Recovering Intrinsic Images from a Single Image

We present an algorithm that uses multiple cues to recover shading and reflectance intrinsic images from a single image. Using both color information and a classifier trained to recognize gray-scale patterns, each image derivative is classified as being caused by shading or a change in the surface's reflectance. Generalized Belief Propagation is then used to propagate information from areas where the correct classification is clear to areas where it is ambiguous. We also show results on real images.

Automatically Recovering Geometry and Texture from Large Sets of Calibrated Images

Three-dimensional models which contain both geometry and texture have numerous applications such as urban planning, physical simulation, and virtual environments. A major focus of computer vision (and recently graphics) research is the automatic recovery of three-dimensional models from two-dimensional images. After many years of research this goal is yet to be achieved. Most practical modeling systems require substantial human input and unlike automatic systems are not scalable. This thesis presents a novel method for automatically recovering dense surface patches using large sets (1000's) of calibrated images taken from arbitrary positions within the scene. Physical instruments, such as Global Positioning System (GPS), inertial sensors, and inclinometers, are used to estimate the position and orientation of each image. Essentially, the problem is to find corresponding points in each of the images. Once a correspondence has been established, calculating its three-dimensional position is simply a matter of geometry. Long baseline images improve the accuracy. Short baseline images and the large number of images greatly simplifies the correspondence problem. The initial stage of the algorithm is completely local and scales linearly with the number of images. Subsequent stages are global in nature, exploit geometric constraints, and scale quadratically with the complexity of the underlying scene. We describe techniques for: 1) detecting and localizing surface patches; 2) refining camera calibration estimates and rejecting false positive surfels; and 3) grouping surface patches into surfaces and growing the surface along a two-dimensional manifold. We also discuss a method for producing high quality, textured three-dimensional models from these surfaces. Some of the most important characteristics of this approach are that it: 1) uses and refines noisy calibration estimates; 2) compensates for large variations in illumination; 3) tolerates significant soft occlusion (e.g. tree branches); and 4) associates, at a fundamental level, an estimated normal (i.e. no frontal-planar assumption) and texture with each surface patch.

Proceedings of the Second PHANToM User's Group Workshop

On October 19-22, 1997 the Second PHANToM Users Group Workshop was held at the MIT Endicott House in Dedham, Massachusetts. Designed as a forum for sharing results and insights, the workshop was attended by more than 60 participants from 7 countries. These proceedings report on workshop presentations in diverse areas including rigid and compliant rendering, tool kits, development environments, techniques for scientific data visualization, multi-modal issues and a programming tutorial.

The Proceedings of the First PHANToM User's Group Workshop

These proceedings summarize the results of the First PHANToM User's Group Workshop held September 27-30, 1996 MIT. The goal of the workshop was to bring together a group of active users of the PHANToM Haptic Interface to discuss the scientific and engineering challenges involved in bringing haptics into widespread use, and to explore the future possibilities of this exciting technology. With over 50 attendees and 25 presentations the workshop provided the first large forum for users of a common haptic interface to share results and engage in collaborative discussions. Short papers from the presenters are contained herein and address the following topics: Research Effort Overviews, Displays and Effects, Applications in Teleoperation and Training, Tools for Simulated Worlds and, Data Visualization.

Recognizing 3-D Objects Using 2-D Images

We discuss a strategy for visual recognition by forming groups of salient image features, and then using these groups to index into a data base to find all of the matching groups of model features. We discuss the most space efficient possible method of representing 3-D models for indexing from 2-D data, and show how to account for sensing error when indexing. We also present a convex grouping method that is robust and efficient, both theoretically and in practice. Finally, we combine these modules into a complete recognition system, and test its performance on many real images.

Finding Edges and Lines in Images

The problem of detecting intensity changes in images is canonical in vision. Edge detection operators are typically designed to optimally estimate first or second derivative over some (usually small) support. Other criteria such as output signal to noise ratio or bandwidth have also been argued for. This thesis is an attempt to formulate a set of edge detection criteria that capture as directly as possible the desirable properties of an edge operator. Variational techniques are used to find a solution over the space of all linear shift invariant operators. The first criterion is that the detector have low probability of error i.e. failing to mark edges or falsely marking non-edges. The second is that the marked points should be as close as possible to the centre of the true edge. The third criterion is that there should be low probability of more than one response to a single edge. The technique is used to find optimal operators for step edges and for extended impulse profiles (ridges or valleys in two dimensions). The extension of the one dimensional operators to two dimentions is then discussed. The result is a set of operators of varying width, length and orientation. The problem of combining these outputs into a single description is discussed, and a set of heuristics for the integration are given.

Presentation Based User Interface

A prototype presentation system base is described. It offers mechanisms, tools, and ready-made parts for building user interfaces. A general user interface model underlies the base, organized around the concept of a presentation: a visible text or graphic for conveying information. Te base and model emphasize domain independence and style independence, to apply to the widest possible range of interfaces. The primitive presentation system model treats the interface as a system of processes maintaining a semantic relation between an application data base and a presentation data base, the symbolic screen description containing presentations. A presenter continually updates the presentation data base from the application data base. The user manipulates presentations with a presentation editor. A recognizer translates the user's presentation manipulation into application data base commands. The primitive presentation system can be extended to model more complex systems by attaching additional presentation systems. In order to illustrate the model's generality and descriptive capabilities, extended model structures for several existing user interfaces are discussed. The base provides support for building the application and presentation data bases, linked together into a single, uniform network, including descriptions of classes of objects as we as the objects themselves. The base provides an initial presentation data base network graphics to continually display it, and editing functions. A variety of tools and mechanisms help create and control presenters and recognizers. To demonstrate the base's utility, three interfaces to an operating system were constructed, embodying different styles: icons, menu, and graphical annotation.

Uso de imagens digitais na avaliação do crescimento da taxa de cobertura do solo.

RESUMO: Existem vários métodos para avaliar o crescimento da vegetação e a taxa de cobertura do solo. Medidas precisas e rápidas podem ser obtidas do tratamento digital de imagens geradas de câmeras fotográficas ou de vídeo. Há disponível, no mercado, diversos processadores de imagens que apresentam funções básicas semelhantes, mas com certas particularidades que poderão trazer maior benefício para o usuário, dependendo da aplicação. O SPRING, desenvolvido pelo INPE, é de domínio público, sendo mais abrangente do que um processador de imagens, incluindo funções de geoprocessamento. O ENVI foi desenvolvido para a análise de imagens multiespectrais e hiperespectrais, podendo também ser utilizado para o processamento de imagens obtidas de câmeras de vídeo, por exemplo. O KS-300 é um conjunto de hardware e de software destinado ao processamento e à quantificação de imagens microscópicas, permitindo a captação direta das imagens geradas por meio de lupas, microscópios eletrônicos ou câmeras de vídeo. O SIARCS foi desenvolvido pela Embrapa Instrumentação Agropecuária para tornar mais ágil o processo de captação de dados de um sistema. Este trabalho apresenta os fundamentos teóricos básicos envolvidos na técnica de análise de imagens, com as principais características dos softwares citados acima e sua aplicação na quantificação da taxa de crescimento e da cobertura do solo por espécies vegetais. ABSTRACT: Several methods exist to evaluate the growth of the vegetation and the tax of covering of the soil. Necessary and fast measures can be obtained of the digital treatment of generated images of photographic cameras or of video. There is available, in the market, several processors of images that you/they present similar basic functions, but with certain particularities that can bring larger benefit for the user, depending on the application. SPRING, developed by INPE, it is public domain, being including than a processor of images, including functions. ENVI was developed for the analysis of images multiespectrais and hiperespectrais, could also be used for the processing of obtained images of video cameras, for instance. The KS-300 it is a hardware group and software destined to the processing and quantification of microscopic images, allowing the direct reception of the images generated through magnifying glasses, eletronic microscopes or video cameras. SIARCS was developed by Embrapa Agricultural Instrumentation to turn more agile the process of reception of data of a system. This work presents the basic theoretical foundations involved in the technique of analysis of images, with the main characteristics of the softwares mentioned above and his application in the quantification of the growth tax and of the covering of the soil for vegetable species.

Fragments of place : revealing sense of place through shared phone images.

Is an interactive new media art installation that explores how the sharing of images, normally hidden on mobile phones, can reveal more about people's sense of place and this ultimately shared experience. Traditional views on sense of place, as exemplified by Wagner (1972) and Relph (1976), characterise the experience as a fusion of meaning, act and context. Indeed, Relph suggests that it is not just the identity of a place that is important, but also the identity that a person or group has with that place, in particular whether they are experiencing it as an ‘insider’ or ‘outsider’. This work stimulates debate concerning the impact of technology on sense of place. Technology offers a number of bridges between the real and virtual worlds, but in so doing places an increased tension on the sense of place and subsequently the identity of the individual. This, coupled with the increased use of camera phones, has enabled the documentation of all aspects of our lives, the things we do, the objects we encounter and the places we inhabit. The installation taps into these hidden electronic resources by letting people share their sense of place associated with a large scale event. The work explores the changing nature of the sense of place of performers, visitors and residents over the duration of the event. Interaction with the installation will transform the viewer into performer, echoing Relph’s insider-outsider dichotomy

Festival Images: brand image and stakeholders' brand relationship types at the Edinburgh Festival Fringe.

The Edinburgh Festival Fringe (The Fringe) is the largest arts festival in the world and it has inspired the creation of similar festivals world-wide. Since its conception in 1947, the Fringe has demonstrated significant growth in visitor numbers; ticket sales; and its economic contribution. Despite this, the sustainable future of Edinburgh’s festivals is debated as Edinburgh, ‘the Festival City’, faces threats from other festival destinations. Festivals position Edinburgh creatively in contrast to the city’s traditionally perceived image as a cultural-historic centre. Despite this, little research has been undertaken into the creative and cultural significance of Edinburgh’s festivals, including the Fringe. This interdisciplinary research grounded in marketing, tourism, and festival and event management; and underpinned by constructivism, presents an understanding of types of brand relationships that exist between the Fringe and its primary stakeholders. This is achieved through defining both the Fringe brand image and its primary stakeholders; and applying these definitions to the development of a typology of Fringe-stakeholders’ brand relationships. The significance of this study is evident within its topic of inquiry and the research methods applied. In the little-considered arena of arts festivals and their stakeholders, this is the first in-depth study into the Fringe as a festival and festival brand. Within this, the definition of a Fringe brand image contributes to understanding the cultural and creative significance of the Fringe. Furthermore, this research contributes a unique understanding of the types of stakeholders that are engaged with the Fringe. The types of brand relationships that exist between these stakeholders and the Fringe are another significant contribution to knowledge and understanding. While specific to the present context, these findings may prove transferable to further festivals or events, and related areas and industries. The contribution made by this research to the methodological developments in festival and event studies is of additional significance. The application of visual research methods, including semiotic analysis and photo-elicitation within phenomenological interviews, has previously been applied in marketing, consumer, and tourism research, but not to the understanding of festival brands and stakeholders’ brand relationship types. Findings of this research illustrate that existing marketing and consumer brand frameworks and stakeholder theories are applicable to festivals. Further, it is possible to define ‘a’ Fringe brand image which is subjective and contradictory. The unique open-access and organic, operational model of the Fringe facilitates its many contributors, and consumers. Fringe stakeholders may be categorised according to their level of engagement with the Fringe (as primary or secondary) and their particular stakeholder role(s), which are varied and multiple. Fringe-stakeholder brand relationship types are overwhelmingly positive; and are based upon interpersonal relationship dimensions (including friendships, marriages, kinships and partnerships). Fringe-stakeholder brand relationship types can be classified therefore as having similar dimensions to those brand relationship types previously described for consumer products and brands.

NHS Wales user needs study including knowledgebase tools report. Report for Informing Healthcare Strategy implementation programme.

Thomas, R., Spink, S., Durbin, J. & Urquhart, C. (2005). NHS Wales user needs study including knowledgebase tools report. Report for Informing Healthcare Strategy implementation programme. Aberystwyth: Department of Information Studies, University of Wales Aberystwyth. Sponsorship: Informing Healthcare, NHS Wales

Animated virtual agents to cue user attention: comparison of static and dynamic deictic cues on gaze and touch responses

This paper describes an experiment developed to study the performance of virtual agent animated cues within digital interfaces. Increasingly, agents are used in virtual environments as part of the branding process and to guide user interaction. However, the level of agent detail required to establish and enhance efficient allocation of attention remains unclear. Although complex agent motion is now possible, it is costly to implement and so should only be routinely implemented if a clear benefit can be shown. Pevious methods of assessing the effect of gaze-cueing as a solution to scene complexity have relied principally on two-dimensional static scenes and manual peripheral inputs. Two experiments were run to address the question of agent cues on human-computer interfaces. Both experiments measured the efficiency of agent cues analyzing participant responses either by gaze or by touch respectively. In the first experiment, an eye-movement recorder was used to directly assess the immediate overt allocation of attention by capturing the participant’s eyefixations following presentation of a cueing stimulus. We found that a fully animated agent could speed up user interaction with the interface. When user attention was directed using a fully animated agent cue, users responded 35% faster when compared with stepped 2-image agent cues, and 42% faster when compared with a static 1-image cue. The second experiment recorded participant responses on a touch screen using same agent cues. Analysis of touch inputs confirmed the results of gaze-experiment, where fully animated agent made shortest time response with a slight decrease on the time difference comparisons. Responses to fully animated agent were 17% and 20% faster when compared with 2-image and 1-image cue severally. These results inform techniques aimed at engaging users’ attention in complex scenes such as computer games and digital transactions within public or social interaction contexts by demonstrating the benefits of dynamic gaze and head cueing directly on the users’ eye movements and touch responses.

The Depiction of Coronal Structure in White-Light Images

Morgan, Huw, Habbal, S.R., Woo, R., (2006) 'The Depiction of Coronal Structure in White-Light Images', Solar Physics 236(2) pp.263-272 RAE2008

Linear structures in mammographic images: detection and classification

R. Zwiggelaar, S.M. Astley, C.J. Taylor and C.R.M. Boggis, 'Linear structures in mammographic images: detection and classification', IEEE Transaction on Medical Imaging 23 (9), 1077-1086 (2004)

Lord of The Rings database user guide

Sponsorship: This research was made possible by a grant from the Economic and Social Research Council (ESRC Grant No. 000-22-0323)