Typescript (photocopy). / Digitized by Kansas Correctional Industries

This thesis documents a research project that has used computer graphics techniques to reconstruct a set of three-dimensional surfaces from a set of two-dimensional sectional drawings. The work has concentrated on the successful reconstruction of palaeontological specimens, such as brachiopods and early land plants. The reconstruction process is based around a two-stage system. First, the underlying topology of each object is determined automatically using the CorresGrow algorithm, which calculates the correspondence between adjacent sections, many of which have complex contour relationships. Unlike previous solutions, CorresGrow can locate solutions for objects that have multiple, disjoint components. The second stage triangulates the three-dimensional surface using the information provided by the correspondence algorithm. Depending on the similarity in shape of a pair of adjacent contours, the algorithm uses either the original contour vertices or those from the convex hull to perform the surface construction. The other aspects of the project work have looked at the implications of using computer graphics techniques for palaeontological reconstruction. This effects the way in which the data are sampled and digitised so that it is suitable for reconstruction. Using computer graphics also means that the reconstructed models can be used for more than visualisation, in areas such as evolutionary and temporal modelling.

Pang Wai Man. / Thesis submitted in: July 2002. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 108-114). / Abstracts in English and Chinese. / Abstract --- p.ii / Acknowledgments --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Image-based Rendering and Modeling --- p.1 / Chapter 1.1.1 --- Image-based versus Geometry-based --- p.5 / Chapter 1.2 --- Capturing for Graphics --- p.6 / Chapter 1.3 --- Organization of this Thesis --- p.8 / Chapter 2 --- Image-based Rendering and Relighting --- p.10 / Chapter 2.1 --- Theoretical Concepts --- p.11 / Chapter 2.1.1 --- Plenoptic Illumination Function --- p.11 / Chapter 2.1.2 --- Apparent BRDF --- p.13 / Chapter 2.1.3 --- Types of lighting --- p.14 / Chapter 2.1.4 --- Image superposition --- p.16 / Chapter 2.2 --- General Rendering Pipeline --- p.18 / Chapter 2.3 --- Rendering Techniques --- p.21 / Chapter 2.3.1 --- Nearest Neighbours and Interpolation --- p.21 / Chapter 2.3.2 --- Image Warping --- p.23 / Chapter 2.4 --- IBR Representations and applications --- p.26 / Chapter 2.4.1 --- Navigation --- p.28 / Chapter 2.4.2 --- Relighting Representations --- p.35 / Chapter 2.4.3 --- High Dynamic Range Imaging --- p.38 / Chapter 2.5 --- Chapter Summary --- p.42 / Chapter 3 --- Capturing Methods --- p.44 / Chapter 3.1 --- Spatial Tracking Approaches --- p.45 / Chapter 3.1.1 --- Mechanical based Method --- p.46 / Chapter 3.1.2 --- Electromagnetic based Method --- p.48 / Chapter 3.1.3 --- Vision based Method --- p.50 / Chapter 3.1.4 --- Comparison --- p.51 / Chapter 3.2 --- High Dynamic Range Imaging --- p.53 / Chapter 3.2.1 --- Successive Exposure Capturing --- p.53 / Chapter 3.2.2 --- Spatial Varing Filter --- p.53 / Chapter 3.2.3 --- Special Designed Hardware --- p.55 / Chapter 3.3 --- Chapter Summary --- p.56 / Chapter 4 --- System Design and Implementation --- p.58 / Chapter 4.1 --- System Overview --- p.58 / Chapter 4.2 --- The Setup --- p.60 / Chapter 4.3 --- Capturing Procedures --- p.61 / Chapter 4.3.1 --- Calibrations --- p.61 / Chapter 4.4 --- Vision based tracking --- p.64 / Chapter 4.4.1 --- The pin-hole camera model --- p.65 / Chapter 4.4.2 --- Basics of Camera Calibration --- p.66 / Chapter 4.5 --- Light Vector Tracking --- p.70 / Chapter 4.5.1 --- The Transformations --- p.70 / Chapter 4.5.2 --- Tracking Accuracy --- p.71 / Chapter 4.5.3 --- Tracking Range Enlargement --- p.72 / Chapter 4.6 --- Capturing Experiment --- p.74 / Chapter 4.7 --- Sampling Analysis --- p.74 / Chapter 4.8 --- Chapter Summary --- p.78 / Chapter 5 --- Data Postprocessing --- p.80 / Chapter 5.1 --- Scattered Data Fitting --- p.81 / Chapter 5.1.1 --- Spherical Delaunay Triangulation --- p.83 / Chapter 5.1.2 --- Interpolation on Sphere --- p.86 / Chapter 5.2 --- Compression --- p.88 / Chapter 5.3 --- Chapter Summary --- p.90 / Chapter 6 --- Relit Results --- p.91 / Chapter 6.1 --- Relighting with Multiple Directional Lights --- p.92 / Chapter 6.2 --- Relighting with Environmental Maps --- p.94 / Chapter 7 --- Conclusion --- p.101 / Chapter 7.1 --- Future Research Aspect --- p.102 / Chapter A --- System User Guide --- p.104 / Chapter A.1 --- Equipment Configuration --- p.104 / Chapter A.2 --- Operation Guide --- p.105 / Chapter A.3 --- Software Components --- p.106 / Chapter A.3.1 --- Image capturing - lightcap --- p.106 / Chapter A.3.2 --- Raw Frame Extraction ´ؤ lfprocess --- p.107 / Chapter A.3.3 --- Resampling and Compression - svscatterppm2urdf . --- p.107 / Bibliography --- p.108

Typescript, etc. / Digitized by Kansas Correctional Industries

No description available.

There are many existing methods for capturing three dimensional data from two dimensional images. Methods based on images captured from multiple view-points require solving the correspondence problem: establishing which points in each image represent the same points in the scene. Most attempts at solving the correspondence problem require carefully controlled lighting and reference points within the scene. A new method captures many consecutive images to form a dense spatiotemporal volume as the camera-or scene-undergoes controlled motion. Feature points in the scene move along predictable paths within this volume. Analysing the exact motion of features determines their three dimensional position in the scene.

Thesis (Ph. D.)--Ohio State University, 2006. / Full text release at OhioLINK's ETD Center delayed at author's request

In this thesis, an efficient font-rendering system for E-book applications was presented. The rendering of vector-type fonts mainly consists of two procedures: the rasterization of outline curves, and the filling of font interiors. Different from the conventional rendering systems which approximate the curve using many tiny straight lines, our system applies the fast adaptive forward-difference algorithm to render the curve. In addition, for the filling of fonts, this thesis adopts the local-minimum table and the vertex table to substitute the conventional global edge table in order to reduce the memory requirement. Finally, in order to improve the rendering quality of the fonts, our system has applied the super-sampling anti-aliasing technique based on the FLIPQUAD sample patterns used in three-dimensional graphic systems in order to reduce both the required buffer size and the filling operation complexity by 25% for the similar rendering quality. Our rendering system has been implemented in an ARM-based platform. The FreeType fonts parser has been used, and transformed into the application programming interface (API) commands of a two-dimensional vector graphics standard called OpenVG. This standard APIs have been built on the QT window and Embedded Linux operational systems. The rendering system proposed by this thesis represents a total open-source solution, and can be applied to many embedded applications.

Bezier curve is one of the most fundamental primitives for the modeling of fonts and two-dimensional (2D) computer graphics objects. How to efficiently render the Bezier curve becomes an important task for many embedded applications. This thesis first proposed a novel adaptive curve-rendering algorithm which can determine the coordinates of all the crossing points of the curve and scan-lines with the required accuracy for the graphics fill operation. Next, for the rendering of stroked Bezier curves, this thesis proposed several possible rendering circuit architectures. The performance and gate count of these architectures have been estimated, and compared in this thesis. It has been found that the design based on the table-lookup normal vector calculator can lead to the fastest circuit, while the design based on the Cordic operator represents the most economic design. A basic Bezier curve rendering circuit has been implemented in this thesis, and used to accelerate a prototype OpenVG embedded systems.

This thesis presents a study of both traditional Chinese painting and threedimensional (3D) digital non-photorealistic shading techniques, the results of which are used to create a short animation illustrating an environment that maintains the aesthetic of a Chinese painting while exploring a two-dimensional art style in a new way through camera movement and parallax. Traditional Chinese painting uses alternative methods to communicate depth, such as value range, water-to-ink ratio and vertical placement of objects. In contrast, perspective and parallax are native characteristics of 3D digital technology and are easily generated using a virtual camera. When combining these two mediums to inject linear perspective into the Chinese painting style, it is equally important to maintain the integrity of the aesthetic by adhering to the stylistic and compositional rules throughout the animation. As a result, the final project may be paused at many key frames and appear to follow these rules closely. This study also describes the methodology of translating the Chinese painting aesthetic into a 3D digital medium, which can also be used in the interpretation of other traditional art styles.