Publications

FXPAL publishes in top scientific conferences and journals.

1999
Publication Details
  • In Proceedings of the International Conference on Acoustics, Speech, and Signal Processing (Phoenix, AZ), vol. 6, pp. 3041-3044, 1999.
  • Mar 14, 1999

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This paper presents methods of generating compact pictorial summarizations of video. By calculating a measure of shot importance video can be summarized by de-emphasizing or discarding less important information, such as repeated or common scenes. In contrast to other approaches that present keyframes for each shot, this measure allows summarization by presenting only the most important shots. Selected keyframes can also be resized depending on their relative importance. We present an efficient packing algorithm that constructs a pictorial representation from differently-sized keyframes. This results in a compact and visually pleasing summary reminiscent of a comic book.
Publication Details
  • In Proceedings of the International Conference on Acoustics, Speech, and Signal Processing (Phoenix, AZ), vol. 6, pp. 3453-3456, 1999.
  • Mar 14, 1999

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This paper describes a technique for automatically creating an index for handwritten notes captured as digital ink. No text recog-nition is performed. Rather, a dictionary of possible index terms is built by clustering groups of ink strokes corresponding roughly to words. Terms whose distribution varies significantly across note pages are selected for the index. An index page containing the index terms is created, and terms are hyper-linked back to their original location in the notes. Further, index terms occurring in a note page are highlighted to aid browsing.
Publication Details
  • In Proceedings of the International Conference on Acoustics, Speech, and Signal Processing (Phoenix, AZ), vol. 6, pp. 3045-3048, 1999.
  • Mar 14, 1999

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This paper describes techniques for classifying video frames using statistical models of reduced DCT or Hadamard transform coefficients. When decimated in time and reduced using truncation or principal component analysis, transform coefficients taken across an entire frame image allow rapid modeling, segmentation, and similarity calculation. Unlike color-histogram metrics, this approach models image composition and works on grayscale images. Modeling the statistics of the transformed video frame images gives a likelihood measure that allows video to be segmented, classified, and ranked by similarity for retrieval. Experiments are presented that show an 87% correct classification rate for different classes. Applications are presented including a content-aware video browser.
Publication Details
  • In Proceedings of the International Conference on Acoustics, Speech, and Signal Processing (Phoenix, AZ), vol. 6, pp. 3029-3032, 1999.
  • Mar 14, 1999

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This paper describes a method for finding segments in video-recorded meetings that correspond to presentations. These segments serve as indexes into the recorded meeting. The system automatically detects intervals of video that correspond to presentation slides. We assume that only one person speaks during an interval when slides are detected. Thus these intervals can be used as training data for a speaker spotting system. An HMM is automatically constructed and trained on the audio data from each slide interval. A Viterbi alignment then resegments the audio according to speaker. Since the same speaker may talk across multiple slide intervals, the acoustic data from these intervals is clustered to yield an estimate of the number of distinct speakers and their order. This allows the individual presentations in the video to be identified from the location of each presenter's speech. Results are presented for a corpus of six meeting videos.
Publication Details
  • In Proceedings of the International Joint Conference on Work Activities Coordination and Collaboration, pp. 147-156, 1999.
  • Feb 22, 1999

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In many hierarchical companies, reports from several independent groups must be merged to form a single, company-wide report. This paper describes a process and system for creating and structuring such reports and for propagating contributions up the organization. The system has been in regular use, in-house, by about 30 users for over a year to create monthly status reports. Our experiences indicate that it is possible to change a monthly reporting practice so that the system is easy to use, improves the quality of the written report, fosters collaboration across projects and creates a corporate memory for the company. These results were achieved as a consequence of our design effort to directly support the hierarchical and collaborative process of creating and assembling the report within the organization. User feedback has led to many improvements in the usability and functionality of the system. Further enhancements using information retrieval and text summarization techniques are in progress.
Publication Details
  • In Proceedings of the Thirty-Second Annual Hawaii International Conference on System Sciences (HICSS-32), R. Sprague, Jr., editor, 1999.
  • Feb 5, 1999

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This is a critical view of the hypothesis that better access to a broader repertoire of media resources will significantly enhance our ability to communicate more effectively. It begins by laying down a foundation of some basic principles concerning the nature of knowledge creation. This foundation is framed in a manner that involves the potential relevance of two particularly creative activities, storytelling and making jazz. This foundation provides the basis for a critical examination of several media-rich presentations that were delivered at the Institute for the Future Outlook Exchange in November of 1997, since these presentations actually pertained to the practices of digital storytelling and jamming. This critique is followed by a more detailed examination of what we may learn from jazz if we wish to invoke it as a metaphor for knowledge creation. The report then concludes by discussing the implications of these observations for a new world of work experiences in which knowledge creation is a critical element.
Publication Details
  • In Proceedings of the Thirty-Second Annual Hawaii International Conference on System Sciences (HICSS-32), R. Sprague, Jr., editor, 1999.
  • Feb 5, 1999

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The genre of mathematics writing has several distinctive features that point to some of the weaknesses of current digital documents. Some of these weaknesses are surprising. While it might be expected that the importance of formatting and special symbols in mathematics writing would pose challenges for digital documents, the linked, chunked style of mathematics writing, with its Theorems, Lemmas, Corollaries and Remarks explicitly referring to each other, resembles standard hypertext so closely that one would expect that mathematics writing would take well to online hypertext form. It does not. This failure points to deficiencies in our understanding of the true strengths and weaknesses of digital documents. This paper describes mathematics writing, with particular emphasis on features of interest with respect to digital documents. The difficulties in producing effective digital mathematics documents are then examined and used as a basis for talking about general challenges for digital documents. The paper then discusses strengths of digital documents and some of the problems that need to be overcome before digital documents can live up to claims made for them. It also examines some of the misguided claims, such as superior support for non-linearity, that are commonly made for digital documents, explains why these claims are unwarranted, and speculates on why the claims have been made anyway. Suggestions are then given as to what the true benefits of digitization are, including performing computations on text, flexible control of time, and better support for hiding information. The paper concludes with a list of questions whose answers are critical to understanding the capabilities, and therefore the future, of digital documents.

Distributed Research Teams: Meeting Asynchronously in Virtual Space.

Publication Details
  • In Proceedings of the Thirty-second Annual Hawaii International Conference on System Sciences (Wailea, Hawaii, January 1999).
  • Feb 1, 1999

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As computer networks improve, more social and work interactions are carried out "virtually" by geographically separated group members. In this paper we discuss the design of a tool, PAVE, to support remote work interactions among colleagues in different time zones. PAVE extends a 2D graphical MOO and supports synchronous and asynchronous interactions. PAVE logs and indexes activities in the space. This capture facility enables playback and augmentation of meeting interactions by non-collocated group members. Thus, members can participate asynchronously in meetings they could not attend in real time, not just review them.

Autonomous Synthetic Computer Characters as Personal Representatives.

Publication Details
  • In Human Cognition and Social Agent Technology, Kerstin Dautenhahn (Guest-editor), Advances in Consciousness Research Series. John Benjamins Publishing Company.
  • Feb 1, 1999
Publication Details
  • In The Computer Journal, 42 (6), pp. 534-546, 1999.
  • Feb 1, 1999

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The Digestor system automatically converts web-based documents designed for desktop viewing into formats appropriate for handheld devices with small display screens, such as Palm-PCs, PDAs, and cellular phones. Digestor employs a heuristic planning algorithm and a set of structural page transformations to produce the "best" looking document for a given display size. Digestor can also be instructed, via a scripting language, to render portions of documents, thereby avoiding navigation through many screens of information. Two versions of Digestor have been deployed, one that re-authors HTML into HTML for conventional browsers, and one that converts HTML into HDML for Unwired Planet's micro-browsers. Digestor provides a crucial technology for rapidly accessing, scanning and processing information from arbitrary web-based documents from any location reachable by wired or unwired communication.
Publication Details
  • In IEEE Multimedia Systems '99, IEEE Computer Society, vol. 1, pp. 756-761, 1999.
  • Feb 1, 1999

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In accessing large collections of digitized videos, it is often difficult to find both the appropriate video file and the portion of the video that is of interest. This paper describes a novel technique for determining keyframes that are different from each other and provide a good representation of the whole video. We use keyframes to distinguish videos from each other, to summarize videos, and to provide access points into them. The technique can determine any number of keyframes by clustering the frames in a video and by selecting a representative frame from each cluster. Temporal constraints are used to filter out some clusters and to determine the representative frame for a cluster. Desirable visual features can be emphasized in the set of keyframes. An application for browsing a collection of videos makes use of the keyframes to support skimming and to provide visual summaries.

As We May Read: The Reading Appliance Revolution.

Publication Details
  • Computer, Vol. 32, No. 1, January 1999, pp. 65-73.
  • Feb 1, 1999

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Reading appliances allow people to work on electronic documents much as they would on paper. They therefore provide an alternative to the standard "browse or search and then print" model of reading online. By integrating a wide variety of document activities, such as searching, organizing, and skimming, and by allowing fluid movement among them, reading appliances eliminate disruptive transitions between paper and digital media.

Collaborating over Portable Reading Appliances.

Publication Details
  • In Personal Technologies, Vol. 3, No. 1, 1999.
  • Feb 1, 1999

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Reading appliances or e-books hold substantial promise to help us collaborate. In this paper, we use a study of a group activity - a reading group that meets to discuss articles of mutual interest - to explore four scenarios for collaborating with e-books: (1) meetings and face-to-face discussions; (2) serendipitous sharing of annotations, as when we borrow a document from a colleague or buy a used book; (3) community-wide use of anonymous annotations to guide future readers; and (4) e-books as a basis for initiating interaction between people. In so doing, we describe some methods for implementing these facilities, and introduce design guidelines.
1998
Publication Details
  • UIST '98, ACM Press, 1998, pp. 195-202.
  • Oct 31, 1998

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In this paper, we describe a technique for dynamically grouping digital ink and audio to support user interaction in freeform note-taking systems. For ink, groups of strokes might correspond to words, lines, or paragraphs of handwritten text. For audio, groups might be a complete spoken phrase or a speaker turn in a conversation. Ink and audio grouping is important for editing operations such as deleting or moving chunks of ink and audio notes. The grouping technique is based on hierarchical agglomerative clustering. This clustering algorithm yields groups of ink or audio in a range of sizes, depending on the level in the hierarchy, and thus provides structure for simple interactive selection and rapid non-linear expansion of a selection. Ink and audio grouping is also important for marking portions of notes for subsequent browsing and retrieval. Integration of the ink and audio clusters provides a flexible way to browse the notes by selecting the ink cluster and playing the corresponding audio cluster.

A Framework for Sharing Handwritten Notes.

Publication Details
  • UIST '98, ACM Press, 1998, pp. 119-120.
  • Oct 31, 1998

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NotePals is an ink-based, collaborative note taking application that runs on personal digital assistants (PDAs). Meeting participants write notes in their own handwriting on a PDA. These notes are shared with other participants by synchronizing later with a shared note repository that can be viewed using a desktop-based web browser. NotePals is distinguished by its lightweight process, interface, and hardware. This demonstration illustrates the design of two different NotePals clients and our web-based note browser.
Publication Details
  • MULTIMEDIA '98, ACM Press, 1998, pp. 375-380.
  • Sep 14, 1998

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Many techniques can extract information from an multimedia stream, such as speaker identity or shot boundaries. We present a browser that uses this information to navigate through stored media. Because automatically-derived information is not wholly reliable, it is transformed into a time-dependent "confidence score." When presented graphically, confidence scores enable users to make informed decisions about regions of interest in the media, so that non-interesting areas may be skipped. Additionally, index points may be determined automatically for easy navigation, selection, editing, and annotation and will support analysis types other than the speaker identification and shot detection used here.

Digital Library Information Appliances.

Publication Details
  • In Proceedings of Digital Libraries 98 (Pittsburgh, PA June 23-26), ACM Press, 1998, pp. 217-226.
  • Jun 23, 1998

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Although digital libraries are intended to support education and knowledge work, current digital library interfaces are narrowly focused on retrieval. Furthermore, they are designed for desktop computers with keyboards, mice, and high-speed network connections. Desktop computers fail to support many key aspects of knowledge work, including active reading, free form ink annotation, fluid movement among document activities, and physical mobility. This paper proposes portable computers specialized for knowledge work, or digital library information appliances, as a new platform for accessing digital libraries. We present a number of ways that knowledge work can be augmented and transformed by the use of such appliances. These insights are based on our implementation of two research prototype systems: XLibris,™ an "active reading machine," and TeleWeb, a mobile World Wide Web browser.

Linking By Inking: Trailblazing in a Paper-like Hypertext

Publication Details
  • In Proceedings of Hypertext '98 (Pittsburgh, PA), ACM Press, 1998, pp. 30-39.
  • Jun 20, 1998

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"Linking by inking" is a new interface for reader-directed link construction that bridges reading and browsing activities. We are developing linking by inking in XLibris,™ a hypertext system based on the paper document metaphor. Readers use a pen computer to annotate page images with free-form ink, much as they would on paper, and the computer constructs hypertext links based on the ink marks. This paper proposes two kinds of reader-directed links: automatic and manual. Automatic links are created in response to readers' annotations. The system extracts the text near free-form ink marks, uses these terms to construct queries, executes queries against a collection of documents, and unobtrusively displays links to related documents in the margin or as "further reading lists." We also present a design for manual (ad hoc) linking: circling an ink symbol generates a multi-way link to other instances of the same symbol.
Publication Details
  • Proceedings of the International Conference on Acoustics, Speech, and Signal Processing (Seattle, WA), Vol. 6, 1998, pp. 3741-3744.
  • May 12, 1998

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This paper describes a technique for segmenting video using hidden Markov models (HMM). Video is segmented into regions defined by shots, shot boundaries, and camera movement within shots. Features for segmentation include an image-based distance between adjacent video frames, an audio distance based on the acoustic difference in intervals just before and after the frames, and an estimate of motion between the two frames. Typical video segmentation algorithms classify shot boundaries by computing an image-based distance between adjacent frames and comparing this distance to fixed, manually determined thresholds. Motion and audio information is used separately. In contrast, our segmentation technique allows features to be combined within the HMM framework. Further, thresholds are not required since automatically trained HMMs take their place. This algorithm has been tested on a video data base, and has been shown to improve the accuracy of video segmentation over standard threshold-based systems.

Animated Autonomous Personal Representatives.

Publication Details
  • In Proceedings of the Second International Conference on Autonomous Agents (Minneapolis, MN), 1998, pp 8-15.
  • May 9, 1998

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We describe the research goals and issues in constructing autonomous personal representatives, and the desirability of using synthetic characters as the user interface for such artifacts. An application of these autonomous representatives is then described in which characters can be attached to a document to express a user's point of view or give guided tours or presentations of the document's contents.

XLibris: The Active Reading Machine.

Publication Details
  • CHI 98 Summary, ACM Press, 1998, pp. 22-23.
  • Apr 18, 1998

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Active reading is the combination of reading with critical thinking and learning, and involves not just reading per se, but also underlining, highlighting and commenting. We have built the XLibris™ "Active Reading Machine" to explore the premise that computation can enhance the active reading process. XLibris™ uses a high-resolution pen tablet display along with a paper-like user interface to emulate the physical experience of reading a document on paper: the reader can hold a scanned image of a page in his lap and mark on it with digital ink. XLibris™ monitors free-form ink annotations made while reading, and uses these to organize and to search for information. Readers can review, sort and filter clippings of their annotated text in a "Reader's Notebook." Finally, XLibris™ searches for material related to the annotated text, and displays links unobtrusively in the margin. XLibris™ demonstrates that computers can help active readers organize and find information while retaining many of the advantages of reading on paper.

The Rise of Personal Web Pages at Work.

Publication Details
  • CHI 98 Summary, ACM Press, 1998, pp. 313-314.
  • Apr 18, 1998

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A series of 20 interviews in four organizations explores the ways in which employees take advantage of personal web pages to support their work and to reflect who they are. Both interviewee comments and web page examples suggest the importance of individual personalizations of information management and dissemination, presentation and perception of personality, and usage from the reader's perspective. These results can inform the development of future web technologies for use in organizations. Furthermore, this self representation on web pages is a way of making individual knowledge more available in the workplace.
Publication Details
  • CHI 98 Summary, ACM Press, 1998, pp. 141-142.
  • Apr 18, 1998

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The World Wide Web is often viewed as the latest and most user friendly way of providing information over the Internet (i.e., server of documents). It is not customarily viewed as a platform for developing and deploying applications. In this tutorial, we introduce, demonstrate, and discuss how Web technologies like CGI scripts, Javascript, and Java can be used in combination with Web browsers to design, create, distribute and execute collaborative applications. We discuss constraints with the Web approach as well as recent extensions that support application development.