Computer graphics

This dissertation studies two independent problems, one is about graph labeling
and the other problem is related to connectivity condition in a simple graph.
Graph labeling is a rapidly developing area of research in graph theory, having connections with a variety of application-oriented areas such as VLSI optimization, data
structures and data representation. Furthermore, the connectivity conditions in a simple graphs may help us to study the new aspects of ad hoc networks, social networks and web graphs. In chapter 2, we study path systems, reduced path systems and how to construct a super edge-graceful tree with any number of edges using path systems. First, we give an algorithm to reduce a labeled path system to a smaller labeled path system of a different type. First, we investigate the cases (m, k) = (3; 5) and
(m, k) = (4; 7), where m is the number of paths and 2k is the length of each path, and then we give a generalization for any k, m = 3 and m = 4. We also describe a procedure to construct a super-edge-graceful tree with any number of edges.

The purpose of this research is to determine the feasibility of introducing the Monte Carlo (MC) dose calculation algorithm into the clinical practice. Unlike the Ray Tracing (RT) algorithm, the MC algorithm is not affected by the tissue inhomogeneities, which are significant inside the chest cavity. A retrospective study was completed for 102 plans calculated using both the RT and MC algorithms. The D95 of the PTV was 26% lower for the MC calculation. The first parameter of conformality, as defined as the ratio of the Prescription Isodose Volume to the PTV Volume was on average 1.27 for RT and 0.67 for MC. The results confirm that the RT algorithm significantly overestimates the dosages delivered confirming previous analyses. Correlations indicate that these overestimates are largest for small PTV and/or when the ratio of the volume of lung tissue to the PTV approaches 1.

The common approach for finding objects buried under the seabed is to use a single channel chirp reflection profiler. Reflection profiles lack information on target location, geometry and size. This thesis investigates methods for visualizing buried objects in noisy 3D acoustic data acquired by a small aperture scanning sonar. Various surface and volume rendering methods are tested with synthetic datasets containing fluid loaded spheres and with experimental data acquired with a 4-by-8 planar hydrophone array towed over buried objects with various aspects and size. The Maximum Intensity Projection is the best of the tested methods for real-time visualization of the data where a global overview of the targets is needed. A surface rendering technique such as the Marching Cubes is useful for offline measurement of the geometry and size of buried objects selected by the operator.

This sturty presents a method for automatically generating and
animating 3-D models of planar linkages. A computer program called
ANIMEC is introduced which serves as a link between two existing
programs KAPCA, and MOVIE. The algorithms of ANIMEC are described in
detail and a program listing is provided.

Computer generated graphics has become an integral part of most
computer systems. Communicating information in an interesting and
understandable manner has become a necessity in the computer industry
due to the increase in users who are interested in animation,
simulation, graphical design, games and graphic representations of
complex mathematical information. The Synchronous System
Architecture described in this paper will illustrate a simple, low
cost and efficient means of creating and displaying images on a
cathode ray tube (CRT). A step-by-step design procedure is presented
which utilizes the Synchronous System Architecture (SSA) in a
standalone system/terminal environment. Finally, the software
alogrithms used in the system will be outlined and discussed.

A method to create 3D-face image using 2D-face images is the objective of this research. The 3D-face image is constructed using a set of 3D-face images of other persons available in a face database. The 3D-face image actually depicts a parameterized form in terms of depth and texture. This concept can be used to facilitate creating a 3D-face image from 2D database. For this purpose, a 3D-face database is first developed. When a 2D-face image is presented to the system, a 3D-face image that starts with an average 3D-face image (derived from the 3D-face database) is projected onto the 2D-image plane, with necessary rotation, translation, scaling and interpolation. The projected image is then compared with the input image; and, an optimization algorithm is applied to minimize an error index by selecting 3D-depth and texture parameters. Hence, the projected image is derived. Once the algorithm converges, the resulting 3D-depth and the texture parameters can be employed to construct a 3D-face image of the subject photographed in the 2D-images. A merit of this method is that only the depth and texture parameters of the compared images are required to be stored in the database. Such data can be used either for the recreation of a 3D-image of the test subject or for any biometric authentication (based on 3D face recognition). Results from an experimental study presented in the thesis illustrate the effectiveness of the proposed approach, which has applications in biometric authentication and 3D computer graphics areas.

In this thesis, realization and implementation of one-dimensional (1-D) and two-dimensional (2-D) recursive digital filters using LabVIEW are presented. A number of direct and state-space realizations for 1-D filters are implemented either as in general form or second-order modules. Implementation programs are provided and simulation results are presented to show the effectiveness of the proposed method. In addition, several realizations for 2-D separable-in-denominator filters are proposed. These realizations have the properties of highly parallel structure and improved throughput delay. The performance as well as the implementation of 2-D filters using LabVIEW is also presented.

While new technologies are often used to facilitate regular people's lives, they often fail to see their potential in helping disabled people. Augmented reality, one of the newest state-of-the-art technologies, offers users the opportunity to add virtual information to their real world surroundings in real time. It also has the potential to not only augment the sense of sight, but also other senses such as hearing. Augmented reality could be used to offer the opportunity to complement users' missing sense. In this thesis, we study augmented reality technologies, systems and applications, and suggest the future of AR applications. We explain how to integrate augmented reality into iOS applications and propose an augmented reality application for hearing augmentation using an iPad2. We believe mobile devices are the best platform for augmented reality as they are widespread and their computational power is rapidly growing to be able to handle true AR applications.

Natural matte extraction is a difficult and generally unsolved problem. Generating a matte from a nonuniform background traditionally requires a tediously hand drawn matte. This thesis studies recent methods requiring the user to place only modest scribbles identifying the foreground and the background. This research demonstrates a new GPU-based implementation of the recently introduced Fuzzy- Matte algorithm. Interactive matte extraction was achieved on a CUDA enabled G80 graphics processor. Experimental results demonstrate improved performance over the previous CPU based version. In depth analysis of experimental data from the GPU and the CPU implementations are provided. The design challenges of porting a variant of Dijkstra's shortest distance algorithm to a parallel processor are considered.