Download or read book Reconstructing 3D Geometry from Multiple Images Via Inverse Rendering written by John William Bastian and published by . This book was released on 2007 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: An image is a two-dimensional representation of the three-dimensional world. Recovering the information which is lost in the process of image formation is one of the fundamental problems in Computer Vision. One approach to this problem involves generating and evaluating a succession of surface hypotheses, with the best hypothesis selected as the final estimate. The fitness of each hypothesis can be evaluated by comparing the reference images against synthetic images of the hypothesised surface rendered with the reference cameras.

Download or read book Mesh Regularization for Multi view Shape Reconstruction Via Inverse Graphics written by Sanjay Ganeshan and published by . This book was released on 2021 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inverse rendering uses 2D images to infer the 3D scene parameters that produced the images. Unfortunately, inverse rendering is an ill-posed problem that is difficult to optimize. In this paper, we explore using a differentiable renderer to solve inverse rendering problems that are constrained to a single object with two unknowns: shape and texture. The inferred 3D scene is thus a single 3D model. We iteratively optimize an input "guess" 3D model to fit a set of input target images of the desired 3D object. The constrained inverse rendering problem remains ill-posed. So, we adapt, develop, and evaluate a number of deformation, regularization, and training techniques that allow the optimization to converge to visually appealing output 3D models. The system consumes a 3D triangle mesh and target images as input. It outputs a 3D mesh and its corresponding 2D texture image that can easily be consumed by other programs. The best results are achieved using a deep-mesh prior neural network, an Image Pyramid coarse-to-fine loss function, a Silhouette Loss function that is robust to inaccuracies in texture, three separate mesh regularizing loss functions – Laplacian, Flatness, and Non-Uniformity, and periodic refinement operations where the output mesh is upsampled and its manifold is recomputed.

Download or read book Inverse Rendering for Computer Graphics written by Stephen Robert Marschner and published by . This book was released on 1998 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 3D Reconstruction from Multiple Images written by Theo Moons and published by Now Publishers Inc. This book was released on 2009-10-23 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: The issue discusses methods to extract 3-dimensional (3D) models from plain images. In particular, the 3D information is obtained from images for which the camera parameters are unknown. The principles underlying such uncalibrated structure-from-motion methods are outlined. First, a short review of 3D acquisition technologies puts such methods in a wider context, and highlights their important advantages. Then, the actual theory behind this line of research is given. The authors have tried to keep the text maximally self-contained, therefore also avoiding to rely on an extensive knowledge of the projective concepts that usually appear in texts about self-calibration 3D methods. Rather, mathematical explanations that are more amenable to intuition are given. The explanation of the theory includes the stratification of reconstructions obtained from image pairs as well as metric reconstruction on the basis of more than 2 images combined with some additional knowledge about the cameras used. Readers who want to obtain more practical information about how to implement such uncalibrated structure-from-motion pipelines may be interested in two more Foundations and Trends issues written by the same authors. Together with this issue they can be read as a single tutorial on the subject.

Download or read book Forward and Inverse Rendering with Gradient based Optimization written by Fujun Luan and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photorealistic rendering is a fundamental component of computer graphics. To render photorealistic 2D images that faithfully represent our 3D world, efforts have been devoted into developing compact scientific models and efficient algorithms that are capable of simulating lighting and physics to capture appearance using the geometry, reflectance and illumination. Inverse Rendering, on the other hand, focuses on recovering unknown scene attributes from photograph measurements by optimization, typically through analysis-by-synthesis technique, or more recently, differentiable rendering. In this thesis, we propose solutions to a few such challenging forward and inverse graphics problems, as described below. The first work is a forward rendering (SIGGRAPH 2020) approach to speeding up Markov chain Monte Carlo (MCMC) rendering with derivatives from recent rendering engines that support end-to-end differentiation. In this work, we build upon Langevin dynamics and propose a suite of Langevin Monte Carlo algorithms with gradient-based adaptation for efficient photorealistic rendering of scenes with complex light transport effects, such as caustics, interreflections, and occlusions. In inverse rendering, we develop multiple solutions for recovering material and shape. In our second work (ICCP 2020) we focus on learning-based inverse subsurface scattering. Given images of transcluent objects, of unknown shape and lighting, we aim to use learning to infer the optical parameters controlling subsurface scattering of light inside the objects. With physics-based priors in the learning framework, we obtain strong improvements in both parameter estimation accuracy and appearance reproduction compared to traditional networks. Our third work is a unified shape and appearance reconstruction framework (EGSR 2021) using differentiable rendering for 3D object scanning. We tackle this problem by introducing a new analysis-by-synthesis technique capable of producing high-quality reconstructions through robust coarse-to-fine optimization and physics-based differentiable rendering. We demonstrate the effectiveness of our method on real-world objects captured with handheld cameras that outperforms previous state-of-the-art approaches. In Appendix A, we tackle the challenge of automatically generating procedural representation of fiber-based yarn models for cloth rendering (SIGGRAPH 2016, EGSR 2017). Appendix B has slightly deviated from rendering and focuses on image style transfer techniques (CVPR 2017, EGSR 2018). With recent advances in physics-based differentiable rendering, we have taken first steps to speeding up MCMC forward rendering with first-order gradients, improving learning-based inverse subsurface scattering, and introducing an end-to-end differentiable rendering pipeline for high-quality handheld object scanning. As for next steps, a promising future direction for computer graphics would be learning-based neural rendering methods that aim for AR/VR-based applications. Exploring differentiable rendering for improving traditional 3D reconstruction would be another promising topic, thanks to the theoretical and practical breakthroughs in the corresponding field.

Download or read book Advances in Photometric 3D Reconstruction written by Jean-Denis Durou and published by Springer Nature. This book was released on 2020-09-16 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest advances in photometric 3D reconstruction. It provides the reader with an overview of the state of the art in the field, and of the latest research into both the theoretical foundations of photometric 3D reconstruction and its practical application in several fields (including security, medicine, cultural heritage and archiving, and engineering). These techniques play a crucial role within such emerging technologies as 3D printing, since they permit the direct conversion of an image into a solid object. The book covers both theoretical analysis and real-world applications, highlighting the importance of deepening interdisciplinary skills, and as such will be of interest to both academic researchers and practitioners from the computer vision and mathematical 3D modeling communities, as well as engineers involved in 3D printing. No prior background is required beyond a general knowledge of classical computer vision models, numerical methods for optimization, and partial differential equations.

Download or read book Computer Vision ACCV 2006 written by P. J. Narayanan and published by Springer Science & Business Media. This book was released on 2006 with total page 1001 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 Image Based 3D Reconstruction of Dynamic Objects Using Instance Aware Multibody Structure from Motion written by Bullinger, Sebastian and published by KIT Scientific Publishing. This book was released on 2020-08-26 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This work proposes a Multibody Structure from Motion (MSfM) algorithm for moving object reconstruction that incorporates instance-aware semantic segmentation and multiple view geometry methods. The MSfM pipeline tracks two-dimensional object shapes on pixel level to determine object specific feature correspondences, in order to reconstruct 3D object shapes as well as 3D object motion trajectories" -- Publicaciones de Arquitectura y Arte.

Download or read book 3 D Surface Geometry and Reconstruction Developing Concepts and Applications written by Chandra Pati, Umesh and published by IGI Global. This book was released on 2012-02-29 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book provides developers and scholars with an extensive collection of research articles in the expanding field of 3D reconstruction, investigating the concepts, methodologies, applications and recent developments in the field of 3D reconstruction"--

Download or read book Recent Advances in 3D Imaging Modeling and Reconstruction written by Voulodimos, Athanasios and published by IGI Global. This book was released on 2020-02-28 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: 3D image reconstruction is used in many fields, such as medicine, entertainment, and computer science. This highly demanded process comes with many challenges, such as images becoming blurry by atmospheric turbulence, getting snowed with noise, or becoming damaged within foreign regions. It is imperative to remain well-informed with the latest research in this field. Recent Advances in 3D Imaging, Modeling, and Reconstruction is a collection of innovative research on the methods and common techniques of image reconstruction as well as the accuracy of these methods. Featuring coverage on a wide range of topics such as ray casting, holographic techniques, and machine learning, this publication is ideally designed for graphic designers, computer engineers, medical professionals, robotics engineers, city planners, game developers, researchers, academicians, and students.

Download or read book 3D Structure from Multiple Images of Large Scale Environments written by Reinhard Koch and published by Springer. This book was released on 2003-05-20 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the strictly refereed post-workshop proceedings of the European Workshop on 3D Structure from Multiple Images of Large-Scale Environments, SMILE'98, held in conjunction with ECCV'98 in Freiburg, Germany, in June 1998. The 21 revised full papers presented went through two cycles of reviewing and were carefully selected for inclusion in the book. The papers are organized in sections on multiview relations and correspondence search, 3D structure from multiple images, callibration and reconstruction using scene constraints, range integration and augmented reality application.

Download or read book Video Based Rendering written by Marcus A. Magnor and published by CRC Press. This book was released on 2005-08-08 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven by consumer-market applications that enjoy steadily increasing economic importance, graphics hardware and rendering algorithms are a central focus of computer graphics research. Video-based rendering is an approach that aims to overcome the current bottleneck in the time-consuming modeling process and has applications in areas such as comput

Download or read book Computer Vision ECCV 2014 written by David Fleet and published by Springer. This book was released on 2014-09-22 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: The seven-volume set comprising LNCS volumes 8689-8695 constitutes the refereed proceedings of the 13th European Conference on Computer Vision, ECCV 2014, held in Zurich, Switzerland, in September 2014. The 363 revised papers presented were carefully reviewed and selected from 1444 submissions. The papers are organized in topical sections on tracking and activity recognition; recognition; learning and inference; structure from motion and feature matching; computational photography and low-level vision; vision; segmentation and saliency; context and 3D scenes; motion and 3D scene analysis; and poster sessions.

Download or read book The Geometry of Multiple Images written by Olivier Faugeras and published by MIT Press. This book was released on 2001 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book formalizes and analyzes the relations between multiple views of a scene from the perspective of various types of geometries. A key feature is that it considers Euclidean and affine geometries as special cases of projective geometry. Over the last forty years, researchers have made great strides in elucidating the laws of image formation, processing, and understanding by animals, humans, and machines. This book describes the state of knowledge in one subarea of vision, the geometric laws that relate different views of a scene. Geometry, one of the oldest branches of mathematics, is the natural language for describing three-dimensional shapes and spatial relations. Projective geometry, the geometry that best models image formation, provides a unified framework for thinking about many geometric problems are relevant to vision. The book formalizes and analyzes the relations between multiple views of a scene from the perspective of various types of geometries. A key feature is that it considers Euclidean and affine geometries as special cases of projective geometry. Images play a prominent role in computer communications. Producers and users of images, in particular three-dimensional images, require a framework for stating and solving problems. The book offers a number of conceptual tools and theoretical results useful for the design of machine vision algorithms. It also illustrates these tools and results with many examples of real applications.

Download or read book Real time 3D Reconstruction and Rendering for Minimally Invasive Surgery with Multi Cameras Array written by Jianwei Ke and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advancements in digital camera technologies have led to significantly smaller camera sensors without compromising imaging quality. This trend opens avenues for replacing single-camera systems with multi-camera arrays, offering benefits such as an expanded field-of-view and 3D information. However, camera arrays require additional processing to interpret the collected image data. This report addresses two significant algorithmic challenges in developing a camera array. The first challenge involves virtual view generation, which is the task of estimating the image for a virtual camera using image data from multiview cameras. Ideally, if the geometry of the underlying scene is known, the virtual view can be generated by projecting the 3D geometry to the virtual camera. However, finding the 3D geometry of a scene from multiview cameras is an active research topic in Computer Vision. Considering the real-time processing requirement (

Download or read book End to end Representation Learning for 3D Reconstruction written by Soroush Saryazdi and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physically based rendering requires the digital representation of a scene to include both 3D geometry and material appearance properties of objects in the scene. Reconstructing such 3D representations from images of real-world environments has been a long-standing goal in the fields of computer vision, computer graphics, robotics, augmented and virtual reality, etc. Recently, representation learning based approaches have transformed the landscape of several domains such as image recognition and semantic segmentation. However, despite many encouraging advances in other domains, how these learning-based approaches can be leveraged in the realm of 3D reconstruction is still an open question. In this thesis, we propose approaches for using neural networks in conjunction with the 3D reconstruction pipeline such that they can be trained end-to-end based on a single end objective (e.g., to reconstruct an accurate 3D representation). Our main contributions include the following: - A fully differentiable dense visual SLAM framework for reconstructing the 3D geometry of a scene from a sequence of RGB-D images, called gradslam. This work, carried out in collaboration with the Robotics and Embodied AI Lab (REAL) at MILA, resulted in the release of the first open-source library for differentiable SLAM. - We propose the disentangled rendering loss for training neural networks to estimate material appearance parameters from image(s) of a near-flat surface. The disentangled rendering loss allows the network to weigh the importance of each material appearance parameter based on its effect on the final appearance of the material, while also having desirable mathematical properties for gradient-based training. - We describe work towards an end-to-end trainable model that can simultaneously reconstruct the 3D geometry and predict the material appearance properties of a scene. A publicly available dataset for training such a model is not currently available. Thus, we have created a dataset of material appearance properties for complex scenes which we intend to release publicly. Our approach enjoys many of the benefits of classical 3D reconstruction approaches such as interpretability (due to the modular nature) and the ability to use well-understood components from the reconstruction pipeline. Further, this approach also enjoys representation learning benefits such as the capability of solving challenging tasks which have been difficult to solve by designing explicit algorithms (e.g., material appearance property estimation for complex scenes), and their strong performance on end-to-end training tasks.