Data on the three?dimensional (3?D) morphology of normal faces and facial deformities as well as objective techniques for evaluating postoperative changes are currently unavailable. With the advent of stereophotography and cone?beam CT (CBCT), it is possible to acquire 3?D images of soft and hard tissues of the maxillofacial complex. A series of studies were conducted aimed at 1) establishing 3?D facial anthropometric norms for Hong Kong young adults, 2) determining 3?D facial anthropometric features in skeletal Class II and III deformities, 3) characterizing the oropharyngeal space in Class II and III skeletal deformities, 4) exploring clinical applications of 3?D colour maps, 5) establishing a non?invasive technique for estimating serial volume changes and 6) creating virtual craniofacial models by fusing 3?D photographs and CBCT images. Study 1: A stereophotographic system was used to capture 3?D images of 103 Hong Kong Chinese young adults with normal balanced faces. An anthropometric analysis protocol with linear, angular and proportional measurements was developed to establish a normative database and quantify dysmorphology. The Hong Kong Chinese norms were distinct from Caucasians, especially with regard to ocular and nasal measurements. Facial height and nasolabial measurements differed significantly between Hong Kong males and females. Study 2: Anthropometric analyses of 3?D facial images from 41 skeletal Class II and 43 Class III subjects were performed. The Class II subjects had increased lower facial height compared with Class III, who had longer total facial heights and narrower faces. While Class II deformity primarily resulted from mandibular deficiency with a normal maxilla, Class III presented as combined midfacial hypoplasia and mandibular hyperplasia. Study 3: Anthropometric characteristics of the oropharygeal space in skeletal Class II and III were evaluated using 62 CBCT scans. The retroglossal (RG) and retropalatal (RP) volumes and average cross sectional areas were significantly larger in Class III than Class II skeletal deformity. The RP compartment was larger but less uniform than the RG compartment in both Classes. Study 4: 3?D photographs or CBCT images acquired at two different time points were superimposed using a common unaffected area. 3?D colour maps were generated depicting distance differences between superimposed images in a graphical format. These maps were used as an objective tool for treatment planning and assessing outcomes after orthognathic surgery, bimaxillary distraction and facial trauma. Study 5: 3?D photogrammetry was employed for planning soft tissue expansion (STE) and transplantation of a vascularised scapular flap in hemifacial microsomia. This technique facilitated the identification of extent and degree of tissue deficiency, selection of the appropriate tissue expander, monitoring volumetric changes during STE and estimation of the free flap dimensions. Study 6: 3?D facial photographs and CBCT scans of 29 subjects were merged to create virtual craniofacial models with natural surface texture. Accuracy was assessed with 3?D colour maps and Root Mean Square (RMS) error. The CBCT and 3?D photographic data were integrated while minimizing average RMS error to 0.441mm. These virtual composite craniofacial models permitted concurrent 3?D assessment of bone and soft tissue. / published_or_final_version / Dentistry / Doctoral / Doctor of Philosophy

We derive the expression for the three-dimensional incoherent optical transfer function when third-order spherical aberration is present. The normalized version of the transfer function is numerically calculated for various amounts of spherical aberration. We find the effects of the aberration to be highly dependent on the spatial frequency in the longitudinal direction. We also calculate a structure content parameter, as a quality criterion, from the normalized transfer function. Remarkably, the structure content parameter dependence on spherical aberration is well-fit by a simple Cauchy curve for aberrations out to two waves at the margin.

No description available.

No description available.

The work embodied in this thesis describes software techniques developed to analyse digital inline holograms of suspended particle fields, particularly in aquatic environ- ments. The primary motivation behind this work has been development of tech- niques to extract useable information from individual holograms within holovideos, producing focused silhouettes of recorded plankton and other particulates with min- imal user intervention. Two automated focusing algorithms are developed and presented in this work, both of which obtain comparable results for holograms of sparse plankton populations. The first approach is based on rectangular regions of interest (ROIs), which are aligned to (x, y) dimensions, and localise particles within the two-dimensional recon- structed planes obtained from holovideo frames. Due to poor immunity to particle merging when applied to denser particle fields, a second approach was developed using arbitrary polygons with which to localise particle positions in reconstructed planes. This new approach offers a greater immunity to the merging of particles lying in close proximity in the (x, y) dimensions of the hologram, and allows better particle localisation for high density particle holograms. Both ROI and polygon based particle localisation are explored to identify strengths and weaknesses, and complete automated scanning procedures developed in both cases. Examples are provided of typical output from automated scanning algorithms when applied to a number of sample holograms, and areas of weakness highlighted for future work.

As esthetic improvement continues to be a primary goal of orthodontic patients and practitioners, it is important to understand the soft tissue movements that occur during the transition from rest to smile. Advances in technology allow capture of 3-dimesional photographs. The purpose of this study was to quantify the soft tissue changes that occur upon smiling and to compare changes between males and females using 3-dimensional photography. Fifty-four participants had resting and smiling photographs taken with the 3dMDface camera system. The two images were registered on stable facial surfaces, landmarks were placed, and measurements were recorded. Three-dimensional changes occurred in the following regions of the face in both males and females: eyes, ears, nose and lips. Intercommissure width of the lips was shown to increase more in females than males, but males showed increased mobility in landmarks at the base of the nose.

by Chu Kin-cheong. / Thesis (M.Ph.)--Chinese University of Hong Kong, 1988. / Bibliography: leaves 106-109.

by Hui Chau Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1991. / Includes bibliographical references. / ABSTRACT --- p.i / ACKNOWLEDGEMENTS --- p.ii / TABLE OF CONTENTS --- p.iii / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- Computer Graphics Today --- p.2 / Chapter 1.1.1 --- 3D Graphics Synthesis Techniques --- p.2 / Chapter 1.1.2 --- Hardware-assisted Computer Graphics --- p.4 / Chapter 1.2 --- About The Thesis --- p.5 / Chapter CHAPTER 2 --- GRAPHICS SYSTEM ARCHITECTURES / Chapter 2.1 --- Basic Structure of a Graphics Subsystem --- p.8 / Chapter 2.2 --- VLSI Graphics Chips --- p.9 / Chapter 2.2.1 --- The CRT Controllers --- p.10 / Chapter 2.2.2 --- The VLSI Graphics Processors --- p.11 / Chapter 2.2.3 --- Design Philosophies for VLSI Graphics Processors --- p.12 / Chapter 2.3 --- Graphics Boards --- p.14 / Chapter 2.3.1 --- The ARTIST 10 Graphics Controller --- p.14 / Chapter 2.3.2 --- The MATROX PG-1281 Graphics Controller --- p.16 / Chapter 2.4 --- High-end Graphics System Architectures --- p.17 / Chapter 2.4.1 --- Graphics Accelerator with Multiple Functional Units --- p.18 / Chapter 2.4.2 --- Parallel Processing Graphics Systems --- p.18 / Chapter 2.4.3 --- The Parallel Processor Architecture --- p.19 / Chapter 2.4.4 --- The Pipelined Architecture --- p.21 / Chapter 2.5 --- Comparisons and Discussions --- p.22 / Chapter 2.5.1 --- Parallel Processors versus Pipelined Processing --- p.23 / Chapter 2.5.2 --- Parallel Processors versus Multiple Functional Units --- p.23 / Chapter 2.6 --- Summary of High-end Graphics Systems --- p.24 / Chapter CHAPTER 3 --- AN ISA 3D GRAPHICS DISPLAY SERVER / Chapter 3.1 --- Common ISA Graphics Cards --- p.26 / Chapter 3.1.1 --- Standard Video Display Cards --- p.26 / Chapter 3.1.2 --- Graphics Processing Boards --- p.27 / Chapter 3.2 --- A Depth Processor for the ISA computers --- p.28 / Chapter 3.2.1 --- The Z-buffer Algorithm for HLHSR --- p.28 / Chapter 3.2.2 --- Our Hardware Solution for HLHSR --- p.29 / Chapter 3.2.3 --- Design of the Depth Processor --- p.31 / Chapter 3.2.4 --- Structure of the Depth Processor --- p.34 / Chapter 3.2.5 --- The Depth Processor Operations --- p.35 / Chapter 3.2.6 --- Software Support --- p.40 / Chapter 3.2.7 --- Performance of the Depth Processor --- p.44 / Chapter 3.3 --- A VGA Accelerator for the ISA Computers --- p.45 / Chapter 3.3.1 --- Display Buffer Structure of the SuperVGA --- p.46 / Chapter 3.3.2 --- Design of the VGA Accelerator --- p.47 / Chapter 3.3.3 --- Structure of the VGA Accelerator --- p.49 / Chapter 3.3.4 --- Combining the VGA Accelerator and the Depth Processor --- p.51 / Chapter 3.3.5 --- Actual Performance of the DP-VA Board --- p.54 / Chapter 3.3.6 --- 3D Graphics Applications Using the DP-VA Board --- p.55 / Chapter 3.4 --- A 3D Graphics Display Server --- p.57 / Chapter 3.5 --- Host Connection for the 3D Graphics Display Server --- p.59 / Chapter 3.5.1 --- The Single Board Computers --- p.60 / Chapter 3.5.2 --- The VME-to-ISA bus convenor --- p.61 / Chapter 3.5.3 --- Structure of the VME-to-ISA Bus Convertor --- p.61 / Chapter 3.5.4 --- Communications through the bus convertor --- p.64 / Chapter 3.6 --- Physical Construction of the DP-VA Board and the Bus Convertor --- p.65 / Chapter 3.7 --- Summary --- p.66 / Chapter CHAPTER 4 --- A MULTI-i860 3D GRAPHICS SYSTEM / Chapter 4.1 --- The i860 Processor --- p.69 / Chapter 4.2 --- Design of a Multiprocessor 3D Graphics System --- p.70 / Chapter 4.2.1 --- A Reconfigurable Processor-Pipeline System --- p.72 / Chapter 4.2.2 --- The Depth-Processing Unit --- p.73 / Chapter 4.2.3 --- A Multiprocessor Graphics System --- p.75 / Chapter 4.3 --- Structure of the Multi-i860 3D --- p.77 / Chapter 4.3.1 --- The 64-bit-wide Global Data Buses --- p.77 / Chapter 4.3.2 --- The 1280x1024 True-colour Display Unit --- p.79 / Chapter 4.3.3 --- The Depth Processing Unit --- p.82 / Chapter 4.3.4 --- The i860 Processing Units --- p.84 / Chapter 4.3.5 --- The System Control Unit --- p.87 / Chapter 4.3.6 --- Performance Prediction --- p.89 / Chapter 4.4 --- Summary --- p.90 / Chapter CHAPTER 5 --- CONCLUSIONS / Chapter 5.1 --- The 3D Graphics Synthesis Pipeline ……… --- p.91 / Chapter 5.2 --- 3D Graphics Hardware --- p.91 / Chapter 5.3 --- Design Approach for the ISA 3D Graphics Display Server --- p.92 / Chapter 5.4 --- Flexibility in the Multi-i860 3D Graphics System --- p.93 / Chapter 5.5 --- Future Work --- p.94 / Chapter APPENDIX A --- DISPLAYING REALISTIC 3D SCENES / Chapter A.1 --- Modelling 3D Objects in Boundary Representation --- p.96 / Chapter A.2 --- Transformations of 3D scenes --- p.98 / Chapter A.2.1 --- Composite Modelling Transformation --- p.98 / Chapter A.2.2 --- Viewing Transformations --- p.99 / Chapter A.2.3 --- Projection --- p.102 / Chapter A.2.4 --- Window to Viewport Mapping --- p.104 / Chapter A.3 --- Implementation of the Viewing Pipeline --- p.105 / Chapter A.3.1 --- Defining the View Volume --- p.105 / Chapter A.3.2 --- Normalization of The View Volume --- p.106 / Chapter A.3.3 --- The Overall Transformation Pipeline --- p.108 / Chapter A.4 --- Rendering Realistic 3D Scenes --- p.108 / Chapter A.4.1 --- Scan-conversion of Lines and Polygons --- p.108 / Chapter A.4.2 --- Hidden Surface Removal --- p.109 / Chapter A.4.3 --- Shading --- p.112 / Chapter A.4.4 --- The Complete 3D Graphics Pipeline --- p.114 / Chapter APPENDIX B --- DEPTH PROCESSOR DESIGN DETAILS / Chapter B.l --- PAL Definitions --- p.116 / Chapter B.2 --- Circuit Diagrams --- p.118 / Chapter B.3 --- Depth Processor User's Guide --- p.121 / Chapter APPENDIX C --- VGA ACCELERATOR DESIGN DETAILS / Chapter C.1 --- PAL Definitions --- p.124 / Chapter C.2 --- Circuit Diagram --- p.125 / Chapter C.3 --- The DP-VA User's Guide --- p.127 / Chapter APPENDIX D --- VME-TO-ISA BUS CONVERTOR DESIGN DETAILS / Chapter D.1 --- PAL Definitions --- p.131 / Chapter D.2 --- Circuit Diagrams --- p.133 / Chapter APPENDIX E --- 3D GRAPHICS LIBRARY ROUTINES FOR THE DP-VA BOARD / Chapter E.1 --- 3D Drawing Routines --- p.136 / Chapter E.2 --- 3D Transformation Routines --- p.137 / Chapter E.3 --- Shading Routines --- p.138 / Chapter APPENDIX F --- PIPELINE CONFIGURATIONS FOR N PROCESSORS / REFERENCES

by Li Lung Ming. / Thesis (M.Sc.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 33-34). / Chapter 0. --- Abstract --- p.3 / Chapter 1. --- Introduction --- p.4 / Chapter 1.1 --- Stereoscopic Applications --- p.4 / Chapter 1.2 --- How to perceive 3-D image --- p.6 / Chapter 1.2.1 --- Monocular Cues --- p.6 / Chapter 1.2.2 --- Binocular cues --- p.7 / Chapter 2 --- Background --- p.9 / Chapter 2.1 --- True 3 -D Display --- p.9 / Chapter 2.1.1 --- Stereoscopic Systems --- p.9 / Chapter 2.1.2 --- Head-Mounted Display --- p.11 / Chapter 2.1.3 --- Varifocal-mirror Display --- p.12 / Chapter 2.1.4 --- Holographic Systems --- p.13 / Chapter 2.2 --- Generation of real-time Stereoscopic Views --- p.15 / Chapter 3. --- A Stereoscopic System --- p.21 / Chapter 3.1 --- Design Considerations --- p.21 / Chapter 3.2 --- The Set-up --- p.22 / Chapter 4. --- Results --- p.26 / Chapter 5. --- Discussions --- p.27 / Chapter 5.1 --- Advantages of the set-up --- p.29 / Chapter 5.2 --- Disadvantages of the set-up --- p.30 / Chapter 6. --- Conclusion --- p.31 / Chapter 7. --- References --- p.33

Jiang, Li. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 149-155). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.