The purpose of the X-Form package is for use in the classroom as an instructional aid for teaching the algorithms and data used to represent, transform, and display objects in three-dimensional space. The program provides various areas containing graphic and textual representations of the data structures used in the creation and transformation of a three-dimensional object. Another area, containing the menu items, serves as an interface to the available demonstration items. These items include various object and viewing parameters which can be input by the user. The user then sees the result of the entered data, including animated graphics and changes in data structures. The graphic areas show the object at various stages of development, so that the user can understand the progression of the required manipulations. The textual representations are also designed to assist the user in understanding how useful information is derived from entered data. Through testing and statistical analysis, XForm has proven to be an effective tool for instruction of three-dimensional graphics. / Department of Computer Science

Early image understanding seeks to derive analytic representations from image data. This thesis presents steps towards this goal for three-dimensional imagery by focusing on the inference of trace points (points belonging to surfaces), and the estimation of associated differential structure given by the principal curvature and direction fields over smooth surfaces. Computation of these fields is posed as the determination of a cross section through the bundle of curvature frames over the estimated trace. Algorithm robustness and the stability of results are essential for analysis of real images; to this end, I present a functional minimization algorithm where the principal direction cross section meets appropriate criteria for a minimum, and develop an implementation as an iterative constraint satisfaction procedure based on local surface smoothness properties. For shape description and eventual object recognition, the exact recovery of local structure everywhere is less important than the identification of singular surface points which prove stable to noise and small surface perturbations, in particular, the umbilic points of surfaces. Such points are computed naturally from the estimated local surface structure embodied in the principal direction cross section of the frame bundle. Examples of the recovery of local structure are presented for synthetic images degraded by noise and for clinical magnetic resonance images.

Thesis (M.F.A.)--Rochester Institute of Technology, 2007. / Typescript. Includes bibliographical references (leaves 20-26).

Thesis (M.S.)--Rochester Institute of Technology, 1990. / "References": leaves 61-63.

Thesis (M.F.A.)--Rochester Institute of Technology, 2008. / Typescript.

Thesis (M.F.A.)--Rochester Institute of Technology, 2008. / Typescript.

Thesis (M.C.S.) - Carleton University, 2002. / Includes bibliographical references (p. 80-83). Also available in electronic format on the Internet.

Thesis (M.C.S.)--Carleton University, 2004. / Includes bibliographical references (p. 110-112). Also available in electronic format on the Internet.

Thesis (M.App.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 107-115). Also available in electronic format on the Internet.

Thesis (M.F.A.)--Rochester Institute of Technology, 1992. / Typescript. Includes bibliographical references (leaf 48).