What you see is what you get [self-calibrating camera lens distortion]

A self-calibration method is presented for self-calibrating camera lens distortion by using only the image correspondences of two views. Two images of a single object are related by the epipolar geometry, which can be described by a 3 /spl times/ 3 singular matrix called fundamental matrix. It captures all geometric information contained in two images. An optimization method is applied to minimize the epipolar distances of the two images by adjusting the camera lens radial distortion coefficient. The merit of the method is that it does not rely on any ground truth data. Simulation and experimental results are given to demonstrate the applicability of the method.     

Hot topics-eye-gaze computer interfaces: what you look at is whatyou get

As computers are becoming more powerful, the critical bottleneck in their use is often in the user interface, not in the computer processing. Research in human-computer interaction that seeks to increase the communication bandwidth between the user and the machine by using input from the user's eye movement is discussed. The speed potential, processing stages, interaction techniques, and problems associated with these eye-gaze interfaces are described     

Do you see what I mean? [Data visualization]

Visualizers, like logicians, have long been concerned with meaning. Generalizing from MacEachren's overview of cartography, visualizers have to think about how people extract meaning from pictures (psychophysics), what people understand from a picture (cognition), how pictures are imbued with meaning (semiotics), and how in some cases that meaning arises within a social and/or cultural context. If we think of the communication acts carried out in the visualization process further levels of meaning are suggested. Visualization begins when someone has data that they wish to explore and interpret; the data are encoded as input to a visualization system, which may in its turn interact with other systems to produce a representation. This is communicated back to the user(s), who have to assess this against their goals and knowledge, possibly leading to further cycles of activity. Each phase of this process involves communication between two parties. For this to succeed, those parties must share a common language with an agreed meaning. We offer the following three steps, in increasing order of formality: terminology (jargon), taxonomy (vocabulary), and ontology. Our argument in this article is that it's time to begin synthesizing the fragments and views into a level 3 model, an ontology of visualization. We also address why this should happen, what is already in place, how such an ontology might be constructed, and why now.     

Testing homogeneous spreadsheet grids with the "what you see iswhat you test" methodology

Although there has been recent research into ways to design environments that enable end users to create their own programs, little attention has been given to helping these end users systematically test their programs. To help address this need in spreadsheet systems (the most widely used type of end-user programming language), we previously introduced a visual approach to systematically testing individual cells in spreadsheet systems. However, the previous approach did not scale well in the presence of largely homogeneous grids, which introduce problems somewhat analogous to the array-testing problems of imperative programs. We present two approaches to spreadsheet testing that explicitly support such grids. We present the algorithms, time complexities, and performance data comparing the two approaches. This is part of our continuing work to bring to end users at least some of the benefits of formalized notions of testing without requiring knowledge of testing beyond a naive level     

Statistical process control: what you don't measure can hurt you!

Statistical control charts are the most commonly used tools to analyze and monitor process variation and stability. Control charts help us isolate nonrandom causes of variation by plotting a measured attribute of the process over time; the upper and lower control limits are empirically derived from the measurements of process variation over time. If a data point falls outside the control limits, we assume that a nonrandom cause of variation is present. It is important that the control limits appropriately reflect the expected behavior of the process being measured. Measuring the number of escaped defects will alert us to problems in the inspection process even though the control charts might not be showing anything abnormal.     

MyDoom: Do you “get it” yet?

Discovered on 26 January, 2004, the MyDoom worm went from seed mailing to major threat within hours. By the following day, managed email provider MessageLabs had already logged over one million instances of MyDoom infected email. During that same period, Frisk Software reported 14.3% of all email passing through their aves.f-prot.com filter was MyDoom infected. Within 48 hours, that percentage had risen to at least 31.85%. Erroneous alerting messages from antivirus and filtering products heightened the impact, bringing the total of MyDoom-centric email to 65%.     

Detecting transient changes in dynamic displays: the more you look, the less you see

OBJECTIVE: Two experiments examined the detectability of transient changes in cluttered and dynamic displays and optimal scan strategies for performance. BACKGROUND: Research has demonstrated that onset changes are prioritized by the attention system and onsets are often used to signal important display changes. However, research has mostly used uncluttered, static displays and has largely ignored the role of scan strategy. METHOD: We had participants monitor a cluttered and dynamic display and respond when an object changed color or onset abruptly. Scan strategies were also evaluated. In another experiment participants were instructed to use particular strategies to detect changes. RESULTS: Consistent with previous results, onset events were detected better than were color change events. Scan strategy accounted for a large proportion of variance in detection performance. Participants who made few eye movements performed best. Participants who actively scanned the display performed worst. When poor performers were instructed to make few eye movements, their performance matched that of the best performers. CONCLUSION: Onset alerts can be an effective means of signaling important events in complex displays. Additionally, scan strategy plays an important role in the detection of transient events. APPLICATION: These results have important implications for training operators to search for transient changes within dynamic and cluttered displays.     

Finding what you want: new tools and tricks

You log in and find an urgent request for information about state-of-the-art tools for finding information on the World Wide Web. No problem. At the click of a mouse, you call up your favorite Web search engine and fire off the query “information retrieval WWW”. You get back lots of information in a nicely ordered list. Problem solved. It's not quite so easy-as library scientists have long known and users of the Web are discovering     

How did you first get into computing?

The route to a computing career is often circuitous. As part of the ongoing research on the history of women in computing, we conducted oral history interviews with pioneers in the field, during which we asked about their first encounters with computers. Although individual experiences varied, a common thread in these stories is that women's opportunities were constrained by gender stereotypes, outright discrimination, and the demands of marriage and family. At the same time, computing was a relatively welcoming field for women, and it offered them a rare chance to put their technical abilities to work. Women's first experiences with computers often led to a challenging, enjoyable, and financially rewarding career.     

RPC in Windows systems: what you don't know could hurt you

The vulnerabilities of the remote procedure call (RPC) in Windows were exposed with devastating effect last year by the MSBlaster worm. This paper examines RPC in detail and suggests some ways to protect this widely used and useful protocol.     

Now you see it, now you don't [graphical user interface design]

Accounting for color vision deficiency in user interface designs would cost little and benefit many users. By following a few basic guidelines, it's possible to ensure that Web browsers and other interfaces do not put color-blind users at a disadvantage. Developers can accomplish this easily and without compromising the designs' wider qualities