context

This research explores distributed sensing techniques for mobile devices using synchronous gestures. These are patterns of activity, contributed by multiple users (or one user with multiple devices), which take on a new meaning when they occur together in time, or in a specific sequence in time. To explore this new area of inquiry, this work uses tablet computers augmented with touch sensors and two-axis linear accelerometers (tilt sensors). The devices are connected via an 802.11 wireless network and synchronize their time-stamped sensor data. This paper describes a few practical examples of interaction techniques using synchronous gestures such as dynamically tiling together displays by physically bumping them together, discusses implementation issues, and speculates on further possibilities for synchronous gestures.

Information cannot be found if it is not recorded. Existing rich graphical application approaches interfere with user input in many ways, forcing complex interactions to enter simple information, requiring complex cognition to decide where the data should be stored, and limiting the kind of information that can be entered to what can fit into specific applications' data models. Freeform text entry suffers from none of these limitations but produces data that is hard to retrieve or visualize. We describe the design and implementation of Jourknow, a system that aims to bridge these two modalities, supporting lightweight text entry and weightless context capture that produces enough structure to support rich interactive presentation and retrieval of the arbitrary information entered.

The increasing mass of information confronting a business or an individual have created a demand for information management applications. Time-based information, in particular, is an important part of many information access tasks. This paper explores how to use 3D graphics and interactive animation to design and implement visualizers that improve access to large masses of time-based information. Two new visualizers have been developed for the Information Visualizer: 1) the Spiral Calendar was designed for rapid access to an individual's daily schedule, and 2) the Time Lattice was designed for analyzing the time relationships among the schedules of groups of people. The Spiral Calendar embodies a new 3D graphics technique for integrating detail and context by placing objects in a 3D spiral. It demonstrates that advanced graphics techniques can enhance routine office information tasks. The Time Lattice is formed by aligning a collection of 2D calendars. 2D translucent shadows provide views and interactive access to the resulting complex 3D object. The paper focuses on how these visualizations were developed. The Spiral Calendar, in particular, has gone through an entire cycle of development, including design, implementation, evaluation, revision and reuse. Our experience should prove useful to others developing user interfaces based on advanced graphics.

We present a novel display metaphor which extends traditional tabletop projections in collaborative environments by introducing freeform, environment-aware display representations and a matching set of interaction schemes. For that purpose, we map personalized widgets or ordinary computer applications that have been designed for a conventional, rectangular layout into space-efficient bubbles whose warping is performed with a potential-based physics approach. With a set of interaction operators based on laser pointer tracking, these freeform displays can be transformed and elastically deformed using focus and context visualization techniques. We also provide operations for intuitive instantiation of bubbles, cloning, cut & pasting, deletion and grouping in an interactive way, and we allow for user-drawn annotations and text entry using a projected keyboard. Additionally, an optional environment-aware adaptivity of the displays is achieved by imperceptible, realtime scanning of the projection geometry. Subsequently, collision-responses of the bubbles with non-optimal surface parts are computed in a rigid body simulation. The extraction of the projection surface properties runs concurrently with the main application of the system. Our approach is entirely based on off the-shelf, low-cost hardware including DLP-projectors and FireWire cameras.

Image retargeting is the problem of adapting images for display on devices different than originally intended. This paper presents a method for adapting large images, such as those taken with a digital camera, for a small display, such as a cellular telephone. The method uses a non-linear fisheye-view warp that emphasizes parts of an image while shrinking others. Like previous methods, fisheye-view warping uses image information, such as low-level salience and high-level object recognition to find important regions of the source image. However, unlike prior approaches, a non-linear image warping function emphasizes the important aspects of the image while retaining the surrounding context. The method has advantages in preserving information content, alerting the viewer to missing information and providing robustness.

Computer users working with large visual documents, such as large layouts, blueprints, or maps perform tasks that require them to simultaneously access overview information while working on details. To avoid the need for zooming, users currently have to choose between using a sufficiently large screen or applying appropriate visualization techniques. Currently available hi-res "wall-size" screens, however, are cost-intensive, space-intensive, or both. Visualization techniques allow the user to more efficiently use the given screen space, but in exchange they either require the user to switch between multiple views or they introduce distortion.In this paper, we present a novel approach to simultaneously display focus and context information. Focus plus context screens consist of a hi-res display and a larger low-res display. Image content is displayed such that the scaling of the display content is preserved, while its resolution may vary according to which display region it is displayed in. Focus plus context screens are applicable to practically all tasks that currently use overviews or fisheye views, but unlike these visualization techniques, focus plus context screens provide a single, non-distorted view. We present a prototype that seamlessly integrates an LCD with a projection screen and demonstrate four applications that we have adapted so far.

We present a new focus+context (fisheye) scheme for visualizing and manipulating large hierarchies. The essence of our approach is to lay out the hierarchy uniformly on the hyperbolic plane and map this plane onto a circular display region. The projection onto the disk provides a natural mechanism for assigning more space to a portion of the hierarchy while still embedding it in a much larger context. Change of focus is accomplished by translating the structure on the hyperbolic plane, which allows a smooth transition without compromising the presentation of the context.

We describe WEST, a WEb browser for Small Terminals, that aims to solve some of the problems associated with accessing web pages on hand-held devices. Through a novel combination of text reduction and focus+context visualization, users can access web pages from a very limited display environment, since the system will provide an overview of the contents of a web page even when it is too large to be displayed in its entirety. To make maximum use of the limited resources available on a typical hand-held terminal, much of the most demanding work is done by a proxy server, allowing the terminal to concentrate on the task of providing responsive user interaction. The system makes use of some interaction concepts reminiscent of those defined in the Wireless Application Protocol (WAP), making it possible to utilize the techniques described here for WAP-compliant devices and services that may become available in the near future.

Many on-line interaction environments have a large number of users. It is difficult for the participants, especially new ones, to form a clear mental image about those with whom they are interacting. How can we compactly convey information about these participants to each other? We propose the data portrait, a novel graphical representation of users based on their past interactions. Data portraits can inform users about each other and the overall social environment. We use a flower metaphor for creating individual data portraits, and a garden metaphor for combining these portraits to represent an on-line environment. We will review previous work in visualizing both individuals and groups. We will then describe our visualizations, explain how to create them, and show how they can be used to address user questions.