Typical web navigation techniques tend to support undirected web browsing, a depth-first search of information pages. This search strategy often results in the unintentional behavior of 'web surfing', where a user starts in search of information, but is sidetracked by tangential links. A mobile user in particular, would prefer to extract the desired information quickly and with minimal mental effort. In this paper, we introduce 'SemantiLynx' to visually augment hyperlinks on web pages for better supporting the task of directed searches on small-screen ubiquitous platforms. Our algorithm comprises four parts: establishing the context of information related to a hyperlink, retrieving relevant imagery based on this context, applying image simplification, and finally compositing a visual icon for the given hyperlink. We evaluated our system by conducting user studies for directed web search tasks and comparing the results to using textual snippets and webpage thumbnails.

Jobs in the computing field demand communication and teamwork skills in addition to programming skills. Focus at the undergraduate level needs to be shifted towards developing these collaborative skills to enable a more smooth transition into employment in industry. The University of Victoria is in its second year of offering a course on game design. In the first offering, new activities were introduced to address issues identified by recent studies on university graduates entering industry. We focused on integrating cooperative learning, group orientation, and peer review activities into the game design process. The course attracted students across multiple disciplines, and an analysis indicated increased student interest in pursuing a computer science degree. Unfortunately, the same pre- and post-surveys suggested that our collaborative activities may have resulted in a decrease in student interest regarding course work and in pursuing studies in game design. In this paper we report on how we used a studio-based pedagogical approach to restructure the peer review activities in our course. In our previous offering, students received peer feedback only on their final game presentation. In our latest offering, we integrated peer review activities into every step of the game development process, allowing students to refine their ideas while progressing through a game project. A quantitative analysis informs us that our refined peer review activities were successful in increasing student presentation confidence, sense of community, and excitement towards their course projects.

Music can significantly effect game play and help players understand underlying patterns in the game, or the effects of their actions on the characters. Conversely, inappropriate music can have a negative effect on players by creating additional difficulties. While game makers recognize the effects of music on game play, solutions that provide users with a choice in personal music are not forthcoming. We design, implement and evaluate an algorithm for automatically adapting an arbitrary music track from a personal library and synchronizing play back to the user, without requiring any access to the video game source code.

Over the past few years, games courses have been gaining in popularity, as there has been growing evidence showing positive enrollment and student engagement results. Nevertheless, new graduates still lack critical teamwork and problemsolving skills required by industry employers. Building upon other game programs that had successful results, we present a game design course developed to attract students of all disciplines. Our course is different because we focus on three main issues directly associated with new graduates entering industry: cooperative learning, peer review, and orientation with a pre-existing large code base. A quantitative analysis reveals both a positive and negative impact on students’ interests, in particular within a cohort of non-Computer Science majors. A qualitative analysis reveals the ways in which students were influenced by a course design where assessment was aligned with key industry issues.

Prior research indicates that gameplay experiences attributed to Massively Multiplayer Online Role Playing Games (MMORPGs) foster foreign language students' ability to communicate with players in the target language. We take a closer look at the role of language socialization in MMORPGs, specifically dialogue between native and non-native speakers. We modify the Dialogue Acts Markup in Several Layers code scheme to represent in-game social interactions and apply this code scheme to players' game dialogue. We then develop ClockWerk©, an evaluation tool that visually depicts communication patterns of game dialogue attributed to MMORPGs. ClockWerk© graphically detects dominant behaviors of linguistically diverse groups of players over time. ClockWerk© enables users to temporally correlate the type of social interactions with gameplay activities, gauging their impact on second language acquisition.

Abstract This work introduces a technique for interactive walk‐throughs of non‐photorealistically rendered (NPR) scenes using three‐dimensional (3D) line primitives to define architectural features of the model, as well as indicate textural qualities. Line primitives are not typically used in this manner in favour of texture mapping techniques which can encapsulate a great deal of information in a single texture map, and take advantage of GPU optimizations for accelerated rendering. However, texture mapped images may not maintain the visual quality or aesthetic appeal that is possible when using 3D lines to simulate NPR scenes such as hand‐drawn illustrations or architectural renderings. In addition, line textures can be modified interactively, for instance changing the sketchy quality of the lines. The technique introduced here extracts feature edges from a model, and using these edges, generates a reduced set of line textures which indicate material properties while maintaining interactive frame rates. A clipping algorithm is presented to enable 3D lines to reside only in the interior of the 3D model without exposing the underlying triangulated mesh. The resulting system produces interactive illustrations with high visual quality that are free from animation artifacts.

We present a semi-automatic framework for construction of curved and polygonal 3D models from a 2D line drawing, such as architectural or mechanical drawings. Despite advances in image-based modeling, 3D modeling from a drawn image remains largely manual. In contrast, our method only requires the user to annotate the source image with a drawn cube for camera calibration. 3D models are then generated automatically. The modeling process has four steps: camera calibration, a novel line detection algorithm for noisy input, line labeling to calculate polygon adjacencies, a new incremental construction method that uses plane hinging-angle optimization to improve scalability over previous approaches. We also present algorithms for handling curved surfaces when they are part of a polygonal model that provides boundary conditions.

Abstract We present a framework for interactive sketching that allows users to create three‐dimensional (3D) architectural models quickly and easily from a source drawing. The sketching process has four steps. (1) The user calibrates a viewing camera by specifying the origin and vanishing points of the drawing. (2) The user outlines surface polygons in the drawing. (3) A 3D reconstruction algorithm uses perceptual constraints to determine the closest visual fit for the polygon. (4) The user can then adjust aesthetic controls to produce several stylistic effects in the scene: a smooth transition between day and night rendering, a horizon knockout effect and entourage figures. The major advantage of our approach lies in the combination of perception‐based techniques, which allow us to minimize unnecessary interactions, and a hinging‐angle scheme, which shows significant improvement in numerical stability over previous optimization‐based 3D reconstruction algorithms. We also demonstrate how our reconstruction algorithm can be extended to work with perspective images, a feature unavailable in previous approaches.

This paper proposes a visualization approach to address Domain Name System (DNS) security challenges, such as distributed denial of service (DDoS) and cache poisoning attacks.We present Flying Term, a new perceptually motivated visual metaphor for visualizing the dynamic nature of DNS queries. The addition of visual metaphors such as Stacking Graphs, Two Tone Pseudo Color, and Chernoff Face Glyph within the same application framework provide enhanced monitoring capability and situational awareness for visualizing DNS queries. We demonstrate our visualization's capability to help administrators identify and understand DNS querying behavior due to anomalies such as misconfiguration and security events with DNS query data acquired from a diverse set of caching servers on the Internet.

We present an automatic, real-time video and image abstraction framework that abstracts imagery by modifying the contrast of visually important features, namely luminance and color opponency. We reduce contrast in low-contrast regions using an approximation to anisotropic diffusion, and artificially increase contrast in higher contrast regions with difference-of-Gaussian edges. The abstraction step is extensible and allows for artistic or data-driven control. Abstracted images can optionally be stylized using soft color quantization to create cartoon-like effects with good temporal coherence. Our framework design is highly parallel, allowing for a GPU-based, real-time implementation. We evaluate the effectiveness of our abstraction framework with a user-study and find that participants are faster at naming abstracted faces of known persons compared to photographs. Participants are also better at remembering abstracted images of arbitrary scenes in a memory task.

We present a non-photorealistic algorithm for retargeting large images to small size displays, particularly on mobile devices. This method adapts large images so that important objects in the image are still recognizable when displayed at a lower target resolution. Existing image manipulation techniques such as cropping works well for images containing a single important object, and down-sampling works well for images containing low frequency information. However, when these techniques are automatically applied to images with multiple objects, the image quality degrades and important information may be lost. Our algorithm addresses the case of multiple important objects in an image. The retargeting algorithm segments an image into regions, identifies important regions, removes them, fills the resulting gaps, resizes the remaining image, and re-inserts the important regions. Our approach lies in constructing a topologically constrained epitome of an image based on a visual attention model that is both comprehensible and size varying, making the method suitable for display-critical applications.

We present a method that preserves the recognizability of key object interactions in a vector animation. The method allows an artist to author an animation once, and then output it to any display device. We specifically target mobile devices with small screen sizes. In order to adapt an animation, the author specifies an importance value for objects in the animation. The algorithm then identifies and categorizes the vector graphics objects that comprise the animation, leveraging the implicit relationship between extensible Markup Language (XML) and scalable vector graphics (SVG). Based on importance, the animation can then be automatically retargeted for any display using artistically motivated resizing and grouping algorithms that budget size and spatial detail for each object.

Semanticons can enhance the representation of files by offering symbols that are both meaningful and easily distinguishable. The semantics of a file is estimated by parsing its name, location, and content to generate a ‘context’, which is used to query an image database. The resulting images are simplified by segmenting them, computing an importance value for each segmented region, and removing unimportant regions. The abstract look-and-feel of icons is achieved using non-photorealistic techniques for image stylization. We increase the effectiveness of the semanticons by compositing them with traditional and familiar interface icons. Two psychophysical studies using semanticons as stimuli demonstrate that semanticons decrease the time necessary to locate a file in a visual search task and enhance performance in a memory task.

We present an algorithm to automatically estimate three-dimensional light positions from an unordered set of images. We collect images using a single stationary camera while manually moving a light source around an object. Rather than measuring light positions directly, the algorithm extracts a threedimensional manifold of positions from the images using dimensionality reduction techniques. This obviates the need for calibration and specialized equipment, making our approach inexpensive, portable and applicable to objects of almost any size. We demonstrate our results using image-based relighting applications.

Visually important image features often disappear when color images are converted to grayscale. The algorithm introduced here reduces such losses by attempting to preserve the salient features of the color image. The Color2Gray algorithm is a 3-step process: 1) convert RGB inputs to a perceptually uniform CIE L*a*b* color space, 2) use chrominance and luminance differences to create grayscale target differences between nearby image pixels, and 3) solve an optimization problem designed to selectively modulate the grayscale representation as a function of the chroma variation of the source image. The Color2Gray results offer viewers salient information missing from previous grayscale image creation methods.

We present a method for creating black-and-white illustrations from photographs of human faces. In addition an interactive technique is demonstrated for deforming these black-and-white facial illustrations to create caricatures which highlight and exaggerate representative facial features. We evaluate the effectiveness of the resulting images through psychophysical studies to assess accuracy and speed in both recognition and learning tasks. These studies show that the facial illustrations and caricatures generated using our techniques are as effective as photographs in recognition tasks. For the learning task we find that illustrations are learned two times faster than photographs and caricatures are learned one and a half times faster than photographs. Because our techniques produce images that are effective at communicating complex information, they are useful in a number of potential applications, ranging from entertainment and education to low bandwidth telecommunications and psychology research.

A rendering is an abstraction that favors, preserves, or even emphasizes some qualities while sacrificing, suppressing, or omitting other characteristics that are not the focus of attention.Most computer graphics rendering activities have been concerned with photorealism, i.e., trying to emulate an image that looks like a highquality photograph.This laudable goal is useful and appropriate in many applications, but not in technical illustration where elucidation of structure and technical information is the preeminent motivation.This calls for a different kind of abstraction in which technical communication is central, but art and appearance are still essential instruments toward this end.Work that has been done on computer generated technical illustrations has focused on static images, and has not included all of the techniques used to hand draw technical illustrations.A paradigm for the display of technical illustrations in a dynamic environment is presented.This display environment includes all of the benefits of computer generated technical illustrations, such as a clearer picture of shape, structure, and material composition than traditional computer graphics methods.It also includes the three-dimensional interactive strength of modem display systems.This is accomplished by using new algorithms for real time drawing of silhouette curves, algorithms which solve a number of the problems inherent in previous methods.We incorporate current non-photorealistic lighting methods, and augment them with new shadowing algorithms based on accepted techniques used by artists and studies carried out in human perception.This paper, all of the images, and a mpeg video clip are available at http

Phong-shaded 3D imagery does not provide geometric information of the same richness as human-drawn technical illustrations.A non-photorealistic lighting model is presented that attempts to narrow this gap.The model is based on practice in traditional technical illustration, where the lighting model uses both luminance and changes in hue to indicate surface orientation, reserving extreme lights and darks for edge lines and highlights.The lighting model allows shading to occur only in mid-tones so that edge lines and highlights remain visually prominent.In addition, we show how this lighting model is modified when portraying models of metal objects.These illustration methods give a clearer picture of shape, structure, and material composition than traditional computer graphics methods.