Qiong Liu, Ph.D.

Principal Research Scientist

Qiong Liu

Qiong Liu joined FXPAL in 2001. His research interests include paper user interface, thermal video processing, immersive conferencing, image/video/audio processing, multimedia, computer vision, machine learning, human-computer interaction, and robotics. Qiong earned his Ph.D. in Computer Science from the University of Illinois at Urbana-Champaign (UIUC) in 2001. He earned his M.S. in Precision Instruments at Tsinghua University in 1992 and his B.S. in Biomedical Engineering and Instrument Science from Zhejiang University in 1989.

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Publications

2011
Publication Details
  • CHI 2011 Workshop on Mobile and Personal Projection (MP2)
  • May 8, 2011

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The field of personal mobile projection is advancing quickly and a variety of work focuses on enhancing physical objects in the real world with dynamically projected digital artifacts. Due to technological restrictions, none of them has yet investigated, what we feel is the most promising research direction: the (bi-manual) interaction with mobile projections on non-planar surfaces. To elicit the challenges of this field of research, we contribute (1) a technology-centered design space for mobile projector-based interfaces and discus related work in light thereof, (2) a discussion on lessons learnt from two of our research projects, which aim at improving both usability and user experience and (3) an outline of open research challenges within this field.
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
  • Fuji Xerox Technical Report
  • Jan 1, 2011

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Embedded Media Markers, or simply EMMs, are nearly transparent iconic marks printed on paper documents that signify the existence of media associated with that part of the document. EMMs also guide users' camera operations for media retrieval. Users take a picture of an EMM-signified document patch using a cell phone, and the media associated with the EMM-signified document location is displayed on the phone. Unlike bar codes, EMMs are nearly transparent and thus do not interfere with the document appearance. Retrieval of media associated with an EMM is based on image local features of the captured EMM-signified document patch. This paper describes a technique for semi-automatically placing an EMM at a location in a document, in such a way that it encompasses sufficient identification features with minimal disturbance to the original document.
Publication Details
  • Encyclopledia of the Sciences of Learning
  • Jan 1, 2011

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Supervised Learning is a machine learning paradigm for acquiring the input-output relationship information of a system based on a given set of paired input-output training samples. As the output is regarded as the label of the input data or the supervision, an input-output training sample is also called labelled training data, or supervised data. Occasionally, it is also referred to as Learning with a Teacher (Haykin 1998), Learning from Labelled Data, or Inductive Machine Learning (Kotsiantis, 2007). The goal of supervised learning is to build an artificial system that can learn the mapping between the input and the output, and can predict the output of the system given new inputs. If the output takes a finite set of discrete values that indicate the class labels of the input, the learned mapping leads to the classification of the input data. If the output takes continuous values, it leads to a regression of the input. The input-output relationship information is frequently represented with learning-model parameters. When these parameters are not directly available from training samples, a learning system needs to go through an estimation process to obtain these parameters. Different form Unsupervised Learning, the training data for Supervised Learning need supervised or labelled information, while the training data for unsupervised learning are unsupervised as they are not labelled (i.e., merely the inputs). If an algorithm uses both supervised and unsupervised training data, it is called a Semi-supervised Learning algorithm. If an algorithm actively queries a user/teacher for labels in the training process, the iterative supervised learning is called Active Learning.
2010
Publication Details
  • ACM International Conference on Multimodal Interfaces
  • Nov 8, 2010

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Embedded Media Barcode Links, or simply EMBLs, are optimally blended iconic barcode marks, printed on paper documents, that signify the existence of multimedia associated with that part of the document content (Figure 1). EMBLs are used for multimedia retrieval with a camera phone. Users take a picture of an EMBL-signified document patch using a cell phone, and the multimedia associated with the EMBL-signified document location is displayed on the phone. Unlike a traditional barcode which requires an exclusive space, the EMBL construction algorithm acts as an agent to negotiate with a barcode reader for maximum user and document benefits. Because of this negotiation, EMBLs are optimally blended with content and thus have less interference with the original document layout and can be moved closer to a media associated location. Retrieval of media associated with an EMBL is based on the barcode identification of a captured EMBL. Therefore, EMBL retains nearly all barcode identification advantages, such as accuracy, speed, and scalability. Moreover, EMBL takes advantage of users' knowledge of a traditional barcode. Unlike Embedded Media Maker (EMM) which requires underlying document features for marker identification, EMBL has no requirement for the underlying features. This paper will discuss the procedures for EMBL construction and optimization. It will also give experimental results that strongly support the EMBL construction and optimization ideas.
Publication Details
  • ACM Multimedia 2010
  • Oct 25, 2010

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An Embedded Media Marker (EMM) is a transparent mark printed on a paper document that signifies the availability of additional media associated with that part of the document. Users take a picture of the EMM using a camera phone, and the media associated with that part of the document is displayed on the phone. Unlike bar codes, EMMs are nearly transparent and thus do not interfere with the document appearance. Retrieval of media associated with an EMM is based on image features of the document within the EMM boundary. Unlike other feature-based retrieval methods, the EMM clearly indicates to the user the existence and type of media associated with the document location. A semi-automatic authoring tool is used to place an EMM at a location in a document, in such a way that it encompasses sufficient identification features with minimal disturbance to the original document. We will demonstrate how to create an EMM-enhanced document, and how the EMM enables access to the associated media on a cell phone.
Publication Details
  • ACM Multimedia
  • Oct 25, 2010

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FACT is an interactive paper system for fine-grained interaction with documents across the boundary between paper and computers. It consists of a small camera-projector unit, a laptop, and ordinary paper documents. With the camera-projector unit pointing to a paper document, the system allows a user to issue pen gestures on the paper document for selecting fine-grained content and applying various digital functions. For example, the user can choose individual words, symbols, figures, and arbitrary regions for keyword search, copy and paste, web search, and remote sharing. FACT thus enables a computer-like user experience on paper. This paper interaction can be integrated with laptop interaction for cross-media manipulations on multiple documents and views. We present the infrastructure, supporting techniques and interaction design, and demonstrate the feasibility via a quantitative experiment. We also propose applications such as document manipulation, map navigation and remote collaboration.
Publication Details
  • In Proc. of CHI 2010
  • Apr 10, 2010

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PACER is a gesture-based interactive paper system that supports fine-grained paper document content manipulation through the touch screen of a cameraphone. Using the phone's camera, PACER links a paper document to its digital version based on visual features. It adopts camera-based phone motion detection for embodied gestures (e.g. marquees, underlines and lassos), with which users can flexibly select and interact with document details (e.g. individual words, symbols and pixels). The touch input is incorporated to facilitate target selection at fine granularity,and to address some limitations of the embodied interaction, such as hand jitter and low input sampling rate. This hybrid interaction is coupled with other techniques such as semi-real time document tracking and loose physical-digital document registration, offering a gesture-based command system. We demonstrate the use of PACER in various scenarios including work-related reading, maps and music score playing. A preliminary user study on the design has produced encouraging user feedback, and suggested future research for better understanding of embodied vs. touch interaction and one vs. two handed interaction.
Publication Details
  • IEEE Pervasive Computing. 9(2). 46-55.
  • Mar 15, 2010

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Paper is static but it is also light, flexible, robust, and has high resolution for reading documents in various scenarios. Digital devices will likely never match the flexibility of paper, but come with all of the benefits of computation and networking. Tags provide a simple means of bridging the gap between the two media to get the most out of both. In this paper, we explore the tradeoffs between two different types of tagging technologies – marker-based and content-based – through the lens of four systems we have developed and evaluated at our lab. From our experiences, we extrapolate issues for designers to consider when developing systems that transition between paper and digital content in a variety of different scenarios.
Publication Details
  • IUI 2010 Best Paper Award
  • Feb 7, 2010

Abstract

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Embedded Media Markers, or simply EMMs, are nearly transparent iconic marks printed on paper documents that signify the existence of media associated with that part of the document. EMMs also guide users' camera operations for media retrieval. Users take a picture of an EMMsignified document patch using a cell phone, and the media associated with the EMM-signified document location is displayed on the phone. Unlike bar codes, EMMs are nearly transparent and thus do not interfere with the document contents. Retrieval of media associated with an EMM is based on image local features of the captured EMMsignified document patch. This paper describes a technique for semi-automatically placing an EMM at a location in a document, in such a way that it encompasses sufficient identification features with minimal disturbance to the original document.
2009
Publication Details
  • ACM Multimedia 2009
  • Oct 19, 2009

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Existing cameraphone-based interactive paper systems fall short of the flexibility of GUIs, partly due to their deficient fine-grained interactions, limited interaction styles and inadequate targeted document types. We present PACER, a platform for applications to interact with document details (e.g. individual words, East Asian characters, math symbols, music notes, and user-specified arbitrary image regions) of generic paper documents through a camera phone. With a see-through phone interface, a user can discover symbol recurrences in a document by pointing the phone's crosshair to a symbol within a printout. The user can also continuously move the phone over a printout for gestures to copy and email an arbitrary region, or play music notes on the printout.
Publication Details
  • 2009 IEEE International Conference on Multimedia and Expo (ICME)
  • Jun 30, 2009

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This paper presents a tool and a novel Fast Invariant Transform (FIT) algorithm for language independent e-documents access. The tool enables a person to access an e-document through an informal camera capture of a document hardcopy. It can save people from remembering/exploring numerous directories and file names, or even going through many pages/paragraphs in one document. It can also facilitate people’s manipulation of a document or people’s interactions through documents. Additionally, the algorithm is useful for binding multimedia data to language independent paper documents. Our document recognition algorithm is inspired by the widely known SIFT descriptor [4] but can be computed much more efficiently for both descriptor construction and search. It also uses much less storage space than the SIFT approach. By testing our algorithm with randomly scaled and rotated document pages, we can achieve a 99.73% page recognition rate on the 2188-page ICME06 proceedings and 99.9% page recognition rate on a 504-page Japanese math book.

2008

Rethinking the Podium

Publication Details
  • Chapter in "Interactive Artifacts and Furniture Supporting Collaborative Work and Learning", ed. P. Dillenbourg, J. Huang, and M. Cherubini. Published Nov. 28, 2008, Springer. Computer Supported Collaborative learning Series Vol 10.
  • Nov 28, 2008

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As the use of rich media in mobile devices and smart environments becomes more sophisticated, so must the design of the everyday objects used as controllers and interfaces. Many new interfaces simply tack electronic systems onto existing forms. However, an original physical design for a smart artefact, that integrates new systems as part of the form of the device, can enhance the end-use experience. The Convertible Podium is an experiment in the design of a smart artefact with complex integrated systems for the use of rich media in meeting rooms. It combines the highly designed look and feel of a modern lectern with systems that allow it to serve as a central control station for rich media manipulation. The interface emphasizes tangibility and ease of use in controlling multiple screens, multiple media sources (including mobile devices) and multiple distribution channels, and managing both data and personal representation in remote telepresence.
Publication Details
  • Proceedings of ACM Multimedia '08, pp. 817-820 (Short Paper).
  • Oct 27, 2008

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We present an automatic zooming technique that leverages content analysis for viewing a document page on a small display such as a mobile phone or PDA. The page can come from a scanned document (bitmap image) or an electronic document (text and graphics data plus metadata). The page with text and graphics is segmented into regions. For each region, a scale-distortion function is constructed based on image analysis of the signal distortion that occurs at different scales. During interactive viewing of the document, as the user navigates by moving the viewport around the page, the zoom factor is automatically adjusted by optimizing the scale-distortion functions of the regions visible in the viewport.
Publication Details
  • ACM Multimedia 2008
  • Oct 27, 2008

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This demo introduces a tool for accessing an e-document by capturing one or more images of a real object or document hardcopy. This tool is useful when a file name or location of the file is unknown or unclear. It can save field workers and office workers from remembering/exploring numerous directories and file names. Frequently, it can convert tedious keyboard typing in a search box to a simple camera click. Additionally, when a remote collaborator cannot clearly see an object or a document hardcopy through remote collaboration cameras, this tool can be used to automatically retrieve and send the original e-document to a remote screen or printer.

Vital Sign Estimation from Passive Thermal Video

Publication Details
  • IEEE Computer Society Conference on Computer Vision and Pattern Recognition
  • Jun 24, 2008

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Conventional wired detection of vital signs limits the use of these important physiological parameters by many applications, such as airport health screening, elder care, and workplace preventive care. In this paper, we explore contact-free heart rate and respiratory rate detection through measuring infrared light modulation emitted near superficial blood vessels or a nasal area respectively. To deal with complications caused by subjects' movements, facial expressions, and partial occlusions of the skin, we propose a novel algorithm based on contour segmentation and tracking, clustering of informative pixels, and dominant frequency component estimation. The proposed method achieves robust subject regions-of-interest alignment and motion compensation in infrared video with low SNR. It relaxes some strong assumptions used in previous work and substantially improves on previously reported performance. Preliminary experiments on heart rate estimation for 20 subjects and respiratory rate estimation for 8 subjects exhibit promising results.
2007
Publication Details
  • The 3rd International Conference on Collaborative Computing: Networking, Applications and Worksharing
  • Nov 12, 2007

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This paper summarizes our environment-image/videosupported collaboration technologies developed in the past several years. These technologies use environment images and videos as active interfaces and use visual cues in these images and videos to orient device controls, annotations and other information access. By using visual cues in various interfaces, we expect to make the control interface more intuitive than buttonbased control interfaces and command-based interfaces. These technologies can be used to facilitate high-quality audio/video capture with limited cameras and microphones. They can also facilitate multi-screen presentation authoring and playback, teleinteraction, environment manipulation with cell phones, and environment manipulation with digital pens.
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.

POEMS: A Paper Based Meeting Service Management Tool

Publication Details
  • ICME 2007
  • Jul 2, 2007

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As more and more tools are developed for meeting support tasks, properly using these tools to get expected results becomes too complicated for many meeting participants. To address this problem, we propose POEMS (Paper Offered Environment Management Service) that allows meeting participants to control services in a meeting environment through a digital pen and an environment photo on digital paper. Unlike state-of-the-art device control interfaces that require interaction with text commands, buttons, or other artificial symbols, our photo enabled service access is more intuitive. Compared with PC and PDA supported control, this new approach is more flexible and cheap. With this system, a meeting participant can initiate a whiteboard on a selected public display by tapping the display image in the photo, or print out a display by drawing a line from the display image to a printer image in the photo. The user can also control video or other active applications on a display by drawing a link between a printed controller and the image of the display. This paper presents the system architecture, implementation tradeoffs, and various meeting control scenarios.
Publication Details
  • ICME 2007
  • Jul 2, 2007

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As more and more tools are developed for meeting support tasks, properly using these tools to get expected results becomes very complicated for many meeting participants. To address this problem, we propose POEMS (Paper Offered Environment Management Service) that can facilitate the activation of various services with a pen and paper based interface. With this tool, meeting participants can control meeting support devices on the same paper that they take notes. Additionally, a meeting participant can also share his/her paper drawings on a selected public display or initiate a collaborative discussion on a selected public display with a page of paper. Compared with traditional interfaces, such as tablet PC or PDA based interfaces, the interface of this tool has much higher resolution and is much cheaper and easier to deploy. The paper interface is also natural to use for ordinary people.
Publication Details
  • Pervasive 2007 Invited Demo
  • May 13, 2007

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We present an investigation of interaction models for slideshow applications in a multi-display environment. Three models are examined: Direct Manipulation, Billiard Ball, and Flow. These concepts can be demonstrated by the ModSlideShow prototype, which is designed as a configurable modular display system where each display unit communicates with its neighbors and fundamental operations that act locally can be composed to support the higher level interaction models. We also describe the gesture input scheme, animation feedback, and other enhancements.
2006
Publication Details
  • Proceedings of IEEE Multimedia Signal Processing 2006
  • Oct 3, 2006

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This paper presents a method for facilitating document redirection in a physical environment via a mobile camera. With this method, a user is able to move documents among electronic devices, post a paper document to a selected public display, or make a printout of a white board with simple point-and-capture operations. More specifically, the user can move a document from its source to a destination by capturing a source image and a destination image in a consecutive order. The system uses SIFT (Scale Invariant Feature Transform) features of captured images to identify the devices a user is pointing to, and issues corresponding commands associated with identified devices. Unlike RF/IR based remote controls, this method uses object visual features as an all time 'transmitter' for many tasks, and therefore is easy to deploy. We present experiments on identifying three public displays and a document scanner in a conference room for evaluation.
2005
Publication Details
  • Proceedings of SPIE International Symposium ITCom 2005 on Multimedia Systems and Applications VIII, Boston, Massachusetts, USA, October 2005.
  • Dec 7, 2005

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Meeting environments, such as conference rooms, executive briefing centers, and exhibition spaces, are now commonly equipped with multiple displays, and will become increasingly display-rich in the future. Existing authoring / presentation tools such as PowerPoint, however, provide little support for effective utilization of multiple displays. Even using advanced multi-display enabled multimedia presentation tools, the task of assigning material to displays is tedious and distracts presenters from focusing on content. This paper describes a framework for automatically assigning presentation material to displays, based on a model of the quality of views of audience members. The framework is based on a model of visual fidelity which takes into account presentation content, audience members' locations, the limited resolution of human eyes, and display location, orientation, size, resolution, and frame rate. The model can be used to determine presentation material placement based on average or worst case audience member view quality, and to warn about material that would be illegible. By integrating this framework with a previous system for multi-display presentation [PreAuthor, others], we created a tool that accepts PowerPoint and/or other media input files, and automatically generates a layout of material onto displays for each state of the presentation. The tool also provides an interface allowing the presenter to modify the automatically generated layout before or during the actual presentation. This paper discusses the framework, possible application scenarios, examples of the system behavior, and our experience with system use.
Publication Details
  • Paper presented at SIGGRAPH 2005, Los Angeles.
  • Sep 29, 2005

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