Typescript. Includes bibliographical references (leaves 96-99).

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W. Eric L. Grimson ; with contributions from Tomá³ Lozano-Pé²¥z, Daniel P. Huttenlocher. / Includes bibliographical references (p. 350-504) and indexes.

Thesis (MScEng)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: We investigate object detection against cluttered backgrounds, based on the MINACE (Minimum Noise and Correlation Energy) filter. Application of the filter is followed by a suitable segmentation algorithm, and the standard techniques of global and local thresholding are compared to watershed-based segmentation. The aim of this approach is to provide a custom region-based object detection algorithm with a concise set of regions of interest. Two industrial case studies are examined: diamond detection in X-ray images, and the reading of a dynamic, and ink stamped, 2D barcode on packaging clutter. We demonstrate the robustness of our approach on these two diverse applications, and develop a complete algorithmic prototype for an automatic stamped code reader. / AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek die herkenning van voorwerpe teen onduidelike agtergronde. Ons benadering maak staat op die MINACE (" Minimum Noise and Correlation Energy") korrelasiefilter. Die filter word aangewend saam met 'n gepaste segmenteringsalgoritme, en die standaard tegnieke van globale en lokale drumpelingsalgoritmes word vergelyk met 'n waterskeidingsgebaseerde segmenteringsalgoritme. Die doel van hierdie deteksiebenadering is om 'n klein stel moontlike voorwerpe te kan verskaf aan enige klassifikasie-algoritme wat fokus op die voorwerpe self. Twee industriële toepassings word ondersoek: die opsporing van diamante in X-straal beelde, en die lees van 'n dinamiese, inkgedrukte, 2D balkieskode op verpakkingsmateriaal. Ons demonstreer die robuustheid van ons benadering met hierdie twee uiteenlopende voorbeelde, en ontwikkel 'n volledige algoritmiese prototipe vir 'n outomatiese stempelkode leser.

In this thesis, we study modellings and numerical algorithms to data analysis with applications to image processing and financial forecast. The thesis is composed of two parts, namely the tensor regression and data assimilation methods for image restoration.;We start with investigating the tensor regression problem in Chapter 2. It is a generalization of a classical regression in order to adopt and analyze much more information by using multi-dimensional arrays. Since the regression problem is subject to multiple solutions, we propose a regularized tensor regression model to the problem. By imposing a low-rank property of the solution and considering the structure of the tensor product, we develop an algorithm which is suitable for scalable implementations. The regularization method is used to select useful solutions which depend on applications. The proposed model is solved by the alternating minimization method and we prove the convergence of the objective function values and iterates by the maximization-minimization (MM) technique. We study different factors which affects the performance of the algorithm, including sample sizes, solution ranks and the noise levels. Applications include image compressing and financial forecast.;In Chapter 3, we apply filtering methods in data assimilation to image restoration problems. Traditionally, data assimilation methods optimally combine a predictive state from a dynamical system with real partially observations. The motivation is to improve the model forecast by real observation. We construct an artificial dynamics to the non-blind deblurring problems. By making use of spatial information of a single image, a span of ensemble members is constructed. A two-stage use of ensemble transform Kalman filter (ETKF) is adopted to deblur corrupted images. The theoretical background of ETKF and the use of artificial dynamics by stage augmentation method are provided. Numerical experiments include image and video processing.;Concluding remarks and discussion on future extensions are included in Chapter 4.

Chan, Man Leung Dunco. / Thesis submitted in: Nov 2008. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 87-91). / Abstracts in English and Chinese. / Abstract --- p.2 / 摘要 --- p.3 / Acknowledgement --- p.4 / Content --- p.5 / List of figures --- p.6 / Chapter Chapter 1 --- Introduction --- p.9 / Chapter 1.1 --- Background --- p.9 / Chapter 1.2 --- Prior work --- p.11 / Chapter 1.3 --- Objectives --- p.13 / Chapter 1.4 --- Proposed method --- p.16 / Chapter 1.5 --- Thesis outline --- p.18 / Chapter Chapter 2 --- Axial curve-pair deformation --- p.19 / Chapter 2.1 --- Axial deformation technique --- p.20 / Chapter 2.1.1 --- Representing objects in axial space --- p.21 / Chapter 2.1.2 --- Defining the frame --- p.23 / Chapter 2.2 --- Axial curve-pair deformation technique --- p.24 / Chapter 2.2.1 --- Framing the curve-pair --- p.25 / Chapter 2.2.2 --- Construction of orientation curve --- p.26 / Chapter 2.2.3 --- Manipulation of the axial curve-pair --- p.28 / Chapter Chapter 3 --- Dynamic axial curve-pair based deformation --- p.32 / Chapter 3.1 --- The dynamic mass spring model --- p.34 / Chapter 3.1.1 --- Dynamic NURBS curve --- p.35 / Chapter 3.1.2 --- Dynamic Free-form deformation --- p.37 / Chapter 3.1.3 --- Dynamic Axial Curve-pair deformation --- p.38 / Chapter 3.2 --- The dynamic mass spring model --- p.41 / Chapter 3.2.1 --- Curve-pair Fitting --- p.41 / Chapter 3.2.2 --- Construction of dynamic curve-pair --- p.44 / Chapter 3.2.3 --- The three-degree torsional spring --- p.48 / Chapter 3.2.4 --- Conserving feature in a twisting deformation --- p.50 / Chapter 3.2.5 --- Comparison of mass spring model --- p.51 / Chapter 3.3 --- Internal and external forces --- p.54 / Chapter 3.3.1 --- Tensile stress --- p.54 / Chapter 3.3.2 --- Torsional stress --- p.55 / Chapter 3.3.3 --- External forces --- p.59 / Chapter 3.4 --- Equations of motion --- p.60 / Chapter 3.5 --- System solver --- p.63 / Chapter 3.6 --- Hierarchical representation --- p.67 / Chapter 3.7 --- Collision detection --- p.72 / Chapter Chapter 4 --- Implementation and experimental result --- p.75 / Chapter 4.1 --- Comparison with original mass-spring system --- p.76 / Chapter 4.2 --- Comparison with dynamic free form deformation --- p.77 / Chapter 4.3 --- Comparison with the axial curve-pair deformation --- p.78 / Chapter 4.4 --- Shape restoring power --- p.80 / Chapter 4.5 --- Applications --- p.81 / Chapter Chapter 5 --- Conclusion --- p.84 / Reference --- p.86

Animating an articulated figure usually requires expensive hardware in terms of motion capture equipment, processing power and rendering power. This implies a high cost system and thus eliminates the use of personal computers to drive avatars in virtual environments. We propose a system to animate an articulated human upper body in real-time, using minimal motion capture trackers to provide position and orientation for the limbs. The system has to drive an avatar in a virtual environment on a low-end computer. The cost of the motion capture equipment must be relatively low (hence the use of minimal trackers). We discuss the various types of motion capture equipment and decide to use electromagnetic trackers which are adequate for our requirements while being reasonably priced. We also discuss the use of inverse kinematics to solve for the articulated chains making up the topology of the articulated figure. Furthermore, we offer a method to describe articulated chains as well as a process to specify the reach of up to four link chains with various levels of redundancy for use in articulated figures. We then provide various types of constraints to reduce the redundancy of non-defined articulated chains, specifically for chains found in an articulated human upper body. Such methods include a way to solve for the redundancy in the orientation of the neck link, as well as three different methods to solve the redundancy of the articulated human arm. The first method involves eliminating a degree of freedom from the chain, thus reducing its redundancy. The second method calculates the elevation angle of the elbow position from the elevation angle of the hand. The third method determines the actual position of the elbow from an average of previous positions of the elbow according to the position and orientation of the hand. The previous positions of the elbow are captured during the calibration process. The redundancy of the neck is easily solved due to the small amount of redundancy in the chain. When solving the arm, the first method which should give a perfect result in theory, gives a poor result in practice due to the limitations of both the motion capture equipment and the design. The second method provides an adequate result for the position of the redundant elbow in most cases although fails in some cases. Still it benefits from a simple approach as well as very little need for calibration. The third method provides the most accurate method of the three for the position of the redundant elbow although it also fails in some cases. This method however requires a long calibration session for each user. The last two methods allow for the calibration data to be used in latter session, thus reducing considerably the calibration required. In combination with a virtual reality system, these processes allow for the real-time animation of an articulated figure to drive avatars in virtual environments or for low quality animation on a low-end computer.

Thesis (Masters Diploma (Electrical Engineering)--Cape Technikon, Cape Town, 1993 / This thesis describes the design and development of a computer vision system. The system (Video Frame Grabber) will give PCUsers the potential to capture any visual image into the memory of a computer. This computer intelligible image opens the way for new development in computer photography, Image recognition and . Desktop Publishing.

University of Macau / Faculty of Science and Technology / Department of Computer and Information Science