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26th International Symposium of ICOMOS/ISPRS-International-Scientific-Committee-on-Heritage-Documentation (CIPA) on Digital Workflows for Heritage Conservation

作者： Inzerillo, L. Di Paola, F. Polytech Sch Dept Architecture DARCH I-90128 Palermo Italy

In In the last years there has been an increasing use of digital techniques for conservation and restoration purposes. Among these, a very dominant rule is played by the use of digital photogrammetry packages (Agisoft Photo scan, 3D Zephir) which allow to obtain in few steps 3D textured models of real objects. Combined with digital documentation technologies digital fabrication technologies can be employed in a variety of ways to assist in heritage documentation, conservation and dissemination. This paper will give to practitioners an overview on the state of the art available technologies and a feasible workflow for optimizing point cloud and polygon mesh datasets for the purpose of fabrication using 3D printing. The goal is to give an important contribute to confer an automation aspect at the whole processing. We tried to individuate a workflow that should be applicable to several types of cases apart from small precautions. In our experimentation we used a DELTA WASP 2040 printer with PLA easyfil.

关键词： SfM image based modeling Automation Restauration Conservation 3D printing

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Automatic 3D Car Model Alignment for Mixed image-based Rendering 4

Automatic 3D Car Model Alignment for Mixed Image-Based Rende...

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4th IEEE International Conference on 3D Vision (3DV)

作者： Ortiz-Cayon, Rodrigo Djelouah, Abdelaziz Massa, Francisco Aubry, Mathieu Drettakis, George INRIA Le Chesnay France Ecole Ponts ParisTech Marne La Vallee France

ISBN: (纸本)9781509054077

image-based Rendering (IBR) allows good-quality free-viewpoint navigation in urban scenes, but suffers from artifacts on poorly reconstructed objects, e.g., reflective surfaces such as cars. To alleviate this problem, we propose a method that automatically identifies stock 3D models, aligns them in the 3D scene and performs morphing to better capture image contours. We do this by first adapting learning-based methods to detect and identify an object class and pose in images. We then propose a method which exploits all available information, namely partial and inaccurate 3D reconstruction, multi-view calibration, image contours and the 3D model to achieve accurate object alignment suitable for subsequent morphing. These steps provide models which are well-aligned in 3D and to contours in all the images of the multi-view dataset, allowing us to use the resulting model in our mixed IBR algorithm. Our results show significant improvement in image quality for free-viewpoint IBR, especially when moving far from the captured viewpoints.

关键词： image based modeling image based rendering scene understanding

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Reflectance-based 3D Shape Refinement of Surfaces with Spatially Varying BRDF Properties 9

Reflectance-Based 3D Shape Refinement of Surfaces with Spati...

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9th IAPR Workshop on Pattern Recognition in Remote Sensing (PRRS)

作者： Lenoch, Malte Woehler, Christian TU Dortmund Univ Fac Elect Engn & Informat Technol Image Anal Grp D-44227 Dortmund Germany

ISBN: (纸本)9781509050413

This paper proposes a novel algorithm to determine the spatially varying reflectance of an arbitrary object based on per-pixel estimates of the bidirectional reflectance distribution function (BRDF). The proposed procedure is especially designed to work in environments that yield relatively sparse reflectance measurements, since the parameter estimation is initialized on regions of similar brightness to ensure sufficient data to rely on. We suppose a physically plausible version of the Blinn BRDF model to be sufficiently accurate in combination with pixelwise parameter maps. Thus, we consider isotropic reflectance only. The initial estimate of the depth data can either be supplied to the algorithm or, as proposed here, be obtained by solving the photometric stereo equations for the diffuse component of the surface reflectance. These data are probably affected by noise and errors due to the simplified diffuse estimate. We use an iterative approach to refine this depth information based on the surface gradient that is computed from BRDF parameter maps. A low-passed version of the initial depth is used as boundary condition when integrating the surface normal field. We apply the proposed method to real-world data sets and show that the gradient information is able to refine the initial depth data. Comparison to an industrial standard 3D scanner shows that accurate results are obtained at a lower noise level without removing high frequency details of the surface that are visible in the image data.

关键词： 3D shape recovery illumination and reflectance modeling image based modeling

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Photogrammetric evaluation options of an ancient monument for different survey levels

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JOURNAL OF ARCHAEOLOGICAL SCIENCE-REPORTS 2016年 8卷 200-205页

作者： Uygun, Funda Turan, Mine Hamamcioglu Ocali, Ogan Izmir Inst Technol Fac Architecture Architectural Restorat Dept IYTE TR-35430 Izmir Turkey Izmir Inst Technol IYTE Dist Technol Dev TR-35430 Izmir Turkey

Recently, for the purpose of data management, more advanced digital data are required for different survey levels of irregular ancient monuments. For irregularly formed monuments and amorphous surfaces, 2D photographs and 2D measured surveys are inadequate to illustrate the condition of the building for condition reports or relationships between components and materials for structural surveys and conservation decisions, especially in archeological remains. However, image-based documentation techniques can be used as simple tools for different types of surveys due to their ease of use and fast and economical properties. Therefore, the aim of the study is to test multi-image photogrammetric documentation techniques to improve and standardize visual data appending condition reports and further detailed reports regarding conservation of irregular ancient monuments. In the literature, there are many studies about image-based documentation techniques. However, the innovation of the study is to provide an improvement of the pipeline of condition and structural surveys of irregular ancient monuments by making use of photogrammetric techniques. In order to measure the effects of the relationship between the type of documentation technique and survey level on the photogrammetric documentation process of an ancient monument, a series of experiments were designed and the results compared. For this purpose, automated image orientation packages Autodesk 123D and Photosynth and manual image orientation package Tgi3D were evaluated in terms of process time, reliability and level of detail to identify appropriate techniques for different survey levels. This study proved that documentation of the structural characteristics of ancient monuments can be achieved successfully with the Tgi3D package, which has manual workflows. The documentation results might support structural intervention decisions. The 3D models based on automatic workflows might support a preliminary condition survey,

关键词： image based modeling Ancient monument Documentation Condition report Structural survey

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image-based modeling for Virtual Museum

Image-Based Modeling for Virtual Museum

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International Conference on Multimedia, Computer Graphics and Broadcasting (MulGraB 2011)

作者： Kim, Jin-Mo Shin, Do-Kyung Ahn, Eun-Young Hanbat Natl Univ Dept Commun Informat & Comp Engn Deajeon City South Korea Dongguk Univ Dept Multimedia Seoul South Korea Hanyang Univ Dept Comp Engn Ansan South Korea

ISBN: (纸本)9783642272035

This method focuses on the making a vivid virtual museum in a proper time for the number of complicated artifacts. And another purpose is minimizing undesirable distortions in the process of the modeling and finally. gaining realistic visual effects. In this paper, we present a new method for constructing 3D VR contents by using Smart Billboard, namely for selecting a proper mapping image among the images captured by rotating camera position at regular intervals. Moreover, we describe a simplified calculation method for selecting an adequate image to the viewer. The proposed method is applicable to the industry like as e-commerce, e-learning on the web site and simulations for saving your efforts and resources to make 3D VR contents. And it is validated with the practical embodiments of a virtual museum in which the exhibitions are represented by Smart Billboard that automatically calculates and selects a proper image according to the view change in a cyber space.

关键词： Texture mapping Billboard Mixed reality image based modeling

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CARDIAC MRI DERIVED EPICARDIAL FAT MAPS TO ASSIST VT ABLATION PROCEDURES FOR SUBJECTS WITH IMPLANTABLE DEVICES 12

CARDIAC MRI DERIVED EPICARDIAL FAT MAPS TO ASSIST VT ABLATIO...

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IEEE 12th International Symposium on Biomedical Imaging

作者： Zimmermann, Judith Rashid, Shams Hu, Peng Katouzian, Amin Navab, Nassir Ennis, Daniel B. Univ Calif Los Angeles Dept Radiol Sci Los Angeles CA 90024 USA Tech Univ Munich Chair Comp Aided Med Procedures D-80290 Munich Germany

ISBN: (纸本)9781479923748

Cardiac electroanatomical mapping (EAM) to locate myocardial scar substrate during ventricular tachycardia (VT) ablation therapy is currently faced with a major limitation. The presence of epicardial fat leads to false-positive low-voltage maps that may interpreted as myocardial scar. Pre-procedural cardiac magnetic resonance (CMR) imaging can produce images of the heart in which both cardiac geometry and epicardial fat are particularly conspicuous. The goal of the present work is to build CMR based geometric models composed of a shell of the cardiac anatomy and epicardial fat. Herein, we first defined a black-blood imaging protocol that is feasible in patients with implanted devices. Then a semi-automated image segmentation method was developed and applied to extract ventricular surface anatomy and epicardial fat maps from which three-dimensional surfaces were built. The results suggest that deriving maps of epicardial fat from MRI data is feasible, accurate when compared to expert observers, and suitable for integration in a clinical catheter-based ablation procedure.

关键词： Cardiac MRI Implantable Cardioverter Defibrillators image Segmentation Epicardial Fat image based modeling

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image-based modeling of inhomogeneous single-scattering participating media

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Science China(Information Sciences) 2010年第6期53卷 1141-1150页

作者： HU Yong 1 , QI Yue 1 & TONG Xin 2 1 State Key Laboratory of Virtual Reality Technology and Systems, Beihang University, Beijing 100191, China 2 Microsoft Research Asia, Beijing 100080, China 1. State Key Laboratory of Virtual Reality Technology and Systems Beihang University Beijing 100191 China2. Microsoft Research Asia Beijing 100080 China

We propose a method to reconstruct inhomogeneous single-scattering participating media, which could preserve fine high-frequency details of density *** data and the ratio of absorption coefficient to scattering coefficient are used to describe the spatial-varying density distribution and optical properties of certain participating media, and a function between the above parameters and captured pixel values is *** the problem of how to find solutions to these parameters is formulated into a nonlinear numerical optimization *** order to reduce large time overheads and numerical instability brought by simultaneously solving large numbers of voxels, we propose an initialization algorithm for enabling the assigned density values to satisfy the regularity of brightness distribution in captured images approximately as well as a progressive refinement algorithm for multi-resolution volumetric ***, we propose a parallel multi-voxel gradient computation algorithm of utilizing hardware acceleration to reduce time overheads in gradient computation for large numbers of *** results indicate that our method is well suited for reconstructing thin smoke, retaining high-frequency details from images captured from multiple viewpoints.

关键词： single-scattering participating media smoke modeling volumetric modeling image based modeling

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The Evaluation of Coke Strength before/after Solution Loss Reaction for an Actual Coke image Using image based modeling

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TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN 2009年第8期95卷 593-599页

作者： Hayashizaki, Hideyuki Ueoka, Kenta Kajiyama, Masashi Yamazaki, Yoshiaki Hiraki, Kenichi Matsushita, Yohsuke Aoki, Hideyuki Miura, Takatoshi Fukuda, Koichi Matsudaira, Kanji Tohoku Univ Grad Sch Engn Aoba Ku Sendai Miyagi 9808579 Japan Nippon Steel Corp Ltd Environm & Proc Technol Ctr Tokyo Japan

In this study, coke strength for an actual microscopic structures before/after solution loss reaction is numerically evaluated using image based modeling. Stress analyses for microscopic structures of coke before/after solution loss reaction at 1173 K are carried Out. In the analyses, microscopic structure of coke is assumed to be composed of active components and pores. Analytical results show that the maximum von Mises stress sharply increases with an increase in conversion for solution loss reaction. It is caused by decrease in both pore wall thickness and a reduction in the connection of coke texture by solution loss reaction. The stress distribution closely relates to change of microscopic structures by solution loss reaction.

关键词： coke coke strength image based modeling microscopic structure solution loss reaction

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Using dense stereo matching techniques in survey

DISEGNARE IDEE IMMAGINI-IDEAS IMAGES

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DISEGNARE IDEE IMMAGINI-IDEAS imageS 2013年第47期24卷 82-91页

作者： Inzerillo, Laura Santagati, Cettina

In recent years there has been an enormous increase in the dissemination of modelling techniques known as dense stereo matching (DSM) or image-based modelling (IBM) using free, low cost, open source software, especially applications involving the survey of cultural heritage (architecture, archaeology, and town planning). The algorithms used by these software programmes process photographic datasets and provide a 3D model of the scene in question. During complex survey and 3D restitution procedures, these techniques save time (processing) and money: these advantages Can he useful to any professional. This is why it is important to identify the real potential and limits of these software programmes and how they should be used to produce the best possible results. We carried out parallel tests to verify how to use the two software packages: 123D Catch by Autodesk and VisualSfM+CMVS/PMVS2 by Changchang Wu. The photographic dataset was the most critical part of the procedure involving DSM or IBM techniques. The article illustrates three case studies in which only the third study, provides an optimal dataset capable of generating a reliable model. The tests were carried out on three different architectural objects, ranging from a small to large scale;terrestrial laser scansions were used for the metric comparisons of the ensuing models.

关键词： Dense stereo matching image based modeling 3D modeling Structure from Motion Digital Heritage

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Dynamic Probabilistic Volumetric Models

Dynamic Probabilistic Volumetric Models

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IEEE International Conference on Computer Vision (ICCV)

作者： Ulusoy, Ali Osman Biris, Octavian Mundy, Joseph L. Brown Univ Sch Engn Providence RI 02912 USA

ISBN: (纸本)9781479928392

This paper presents a probabilistic volumetric framework for image based modeling of general dynamic 3-d scenes. The framework is targeted towards high quality modeling of complex scenes evolving over thousands of frames. Extensive storage and computational resources are required in processing large scale space-time (4-d) data. Existing methods typically store separate 3-d models at each time step and do not address such limitations. A novel 4-d representation is proposed that adaptively subdivides in space and time to explain the appearance of 3-d dynamic surfaces. This representation is shown to achieve compression of 4-d data and provide efficient spatio-temporal processing. The advances of the proposed framework is demonstrated on standard datasets using free-viewpoint video and 3-d tracking applications.

关键词： 3-d tracking 4-d compression dynamic scene analysis free viewpoint video image based modeling

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