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by Kenneth Y.P. Lee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1989. / Bibliography: leaves 120-123.

Ng Lai Sze. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 135-140). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Spherical Data Representation --- p.4 / Chapter 3 --- Rhombic Dodecahedron --- p.7 / Chapter 3.1 --- Introduction --- p.7 / Chapter 3.2 --- "Platonic Solids, Archimedean Solids and Dual Polyhedron" --- p.8 / Chapter 3.2.1 --- Platonic Solids --- p.8 / Chapter 3.2.2 --- Archimedean Solids --- p.10 / Chapter 3.2.3 --- Dual Polyhedron --- p.13 / Chapter 3.3 --- Rhombic Dodecahedron --- p.16 / Chapter 3.3.1 --- Basic Property of Rhombic Dodecahedron --- p.16 / Chapter 3.3.2 --- Construction of Rhombic Dodecahedron --- p.16 / Chapter 3.3.3 --- Advantages of Rhombic Dodecahedron --- p.16 / Chapter 3.4 --- Summary --- p.19 / Chapter 4 --- Subdivision Scheme --- p.21 / Chapter 4.1 --- Introduction --- p.21 / Chapter 4.2 --- Motivation --- p.22 / Chapter 4.3 --- Great Circle Subdivision --- p.22 / Chapter 4.3.1 --- Normal Space Analysis --- p.23 / Chapter 4.4 --- Small Circle Subdivision --- p.25 / Chapter 4.5 --- Skew Great Circle Subdivision --- p.27 / Chapter 4.6 --- Analysis --- p.28 / Chapter 4.6.1 --- Sampling Uniformity --- p.29 / Chapter 4.6.2 --- Area Uniformity --- p.32 / Chapter 4.6.3 --- Stretch Measurement --- p.35 / Chapter 4.6.4 --- Query Efficiency --- p.39 / Chapter 4.7 --- Summary --- p.40 / Chapter 5 --- Data Querying and Indexing --- p.42 / Chapter 5.1 --- Introduction --- p.42 / Chapter 5.2 --- Location of base polygon --- p.43 / Chapter 5.2.1 --- General Method --- p.43 / Chapter 5.2.2 --- Tailored Table Look Up Method --- p.45 / Chapter 5.3 --- Location of the subdivided area --- p.49 / Chapter 5.3.1 --- On Deriving the Indexing Equation --- p.50 / Chapter 5.4 --- Summary --- p.54 / Chapter 6 --- Environment Mapping --- p.56 / Chapter 6.1 --- Introduction --- p.56 / Chapter 6.2 --- Related Work --- p.57 / Chapter 6.3 --- Methodology --- p.58 / Chapter 6.4 --- Data Preparation --- p.59 / Chapter 6.4.1 --- Re-sampling of Data on Sphere --- p.60 / Chapter 6.4.2 --- Preparation of Texture --- p.65 / Chapter 6.5 --- Reflection and Refraction by environment mapping --- p.68 / Chapter 6.5.1 --- Location and Retrieval of Data --- p.68 / Chapter 6.5.2 --- Cg Implementation --- p.70 / Chapter 6.6 --- Experiments --- p.76 / Chapter 6.6.1 --- Experiment Setup --- p.76 / Chapter 6.6.2 --- Experiment Result and Analysis --- p.78 / Chapter 6.7 --- Summary --- p.89 / Chapter 7 --- Shadow Mapping --- p.92 / Chapter 7.1 --- Introduction --- p.92 / Chapter 7.2 --- Related Work --- p.93 / Chapter 7.3 --- Methodology --- p.95 / Chapter 7.4 --- Data Preparation --- p.97 / Chapter 7.5 --- Shadow Determination and Scene Illumination --- p.98 / Chapter 7.6 --- Experiments --- p.100 / Chapter 7.6.1 --- Experiment Setup --- p.100 / Chapter 7.6.2 --- Experiment Result and Analysis --- p.101 / Chapter 7.7 --- Summary --- p.107 / Chapter 8 --- Dynamic HDR Environment Sequences Sampling --- p.110 / Chapter 8.1 --- Introduction --- p.110 / Chapter 8.2 --- Related Work on HDR Distant Environment Map Sampling --- p.112 / Chapter 8.3 --- Static Sampling by Spherical Quad-Quad Tree --- p.114 / Chapter 8.3.1 --- Importance Metric --- p.117 / Chapter 8.4 --- Dynamic Sampling by Spherical Quad-Quad Tree --- p.121 / Chapter 8.5 --- Experiments --- p.125 / Chapter 8.5.1 --- Static Sampling --- p.125 / Chapter 8.5.2 --- Dynamic Sampling --- p.126 / Chapter 8.6 --- Summary --- p.132 / Chapter 9 --- Conclusion --- p.133 / Bibliography --- p.135

The overall argument this thesis makes is that topological object structures captured within hierarchical image descriptions are invariant to depictive styles and offer a level of abstraction found in many modern abstract artworks. To show how object structures can be extracted from images, two hierarchical image descriptions are proposed. The first of these is inspired by perceptual organisation; whereas, the second is based on agglomerative clustering of image primitives. This thesis argues the benefits and drawbacks of each image description and empirically show why the second is more suitable in capturing object strucutures. The value of graph theory is demonstrated in extracting object structures, especially from the second type of image description. User interaction during the structure extraction process is also made possible via an image hierarchy editor. Two applications of object structures are studied in depth. On the computer vision side, the problem of object classification is investigated. In particular, this thesis shows that it is possible to classify objects regardless of their depictive styles. This classification problem is approached using a graph theoretic paradigm; by encoding object structures as feature vectors of fixed lengths, object classification can then be treated as a clustering problem in structural feature space and that actual clustering can be done using conventional machine learning techniques. The benefits of object structures in computer graphics are demonstrated from a Non-Photorealistic Rendering (NPR) point of view. In particular, it is shown that topological object structures deliver an appropriate degree of abstraction that often appears in well-known abstract artworks. Moreover, the value of shape simplification is demonstrated in the process of making abstract art. By integrating object structures and simple geometric shapes, it is shown that artworks produced in child-like paintings and from artists such as Wassily Kandinsky, Joan Miro and Henri Matisse can be synthesised and by doing so, the current gamut of NPR styles is extended. The whole process of making abstract art is built into a single piece of software with intuitive GUI.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Thesis. 1979. M.S.--Massachusetts Institute of Technology. Dept. of Architecture. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Bibliography: leaf 31. / M.S.