Athula Ginige

Hypermedia authoring

Authoring involves identifying the links within information and structuring them to enhance accessibility. Developers of large hypermedia systems, or systems likely to require maintenance over a period of time, must select a structured approach to authoring or risk greatly inflated development costs, a less than desired level of functionality, and difficulties in use and maintenance.

Segmentation of medical images using an active-contour model incorporating region-based image features

An improved segmentation algorithm based on the active contour model is developed. A distinguishing element of our algorithm is the incorporation of region-based image features which improves signifcantly the reliability of the algorithm, and allows multi- region segmentation of an image. We use simulated annealing in the energy minimization in order to locate the globally optimal solution and enhance flexibility in the construction of energy functional.

The Hypermedia Authoring Research Toolkit (HART)

A major obstacle hindering the advancement and commercial acceptance of hypermedia is the cost of converting paper based information into hypermedia form. The Hypermedia Authoring Research Toolkit (HART) was developed to support the human editor during this media-to-hypermedia conversion process. The tools goal is to help improve the correctness and completeness of the hypermedia database, as well as reduce the media-to-hypermedia conversion cost. We believe it is not possible to properly convert media to hypermedia without the participation of a human editor during the transformation. It is therefore necessary to develop tools to assist the human during this process. By reducing the overhead associated with the physical management of the hyper-database construction, the subject specialist is better able to concentrate on the information content. Support is provided in two basic ways: By providing procedural guidance. From our experience constructing hypermedia systems we have developeds an efficient process for this media-to-hypermedia transformation. By providing intelligent assistance. At each phase in the transformation the system can suggest likely nodes, key phrases, index values, anchors, and links to the editor. The projects research focus is to identify the most effective methodologies to assist the human editor transform linear text, images and video into hypermedia structure.

Edge-preserving smoothing of medical images using spatially adaptive filters

ADsfracr- Noise reduction is m important component in biomedical image processing and analysis. We propose a smoothing algorithm which preserves edges and thus fine structures common in biomedical images. The algorithm is based on averaging over an independently generated mask at each pixel. The mask genention takes into account local image information and conforms to tissue boundaries. Comparison of the proposed algorithm with other common smoothing techniques favours our algorithm.

Hyperimages: using object recognition for navigation through images in multimedia

Multimedia involves the use of multiple forms of communication media in an interactive and integrated manner. At present, textual data is the media predominantly used to provide the interactivity due to the ease with which discrete semantic elements are identified. It is common practice to follow links from words or phrases within text to associated information elsewhere in the database. To achieve a similar degree of functionality with visual information typically requires that each image (or video sequence) be processed by hand, indicating the objects and locations within the image -- a process that is excessively expensive and time-consuming for large databases. This paper describes the implementation of a simple object recognition system that allows the specification of 3D models that can then be used to recognize objects within any image, in an analogous fashion to words within text. This enables image data to become a truly active media, within a multimedia database. It provides a significantly enhanced level of functionality while keeping the authoring effort to a minimum. The basic algorithms are described and then an example application is outlined, along with feedback from users of the system.

Direct comparison of 2 set of results from testability analysis by using correlation and statistical testability analysis of transient (delay) faults

A basis (framework) for comparing different testability measures was developed. Using this method testability values obtained for a set of ISCAS85 benchmark circuits using STAFAN and SCOAP techniques were compared. Also the authors extended the statistical testability analysis technique to cover transient (delay) faults and compared the results with values from a probabilistic technique. They observed that the values from their technique generally agree with the values from the probabilistic model.<<ETX>>

An experimental multimedia system

This video coding algorithm was developed taking into account the characteristics of existing computer display systems. One of the main characteristics of many frame buffers is that they are colour mapped . Commonly onl y 256 colours are available for image composition . However quantisation to a level of 256 colours generall y introduces unacceptable image degradation and artefacts such as contouring .