Richard Fryer

A New Approach to Active Illumination

The design and development of a versatile active illumination system is described. The necessary system components are related to existing techniques which utilise various forms of structured light to extract range data. The system is composed of a high power stroboscopic illuminator coupled with a high resolution liquid crystal display and a precision actuated mirror. A colour filtering device enables projection colour control. The performance of a prototype system is demonstrated through application to temporal modulation, a range finding technique which relies heavily on the performance of the illuminating system.

Integrating virtual reality and telepresence to remotely monitor construction sites: A ViRTUE project

The paper presents VIRTUE, a funded research project, which aims to integrate the Virtual Reality (VR), Telepresence (TP) and mobile video telecommunications technologies. A mobile, real-time, 3D-hybrid VR/TP system is being built at Strathclyde University, Glasgow. A system prototype has been completed and is being tested. The system will permit the user to integrate telepresence images with computer generated virtual environments superimposed over the remote real worldview. This integrated system incorporates emerging mobile telecommunications technologies to give rapid and easy access to the real and virtual construction sites from arbitrary locations. This system allows remote surveillance of the construction site, and integration of real world images of the site with virtual reality representations, derived from planning models, for progress monitoring.

Hybrid virtual reality and telepresence utilising mobile phone technology

An overview of the design and application of a unique mobile hybrid telepresence and virtual reality system is first provided. This is followed by a description of each of the integrated sub-systems. These include the telepresence and teleoperation sub-system comprising display, control, and communication elements together with camera platforms and a mobile vehicle, a virtual reality module capable of modeling capable of modeling a 4D civil engineering environment, in this case a construction site, and the image compression and decompression techniques which allow the video from the remote site to be transmitted across a very low bandwidth mobile phone network. The mobile telepresence system can be located on a real world construction site to observe work in progress. This video information can be accessed by a user from any remote location and compared with the VR model of planned progress. The user can then guide the vehicle and camera system to any desired viewpoint. Illustrations of the first trials of the full system, comments on problems experienced, and suggestions for further work are provided.

Texture Boundary Detection - A Structural Approach

Perception of different textures is caused by differences in distribution of properties of texture elements. However, in practice it is difficult to extract useful texture elements, especially from natural images in which texture elements exist at various scales. To extract texture elements of all sizes a multiscale approach is unavoidable. This paper describes a multiscale method, based on measurements in a Laplacian-of-Gaussian scale-space, to extract texture elements. Histograms are used to describe the distribution of properties of extracted texture elements in a region. The edge significance at a pixel reflects the difference in the histograms of the regions surrounding the pixel. High edge significance pixels constitute the texture boundaries. Performance of the approach is shown for various natural textured images.

The Active Stereo Probe: Dynamic Video Feedback

This paper sets out to overview the progress of a binocular robot vision project titled the “Active Stereo Probe” (ASP) and present the novel aspects of an active controllable illumination system to be integrated with a robot vision head now under development.

Multiscale texture element detection

Abstract A multiscale algorithm is described, mathematically justified, and demonstrated, which enables extraction of various sizes and shapes of texture elements from natural images without need for tuning parameters.

Edge detection algorithm and its video-rate implementation

Abstract A novel three-stage edge detection strategy is outlined, and an algorithm based on it is demonstrated. Each stage is discussed in relation to current research trends in edge detection. The first two stages of the algorithm have been implemented in hardware operating at video rate: the third stage is to be implemented shortly. A full software implementation has been written and its performance is illustrated.

A Scalable Neural Architecture Combining Unsupervised and Suggestive Learning

Multi-layered perceptions are, in theory, capable of solving a wide range of problems. However, as the scale of many problems is increased, or requirements change, multi-layered perceptrons fail to learn or become impractical to implement. Self-organizing networks are not so limited by scale, but require a-priori information, typically in the form of preset weights or suitable control parameters to achieve a good categorization of a data set.

Imaging Polarimetry for Industrial Inspection

The use of the polarisation properties of light for the determination of significant aspects of surfaces in an industrial setting is considered. It is concluded that the technique is both general and robust enough to warrant development. An example is presented of the use of the polarisation signature of surfaces to achieve efficient segmentation of metals and dielectrics in the presence both of uneven lighting and of a lacquer coating. The technique is intrinsically simple given a suitable image acquisition scheme and the necessary images could be acquired at video rates using only simple circuitry. The design of polarising optics is considered briefly.