTZ cameras and a video switcher based on both signal characteristics and users' view selections. Additionally, it can automate the video composition process based on past users' view-selections when immediate selections are not available. We demonstrate the performance of this system with real meetings.
Publication Details
  • CHI 2005 Extended Abstracts, ACM Press, pp. 1395-1398
  • Apr 1, 2005

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We present a search interface for large video collections with time-aligned text transcripts. The system is designed for users such as intelligence analysts that need to quickly find video clips relevant to a topic expressed in text and images. A key component of the system is a powerful and flexible user interface that incorporates dynamic visualizations of the underlying multimedia objects. The interface displays search results in ranked sets of story keyframe collages, and lets users explore the shots in a story. By adapting the keyframe collages based on query relevance and indicating which portions of the video have already been explored, we enable users to quickly find relevant sections. We tested our system as part of the NIST TRECVID interactive search evaluation, and found that our user interface enabled users to find more relevant results within the allotted time than those of many systems employing more sophisticated analysis techniques.