Publications

By Andreas Girgensohn (Clear Search)

2016

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We previously created the HyperMeeting system to support a chain of geographically and temporally distributed meetings in the form of a hypervideo. This paper focuses on playback plans that guide users through the recorded meeting content by automatically following available hyperlinks. Our system generates playback plans based on users' interests or prior meeting attendance and presents a dialog that lets users select the most appropriate plan. Prior experience with playback plans revealed users' confusion with automatic link following within a sequence of meetings. To address this issue, we designed three timeline visualizations of playback plans. A user study comparing the timeline designs indicated that different visualizations are preferred for different tasks, making switching among them important. The study also provided insights that will guide research of personalized hypervideo, both inside and outside a meeting context.
2015
Publication Details
  • ACM Multimedia
  • Oct 18, 2015

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While synchronous meetings are an important part of collaboration, it is not always possible for all stakeholders to meet at the same time. We created the concept of hypermeetings to support meetings with asynchronous attendance. Hypermeetings consist of a chain of video-recorded meetings with hyperlinks for navigating through the video content. HyperMeeting supports the synchronized viewing of prior meetings during a videoconference. Natural viewing behavior such as pausing generates hyperlinks between the previously recorded meetings and the current video recording. During playback, automatic link-following guided by playback plans present the relevant content to users. Playback plans take into account the user's meeting attendance and viewing history and match them with features such as speaker segmentation. A user study showed that participants found hyperlinks useful but did not always understand where they would take them. The study results provide a good basis for future system improvements.
2014
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  • DocEng 2014
  • Sep 16, 2014

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Distributed teams must co-ordinate a variety of tasks. To do so they need to be able to create, share, and annotate documents as well as discuss plans and goals. Many workflow tools support document sharing, while other tools support videoconferencing, however there exists little support for connecting the two. In this work we describe a system that allows users to share and markup content during web meetings. This shared content can provide important conversational props within the context of a meeting; it can also help users review archived meetings. Users can also extract shared content from meetings directly into other workflow tools.
Publication Details
  • International Journal of Multimedia Information Retrieval Special Issue on Cross-Media Analysis
  • Sep 4, 2014

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Media Embedded Target, or MET, is an iconic mark printed in a blank margin of a page that indicates a media link is associated with a nearby region of the page. It guides the user to capture the region and thus retrieve the associated link through visual search within indexed content. The target also serves to separate page regions with media links from other regions of the page. The capture application on the cell phone displays a sight having the same shape as the target near the edge of a camera-view display. The user moves the phone to align the sight with the target printed on the page. Once the system detects correct sight-target alignment, the region in the camera view is captured and sent to the recognition engine which identifies the image and causes the associated media to be displayed on the phone. Since target and sight alignment defines a capture region, this approach saves storage by only indexing visual features in the predefined capture region, rather than indexing the entire page. Target-sight alignment assures that the indexed region is fully captured. We compare the use of MET for guiding capture with two standard methods: one that uses a logo to indicate that media content is available and text to define the capture region and another that explicitly indicates the capture region using a visible boundary mark.
2012
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  • International Journal on Document Analysis and Recognition (IJDAR): Volume 15, Issue 3 (2012), pp. 167-182.
  • Sep 1, 2012

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When searching or browsing documents, the genre of a document is an important consideration that complements topical characterization. We examine design considerations for automatic tagging of office document pages with genre membership. These include selecting features that characterize genre-related information in office documents, examining the utility of text-based features and image-based features, and proposing a simple ensemble method to improve genre identification performance. In the open-set identification of four office document genres, our experiments show that when combined with image-based features, text-based features do not significantly influence performance. These results provide support for a topic-independent approach to genre identification of office documents. Experiments also show that our simple ensemble method significantly improves performance relative to using a support vector machine (SVM) classifier alone. We demonstrate the utility of our approach by integrating our automatic genre tags in a faceted search and browsing application for office document collections.
Publication Details
  • Fuji Xerox Technical Report No.21 2012
  • Feb 2, 2012

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Modern office work practices increasingly breach traditional boundaries of time and place, making it difficult to interact with colleagues. To address these problems, we developed myUnity, a software and sensor platform that enables rich workplace awareness and coordination. myUnity is an integrated platform that collects information from a set of independent sensors and external data aggregators to report user location, availability, tasks, and communication channels. myUnity's sensing architecture is component-based, allowing channels of awareness information to be added, updated, or removed at any time. Multiple channels of input are combined and composited into a single, high-level presence state. Early studies of a myUnity deployment have demonstrated that the platform allows quick access to core awareness information and show that it has become a useful tool for supporting communication and collaboration in the modern workplace.
2011
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  • ACM Multimedia 2011
  • Nov 28, 2011

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Embedded Media Markers (EMMs) are nearly transparent icons printed on paper documents that link to associated digital media. By using the document content for retrieval, EMMs are less visually intrusive than barcodes and other glyphs while still providing an indication for the presence of links. An initial implementation demonstrated good overall performance but exposed difficulties in guaranteeing the creation of unambiguous EMMs. We developed an EMM authoring tool that supports the interactive authoring of EMMs via visualizations that show the user which areas on a page may cause recognition errors and automatic feedback that moves the authored EMM away from those areas. The authoring tool and the techniques it relies on have been applied to corpora with different visual characteristics to explore the generality of our approach.
Publication Details
  • ACM Multimedia Industrial Exhibits
  • Nov 28, 2011

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Modern office work practices increasingly breach traditional boundaries of time and place, making it difficult to interact with colleagues. To address these problems, we developed myUnity, a software and sensor platform that enables rich workplace awareness and coordination. myUnity is an integrated platform that collects information from a set of independent sensors and external data aggregators to report user location, availability, tasks, and communication channels. myUnity's sensing architecture is component-based, allowing channels of awareness information to be added, updated, or removed at any time. Our current system includes a variety of sensor and data input, including camera-based activity classification, wireless location trilateration, and network activity monitoring. These and other input channels are combined and composited into a single, high-level presence state. Early studies of a myUnity deployment have demonstrated that use of the platform allows quick access to core awareness information and show it has become a useful tool supporting communication and collaboration in the modern workplace.
Publication Details
  • MobileHCI
  • Aug 30, 2011

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Modern office work practices increasingly breach traditional boundaries of time and place, increasing breakdowns workers encounter when coordinating interaction with colleagues. We conducted interviews with 12 workers and identified key problems introduced by these practices. To address these problems we developed myUnity, a fully functional platform enabling rich workplace awareness and coordination. myUnity is one of the first integrated platforms to span mobile and desktop environments, both in terms of access and sensing. It uses multiple sources to report user location, availability, tasks, and communication channels. A pilot field study of myUnity demonstrated the significant value of pervasive access to workplace awareness and communication facilities, as well as positive behavioral change in day-to-day communication practices for most users. We present resulting insights about the utility of awareness technology in flexible work environments.
Publication Details
  • ACM International Conference on Multimedia Retrieval (ICMR)
  • Apr 17, 2011

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User-generated video from mobile phones, digital cameras, and other devices is increasing, yet people rarely want to watch all the captured video. More commonly, users want a single still image for printing or a short clip from the video for creating a panorama or for sharing. Our interface aims to help users search through video for these images or clips in a more efficient fashion than fast-forwarding or "scrubbing" through a video by dragging through locations on a slider. It is based on a hierarchical structure of keyframes in the video, and combines a novel user interface design for browsing a video segment tree with new algorithms for keyframe selection, segment identification, and clustering. These algorithms take into account the need for quality keyframes and balance the desire for short navigation paths and similarity-based clusters. Our user interface presents keyframe hierarchies and displays visual cues for keeping the user oriented while browsing the video. The system adapts to the task by using a non-temporal clustering algorithm when a the user wants a single image. When the user wants a video clip, the system selects one of two temporal clustering algorithm based on a measure of the repetitiveness of the video. User feedback provided us with valuable suggestions for improvements to our system.
Publication Details
  • ACM International Conference on Multimedia Retrieval (ICMR) 2011
  • Apr 17, 2011

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Embedded Media Marker (EMM) identification system allows users to retrieve relevant dynamic media associated with a static paper document via camera phones. The user supplies a query image by capturing an EMM-signified patch of a paper document through a camera phone; the system recognizes the query and in turn retrieves and plays the corresponding media on the phone. Accurate image matching is crucial for positive user experience in this application. To address the challenges posed by large datasets and variations in camera-phone-captured query images, we introduce a novel image matching scheme based on geometrically consistent correspondences. Two matching constraints - "injection" and "approximate global geometric consistency" (AGGC), which are unique in EMM identification, are presented. A hierarchical scheme, combined with two constraining functions, is designed to detect the "injective-AGGC" correspondences between images. A spatial neighborhood search approach is further proposed to address challenging cases with large translational shift. Experimental results on a 100k+ dataset show that our solution achieves high accuracy with low memory and time complexity and outperforms the standard bag-of-words approach.
Publication Details
  • IS&T and SPIE International Conference on Multimedia Content Access: Algorithms and Systems
  • Jan 23, 2011

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This paper describes research activities at FX Palo Alto Laboratory (FXPAL) in the area of multimedia browsing, search, and retrieval. We first consider interfaces for organization and management of personal photo collections. We then survey our work on interactive video search and retrieval. Throughout we discuss the evolution of both the research challenges in these areas and our proposed solutions.
2010
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  • JCDL 2010
  • Jun 21, 2010

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Photo libraries are growing in quantity and size, requiring better support for locating desired photographs. MediaGLOW is an interactive visual workspace designed to address this concern. It uses attributes such as visual appearance, GPS locations, user-assigned tags, and dates to filter and group photos. An automatic layout algorithm positions photos with similar attributes near each other to support users in serendipitously finding multiple relevant photos. In addition, the system can explicitly select photos similar to specified photos. We conducted a user evaluation to determine the benefit provided by similarity layout and the relative advantages offered by the different layout similarity criteria and attribute filters. Study participants had to locate photos matching probe statements. In some tasks, participants were restricted to a single layout similarity criterion and filter option. Participants used multiple attributes to filter photos. Layout by similarity without additional filters turned out to be one of the most used strategies and was especially beneficial for geographical similarity. Lastly, the relative appropriateness of the single similarity criterion to the probe significantly affected retrieval performance.

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Browsing and searching for documents in large, online enterprise document repositories are common activities. While internet search produces satisfying results for most user queries, enterprise search has not been as successful because of differences in document types and user requirements. To support users in finding the information they need in their online enterprise repository, we created DocuBrowse, a faceted document browsing and search system. Search results are presented within the user-created document hierarchy, showing only directories and documents matching selected facets and containing text query terms. In addition to file properties such as date and file size, automatically detected document types, or genres, serve as one of the search facets. Highlighting draws the user’s attention to the most promising directories and documents while thumbnail images and automatically identified keyphrases help select appropriate documents. DocuBrowse utilizes document similarities, browsing histories, and recommender system techniques to suggest additional promising documents for the current facet and content filters.
Publication Details
  • Fuji Xerox Technical Report No. 19, pp. 88-100
  • Jan 1, 2010

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Browsing and searching for documents in large, online enterprise document repositories is an increasingly common problem. While users are familiar and usually satisfied with Internet search results for information, enterprise search has not been as successful because of differences in data types and user requirements. To support users in finding the information they need from electronic and scanned documents in their online enterprise repository, we created an automatic detector for genres such as papers, slides, tables, and photos. Several of those genres correspond roughly to file name extensions but are identified automatically using features of the document. This genre identifier plays an important role in our faceted document browsing and search system. The system presents documents in a hierarchy as typically found in enterprise document collections. Documents and directories are filtered to show only documents matching selected facets and containing optional query terms and to highlight promising directories. Thumbnail images and automatically identified keyphrases help select desired documents.
2009
Publication Details
  • ACM Transactions on Multimedia Computing, Communications and Applications, Vol. 5, Issue 2
  • May 1, 2009

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Hyper-Hitchcock consists of three components for creating and viewing a form of interactive video called detail-on-demand video: a hypervideo editor, a hypervideo player, and algorithms for automatically generating hypervideo summaries. Detail-on-demand video is a form of hypervideo that supports one hyperlink at a time for navigating between video sequences. The Hyper-Hitchcock editor enables authoring of detail-on-demand video without programming and uses video processing to aid in the authoring process. The Hyper-Hitchcock player uses labels and keyframes to support navigation through and back hyperlinks. Hyper-Hitchcock includes techniques for automatically generating hypervideo summaries of one or more videos that take the form of multiple linear summaries of different lengths with links from the shorter to the longer summaries. User studies on authoring and viewing provided insight into the various roles of links in hypervideo and found that player interface design greatly affects people's understanding of hypervideo structure and the video they access.

WebNC: efficient sharing of web applications

Publication Details
  • WWW 2009
  • Apr 22, 2009

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WebNC is a browser plugin that leverages the Document Object Model for efficiently sharing web browser windows or recording web browsing sessions to be replayed later. Unlike existing screen-sharing or screencasting tools, WebNC is optimized to work with web pages where a lot of scrolling happens. Rendered pages are captured as image tiles, and transmitted to a central server through http post. Viewers can watch the webcasts in realtime or asynchronously using a standard web browser: WebNC only relies on html and javascript to reproduce the captured web content. Along with the visual content of web pages, WebNC also captures their layout and textual content for later retrieval. The resulting webcasts require very little bandwidth, are viewable on any modern web browser including the iPhone and Android phones, and are searchable by keyword.
Publication Details
  • Proceedings of TRECVID 2008 Workshop
  • Mar 1, 2009

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In 2008 FXPAL submitted results for two tasks: rushes summarization and interactive search. The rushes summarization task has been described at the ACM Multimedia workshop [1]. Interested readers are referred to that publication for details. We describe our interactive search experiments in this notebook paper.
Publication Details
  • IUI '09
  • Feb 8, 2009

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We designed an interactive visual workspace, MediaGLOW, that supports users in organizing personal and shared photo collections. The system interactively places photos with a spring layout algorithm using similarity measures based on visual, temporal, and geographic features. These similarity measures are also used for the retrieval of additional photos. Unlike traditional spring-based algorithms, our approach provides users with several means to adapt the layout to their tasks. Users can group photos in stacks that in turn attract neighborhoods of similar photos. Neighborhoods partition the workspace by severing connections outside the neighborhood. By placing photos into the same stack, users can express a desired organization that the system can use to learn a neighborhood-specific combination of distances.
2008

Interactive Multimedia Search: Systems for Exploration and Collaboration

Publication Details
  • Fuji Xerox Technical Report
  • Dec 15, 2008

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We have developed an interactive video search system that allows the searcher to rapidly assess query results and easily pivot off those results to form new queries. The system is intended to maximize the use of the discriminative power of the human searcher. The typical video search scenario we consider has a single searcher with the ability to search with text and content-based queries. In this paper, we evaluate a new collaborative modification of our search system. Using our system, two or more users with a common information need search together, simultaneously. The collaborative system provides tools, user interfaces and, most importantly, algorithmically-mediated retrieval to focus, enhance and augment the team's search and communication activities. In our evaluations, algorithmic mediation improved the collaborative performance of both retrieval (allowing a team of searchers to find relevant information more efficiently and effectively), and exploration (allowing the searchers to find relevant information that cannot be found while working individually). We present analysis and conclusions from comparative evaluations of the search system.
Publication Details
  • ACM Multimedia
  • Oct 27, 2008

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Retail establishments want to know about traffic flow and patterns of activity in order to better arrange and staff their business. A large number of fixed video cameras are commonly installed at these locations. While they can be used to observe activity in the retail environment, assigning personnel to this is too time consuming to be valuable for retail analysis. We have developed video processing and visualization techniques that generate presentations appropriate for examining traffic flow and changes in activity at different times of the day. Taking the results of video tracking software as input, our system aggregates activity in different regions of the area being analyzed, determines the average speed of moving objects in the region, and segments time based on significant changes in the quantity and/or location of activity. Visualizations present the results as heat maps to show activity and object counts and average velocities overlaid on the map of the space.
2007

DOTS: Support for Effective Video Surveillance

Publication Details
  • Fuji Xerox Technical Report No. 17, pp. 83-100
  • Nov 1, 2007

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DOTS (Dynamic Object Tracking System) is an indoor, real-time, multi-camera surveillance system, deployed in a real office setting. DOTS combines video analysis and user interface components to enable security personnel to effectively monitor views of interest and to perform tasks such as tracking a person. The video analysis component performs feature-level foreground segmentation with reliable results even under complex conditions. It incorporates an efficient greedy-search approach for tracking multiple people through occlusion and combines results from individual cameras into multi-camera trajectories. The user interface draws the users' attention to important events that are indexed for easy reference. Different views within the user interface provide spatial information for easier navigation. DOTS, with over twenty video cameras installed in hallways and other public spaces in our office building, has been in constant use for a year. Our experiences led to many changes that improved performance in all system components.
Publication Details
  • ICDSC 2007, pp. 132-139
  • Sep 25, 2007

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Our analysis and visualization tools use 3D building geometry to support surveillance tasks. These tools are part of DOTS, our multicamera surveillance system; a system with over 20 cameras spread throughout the public spaces of our building. The geometric input to DOTS is a floor plan and information such as cubicle wall heights. From this input we construct a 3D model and an enhanced 2D floor plan that are the bases for more specific visualization and analysis tools. Foreground objects of interest can be placed within these models and dynamically updated in real time across camera views. Alternatively, a virtual first-person view suggests what a tracked person can see as she moves about. Interactive visualization tools support complex camera-placement tasks. Extrinsic camera calibration is supported both by visualizations of parameter adjustment results and by methods for establishing correspondences between image features and the 3D model.

DOTS: Support for Effective Video Surveillance

Publication Details
  • ACM Multimedia 2007, pp. 423-432
  • Sep 24, 2007

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DOTS (Dynamic Object Tracking System) is an indoor, real-time, multi-camera surveillance system, deployed in a real office setting. DOTS combines video analysis and user interface components to enable security personnel to effectively monitor views of interest and to perform tasks such as tracking a person. The video analysis component performs feature-level foreground segmentation with reliable results even under complex conditions. It incorporates an efficient greedy-search approach for tracking multiple people through occlusion and combines results from individual cameras into multi-camera trajectories. The user interface draws the users' attention to important events that are indexed for easy reference. Different views within the user interface provide spatial information for easier navigation. DOTS, with over twenty video cameras installed in hallways and other public spaces in our office building, has been in constant use for a year. Our experiences led to many changes that improved performance in all system components.
Publication Details
  • ICME 2007, pp. 1015-1018
  • Jul 2, 2007

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We describe a new interaction technique that allows users to control nonlinear video playback by directly manipulating objects seen in the video. This interaction technique is simi-lar to video "scrubbing" where the user adjusts the playback time by moving the mouse along a slider. Our approach is superior to variable-scale scrubbing in that the user can con-centrate on interesting objects and does not have to guess how long the objects will stay in view. Our method relies on a video tracking system that tracks objects in fixed cameras, maps them into 3D space, and handles hand-offs between cameras. In addition to dragging objects visible in video windows, users may also drag iconic object representations on a floor plan. In that case, the best video views are se-lected for the dragged objects.
Publication Details
  • CHI 2007, pp. 1167-1176
  • Apr 28, 2007

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A common video surveillance task is to keep track of people moving around the space being monitored. It is often difficult to track activity between cameras because locations such as hallways in office buildings can look quite similar and do not indicate the spatial proximity of the cameras. We describe a spatial video player that orients nearby video feeds with the field of view of the main playing video to aid in tracking between cameras. This is compared with the traditional bank of cameras with and without interactive maps for identifying and selecting cameras. We additionally explore the value of static and rotating maps for tracking activity between cameras. The study results show that both the spatial video player and the map improve user performance when compared to the camera-bank interface. Also, subjects change cameras more often with the spatial player than either the camera bank or the map, when available.
2006
Publication Details
  • In Proceedings of the fourth ACM International Workshop on Video Surveillance & Sensor Networks VSSN '06, Santa Barbara, CA, pp. 19-26
  • Oct 27, 2006

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Video surveillance systems have become common across a wide number of environments. While these installations have included more video streams, they also have been placed in contexts with limited personnel for monitoring the video feeds. In such settings, limited human attention, combined with the quantity of video, makes it difficult for security personnel to identify activities of interest and determine interrelationships between activities in different video streams. We have developed applications to support security personnel both in analyzing previously recorded video and in monitoring live video streams. For recorded video, we created storyboard visualizations that emphasize the most important activity as heuristically determined by the system. We also developed an interactive multi-channel video player application that connects camera views to map locations, alerts users to unusual and suspicious video, and visualizes unusual events along a timeline for later replay. We use different analysis techniques to determine unusual events and to highlight them in video images. These tools aid security personnel by directing their attention to the most important activity within recorded video or among several live video streams.
Publication Details
  • UIST 2006 Companion
  • Oct 16, 2006

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Video surveillance requires keeping the human in the loop. Software can aid security personnel in monitoring and using video. We have developed a set of interface components designed to locate and follow important activity within security video. By recognizing and visualizing localized activity, presenting overviews of activity over time, and temporally and geographically contextualizing video playback, we aim to support security personnel in making use of the growing quantity of security video.
Publication Details
  • UIST 2006 Companion
  • Oct 16, 2006

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With the growing quantity of security video, it becomes vital that video surveillance software be able to support security personnel in monitoring and tracking activities. We have developed a multi-stream video player that plays recorded and live videos while drawing the users' attention to activity in the video. We will demonstrate the features of the video player and in particular, how it focuses on keeping the human in the loop and drawing their attention to activities in the video.
Publication Details
  • Interactive Video; Algorithms and Technologies Hammoud, Riad (Ed.) 2006, XVI, 250 p., 109 illus., Hardcover.
  • Jun 7, 2006

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This chapter describes tools for browsing and searching through video to enable users to quickly locate video passages of interest. Digital video databases containing large numbers of video programs ranging from several minutes to several hours in length are becoming increasingly common. In many cases, it is not sufficient to search for relevant videos, but rather to identify relevant clips, typically less than one minute in length, within the videos. We offer two approaches for finding information in videos. The first approach provides an automatically generated interactive multi-level summary in the form of a hypervideo. When viewing a sequence of short video clips, the user can obtain more detail on the clip being watched. For situations where browsing is impractical, we present a video search system with a flexible user interface that incorporates dynamic visualizations of the underlying multimedia objects. The system employs automatic story segmentation, and displays the results of text and image-based queries in ranked sets of story summaries. Both approaches help users to quickly drill down to potentially relevant video clips and to determine the relevance by visually inspecting the material.
2005
Publication Details
  • ACM Multimedia 2005, Technical Demonstrations.
  • Nov 5, 2005

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The MediaMetro application provides an interactive 3D visualization of multimedia document collections using a city metaphor. The directories are mapped to city layouts using algorithms similar to treemaps. Each multimedia document is represented by a building and visual summaries of the different constituent media types are rendered onto the sides of the building. From videos, Manga storyboards with keyframe images are created and shown on the façade; from slides and text, thumbnail images are produced and subsampled for display on the building sides. The images resemble windows on a building and can be selected for media playback. To support more facile navigation between high overviews and low detail views, a novel swooping technique was developed that combines altitude and tilt changes with zeroing in on a target.
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
  • 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.
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.
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
  • 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.
2004
Publication Details
  • UIST 2004 Companion, pp. 37-38
  • Oct 24, 2004

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As the size of the typical personal digital photo collection reaches well into the thousands or photos, advanced tools to manage these large collections are more and more necessary. In this demonstration, we present a semi-automatic approach that opportunistically takes advantage of the current state-of-the-art technology in face detection and recognition and combines it with user interface techniques to facilitate the task of labeling people in photos. We show how we use an accurate face detector to automatically extract faces from photos. Instead of having a less accurate face recognizer classify faces, we use it to sort faces by their similarity to a face model. We demonstrate our photo application that uses the extracted faces as UI proxies for actions on the underlying photos along with the sorting strategy to identify candidate faces for quick and easy face labeling.
Publication Details
  • UIST 2004 Companion, pp. 13-14
  • Oct 24, 2004

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We developed a novel technique for creating visually pleasing collages from photo regions. The technique is called "stained glass" because the resulting collage with irregular shapes is reminiscent of a stained glass window. The collages reuse photos in novel ways to present photos with faces that can be printed, included in Web pages, or shared via email. The poster describes the requirements for creating stained glass visualizations from photos of faces, our approach for creating face stained glass, and techniques used to improve the aesthetics and flexibility of the stained glass generation. Early user feedback with face stained glass have been very positive.
Publication Details
  • Proceedings of the International Workshop on Multimedia Information Retrieval, ACM Press, pp. 99-106
  • Oct 10, 2004

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With digital still cameras, users can easily collect thousands of photos. We have created a photo management application with the goal of making photo organization and browsing simple and quick, even for very large collections. A particular concern is the management of photos depicting people. We present a semi-automatic approach designed to facilitate the task of labeling photos with people that opportunistically takes advantage of the strengths of current state-of-the-art technology in face detection and recognition. In particular, an accurate face detector is used to automatically extract faces from photos while the less accurate face recognizer is used not to classify the detected faces, but to sort faces by their similarity to a chosen model. This sorting is used to present candidate faces within a user interface designed for quick and easy face labeling. We present results of a simulation of the usage model that demonstrate the improved ease that is achieved by our method.
Publication Details
  • IEEE Computer Graphics & Applications, pp. 66-75
  • Sep 1, 2004

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Information sharing, computation and social interaction are main features of the Web that has enabled online communities to abound and flourish. However, this trend has not been coupled with the development of cues and browsing mechanisms for the social space. On the flip side, active contributors to social spaces (i.e., Web communities) lack the means to present a public face to visitors that can be important for social organizations. Social browsers that combine social visualization and tools can enable newcomers and visitors to view and explore information and patterns. We present two social browsers for two Web communities. The CHIplace People browser provides an abstract graphical view of the CHIplace community based on the self-described work roles of its membership. The Portkey eTree browser uses a life-like tree ecosystem metaphor to reflect the people, activities and discussions occurring on the Portkey Web site.
Publication Details
  • Proceedings of 2004 IEEE International Conference on Multimedia and Expo (ICME 2004)
  • Jun 27, 2004

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This paper presents a method for creating highly condensed video summaries called Stained-Glass visualizations. These are especially suitable for small displays on mobile devices. A morphological grouping technique is described for finding 3D regions of high activity or motion from a video embedded in x-y-t space. These regions determine areas in the keyframes, which can be subsumed in a more general geometric framework of germs and supports: germs are the areas of interest, and supports give the context. Algorithms for packing and laying out the germs are provided. Gaps between the germs are filled using a Voronoi-based method. Irregular shapes emerge, and the result looks like stained glass.
Publication Details
  • Journal of Human Interface Society, 6(2), pp. 51-58
  • Jun 1, 2004

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FX Palo Alto Laboratory provides multimedia and information technology research for the Fuji Xerox corporation based in Tokyo, Japan. FXPAL's mission is to help Fuji Xerox with a digital information technology infrastructure to support services in Fuji Xerox's Open Office Frontier. Our research spans interactive media, immersive conferencing, social computing, mobile and adaptive computing, natural language inquiry, and emerging technologies such as quantum computing and bioinformatics. Our research methods combine determining user needs, inventing new technologies, building prototype systems, informing professional communities, and transferring technology to Fuji Xerox. The physical distance between our laboratory and our parent company makes it natural for us to research problems with collaborations across time zones and cultures. To address these problems, to test our ideas, and to prepare for technology transfers, we actively create prototype systems for interactive media, immersive conferencing, and social and mobile computing. We also foster collaboration with our Japanese colleagues through a combination of face-to-face visits and both synchronous and asynchronous remote communication.
Publication Details
  • Proceedings of the Working Conference on Advanced Visual Interfaces, AVI 2004, pp. 290-297
  • May 25, 2004

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We introduced detail-on-demand video as a simple type of hypervideo that allows users to watch short video segments and to follow hyperlinks to see additional detail. Such video lets users quickly access desired information without having to view the entire contents linearly. A challenge for presenting this type of video is to provide users with the appropriate affordances to understand the hypervideo structure and to navigate it effectively. Another challenge is to give authors tools that allow them to create good detail-on-demand video. Guided by user feedback, we iterated designs for a detail-on-demand video player. We also conducted two user studies to gain insight into people's understanding of hypervideo and to improve the user interface. We found that the interface design was tightly coupled to understanding hypervideo structure and that different designs greatly affected what parts of the video people accessed. The studies also suggested new guidelines for hypervideo authoring.
Publication Details
  • Communications of the ACM, February 2004, Vol. 47, No. 2, pp. 38-44
  • Feb 1, 2004

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Blurring the boundary between the digital and physical in social activity spaces helps blend - and motivate - online and face-to-face community participation. This paper discusses two experimental installations of large screen displays at conferences - CHI 2002 and CSCW 2002. The displays offered a window in the conference arena onto online community information.
2003
Publication Details
  • Proc. ACM Multimedia 2003. pp. 364-373
  • Nov 1, 2003

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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 results for the algorithm based solely on temporal similarity, and jointly on temporal and content-based similarity. We also describe a supervised algorithm based on learning vector quantization. Finally, we include experimental results for the proposed algorithms and several competing approaches on two test collections.
Publication Details
  • Proc. ACM Multimedia 2003. pp. 92-93
  • Nov 1, 2003

Abstract

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To simplify the process of editing interactive video, we developed the concept of "detail-on-demand" video as a subset of general hypervideo. Detail-on-demand video keeps the authoring and viewing interfaces relatively simple while supporting a wide range of interactive video applications. Our editor, Hyper-Hitchcock, provides a direct manipulation environment in which authors can combine video clips and place hyperlinks between them. To summarize a video, Hyper-Hitchcock can also automatically generate a hypervideo composed of multiple video summary levels and navigational links between these summaries and the original video. Viewers may interactively select the amount of detail they see, access more detailed summaries, and navigate to the source video through the summary.
Publication Details
  • Proc. ACM Multimedia 2003. pp. 392-401
  • Nov 1, 2003

Abstract

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In this paper, we describe how a detail-on-demand representation for interactive video is used in video summarization. Our approach automatically generates a hypervideo composed of multiple video summary levels and navigational links between these summaries and the original video. Viewers may interactively select the amount of detail they see, access more detailed summaries, and navigate to the source video through the summary. We created a representation for interactive video that supports a wide range of interactive video applications and Hyper-Hitchcock, an editor and player for this type of interactive video. Hyper-Hitchcock employs methods to determine (1) the number and length of levels in the hypervideo summary, (2) the video clips for each level in the hypervideo, (3) the grouping of clips into composites, and (4) the links between elements in the summary. These decisions are based on an inferred quality of video segments and temporal relations those segments.

Detail-on-Demand Hypervideo

Publication Details
  • Proc. ACM Multimedia 2003. pp. 600-601
  • Nov 1, 2003

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We demonstrate the use of detail-on-demand hypervideo in interactive training and video summarization. Detail-on-demand video allows viewers to watch short video segments and to follow hyperlinks to see additional detail. The player for detail-ondemand video displays keyframes indicating what links are available at each point in the video. The Hyper-Hitchcock authoring tool helps users create hypervideo by automatically dividing video into clips that can be combined in a direct manipulation interface. Clips can be grouped into composites and hyperlinks can be placed between clips and composites. A summarization algorithm creates multi-level hypervideo summaries from linear video by automatically selecting clips and placing links between them.
Publication Details
  • Proc. IEEE Intl. Conf. on Image Processing
  • Sep 14, 2003

Abstract

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We present similarity-based methods to cluster digital photos by time and image content. This approach is general, unsupervised, and makes minimal assumptions regarding the structure or statistics of the photo collection. We describe versions of the algorithm using temporal similarity with and without content-based similarity, and compare the algorithms with existing techniques, measured against ground-truth clusters created by humans.
Publication Details
  • SPIE Information Technologies and Communications
  • Sep 9, 2003

Abstract

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Hypervideo is a form of interactive video that allows users to follow links to other video. A simple form of hypervideo, called "detail-on-demand video," provides at most one link from one segment of video to another, supporting a singlebutton interaction. Detail-on-demand video is well suited for interactive video summaries, because the user can request a more detailed summary while watching the video. Users interact with the video is through a special hypervideo player that displays keyframes with labels indicating when a link is available. While detail-on-demand summaries can be manually authored, it is a time-consuming task. To address this issue, we developed an algorithm to automatically generate multi-level hypervideo summaries. The highest level of the summary consists of the most important clip from each take or scene in the video. At each subsequent level, more clips from each take or scene are added in order of their importance. We give one example in which a hypervideo summary is created for a linear training video. We also show how the algorithm can be modified to produce a hypervideo summary for home video.

The Plasma Poster Network: Posting Multimedia Content in Public Places

Publication Details
  • Human-Computer Interaction INTERACT '03, IOS Press, pp. 599-606
  • Sep 1, 2003

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Much effort has been expended in creating online information resources to foster social networks, create synergies between collocated and remote colleagues, and enhance social capital within organizations. Following the observation that physical bulletin boards serve an important community building and maintenance function, in this paper we describe a network of large screen, digital bulletin boards, the Plasma Poster Network. The function of this system is to bridge the gap between online community interactions and shared physical spaces. We describe our motivation, a fieldwork study of information sharing practices within our organization, and an internal deployment of Plasma Posters.

Weaving Between Online and Offline Community Participation

Publication Details
  • Human-Computer Interaction INTERACT '03, IOS Press, pp. 729-732
  • Sep 1, 2003

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Much effort has been expended in creating online spaces for people to meet, network, share and organize. However, there is relatively little work, in comparison, that has addressed creating awareness of online community activities for those gathered together physically. We describe our efforts to advertise the online community spaces of CHIplace and CSCWplace using large screen, interactive bulletin boards that show online community information mixed with content generated at the conference itself. Our intention was to raise awareness of the online virtual community within the offline, face-to-face event. We describe the two deployments, at CHI 2002 and at CSCW 2002, and provide utilization data regarding people's participation within the physical and virtual locales.
Publication Details
  • Human-Computer Interaction INTERACT '03, IOS Press, pp. 33-40
  • Sep 1, 2003

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To simplify the process of editing interactive video, we developed the concept of "detail-on-demand" video as a subset of general hypervideo where a single button press reveals additional information about the current video sequence. Detail-on-demand video keeps the authoring and viewing interfaces relatively simple while supporting a wide range of interactive video applications. Our editor, Hyper-Hitchcock, builds on prior work on automatic analysis to find the best quality video clips. It introduces video composites as an abstraction for grouping and manipulating sets of video clips. Navigational links can be created between any two video clips or composites. Such links offer a variety of return behaviors for when the linked video is completed that can be tailored to different materials. Initial impressions from a pilot study indicate that Hyper-Hitchcock is easy to learn although the behavior of links is not immediately intuitive for all users.
Publication Details
  • Human-Computer Interaction INTERACT '03, IOS Press, pp. 196-203
  • Sep 1, 2003

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With digital still cameras, users can easily collect thousands of photos. Our goal is to make organizing and browsing photos simple and quick, while retaining scalability to large collections. To that end, we created a photo management application concentrating on areas that improve the overall experience without neglecting the mundane components of such an application. Our application automatically divides photos into meaningful events such as birthdays or trips. Several user interaction mechanisms enhance the user experience when organizing photos. Our application combines a light table for showing thumbnails of the entire photo collection with a tree view that supports navigating, sorting, and filtering photos by categories such as dates, events, people, and locations. A calendar view visualizes photos over time and allows for the quick assignment of dates to scanned photos. We fine-tuned our application by using it with large personal photo collections provided by several users.
Publication Details
  • Proceedings of Hypertext '03, pp. 124-125
  • Aug 26, 2003

Abstract

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Existing hypertext systems have emphasized either the navigational or spatial expression of relationships between objects. We are exploring the combination of these modes of expression in Hyper-Hitchcock, a hypervideo editor. Hyper-Hitchcock supports a form of hypervideo called "detail-on-demand video" due to its applicability to situations where viewers need to take a link to view more details on the content currently being presented. Authors of detail-on-demand video select, group, and spatially arrange video clips into linear sequences in a two-dimensional workspace. Hyper-Hitchcock uses a simple spatial parser to determine the temporal order of selected video clips. Authors add navigational links between the elements in those sequences. This combination of navigational and spatial hypertext modes of expression separates the clip sequence from the navigational structure of the hypervideo. Such a combination can be useful in cases where multiple forms of inter-object relationships must be expressed on the same content.
Publication Details
  • IEEE International Conference on Multimedia and Expo, v. I, pp. 221-224
  • Jul 7, 2003

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A novel method is presented for inaudibly hiding information in an audio signal by subtly applying time-scale modification to segments of the signal. The sequence, duration, and degree of the time-scale modifications are the parameters which encode information in the altered signal. By comparing the altered signal with a reference copy, compressed and expanded regions can be identified and the hidden data recovered. This approach is novel and has several advantages over other methods: it is theoretically noiseless, it introduces no spectral distortion, and it is robust to all known methods of reproduction, compression, and transmission.
Publication Details
  • IEEE International Conference on Multimedia and Expo, v. II, pp. 77-80
  • Jul 7, 2003

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We created an improved layout algorithm for automatically generating visual video summaries reminiscent of comic book pages. The summaries are comprised of images from the video that are sized according to their importance. The algorithm performs a global optimization with respect to a layout cost function that encompasses features such as the number of resized images and the amount of whitespace in the presentation. The algorithm creates summaries that: always fit exactly into the requested area, are varied by containing few rows with images of the same size, and have little whitespace at the end of the last row. The layout algorithm is fast enough to allow the interactive resizing of the summaries and the subsequent generation of a new layout.
Publication Details
  • IEEE International Conference on Multimedia and Expo, v. II, pp. 753-756
  • Jul 7, 2003

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We created an alternative approach to existing video summaries that gives viewers control over the summaries by selecting hyperlinks to other video with additional information. We structure such summaries as "detail-on-demand" video, a subset of general hypervideo in which at most one link to another video sequence is available at any given time. Our editor for such video, Hyper-Hitchcock, provides a workspace in which an author can select and arrange video clips, generate composites from clips and from other composites, and place links between composites. To simplify dealing with a large number of clips, Hyper-Hitchcock generates iconic representations for composites that can be used to manipulate the composite as a whole. In addition to providing an authoring environment, Hyper-Hitchcock can automatically generate multi-level hypervideo summaries for immediate use or as the starting point for author modification.
2002
Publication Details
  • ACM Multimedia 2002
  • Dec 1, 2002

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We present methods for automatic and semi-automatic creation of music videos, given an arbitrary audio soundtrack and source video. Significant audio changes are automatically detected; similarly, the source video is automatically segmented and analyzed for suitability based on camera motion and exposure. Video with excessive camera motion or poor contrast is penalized with a high unsuitability score, and is more likely to be discarded in the final edit. High quality video clips are then automatically selected and aligned in time with significant audio changes. Video clips are adjusted to match the audio segments by selecting the most suitable region of the desired length. Besides a fully automated solution, our system can also start with clips manually selected and ordered using a graphical interface. The video is then created by truncating the selected clips (preserving the high quality portions) to produce a video digest that is synchronized with the soundtrack music, thus enhancing the impact of both.
Publication Details
  • ACM 2002 Conference on Computer Supported Cooperative Work
  • Nov 16, 2002

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Technology can play an important role in enabling people to interact with each other. The Web is one such technology with the affordances for sharing information and for connecting people to people. In this paper, we describe the design of two social interaction Web sites for two different social groups. We review several related efforts to provide principles for creating social interaction environments and describe the specific principles that guided our design. To examine the effectiveness of the two sites, we analyze the usage data. Finally, we discuss approaches for encouraging participation and lessons learned.
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
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.

Publication Details
  • In Proceedings of Human-Computer Interaction (INTERACT '01), IOS Press, Tokyo, Japan, pp. 464-471
  • Jul 9, 2001

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Hitchcock is a system to simplify the process of editing video. Its key features are the use of automatic analysis to find the best quality video clips, an algorithm to cluster those clips into meaningful piles, and an intuitive user interface for combining the desired clips into a final video. We conducted a user study to determine how the automatic clip creation and pile navigation support users in the editing process. The study showed that users liked the ease-of-use afforded by automation, but occasionally had problems navigating and overriding the automated editing decisions. These findings demonstrate the need for a proper balance between automation and user control. Thus, we built a new version of Hitchcock that retains the automatic editing features, but provides additional controls for navigation and for allowing users to modify the system decisions.
2000
Publication Details
  • In Proceedings of UIST '00, ACM Press, pp. 81-89, 2000.
  • Nov 4, 2000

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Hitchcock is a system that allows users to easily create custom videos from raw video shot with a standard video camera. In contrast to other video editing systems, Hitchcock uses automatic analysis to determine the suitability of portions of the raw video. Unsuitable video typically has fast or erratic camera motion. Hitchcock first analyzes video to identify the type and amount of camera motion: fast pan, slow zoom, etc. Based on this analysis, a numerical "unsuitability" score is computed for each frame of the video. Combined with standard editing rules, this score is used to identify clips for inclusion in the final video and to select their start and end points. To create a custom video, the user drags keyframes corresponding to the desired clips into a storyboard. Users can lengthen or shorten the clip without specifying the start and end frames explicitly. Clip lengths are balanced automatically using a spring-based algorithm.
Publication Details
  • In Multimedia Tools and Applications, 11(3), pp. 347-358, 2000.
  • Aug 1, 2000

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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.
Publication Details
  • In Proceedings of IEEE International Conference on Multimedia and Expo, vol. III, pp. 1329-1332, 2000.
  • Jul 30, 2000

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We describe a genetic segmentation algorithm for video. This algorithm operates on segments of a string representation. It is similar to both classical genetic algorithms that operate on bits of a string and genetic grouping algorithms that operate on subsets of a set. For evaluating segmentations, we define similarity adjacency functions, which are extremely expensive to optimize with traditional methods. The evolutionary nature of genetic algorithms offers a further advantage by enabling incremental segmentation. Applications include video summarization and indexing for browsing, plus adapting to user access patterns.
Publication Details
  • In Proceedings of the Genetic and Evolutionary Computation Conference, Morgan Kaufmann Publishers, pp. 666-673, 2000.
  • Jul 8, 2000

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We describe a genetic segmentation algorithm for image data streams and video. This algorithm operates on segments of a string representation. It is similar to both classical genetic algorithms that operate on bits of a string and genetic grouping algorithms that operate on subsets of a set. It employs a segment fair crossover operation. For evaluating segmentations, we define similarity adjacency functions, which are extremely expensive to optimize with traditional methods. The evolutionary nature of genetic algorithms offers a further advantage by enabling incremental segmentation. Applications include browsing and summarizing video and collections of visually rich documents, plus a way of adapting to user access patterns.
Publication Details
  • In Proceedings of Hypertext '00, ACM Press, pp. 244-245, 2000.
  • May 30, 2000

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We describe a way to make a hypermedia meeting record from multimedia meeting documents by automatically generating links through image matching. In particular, we look at video recordings and scanned paper handouts of presentation slides with ink annotations. The algorithm that we employ is the Discrete Cosine Transform (DCT). Interactions with multipath links and paper interfaces are discussed.
Publication Details
  • In RIAO'2000 Conference Proceedings, Content-Based Multimedia Information Access, C.I.D., pp. 637-648, 2000.
  • Apr 12, 2000

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We present and interactive system that allows a user to locate regions of video that are similar to a video query. Thus segments of video can be found by simply providing an example of the video of interest. The user selects a video segment for the query from either a static frame-based interface or a video player. A statistical model of the query is calculated on-the-fly, and is used to find similar regions of video. The similarity measure is based on a Gaussian model of reduced frame image transform coefficients. Similarity in a single video is displayed in the Metadata Media Player. The player can be used to navigate through the video by jumping between regions of similarity. Similarity can be rapidly calculated for multiple video files as well. These results are displayed in MBase, a Web-based video browser that allows similarity in multiple video files to be visualized simultaneously.
Publication Details
  • In CHI 2000 Conference Proceedings, ACM Press, pp. 185-192, 2000.
  • Mar 31, 2000

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This paper presents a method for generating compact pictorial summarizations of video. We developed a novel approach for selecting still images from a video suitable for summarizing the video and for providing entry points into it. Images are laid out in a compact, visually pleasing display reminiscent of a comic book or Japanese manga. Users can explore the video by interacting with the presented summary. Links from each keyframe start video playback and/or present additional detail. Captions can be added to presentation frames to include commentary or descriptions such as the minutes of a recorded meeting. We conducted a study to compare variants of our summarization technique. The study participants judged the manga summary to be significantly better than the other two conditions with respect to their suitability for summaries and navigation, and their visual appeal.
1999
Publication Details
  • In Proceedings ACM Multimedia, (Orlando, FL) ACM Press, pp. 383-392, 1999.
  • Oct 30, 1999

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This paper presents methods for automatically creating pictorial video summaries that resemble comic books. The relative importance of video segments is computed from their length and novelty. Image and audio analysis is used to automatically detect and emphasize meaningful events. Based on this importance measure, we choose relevant keyframes. Selected keyframes are sized by importance, and then efficiently packed into a pictorial summary. We present a quantitative measure of how well a summary captures the salient events in a video, and show how it can be used to improve our summaries. The result is a compact and visually pleasing summary that captures semantically important events, and is suitable for printing or Web access. Such a summary can be further enhanced by including text captions derived from OCR or other methods. We describe how the automatically generated summaries are used to simplify access to a large collection of videos.
Publication Details
  • In Human-Computer Interaction INTERACT '99, IOS Press, pp. 458-465, 1999.
  • Aug 30, 1999

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In our Portholes research, we found that users needed to have a sense of being in public and to know who can see them (audience) and who is looking currently at them (lookback). Two redesigns of the Portholes display present a 3D theater view of the audience. Different sections display core team members, non-core team members and lookback. An experiment determined that people have strong preferences about audience information and how it should be displayed. Layout preferences are varied, but unfolding techniques and cluster analysis reveal that these preference perspectives fall into four groups of similar preferences.
Publication Details
  • In Human-Computer Interaction INTERACT '99, IOS Press, pp. 205-212, 1999.
  • Aug 30, 1999

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When reviewing collections of video such as recorded meetings or presentations, users are often interested only in an overview or short segments of these documents. We present techniques that use automatic feature analysis, such as slide detection and applause detection, to help locate the desired video and to navigate to regions of interest within it. We built a web-based interface that graphically presents information about the contents of each video in a collection such as its keyframes and the distribution of a particular feature over time. A media player is tightly integrated with the web interface. It supports navigation within a selected file by visualiz-ing confidence scores for the presence of features and by using them as index points. We conducted a user study to refine the usability of these tools.
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 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 IEEE Multimedia Systems '99, IEEE Computer Society, vol. 1, pp. 756-761, 1999.
  • Feb 1, 1999

Abstract

Close
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.
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.
1998
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.
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.
1997
Publication Details
  • In GROUP'97, Proceedings of the International ACM SIGGROUP Conference on Supporting Group Work, ACM Press, 1997, pp. 385-394.
  • Nov 16, 1997

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The prevalence of audio and video options on computers, coupled with the promise of bandwidth, have many prognosticators predicting a revolution in human communications. But what if the revolution materializes and no users show up? We were confronted with this question when we began deploying and studying the use of a video-based, background awareness application within our organization. Repeatedly, new users raised strong concerns about self-presentation, surveillance, privacy, video snapshots, and lack of audience cues. We describe how we addressed these concerns by evolving the application. As a consequence, we are also redesigning the user interface to the application.
Publication Details
  • Computer Networks and ISDN Systems, 29(8-13), pp. 1531-1542
  • Sep 30, 1997

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The phenomenal interest and growth of the World Wide Web as an application server has pushed the Web model to its limits. Specifically, the Web offers limited interactivity and versatility as a platform for networked applications. One major challenge for the HCI community is to determine how to improve the human-computer interface for Web-based applications. This paper focuses on a significant Web deficiency - supporting truly interactive and dynamic form-based input. We propose a well-worked form interaction abstraction that alleviates this Web deficiency. We describe how the abstraction is seamlessly integrated into the Web framework by leveraging on the virtues of the Web and fitting within the interaction and usage model of the Web.

Sensing Activity in Video Images.

Publication Details
  • In CHI 97 Extended Abstracts, ACM Press, 1997, pp. 319-320.
  • Mar 21, 1997

Abstract

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Video-based awareness tools increase familiarity among remote group members and provide pre-communication information. Low-cost iconic indicators provide less but more succinct information than video images while preserving privacy. Observations of and feedback from users of our video awareness tool suggest that an activity sensing feature along with a variety of privacy options combines advantages of both the video images and iconic indicator approaches. We introduced the activity sensing feature in response to user requests. It derives activity information from video images and provides options to control privacy and improves the usability of video-based awareness tools.