Download or read book Design of an Active Stereo Vision 3D Scene Reconstruction System Based on the Linear Position Sensor Module written by and published by . This book was released on 2006 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Active vision systems and passive vision systems currently exist for three-dimensional (3D) scene reconstruction. Active systems use a laser that interacts with the scene. Passive systems implement stereo vision, using two cameras and geometry to reconstruct the scene. Each type of system has advantages and disadvantages in resolution, speed, and scene depth. It may be possible to combine the advantages of both systems as well as new hardware technologies such as position sensitive devices (PSDs) and field programmable gate arrays (FPGAs) to create a real-time, mid-range 3D scene reconstruction system. Active systems usually reconstruct long-range scenes so that a measurable amount of time can pass for the laser to travel to the scene and back. Passive systems usually reconstruct close-range scenes but must overcome the correspondence problem. If PSDs are placed in a stereo vision configuration and a laser is directed at the scene, the correspondence problem can be eliminated. The laser can scan the entire scene as the PSDs continually pick up points, and the scene can be reconstructed. By eliminating the correspondence problem, much of the computation time of stereo vision is removed, allowing larger scenes, possibly at mid-range, to be modeled. To give good resolution at a real-time frame rate, points would have to be recorded very quickly. PSDs are analog devices that give the position of a light spot and have very fast response times. The cameras in the system can be replaced by PSDs to help achieve realtime refresh rates and better resolution. A contribution of this thesis is to design a 3D scene reconstruction system by placing two PSDs in a stereo vision configuration and to use FPGAs to perform calculations to achieve real-time frame rates of mid-range scenes. The linear position sensor module (LPSM) made by Noah Corp is based on a PSD and outputs a position in terms of voltage. The LPSM is characterized for this application by testing it with different power lasers while also varying environment variables such as background light, scene type, and scene distance. It is determined that the LPSM is sensitive to red wavelength lasers. When the laser is reflected off of diffuse surfaces, the laser must output at least 500 mW to be picked up by the LPSM and the scene must be within 15 inches, or the power intensity will not meet the intensity requirements of the LPSM. The establishment of these performance boundaries is a contribution of the thesis along with characterizing and testing the LPSM as a vision sensor in the proposed scene reconstruction system. Once performance boundaries are set, the LPSM is used to model calibrated objects. LPSM sensitivity to power intensity changes seems to cause considerable error. The change in power appears to be a function of depth due to the dispersion of the laser beam. The model is improved by using a correction factor to find the position of the light spot. Using a better-focused laser may improve the results. Another option is to place two PSDs in the same configuration and test to see whether the intensity problem is intrinsic to all PSDs or if the problem is unique to the LPSM.
Download or read book Modeling and Calibration of an Active Stereo Vision System written by Jeremiah J. Neubert and published by . This book was released on 2001 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 3D Computer Vision written by Christian Wöhler and published by Springer Science & Business Media. This book was released on 2009-07-28 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work provides an introduction to the foundations of three-dimensional c- puter vision and describes recent contributions to the ?eld, which are of methodical and application-speci?c nature. Each chapter of this work provides an extensive overview of the corresponding state of the art, into which a detailed description of new methods or evaluation results in application-speci?c systems is embedded. Geometric approaches to three-dimensional scene reconstruction (cf. Chapter 1) are primarily based on the concept of bundle adjustment, which has been developed more than 100 years ago in the domain of photogrammetry. The three-dimensional scene structure and the intrinsic and extrinsic camera parameters are determined such that the Euclidean backprojection error in the image plane is minimised, u- ally relying on a nonlinear optimisation procedure. In the ?eld of computer vision, an alternative framework based on projective geometry has emerged during the last two decades, which allows to use linear algebra techniques for three-dimensional scene reconstructionand camera calibration purposes. With special emphasis on the problems of stereo image analysis and camera calibration, these fairly different - proaches are related to each other in the presented work, and their advantages and drawbacks are stated. In this context, various state-of-the-artcamera calibration and self-calibration methods as well as recent contributions towards automated camera calibration systems are described. An overview of classical and new feature-based, correlation-based, dense, and spatio-temporal methods for establishing point c- respondences between pairs of stereo images is given.
Download or read book An Online Interactive Web based Stereo Vision Framework written by Minh Nguyen and published by . This book was released on 2014 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis addresses theoretical basics and applications of graphically interactive web- based image processing and computer vision frameworks which extract depth information from different forms of digital two-/three-dimensional (2D/3D) inputs and other collaborative online research meta-tools of 3D data generation, visualisation, and analysis for stereo images. Such efficient and effective online processing tools have not been adequately explored so far. The thesis also discusses various novel and existing algorithms and practicable functionalities of many techniques such as camera control, calibration and rectification, 3D data segmentation, 3D graphic rendering, face modelling, feature detection with active contours, image matching, and stereo reconstruction. Within this thesis, a guided dynamic programming technique is proposed. It uses full or partial pro- les generated by other algorithms to guide the process an efficient symmetric dynamic programming stereo matching to produce higher-quality disparity maps. The evaluated results have shown that this algorithm was demonstrably accurate, fast, and relatively robust for stereo correspondence when tested with modern evaluation techniques and datasets. Along with the theory development, a versatile interactive system is built, allowing users to dynamically reconstruct visible surfaces of 3D scenes from stereo pairs of images acquired with o -the-shelf monocular and stereo cameras including cell-phones and webcams. The system communicates with potential users via the Internet and allows uploading of individual static images or live video sequences. Images are automatically or manually co-aligned into epipolar stereo pairs using either calibrated or uncalibrated image rectification. A rectified pair is processed by one of the available stereo matching algorithms to reconstruct a visible surface of a 3D scene. The user's computer or cell- phone is used to provide an immediate, controllable, 3D display. Within a short waiting time, many results are returned to the user including aligned 3D side-by-side photos, dis- parity and texture maps, anaglyphs, autostereograms, virtual 3D scenes, 3D .OBJ les, or even live depth video sequences; all of which can be shared with others in a public gallery. This portable, simple to set up and operate system, currently very rare on the Internet, is located at http://www.ivs.auckland.ac.nz/quick_stereo and has been visited by thousands of people spread across more than 50 countries. At the present, the public gallery page contains 3,000 real life stereo datasets in over 30 categories; each of them has a pair of raw images, rectified images, and other 3D related data, which are believed to be useful for testing and learning purposes. A few further potential applications such as remote camera control for online calibration and rectification, stereo-vision-based autostereogram creation, modelling of a 3D facial avatar, stand-alone stereo reconstruction application for commodity stereo cameras, and mobile-phone applications are also discussed.
Download or read book Science Abstracts written by and published by . This book was released on 1993 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Few Steps Towards 3D Active Vision written by Thierry Vieville and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: T. Viéville: A Few Steps Towards 3D Active Vision appears as Vol. 33 in the Springer Series in Information Sciences. A specific problem in the field of active vision is analyzed, namely how suitable is it to explicitly use 3D visual cues in a reactive visual task? The author has collected a set of studies on this subject and has used these experimental and theoretical developments to propose a synthetic view on the problem, completed by some specific experiments. With this book scientists and graduate students will have a complete set of methods, algorithms, and experiments to introduce 3D visual cues in active visual perception mechanisms, e.g. autocalibration of visual sensors on robotic heads and mobile robots. Analogies with biological visual systems provide an easy introduction to this subject.
Download or read book 3D Dynamic Scene Analysis written by Zhengyou Zhang and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: he problem of analyzing sequences of images to extract three-dimensional T motion and structure has been at the heart of the research in computer vi sion for many years. It is very important since its success or failure will determine whether or not vision can be used as a sensory process in reactive systems. The considerable research interest in this field has been motivated at least by the following two points: 1. The redundancy of information contained in time-varying images can over come several difficulties encountered in interpreting a single image. 2. There are a lot of important applications including automatic vehicle driv ing, traffic control, aerial surveillance, medical inspection and global model construction. However, there are many new problems which should be solved: how to effi ciently process the abundant information contained in time-varying images, how to model the change between images, how to model the uncertainty inherently associated with the imaging system and how to solve inverse problems which are generally ill-posed. There are of course many possibilities for attacking these problems and many more remain to be explored. We discuss a few of them in this book based on work carried out during the last five years in the Computer Vision and Robotics Group at INRIA (Institut National de Recherche en Informatique et en Automatique).
Download or read book Using Wireless Multimedia Sensor Networks for 3D Scene Asquisition and Reconstruction written by Anthony Tannouri and published by . This book was released on 2018 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, the WMSNs are promising for different applications and fields, specially with the development of the IoT and cheap efficient camera sensors. The stereo vision is also very important for multiple purposes like Cinematography, games, Virtual Reality, Augmented Reality, etc. This thesis aim to develop a 3D scene reconstruction system that proves the concept of using multiple view stereo disparity maps in the context of WMSNs. Our work can be divided in three parts. The first one concentrates on studying all WMSNs applications, components, topologies, constraints and limitations. Adding to this stereo vision disparity map calculations methods in order to choose the best method(s) to make a 3d reconstruction on WMSNs with low cost in terms of complexity and power consumption. In the second part, we experiment and simulate different disparity map calculations on a couple of nodes by changing scenarios (indoor and outdoor), coverage distances, angles, number of nodes and algorithms. In the third part, we propose a tree-based network model to compute accurate disparity maps on multi-layer camera sensor nodes that meets the server needs to make a 3d scene reconstruction of the scene or object of interest. The results are acceptable and ensure the proof of the concept to use disparity maps in the context of WMSNs.
Download or read book 3D Video and Its Applications written by Takashi Matsuyama and published by Springer Science & Business Media. This book was released on 2012-05-31 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a broad review of state-of-the-art 3D video production technologies and applications. The text opens with a concise introduction to the field, before examining the design and calibration methods for multi-view camera systems, including practical implementation technologies. A range of algorithms are then described for producing 3D video from video data. A selection of 3D video applications are also demonstrated. Features: describes real-time synchronized multi-view video capture, and object tracking with a group of active cameras; discusses geometric and photometric camera calibration, and 3D video studio design with active cameras; examines 3D shape and motion reconstruction, texture mapping and image rendering, and lighting environment estimation; demonstrates attractive 3D visualization, visual contents analysis and editing, 3D body action analysis, and data compression; highlights the remaining challenges and the exciting avenues for future research in 3D video technology.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1860 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Autonomous Active Vision System for Complete and Accurate 3D Scene Reconstruction written by Éric Marchand and published by . This book was released on 1998 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Framework for Realtime 3 D Reconstruction by Space Carving Using Graphics Hardware written by Christian Nitschke and published by diplom.de. This book was released on 2007-03-05 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inhaltsangabe:Introduction: Reconstruction of real-world scenes from a set of multiple images is a topic in Computer Vision and 3D Computer Graphics with many interesting applications. There is a relation to Augmented and Mixed Reality (AR/MR), Computer-Supported Collaborative Work (CSCW), Computer-Aided industrial/architectural Design (CAD), modeling of the real-world (e.g. computer games, scenes/effects in movies), entertainment (e.g. 3D TV/Video) and recognition/analyzing of real-world characteristics by computer systems and robots. There exists a powerful algorithm theory for shape reconstruction from arbitrary viewpoints, called shape from photo-consistency. However, it is computationally expensive and hence can not be used with applications in the field of 3D video or CSCW as well as interactive 3D model creation. Attempts have been made to achieve real-time framerates using PC cluster systems. While these provide enough performance they are also expensive and less flexible. Approaches that use GPU hardware-acceleration on single workstations achieve interactive framerates for novel-view synthesis, but do not provide an explicit volumetric representation of the whole scene. The proposed approach shows the efforts in developing a GPU hardware-accelerated framework for obtaining the volumetric photo hull of a dynamic 3D scene as seen from multiple calibrated cameras. High performance is achieved by employing a shape from silhouette technique in advance to obtain a tight initial volume for shape from photo-consistency. Also several speed-up techniques are presented to increase efficiency. Since the entire processing is done on a single PC, the framework can be applied to mobile setups, enabling a wide range of further applications. The approach is explained using programmable vertex and fragment processors and compared to highly optimized CPU implementations. It is shown that the new approach can outperform the latter by more than one magnitude. The thesis is organized as follows: Chapter 1 contains an introduction, giving an overview with classification of related techniques, statement of the main problem, novelty of the proposed approach and its fields of application. Chapter 2 surveys related work in the area of dynamic scene reconstruction by shape from silhouette and shape from photo-consistency. The focus lies on high performance reconstruction and hardware-acceleration. Chapter 3 introduces the theoretical basis for the proposed [...]
Download or read book Deformable Surface 3D Reconstruction from Monocular Images written by Matthieu Salzmann and published by Morgan & Claypool Publishers. This book was released on 2010-03-03 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Being able to recover the shape of 3D deformable surfaces from a single video stream would make it possible to field reconstruction systems that run on widely available hardware without requiring specialized devices. However, because many different 3D shapes can have virtually the same projection, such monocular shape recovery is inherently ambiguous. In this survey, we will review the two main classes of techniques that have proved most effective so far: The template-based methods that rely on establishing correspondences with a reference image in which the shape is already known, and non-rigid structure-from-motion techniques that exploit points tracked across the sequences to reconstruct a completely unknown shape. In both cases, we will formalize the approach, discuss its inherent ambiguities, and present the practical solutions that have been proposed to resolve them. To conclude, we will suggest directions for future research. Table of Contents: Introduction / Early Approaches to Non-Rigid Reconstruction / Formalizing Template-Based Reconstruction / Performing Template-Based Reconstruction / Formalizing Non-Rigid Structure from Motion / Performing Non-Rigid Structure from Motion / Future Directions
Download or read book An Autonomous Active Vision System for Complete and Accurate 3D Scene Reconstruction written by Éric Marchand and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rectification Technique in Active Light Stereo Vision System written by Dong-Hyun Kim and published by . This book was released on 2002 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improving the Accuracy of 3 D Reconstruction in Robotic Vision Applications written by Yuanzheng Gong and published by . This book was released on 2016 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three-dimensional (3D) surface reconstruction is a process for retrieving the 3D shape and appearance of real objects or scenes. The generated 3D point clouds can be used in many fields, including entertainment, measurement, design, reverse engineering, homeland security and {\it etc}. Over the past decades, 3D reconstruction has been widely used in clinical diagnosis and surgical treatment of diseases, such as X-ray, ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). However, all of these technologies are radiography-based volumetric 3D reconstruction instead of 3D surface reconstruction. With the growing need of tissue texture information for clinical purposes, the 3D reconstruction based on endoscopic images plays a more vital role than ever, especially in tumor diagnosis and surveillance of esophagus, lung, stomach, bladder and etc. In this work, new algorithms were developed to solve specific 3D reconstruction problems in biomedical applications. To reconstruct the 3D internal surface of a human organ, such as bladder or stomach, a sequence of 2D endoscopic images were captured by rotating and moving the scope around inside of the organs. This 3D reconstruction solely based on images is called Structure-from-Motion (SfM). To overcome the problems of insufficient features in medical images and short camera baselines, the camera poses were initially estimated by constraining the surface on a spherical shape at the first step. The more realistic organ surface was then reconstructed by releasing the spherical constraints. Extra features were built to handle multiple scanning videos and recover the physical scale of the 3D surface with reference lesion target. To reduce the human error and surgical operating time in removing the tumor/cancer in brain, a semi-automated surgical robotic system with 3D vision is being developed. By providing an accurate 3D surface model of the surgical field based on a RGB (red, green and blue) camera attached to the surgical tool, the robot could perform tedious operation of residual tumor tissue removal automatically. Camera position and orientation were also known throughout the surgery from the robotic system. This 3D reconstruction with known camera parameters is called Multi-view Stereo. Due to the mechanical limitation of robotic system, the camera pose parameters were with certain errors (tolerance). To utilize these inaccurate but bound constrained variables, Bound Constrained Bundle Adjustment (BCBA) algorithm was developed based on gradient projection to generate accurate 3D model efficiently. Besides biomedical applications, 3D computer vision is emerging in traditional industries, such as manufacture and quality control applications. To build a potential in-line 3D metrology tool for internal threads in automobile engine blocks, two 3D reconstruction algorithms were developed with forward-view and side-view cameras, respectively. Axial-stereo vision algorithm was proposed to create dense 3D point cloud of internal surface based on two forward-view images that are aligned on the optical axis. Feature-based panoramic 3D registration algorithm was developed to register different side-view image-generated 3D surface patches together, by taking advantage of the robustness and accuracy of SIFT features. Each side-view patch of the repeated geometry of a threaded hole was reconstructed by multi-view stereo. Comparing with traditional 3D point clouds registration algorithm Iterative Closest Point (ICP), our algorithm has the advantages of high-efficiency and high-accuracy, especially for the registration of repetitive geometries.
Download or read book Snake Robots written by Pål Liljebäck and published by Springer Science & Business Media. This book was released on 2012-06-13 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: Snake Robots is a novel treatment of theoretical and practical topics related to snake robots: robotic mechanisms designed to move like biological snakes and able to operate in challenging environments in which human presence is either undesirable or impossible. Future applications of such robots include search and rescue, inspection and maintenance, and subsea operations. Locomotion in unstructured environments is a focus for this book. The text targets the disparate muddle of approaches to modelling, development and control of snake robots in current literature, giving a unified presentation of recent research results on snake robot locomotion to increase the reader’s basic understanding of these mechanisms and their motion dynamics and clarify the state of the art in the field. The book is a complete treatment of snake robotics, with topics ranging from mathematical modelling techniques, through mechatronic design and implementation, to control design strategies. The development of two snake robots is described and both are used to provide experimental validation of many of the theoretical results. Snake Robots is written in a clear and easily understandable manner which makes the material accessible by specialists in the field and non-experts alike. Numerous illustrative figures and images help readers to visualize the material. The book is particularly useful to new researchers taking on a topic related to snake robots because it provides an extensive overview of the snake robot literature and also represents a suitable starting point for research in this area.
