Shape from perspective trihedral angle constraint

Abstract: This paper defines and investigates a fundamental problem of determining the position and orientation of a 3 0 object using $ingle perspective i m g e view. The technique is based on the interpretation of trihedral angle constraid informution. A new closed form solution io the problem is proposed. The method also provides a general analytic technique for dealing with a class of problem of shape from inverse perspective projection by using "Angle to Angle Correspondence Information ". Simulation experiments show that our method is enective and robust for real application. t This research ispariially supported by ONR NooO14-91-J1306

Self-localization in urban environment via mobile imaging facility.

Chim, Ho Ming.Thesis (M.Phil.)--Chinese University of Hong Kong, 2008.Includes bibliographical references (leaves 58-62).Abstracts in English and Chinese.Acknowledgements --- p.iAbstract --- p.iiChapter 1 --- Introduction --- p.1Chapter 1.1 --- Objectives --- p.1Chapter 1.2 --- Motivations --- p.1Chapter 1.3 --- Problem Statement --- p.2Chapter 1.4 --- Camera Self-Localization Approaches --- p.3Chapter 1.4.1 --- Based on Calibration Patterns --- p.3Chapter 1.4.2 --- Based on Self-calibration --- p.3Chapter 1.4.3 --- Based on Shape and Motion --- p.4Chapter 1.4.4 --- The Proposed Approach - Based on Junctions --- p.5Chapter 1.5 --- Thesis Organization --- p.6Chapter 2 --- Previous Work --- p.7Chapter 2.1 --- Camera Self-Localization --- p.7Chapter 2.1.1 --- Parallel Plane Features --- p.7Chapter 2.1.2 --- Parallelepiped Features --- p.8Chapter 2.1.3 --- Single View Geometric Features --- p.8Chapter 2.1.4 --- Shape and Motion --- p.8Chapter 2.1.5 --- Other Estimation Methods --- p.9Chapter 2.2 --- Feature Correspondences Establishment --- p.9Chapter 2.2.1 --- Feature-based Object Recognition --- p.9Chapter 2.2.2 --- Model-based Object Recognition --- p.10Chapter 3 --- Preliminaries --- p.11Chapter 3.1 --- Perspective Camera Model --- p.11Chapter 3.2 --- Camera Pose from Point Correspondences --- p.15Chapter 3.3 --- Camera Pose from Direction Correspondences --- p.16Chapter 4 --- A Junction-based Approach --- p.18Chapter 4.1 --- Use of Junction Correspondences for Determining Camera Pose --- p.18Chapter 4.1.1 --- Constraints from Point Information --- p.19Chapter 4.1.2 --- Constraint from Direction Information --- p.21Chapter 4.1.3 --- Junction Triplet Correspondences --- p.22Chapter 4.2 --- Extraction of Junctions and Junction Triplets from Image --- p.24Chapter 4.2.1 --- Handling Image Data --- p.24Chapter 4.2.2 --- Bridging Lines --- p.25Chapter 4.2.3 --- """L""-junctions" --- p.26Chapter 4.2.4 --- """Y"" and ""Adjunctions" --- p.27Chapter 4.2.5 --- Junction Triplets --- p.28Chapter 4.3 --- Establishment of the First Junction Triplet Correspondence --- p.30Chapter 4.3.1 --- Ordered Junction Triplets from Model --- p.30Chapter 4.3.2 --- A Junction Hashing Scheme --- p.31Chapter 4.4 --- Establishment of Points Correspondence --- p.33Chapter 4.4.1 --- Viewing Sphere Tessellation --- p.33Chapter 4.4.2 --- Model Views Synthesizing --- p.35Chapter 4.4.3 --- Affine Coordinates Computation --- p.35Chapter 4.4.4 --- Hash Table Filling --- p.38Chapter 4.4.5 --- Hash Table Voting --- p.38Chapter 4.4.6 --- Hypothesis and Confirmation --- p.39Chapter 4.4.7 --- An Example of Geometric Hashing --- p.40Chapter 5 --- Experimental Results --- p.43Chapter 5.1 --- Results from Synthetic Image Data --- p.43Chapter 5.2 --- Results from Real Image Data --- p.45Chapter 5.2.1 --- Results on Laboratory Scenes --- p.46Chapter 5.2.2 --- Results on Outdoor Scenes --- p.48Chapter 6 --- Conclusion --- p.51Chapter 6.1 --- Contributions --- p.51Chapter 6.2 --- Advantages --- p.52Chapter 6.3 --- Summary and Future Work --- p.52Chapter A --- Least-Squares Method --- p.54Chapter B --- RQ Decomposition --- p.56Bibliography --- p.5

Motion Structures

Motion structures are simply assemblies of resistant bodies connected by movable joints. Unlike conventional structures, they allow large shape transformations to satisfy practical requirements and they can be used in:shelters, emergency structures and exhibition standsaircraft morphing wingssatellite solar panels and space antennasmorphing core m

Frequency Modulated Continuous Wave Radar and Video Fusion for Simultaneous Localization and Mapping

There has been a push recently to develop technology to enable the use of UAVs in GPS-denied environments. As UAVs become smaller, there is a need to reduce the number and sizes of sensor systems on board. A video camera on a UAV can serve multiple purposes. It can return imagery for processing by human users. The highly accurate bearing information provided by video makes it a useful tool to be incorporated into a navigation and tracking system. Radars can provide information about the types of objects in a scene and can operate in adverse weather conditions. The range and velocity measurements provided by the radar make it a good tool for navigation. FMCW radar and color video were fused to perform SLAM in an outdoor environment. A radar SLAM solution provided the basis for the fusion. Correlations between radar returns were used to estimate dead-reckoning parameters to obtain an estimate of the platform location. A new constraint was added in the radar detection process to prevent detecting poorly observable reflectors while maintaining a large number of measurements on highly observable reflectors. The radar measurements were mapped as landmarks, further improving the platform location estimates. As images were received from the video camera, changes in platform orientation were estimated, further improving the platform orientation estimates. The expected locations of radar measurements, whose uncertainty was modeled as Gaussian, were projected onto the images and used to estimate the location of the radar reflector in the image. The colors of the most likely reflector were saved and used to detect the reflector in subsequent images. The azimuth angles obtained from the image detections were used to improve the estimates of the landmarks in the SLAM map over previous estimates where only the radar was used

Bio-inspired design of a kinetic node for adaptable structures

Thesis (Master)--İzmir Institute Of Technology, Architecture, İzmir, 2011Includes bibliographical references (leaves: 112-119)Text in English; Abstract: Turkish and Englishxiii, 119 leavesThe architectural design should no longer consider just in terms of today's demands, but also the life cycle and the further requirements of the built environment. The design process should consider the adaptation to the changing conditions which can be in terms of the building usage, environmental factors or even in the changes ofsociological demands. Rapid change in activities of modern society and building technologies, has led to the need for adaptable spaces. Those spaces can be obtained by the adaptable structures which have potential for using our resources in efficient way and also for responding to the era's needs. This can be achieved with kinetic structural systems and learning adaptable structures from nature.Nature has always inspired humanity by solving the basic needs with minimum material and sustainable solutions. Observation of nature enables architects and engineers familiar with highly developed structures and lead to the creation of new forms. The designs that are produced by learning from nature lead to practical engineering solutions in terms of sustainability. The aim of this research is to propose a joint; kinetic node with multidisciplinary approach. This kinetic node is designed by inspiring from the minimum energy shape configurations and the structural orders in natural structures especially the cell membrane and analyzing the joining details of space truss structural systems and the geometric principles of Bricard linkage mechanism. This new kinetic node gives capability to construct variable static and dynamic structural systems while constructing in different structural orders

Motion Structures

Motion structures are simply assemblies of resistant bodies connected by movable joints. Unlike conventional structures, they allow large shape transformations to satisfy practical requirements and they can be used in:shelters, emergency structures and exhibition standsaircraft morphing wingssatellite solar panels and space antennasmorphing core m

Salient Feature Identification and Analysis using Kernel-Based Classification Techniques for Synthetic Aperture Radar Automatic Target Recognition

An investigation into feature saliency for application to synthetic aperture radar (SAR) automatic target recognition (ATR) is presented. Specifically, research is focused on improving the SAR binary classification performance aspect of ATR, or the ability to accurately determine the class of a SAR target. The key to improving ATR classification performance lies in characterizing the salient target features. Salient features may be loosely defined as the most consistently impactful parts of a SAR target contributing to effective SAR ATR classification. To better understand the notion of salience, an investigation is conducted into the nature of saliency as applied to Air Force Research Lab\u27s (AFRL) civilian vehicle (CV) data domes simulated phase history data set. After separating vehicles into two SAR data classes, sedan and SUV, frequency and polarization features are extracted from SAR data and formed into either 1D high range resolution (HRR) or 2D spectrum parted linked image test (SPLIT) feature vectors. A series of experiments comparing vehicle classes are designed and conducted to focus specifically on the saliency effects of various SAR collection parameters including azimuth angle, aperture size, elevation angle, and bandwidth. The popular kernel-based Bayesian Relevance Vector Machine (RVM) classifier is utilized for sparse identification of relevant vectors contributing most to the creation of a hyperplane decision boundary. Analysis of experimental results ultimately leads to recommendations of the salient feature vectors and SAR collection parameters which provide the most potential impact to improving vehicle classification. Demonstrating the proposed saliency characterization algorithm with simulated civilian vehicle data provides a road map for salient feature identification and analysis of other SAR data classes in future operational scenarios. ATR practitioners may use saliency results to focus more attention on the identified salient features of a target class, improving efficiency and effectiveness of SAR ATR

Automatic creation of boundary-representation models from single line drawings

This thesis presents methods for the automatic creation of boundary-representation models of polyhedral objects from single line drawings depicting the objects. This topic is important in that automated interpretation of freehand sketches would remove a bottleneck in current engineering design methods. The thesis does not consider conversion of freehand sketches to line drawings or methods which require manual intervention or multiple drawings. The thesis contains a number of novel contributions to the art of machine interpretation of line drawings. Line labelling has been extended by cataloguing the possible tetrahedral junctions and by development of heuristics aimed at selecting a preferred labelling from many possible. The ”bundling” method of grouping probably-parallel lines, and the use of feature detection to detect and classify hole loops, are both believed to be original. The junction-line-pair formalisation which translates the problem of depth estimation into a system of linear equations is new. Treating topological reconstruction as a tree-search is not only a new approach but tackles a problem which has not been fully investigated in previous work