Publications

FXPAL publishes in top scientific conferences and journals.

2012
Publication Details
  • IPIN2012
  • Nov 13, 2012

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Audio-based receiver localization in indoor environ-ments has multiple applications including indoor navigation, loca-tion tagging, and tracking. Public places like shopping malls and consumer stores often have loudspeakers installed to play music for public entertainment. Similarly, office spaces may have sound conditioning speakers installed to soften other environmental noises. We discuss an approach to leverage this infrastructure to perform audio-based localization of devices requesting local-ization in such environments, by playing barely audible controlled sounds from multiple speakers at known positions. Our approach can be used to localize devices such as smart-phones, tablets and laptops to sub-meter accuracy. The user does not need to carry any specialized hardware. Unlike acoustic approaches which use high-energy ultrasound waves, the use of barely audible (low energy) signals in our approach poses very different challenges. We discuss these challenges, how we addressed those, and experimental results on two prototypical implementations: a request-play-record localizer, and a continuous tracker. We evaluated our approach in a real world meeting room and report promising initial results with localization accuracy within half a meter 94% of the time. The system has been deployed in multiple zones of our office building and is now part of a location service in constant operation in our lab.
Publication Details
  • ICPR 2012
  • Nov 11, 2012

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Images of document pages have different characteristics than images of natural scenes, and so the sharpness measures developed for natural scene images do not necessarily extend to document images primarily composed of text. We present an efficient and simple method for effectively estimating the sharpness/ blurriness of document images that also performs well on natural scenes. Our method can be used to predict the sharpness in scenarios where images are blurred due to camera-motion (or hand-shake), defocus, or inherent properties of the imaging system. The proposed method outperforms the perceptually-based, no-reference sharpness work of [1] and [4], which was shown to perform better than 14 other no-reference sharpness measures on the LIVE dataset.
Publication Details
  • ACM Multimedia 2012
  • Oct 29, 2012

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Paper and Computers have complementary advantages and are used side by side in many scenarios. Interactive paper systems aim to combine the two media. However, most such systems only allow fingers and pens to interact with content on paper. This finger-pen-only input suffers from low precision, lag, instability and occlusion. Moreover, it incurs frequent device switch (e.g. pen vs. mouse) in users' hand during cross-media interactions, yielding inefficiency and interruptions of a document workspace continuum. To address these limitations, we propose MixPad, a novel interactive paper system which incorporates mice and keyboards to enhance the conventional pen-finger-based paper interaction. Similar to many other systems, MixPad adopts a mobile camera-projector unit to recognize paper documents, detect pen and finger gestures and provide visual feedback. Unlike these systems, MixPad supports users to use mice and keyboards to select fine-grained content and create annotation on paper, and to facilitate bimanual operations for more efficient and smoother cross-media interaction. This novel interaction style combines the advantages of mice, keyboards, pens and fingers, enabling richer digital functions on paper.
Publication Details
  • ACM Multimedia 2012
  • Oct 29, 2012

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Faithful sharing of screen contents is an important collaboration feature. Prior systems were designed to operate over constrained networks. They performed poorly even without such bottlenecks. To build a high performance screen sharing system, we empirically analyzed screen contents for a variety of scenarios. We showed that screen updates were sporadic with long periods of inactivity. When active, screens were updated at far higher rates than was supported by earlier systems. The mismatch was pronounced for interactive scenarios. Even during active screen updates, the number of updated pixels were frequently small. We showed that crucial information can be lost if individual updates were merged. When the available system resources could not support high capture rates, we showed ways in which updates can be effectively collapsed. We showed that Zlib lossless compression performed poorly for screen updates. By analyzing the screen pixels, we developed a practical transformation that significantly improved compression rates. Our system captured 240 updates per second while only using 4.6 Mbps for interactive scenarios. Still, while playing movies in fullscreen mode, our approach could not achieve higher capture rates than prior systems; the CPU remains the bottleneck. A system that incorporates our findings is deployed within the lab.
Publication Details
  • ACM Multimedia '12
  • Oct 29, 2012

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DisplayCast is a many to many screen sharing system that is targeted towards Intranet scenarios. The capture software runs on all computers whose screens need to be shared. It uses an application agnostic screen capture mechanism that creates a sequence of pixmap images of the screen updates. It transforms these pixmaps to vastly improve the lossless Zlib compression performance. These algorithms were developed after an extensive analysis of typical screen contents. DisplayCast shares the processor and network resources required for screen capture, compression and transmission with host applications whose output needs to be shared. It balances the need for high performance screen capture with reducing its resource interference with user applications. DisplayCast uses Zeroconf for naming and asynchronous location. It provides support for Cisco WiFi and Bluetooth based localization. It also includes a HTTP/REST based controller for remote session initiation and control. DisplayCast supports screen capture and playback in computers running Windows 7 and Mac OS X operating systems. Remote screens can be archived into a H.264 encoded movie on a Mac. They can also be played back in real time on Apple iPhones and iPads. The software is released under a New BSD license.
Publication Details
  • CIKM 2012 Books Online Workshop Keynote Address
  • Oct 29, 2012

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Reading is part of how we understand the world, how we share knowledge, how we play, and even how we think. Although reading text is the dominant form of reading, most of the text we read— letters, numbers, words, and sentences—is surrounded by illustrations, photographs, and other kinds of symbols that we include as we read. As dynamic displays migrate into the real world at many scales, whether personal devices, handhelds, or large screens in both interior and exterior spaces, opportunities for reading migrate as well. As has happened continually throughout the history of reading, new technologies, physical forms and social patterns create new genres, which themselves may then combine or collide to morph into something new. At PARC, the RED (Research in Experimental Design) group examined emerging technologies for impact on media and the human relationship to information, especially reading. We explored new ways of experiencing text: new genres, new styles of interaction, and unusual media. Among the questions we considered: how might “the book” change? More particularly, how does the experience of reading change with the introduction of new technologies…and how does it remain the same? In this talk, we'll discuss the ideas behind the design and research process that led to creating eleven different experiences of new forms of reading. We’ll also consider how our technological context for reading has changed in recent years, and what influence the lessons from XFR may have on our ever-developing online reading experiences.

Through the Looking-Glass: Mirror Worlds for Augmented Awareness & Capability

Publication Details
  • ACM MM 2012
  • Oct 29, 2012

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We describe a system for supporting mirror worlds - 3D virtual models of physical spaces that reflect the structure and activities of those spaces to help support context awareness and tasks such as planning and recollection of events. Through views on web pages, portable devices, or on 'magic window' displays located in the physical space, remote people may 'look in' to the space, while people within the space are provided information not apparent through unaided perception. For example, by looking at a mirror display, people can learn how long others have been present, or where they have been. People in one part of a building can get a sense of activities in the rest of the building, know who is present in their office, and look in to presentations in other rooms. The system can be used to bridge across sites and help provide different parts of an organization with a shared awareness of each other's space and activities. We describe deployments of our mirror world system at several locations.
Publication Details
  • Mobile HCI 2012 demo track
  • Sep 21, 2012

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In this demonstration we will show a mobile remote control and monitoring application for a recipe development laboratory at a local chocolate production company. In collaboration with TCHO, a chocolate maker in San Francisco, we built a mobile Web app designed to allow chocolate makers to control their laboratory's machines. Sensor data is imported into the app from each machine in the lab. The mobile Web app is used for control, monitoring, and collaboration. We have tested and deployed this system at the real-world factory and it is now in daily use. This project is designed as part of a research exploration into enhanced collaboration in industrial settings between physically remote people and places, e.g. factories in China with clients in the US.
Publication Details
  • Workshop on Social Mobile Video and Panoramic Video
  • Sep 20, 2012

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The ways in which we come to know and share what we know with others are deeply entwined with the technologies that enable us to capture and share information. As face-to-face communication has been supplemented with ever-richer media––textual books, illustrations and photographs, audio, film and video, and more––the possibilities for knowledge transfer have only expanded. One of the latest trends to emerge amidst the growth of Internet sharing and pervasive mobile devices is the mass creation of online instructional videos. We are interested in exploring how smart phones shape this sort of mobile, rich media documentation and sharing.
Publication Details
  • USENIX/ACM/IFIP Middleware
  • Sep 19, 2012

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Faunus addresses the challenge of specifying and managing complex collaboration sessions. Many entities from various administrative domains orchestrate such sessions. Faunus decouples the entities that specify the session from entities that activate and manage them. It restricts the operations to specific agents using capabilities. It unifies the specification and management operations through its naming system. Each Faunus name is persistent and globally unique. A collection of attributes are attached to each name. Together, they represent a collection of services that form a collaboration session. Anyone can create a name; the creator has full read and write privileges that can be delegated to others. With the proper capability, anyone can modify session attributes between an active and inactive state. Though the system is designed for Internet scale deployments, the security model for providing and revoking capabilities currently assumes an Intranet style deployment. We have incorporated Faunus into a DisplayCast system that originally used Zeroconf. We are incorporating Faunus into another project that will fully exercise the power of Faunus.
Publication Details
  • 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
  • IIiX 2012
  • Aug 21, 2012

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Exploratory search activities tend to span multiple sessions and involve finding, analyzing and evaluating information and collab-orating with others. Typical search systems, on the other hand, are designed to support a single searcher, precision-oriented search tasks. We describe a search interface and system design of a multi-session exploratory search system, discuss design challenges en-countered, and chronicle the evolution of our design. Our design describes novel displays for visualizing retrieval history infor-mation, and introduces ambient displays and persuasive elements to interactive information retrieval.
Publication Details
  • DIS (Designing Interactive Systems) 2012 Demos track
  • Jun 11, 2012

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We will demonstrate successive and final stages in the iterative design of a complex mixed reality system in a real-world factory setting. In collaboration with TCHO, a chocolate maker in San Francisco, we built a virtual “mirror” world of a real-world chocolate factory and its processes. Sensor data is imported into the multi-user 3D environment from hundreds of sensors and a number of cameras on the factory floor. The resulting virtual factory is used for simulation, visualization, and collaboration, using a set of interlinked, real-time layers of information. It can be a stand-alone or a web-based application, and also works on iOS and Android cell phones and tablet computers. A unique aspect of our system is that it is designed to enable the incorporation of lightweight social media-style interactions with co-workers along with factory data. Through this mixture of mobile, social, mixed and virtual technologies, we hope to create systems for enhanced collaboration in industrial settings between physically remote people and places, such as factories in China with managers in the US.
Publication Details
  • CHI 2012
  • May 7, 2012

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Affect influences workplace collaboration and thereby impacts a workplace's productivity. Participants in face-toface interactions have many cues to each other's affect, but work is increasingly carried out via computer-mediated channels that lack many of these cues. Current presence systems enable users to estimate the availability of other users, but not their affect states or communication preferences. This work investigates relationships between affect state and communication preferences and demonstrates the feasibility of estimating affect state and communication preferences from a presence state stream.
Publication Details
  • CHI 2012
  • May 5, 2012

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Abstract: Pico projectors have lately been investigated as mobile display and interaction devices. We propose to use them as ‘light beams’: Everyday objects sojourning in a beam are turned into dedicated projection surfaces and tangible interaction devices. While this has been explored for large projectors, the affordances of pico projectors are fundamentally different: they have a very small and strictly limited projection ray and can be carried around in a nomadic way during the day. Thus it is unclear how this could be actually leveraged for tangible interaction with physical, real world objects. We have investigated this in an exploratory field study and contribute the results. Based upon these, we present exemplary interaction techniques and early user feedback.

Designing a tool for exploratory information seeking

Publication Details
  • CHI 2012
  • May 5, 2012

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In this paper we describe our on-going design process in building a search system designed to support people's multi-session exploratory search tasks. The system, called Querium, allows people to run queries and to examine results as do conventional search engines, but it also integrates a sophisticated search history that helps people make sense of their search activity over time. Information seeking is a cognitively demanding process that can benefit from many kinds of information, if that information is presented appropriately. Our design process has been focusing on creating displays that facilitate on-going sense-making while keeping the interaction efficient, fluid, and enjoyable.

Querium: A Session-Based Collaborative Search System

Publication Details
  • European Conference on Information Retrieval 2012
  • Apr 1, 2012

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People's information-seeking can span multiple sessions, and can be collaborative in nature. Existing commercial offerings do not effectively support searchers to share, save, collaborate or revisit their information. In this demo paper we present Querium: a novel session-based collaborative search system that lets users search, share, resume and collaborate with other users. Querium provides a number of novel search features in a collaborative setting, including relevance feedback, query fusion, faceted search, and search histories
Publication Details
  • DAS 2012
  • Mar 27, 2012

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This paper describes a system for capturing images of a book with a 3D stereo camera which performs dewarping to produce output images that are flattened. A Fujifilm consumer grade 3D camera (FinePix W3) provides a highly mobile and low cost 3D capture device. Applying standard computer vision algorithms, the camera is calibrated and the captured images are stereo rectified. Due to technical limitations, the resulting point cloud has defects such as splotches and noise, which make it hard to recover the precise 3D locations of the points on the book pages. We address this problem by computing curve profiles of the depth map and using them to build a cylinder model of the pages. We then generate a mesh M1 on the source image and project this into a mesh M2 on the cylinder model in virtual space. Finally, the mesh M2 is flattened and the pixels in M1 are interpolated and rendered via M2 onto the output image. We have implemented a prototype of the system and report on some preliminary evaluation results.
Publication Details
  • ACM Transactions on Computer Human Interaction
  • Mar 1, 2012

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To combine the affordances of paper and computers, prior research has proposed numerous interactive paper systems that link specific paper document content to digital operations such as multimedia playback and proofreading. Yet, it remains unclear to what degree these systems bridge the inherent gap between paper and computers when compared to existing paper-only and computer-only interfaces. In particular, given the special properties of paper, such as limited dynamic feedback, how well does an average new user learn to master the interactive paper system? What factors affect the user performance? And how does the paper interface work in a typical use scenario? To answer these questions, we conducted two empirical experiments on a generic pen gesture based command system, called PapierCraft [Liao, et al., 2008], for paper-based interfaces. With it, people can select sections of printed document and issue commands such as copy and paste, linking and in-text search. The first experiment focused on the user performance of drawing pen gestures on paper. It proves that users can learn the command system in about 30 minutes and achieve a performance comparable to a Table PC-based interface supporting the same gestures. The second experiment examined the application of the command system in Active Reading tasks. The results show promise for seamless integration of paper and computers in Active Reading for their combined affordances. In addition, our study identifies some key design issues, such as the pen form factor and feedback of gestures. This paper contributes to better understanding on pros and cons of paper and computers, and sheds light on the design of future interfaces for document interaction.

TalkMiner: A Lecture Video Search Engine

Publication Details
  • Fuji Xerox Technical Report, No. 21, 2012, pp. 118-128
  • Feb 3, 2012

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The design and implementation of a search engine for lecture webcasts is described. A searchable text index is created allowing users to locate material within lecture videos found on a variety of websites such as YouTube and Berkeley webcasts. The searchable index is built from the text of presentation slides appearing in the video along with other associated metadata such as the title and abstract when available. The automatic identification of distinct slides within the video stream presents several challenges. For example, picture-in-picture compositing of a speaker and a presentation slide, switching cameras, and slide builds confuse basic algorithms for extracting keyframe slide images. Enhanced algorithms are described that improve slide identification. A public system was deployed to test the algorithms and the utility of the search engine at www.talkminer.com. To date, over 17,000 lecture videos have been indexed from a variety of public sources.
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.
Publication Details
  • Personal and Ubiquitous Computing (PUC)
  • Feb 1, 2012

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Presence systems are valuable in supporting workplace communication and collaboration. These systems are only effective if widely adopted and used. User perceptions of the utility of the information being shared and their comfort sharing such information strongly impact adoption and use. This paper describes the results of a survey of user preferences regarding comfort with and utility of workplace presence systems; the effects of sampling frequency, fidelity, and aggregation; and design implications of these results. We present new results that extend some past findings while challenging others. We contribute new design insights that inform the design of presence technologies to increase both utility and adoption.
2011
Publication Details
  • The 10th International Conference on Virtual Reality Continuum and Its Applications in Industry
  • Dec 11, 2011

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Augmented Paper (AP) is an important area of Augmented Reality (AR). Many AP systems rely on visual features for paper doc-ument identification. Although promising, these systems can hardly support large sets of documents (i.e. one million documents) because of the high memory and time cost in handling high-dimensional features. On the other hand, general large-scale image identification techniques are not well customized to AP, costing unnecessarily more resource to achieve the identification accuracy required by AP. To address this mismatching between AP and image identification techniques, we propose a novel large-scale image identification technique well geared to AP. At its core is a geometric verification scheme based on Minimum visual-word Correspondence Set (MICSs). MICS is a set of visual word (i.e. quantized visual fea-ture) correspondences, each of which contains a minimum number of correspondences that are sufficient for deriving a transformation hypothesis between a captured document image and an indexed image. Our method selects appropriate MICSs to vote in a Hough space of transformation parameters, and uses a robust dense region detection algorithm to locate the possible transformation models in the space. The models are then utilized to verify all the visual word correspondence to precisely identify the matching indexed image. By taking advantage of unique geometric constraints in AP, our method can significantly reduce the time and memory cost while achieving high accuracy. As showed in evaluation with two AP systems called FACT and EMM, over a dataset with 1M+ images, our method achieves 100% identification accuracy and 0.67% registration error for FACT; For EMM, our method outperforms the state-of-the-art image identification approach by achieving 4% improvements in detection rate and almost perfect precision, while saving 40% and 70% memory and time cost.

PaperUI

Publication Details
  • Springer LNCS
  • Dec 1, 2011

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PaperUI is a human-information interface concept that advocates using paper as displays and using mobile devices, such as camera phones or camera pens, as traditional computer-mice. When emphasizing technical efforts, some researchers like to refer the PaperUI related underlying work as interactive paper system. We prefer the term PaperUI for emphasizing the final goal, narrowing the discussion focus, and avoiding terminology confusion between interactive paper system and interactive paper computer [40]. PaperUI combines the merits of paper and the mobile devices, in that users can comfortably read and flexibly arrange document content on paper, and access digital functions related to the document via the mobile computing devices. This concept aims at novel interface technology to seamlessly bridge the gap between paper and computers for better user experience in handling documents. Compared with traditional laptops and tablet PCs, devices involved in the PaperUI concept are more light-weight, compact, energy efficient, and widely adopted. Therefore, we believe this interface vision can make computation more convenient to access for general public.