Patrick Chiu, Ph. D.

Senior Research Scientist

Patrick Chiu

Patrick’s current research interests include multimedia applications and content analysis, human-computer interaction, and ubiquitous computing. Before joining FXPAL, he worked at Xerox PARC and LiveWorks, Inc. He graduated summa cum laude with a BA from UC San Diego, and received a PhD in mathematics from Stanford University.

 

 

 

 

 

Co-Authors

Publications

2017
Publication Details
  • IEEE Transactions on Visualization and Computer Graphics (Proceedings of VAST 2017)
  • Oct 1, 2017

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Discovering and analyzing biclusters, i.e., two sets of related entities with close relationships, is a critical task in many real-world applications, such as exploring entity co-occurrences in intelligence analysis, and studying gene expression in bio-informatics. While the output of biclustering techniques can offer some initial low-level insights, visual approaches are required on top of that due to the algorithmic output complexity.This paper proposes a visualization technique, called BiDots, that allows analysts to interactively explore biclusters over multiple domains. BiDots overcomes several limitations of existing bicluster visualizations by encoding biclusters in a more compact and cluster-driven manner. A set of handy interactions is incorporated to support flexible analysis of biclustering results. More importantly, BiDots addresses the cases of weighted biclusters, which has been underexploited in the literature. The design of BiDots is grounded by a set of analytical tasks derived from previous work. We demonstrate its usefulness and effectiveness for exploring computed biclusters with an investigative document analysis task, in which suspicious people and activities are identified from a text corpus.
2016
Publication Details
  • UIST 2016 (Demo)
  • Oct 16, 2016

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We propose a robust pointing detection with virtual shadow representation for interacting with a public display. Using a depth camera, our shadow is generated by a model with an angled virtual sun light and detects the nearest point as a pointer. Position of the shadow becomes higher when user walks closer, which conveys the notion of correct distance to control the pointer and offers accessibility to the higher area of the display.
Publication Details
  • IUI 2016
  • Mar 7, 2016

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We describe methods for analyzing and visualizing document metadata to provide insights about collaborations over time. We investigate the use of Latent Dirichlet Allocation (LDA) based topic modeling to compute areas of interest on which people collaborate. The topics are represented in a node-link force directed graph by persistent fixed nodes laid out with multidimensional scaling (MDS), and the people by transient movable nodes. The topics are also analyzed to detect bursts to highlight "hot" topics during a time interval. As the user manipulates a time interval slider, the people nodes and links are dynamically updated. We evaluate the results of LDA topic modeling for the visualization by comparing topic keywords against the submitted keywords from the InfoVis 2004 Contest, and we found that the additional terms provided by LDA-based keyword sets result in improved similarity between a topic keyword set and the documents in a corpus. We extended the InfoVis dataset from 8 to 20 years and collected publication metadata from our lab over a period of 21 years, and created interactive visualizations for exploring these larger datasets.
2015

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New technology comes about in a number of different ways. It may come from advances in scientific research, through new combinations of existing technology, or by simply from imagining what might be possible in the future. This video describes the evolution of Tabletop Telepresence, a system for remote collaboration through desktop videoconferencing combined with a digital desk. Tabletop Telepresence provides a means to share paper documents between remote desktops, interact with documents and request services (such as translation), and communicate with a remote person through a teleconference. It was made possible by combining advances in camera/projector technology that enable a fully functional digital desk, embodied telepresence in video conferencing and concept art that imagines future workstyles.
Publication Details
  • DocEng 2015
  • Sep 8, 2015

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We present a novel system for detecting and capturing paper documents on a tabletop using a 4K video camera mounted overhead on pan-tilt servos. Our automated system first finds paper documents on a cluttered tabletop based on a text probability map, and then takes a sequence of high-resolution frames of the located document to reconstruct a high quality and fronto-parallel document page image. The quality of the resulting images enables OCR processing on the whole page. We performed a preliminary evaluation on a small set of 10 document pages and our proposed system achieved 98% accuracy with the open source Tesseract OCR engine.
Publication Details
  • CSCW 2015
  • Mar 14, 2015

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Collaboration Map (CoMap) is an interactive visualization tool showing temporal changes of small group collaborations. As dynamic entities, collaboration groups have flexible features such as people involved, areas of work, and timings. CoMap shows a graph of collaborations during user-adjustable periods, providing overviews of collaborations' dynamic features. We demonstrate CoMap with a co-authorship dataset extracted from DBLP to visualize 587 publications by 29 researchers at a research organization.
2014
Publication Details
  • ICME 2014, Best Demo Award
  • Jul 14, 2014

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In this paper, we describe Gesture Viewport, a projector-camera system that enables finger gesture interactions with media content on any surface. We propose a novel and computationally very efficient finger localization method based on the detection of occlusion patterns inside a virtual sensor grid rendered in a layer on top of a viewport widget. We develop several robust interaction techniques to prevent unintentional gestures to occur, to provide visual feedback to a user, and to minimize the interference of the sensor grid with the media content. We show the effectiveness of the system through three scenarios: viewing photos, navigating Google Maps, and controlling Google Street View.
Publication Details
  • HotMobile 2014
  • Feb 26, 2014

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In this paper, we propose HiFi system which enables users to interact with surrounding physical objects. It uses coded light to encode position in an environment. By attaching a tiny light sensor on a user’s mobile device, the user can attach digital info to arbitrary static physical objects or retrieve/modify them anchored to these objects. With this system, a family member may attach a digital maintenance schedule to a fish tank or indoor plants, etc. In a store, a store manager may use such system to attach price tag, discount info and multimedia contents to any products and customers can get the attached info by moving their phone close to the focused product. Similarly, a museum can use this system to provide extra info of displayed items to visitors. Different from computer vision based systems, HiFi does not have requests on texture, bright illumination, etc. Different from regular barcode approaches, HiFi does not require extra physical attachments that may change an object’s native appearance. HiFi has much higher spatial resolution for distinguishing close objects or attached parts of the same object. As HiFi system can track a mobile device at 80 positions per second, it also has much faster response than any above listed system.
2013
Publication Details
  • IEEE ISM 2013
  • Dec 9, 2013

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Real-time tele-immersion requires low latency, synchronized multi-camera capture. Prior high definition (HD) capture systems were bulky. We in vestigate the suitability of using flocks of smartphone cameras for tele-immersion. Smartphones can potentially integrate HD capture and streaming into a single portable package. However, they are designed for archiving the captured video into a movie. Hence, we create a sequence of H.264 movies and stream them. We lower the capture delay by reducing the number of frames in each movie segment. Increasing the number of movie segments adds compression overhead. Smartphone video encoders do not sacrifice video quality to lower the compression latency or the stream size. On an iPhone 4S, our application that uses published APIs streams 1920x1080 videos at 16.5 fps with a delay of 712 msec between a real-life event and displaying an uncompressed bitmap of this event on a local laptop. For comparison, the bulky Cisco Tandberg required 300 msec delay. Stereoscopic video from two unsynchronized smartphones showed minimal visual artifacts in an indoor teleconference setting.
Publication Details
  • Interactive Tabletops and Surfaces (ITS) 2013
  • Oct 6, 2013

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The expressiveness of touch input can be increased by detecting additional finger pose information at the point of touch such as finger rotation and tilt. PointPose is a prototype that performs finger pose estimation at the location of touch using a short-range depth sensor viewing the touch screen of a mobile device. We present an algorithm that extracts finger rotation and tilt from a point cloud generated by a depth sensor oriented towards the device's touchscreen. The results of two user studies we conducted show that finger pose information can be extracted reliably using our proposed method. We show this for controlling rotation and tilt axes separately and also for combined input tasks using both axes. With the exception of the depth sensor, which is mounted directly on the mobile device, our approach does not require complex external tracking hardware, and, furthermore, external computation is unnecessary as the finger pose extraction algorithm can run directly on the mobile device. This makes PointPose ideal for prototyping and developing novel mobile user interfaces that use finger pose estimation.
Publication Details
  • CBDAR 2013
  • Aug 23, 2013

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Capturing book images is more convenient with a mobile phone camera than with more specialized flat-bed scanners or 3D capture devices. We built an application for the iPhone 4S that captures a sequence of hi-res (8 MP) images of a page spread as the user sweeps the device across the book. To do the 3D dewarping, we implemented two algorithms: optical flow (OF) and structure from motion (SfM). Making further use of the image sequence, we examined the potential of multi-frame OCR. Preliminary evaluation on a small set of data shows that OF and SfM had comparable OCR performance for both single-frame and multi-frame techniques, and that multi-frame was substantially better than single-frame. The computation time was much less for OF than for SfM.
2012
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.
2011
Publication Details
  • CHI 2011
  • May 7, 2011

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For document visualization, folding techniques provide a focus-plus-context approach with fairly high legibility on flat sections. To enable richer interaction, we explore the design space of multi-touch document folding. We discuss several design considerations for simple modeless gesturing and compatibility with standard Drag and Pinch gestures, and categorize gesture models along the characteristics of Symmetric/Asymmetric and Sequential/Parallel, which yields three gesture models. We built a prototype document workspace application that integrates folding and standard gestures, and a prototype for experimenting with the gesture models. A user study was conducted to compare the three models and to analyze the factors of fold direction, target symmetry, and target tolerance in user performance of folding a document to a specific shape. Our results indicate that all three factors were significant for task times, and parallelism was greater for symmetric targets.
2010
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
  • ACM DocEng 2010
  • Sep 21, 2010

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We present a method for picture detection in document page images, which can come from scanned or camera images, or rendered from electronic file formats. Our method uses OCR to separate out the text and applies the Normalized Cuts algorithm to cluster the non-text pixels into picture regions. A refinement step uses the captions found in the OCR text to deduce how many pictures are in a picture region, thereby correcting for under- and over-segmentation. A performance evaluation scheme is applied which takes into account the detection quality and fragmentation quality. We benchmark our method against the ABBYY application on page images from conference papers.

Seamless Document Handling

Publication Details
  • Fuji Xerox Technical Report, No.19, 2010, pp. 57-65.
  • Jan 12, 2010

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The current trend toward high-performance mobile networks and increasingly sophisticated mobile devices has fostered the growth of mobile workers. In mobile environments, an urgent need exists for handling documents using a mobile phone, especially for browsing documents and viewing Rich Contents created on computers. This paper describes Seamless Document Handling, which is a technology for viewing electronic documents and Rich Contents on the small screen of a mobile phone. To enhance operability and readability, we devised a method of scrolling documents efficiently by applying document image processing technology, and designed a novel user interface with a pan-and-zoom technique. We conducted on-site observations to test usability of the prototype, and gained insights difficult to acquire in a lab that led to improved functions in the prototype.
2009
Publication Details
  • Pervasive 2009
  • May 11, 2009

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Recorded presentations are difficult to watch on a mobile phone because of the small screen, and even more challenging when the user is traveling or commuting. This demo shows an application designed for viewing presentations in a mobile situation, and describes the design process that involved on-site observation and informal user testing at our lab. The system generates a user-controllable movie by capturing a slide presentation, extracting active regions of interest using cues from the presenter, and creating pan-and-zoom effects to direct the active regions within a small screen. During playback, the user can simply watch the movie in automatic mode using a minimal amount of effort to operate the application. When more flexible control is needed, the user can switch into manual mode to temporarily focus on specific regions of interest.
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.

mTable: Browsing Photos and Videos on a Tabletop System

Publication Details
  • ACM Multimedia 2008 (Video)
  • Oct 27, 2008

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In this video demo, we present mTable, a multimedia tabletop system for browsing photo and video collections. We have developed a set of applications for visualizing and exploring photos, a board game for labeling photos, and a 3D cityscape metaphor for browsing videos. The system is suitable for use in a living room or office lounge, and can support multiple displays by visualizing the collections on the tabletop and showing full-size images and videos on another flat panel display in the room.
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.
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
  • UIST 2007 Poster & Demo
  • Oct 7, 2007

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We are exploring the use of collaborative games to generate meaningful textual tags for photos. We have designed Pho-toPlay to take advantage of the social engagement typical of board games and provide a collocated ludic environment conducive to the creation of text tags. We evaluated Photo-Play and found that it was fun and socially engaging for players. The milieu of the game also facilitated playing with personal photos, which resulted in more specific tags such as named entities than when playing with randomly selected online photos. Players also had a preference for playing with personal photos.
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.