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Three-Dimensional Traffic Scenes Simulation From Road image Sequences

IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS 2016年第4期17卷 1121-1134页

作者： Li, Yaochen Liu, Yuehu Su, Yuanqi Hua, Gang Zheng, Nanning Xi An Jiao Tong Univ Inst Artificial Intelligence & Robot Xian 710049 Peoples R China Xi An Jiao Tong Univ Dept Comp Sci & Technol Xian 710049 Peoples R China Microsoft Res Asia Visual Comp Grp Beijing 100080 Peoples R China

In this paper, we present a novel framework to allow users to tour simulated traffic scenes from the first-person view. Constructing 3-D scenes from road image sequences is in general difficult, due to the intrinsic complexity of dynamic road scenes, which are composed of a drastically moving background, not to mention numerous other surrounding vehicles. With the definitions of the traffic scenemodels, we first introduce the construction process of the simple traffic scenes. After the detection of road boundaries by a semantic fast two-cycle (FTC) level set method, we generate the control points on road sides to construct the "floor-wall" background scene that is subsequently propagated to each frame. Furthermore, we approach the cluttered traffic scenes through a three-component processing pipeline as follows: 1) traffic elements segmentation;2) background images inpainting;and 3) traffic scenes construction. The traffic elements in the cluttered images are segmented by the semantic FTC level set method first. A Gaussian mixture model is then employed to inpaint the occluded background utilizing the optical flows. The cluttered traffic scenes can be constructed after the segmentation and inpainting components. The foreground polygons such as vehicles and traffic signs are then modeled. Users can change their viewpoints according to their own interpretations. We present the evaluations of each technical component, followed by our findings from comprehensive user studies, which well demonstrate the effectiveness of the proposed framework in delivering good touring experience to users.

关键词： Traffic scenes simulation image-based modeling road boundaries detection foreground/background separation new viewpoint

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New advances in obtaining three-dimensional models from conical perspectives

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ADVANCES IN ENGINEERING SOFTWARE 2016年 98卷 38-57页

作者： Conesa, J. Mula, F. Univ Politecn Cartagena Graph Express Dept Campus Muralla MarC Doctor Fleming S-N Cartagena 30202 Spain

In a previous work we presented algorithms which allow obtaining three-dimensional models from graphs which represent a projection in conical parallel perspectives and conical oblique perspectives of polyhedral models with normalon and quasi-normalon typology. In this paper the new advances that we have achieved in this field are presented, allowing increasing the set of models which can be reconstructed to other typologies different from the normalon and quasi-normalon ones. Moreover, we present a new technique which extends the previous work in order to be implemented to conical perspectives with three vanishing points, and the method proposed for the detection of the type of conical perspective represented by the graph, including the detection and subsequent reconstruction of graphs which represent a flat shape, has been improved. The results obtained on a total of 336 tests, with a success ratio of 100%, make the method a proposal to be considered for obtaining models from conical perspectives automatically. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： image reconstruction Single image technique image-based modeling Conical perspective

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Towards asphalt mixture morphology evaluation with the virtual specimen approach

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ROAD MATERIALS AND PAVEMENT DESIGN 2016年第3期17卷 579-599页

作者： Onifade, Ibrahim Jelagin, Denis Birgisson, Bjoern Kringos, Nicole Royal Inst Technol Dept Civil & Architectural Engn Stockholm Sweden Aston Univ Sch Engn & Appl Sci Birmingham W Midlands England

The morphology of asphalt mixture can be defined as a set of parameters describing the geometrical characteristics of its constituent materials, their relative proportions as well as spatial arrangement in the mixture. The present study is carried out to investigate the effect of the morphology on its meso- and macro-mechanical response. An analysis approach is used for the meso-structural characterisation based on the X-ray computed tomography (CT) data. image processing techniques are used to systematically vary the internal structure to obtain different morphology structures. A morphology framework is used to characterise the average mastic coating thickness around the main load carrying structure in the structures. The uniaxial tension simulation shows that the mixtures with the lowest coating thickness exhibit better inter-particle interaction with more continuous load distribution chains between adjacent aggregate particles, less stress concentrations and less strain localisation in the mastic phase.

关键词： asphalt concrete morphology image-based modeling X-ray computed tomography micromechanical modeling

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3D Body Shapes Estimation from Dressed-Human Silhouettes

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COMPUTER GRAPHICS FORUM 2016年第7期35卷 147-156页

作者： Song, Dan Tong, Ruofeng Chang, Jian Yang, Xiaosong Tang, Min Zhang, Jian Jun Zhejiang Univ Hangzhou Zhejiang Peoples R China Bournemouth Univ Poole Dorset England

Estimation of 3D body shapes from dressed-human photos is an important but challenging problem in virtual fitting. We propose a novel automatic framework to efficiently estimate 3D body shapes under clothes. We construct a database of 3D naked and dressed body pairs, based on which we learn how to predict 3D positions of body landmarks (which further constrain a parametric human body model) automatically according to dressed-human silhouettes. Critical vertices are selected on 3D registered human bodies as landmarks to represent body shapes, so as to avoid the time-consuming vertices correspondences finding process for parametric body reconstruction. Our method can estimate 3D body shapes from dressed-human silhouettes within 4 seconds, while the fastest method reported previously need 1 minute. In addition, our estimation error is within the size tolerance for clothing industry. We dress 6042 naked bodies with 3 sets of common clothes by physically based cloth simulation technique. To the best of our knowledge, We are the first to construct such a database containing 3D naked and dressed body pairs and our database may contribute to the areas of human body shapes estimation and cloth simulation.

关键词： Categories and Subject Descriptors (according to ACM CCS) I.3.m [Computer Graphics]: Miscellaneous&mdash image-based modeling

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Monte Carlo simulations of meso-scale dynamic compressive behavior of concrete based on X-ray computed tomography images

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INTERNATIONAL JOURNAL OF IMPACT ENGINEERING 2016年第Nov.期97卷 102-115页

作者： Huang, Y. J. Yang, Z. J. Chen, X. W. Liu, G. H. Zhejiang Univ Coll Civil Engn & Architecture Hangzhou 310058 Zhejiang Peoples R China China Acad Engn Phys Inst Syst Engn Mianyang 621999 Peoples R China

The dynamic damage and fracture behavior of concrete under compression with strain rate up to 100 s(-1) is investigated by Monte Carlo simulations (MCSs) of realistic meso-scale models based on high resolution micro-scale X-ray computed tomography (XCT) images, using the concrete damaged plasticity (CDP) model. For a given strain rate, 93 2D XCT images of a 37.2 mm concrete cube are simulated to obtain statistical results of macroscopic stress-strain curves. The predicted compressive dynamic increase factor (CDIF)-strain rate curve is in good agreement with existing experimental data and empirical curves. The effects of aggregate/void area fraction on dynamic compressive strength are also analyzed, and an augmented compressive strength -strain rate relation considering the void area fraction is proposed. A full 3D model is also simulated under various strain rates. It is found that the realistic XCT-image based meso-models with the CDP model are very promising in effectively elucidating the complicated and fundamental dynamic failure mechanisms of concrete. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Dynamic damage and fracture Meso-scale modeling Concrete In-situ X-ray computed tomography image-based modeling

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Building cell models and simulations from microscope images

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METHODS 2016年 96卷 33-39页

作者： Murphy, Robert F. Carnegie Mellon Univ Computat Biol Dept Ctr Bioimage Informat 5000 Forbes Ave Pittsburgh PA 15213 USA Carnegie Mellon Univ Dept Biol Sci 5000 Forbes Ave Pittsburgh PA USA Carnegie Mellon Univ Dept Biomed Engn 5000 Forbes Ave Pittsburgh PA 15213 USA Carnegie Mellon Univ Dept Machine Learning 5000 Forbes Ave Pittsburgh PA 15213 USA Univ Freiburg Freiburg Inst Adv Studies Freiburg Germany Univ Freiburg Fac Biol Freiburg Germany

The use of fluorescence microscopy has undergone a major revolution over the past twenty years, both with the development of dramatic new technologies and with the widespread adoption of image analysis and machine learning methods. Many open source software tools provide the ability to use these methods in a wide range of studies, and many molecular and cellular phenotypes can now be automatically distinguished. This article presents the next major challenge in microscopy automation, the creation of accurate models of cell organization directly from images, and reviews the progress that has been made towards this challenge. (C) 2015 Elsevier Inc. All rights reserved.

关键词： Computational biology image-based modeling Cell organization Cell shape Generative models

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Full Three-Dimensional Seismic Response Analysis of Underground Structures with Large Complex Cross Sections and Two-Step Analysis Method for Reducing the Computational Costs

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JOURNAL OF EARTHQUAKE AND TSUNAMI 2016年第5期10卷

作者： Ichimura, Tsuyoshi Tanaka, Seizo Hori, Muneo Yamamoto, Yujin Dobashi, Hiroshi Osada, Mitsumasa Ohbo, Naoto Yamada, Takemine Univ Tokyo Earthquake Res Inst Tokyo Japan Univ Tsukuba Informat & Syst Tsukuba Ibaraki Japan Univ Tokyo Dept Civil Engn Tokyo Japan Metropolitan Expressway Co Ltd Tokyo Japan Assoc Dev Earthquake Predict Tokyo Japan Kajima Corp Tokyo Japan

To enhance the reliability of estimates of seismic behavior, with a special emphasis on quality assurance of numerical simulations, this paper presents a full three-dimensional (3D) seismic response analysis of a large underground structure with a complex cross section. We conduct a full 3D seismic-response analysis using a high-fidelity model with quality assurance and a high-performance computing technique in a supercomputer environment. Due to the large computational costs of such analyses, we propose a two-step numerical simulation method based on multi-scale analysis, image-based modeling, and sophisticated approximation techniques. We provide numerical examples showing that the method can successfully reproduce the dynamic behavior of a full 3D model, but with a considerable reduction in computational costs. Our method is expected to support practical seismic safety inspections and the design of underground structures with complex large-cross-sectional configurations, as it has already been applied to the practical seismic safety inspection of an actual underground highway.

关键词： Seismic structural response large underground structure with a complex cross section finite element analysis with solid element high-performance computing multi-scale analysis image-based modeling quality assurance of numerical simulation

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image-based modeling of Blood Flow and Vessel Wall Dynamics: Applications, Methods and Future Directions

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ANNALS OF BIOMEDICAL ENGINEERING 2010年第3期38卷 1188-1203页

作者： Taylor, Charles A. Steinman, David A. Stanford Univ Dept Bioengn Stanford CA 94305 USA Stanford Univ Dept Surg Stanford CA 94305 USA Univ Toronto Dept Mech & Ind Engn Toronto ON Canada

The objective of our session at the 2008 International Bio-Fluid Symposium and Workshop was to review the state-of-the-art in image-based modeling of blood flow, and identify future directions. Here we summarize progress in the field of image-based modeling of blood flow and vessel wall dynamics from mid-2005 to early 2009. We first describe the tremendous progress made in the application of image-based modeling techniques to elucidate the role of hemodynamics in vascular pathophysiology, plan treatments for congenital and acquired diseases in individual patients, and design and evaluate endovascular devices. We then review the advances that have been made in improving the methodology for modeling blood flow and vessel wall dynamics in image-based models, and consider issues related to extracting hemodynamic parameters and verification and validation. Finally, the strengths and weaknesses of current work in image-based modeling and the opportunities and threats to the field are described. We believe that with a doubling of our efforts toward the clinical application of image-based modeling tools, the next few years could surpass the tremendous gains made in the last few.

关键词： image-based modeling Patient-specific Hemodynamics Atherosclerosis Aneurysms Surgical planning

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Three-dimensional numerical modeling of ultrasonic wave propagation in concrete and its experimental validation

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CONSTRUCTION AND BUILDING MATERIALS 2015年第Mar.1期78卷 217-223页

作者： Nakahata, K. Kawamura, G. Yano, T. Hirose, S. Ehime Univ Dept Civil & Environm Engn Matsuyama Ehime 7908577 Japan Tokyo Inst Technol Dept Mech & Environm Informat Meguro Ku Tokyo 1528552 Japan

To understand the characteristics of ultrasonic wave propagation in concrete more completely, we propose a time domain simulation tool based on the finite integration technique (FIT) and an image-based modeling approach. When modeling ultrasonic wave propagation in concrete, it is important to introduce three-dimensional mesoscopic and microscopic structures because ultrasonic waves in solids are transmitted by mechanical interaction between adjacent media. In this paper, wave velocity, center frequency, and attenuation of ultrasonic waves in concrete are evaluated quantitatively by comparing the waveforms obtained by FIT simulation with those obtained by experimental measurement. It was observed that these factors were in good agreement between the simulation and measurements. It was also observed that amplitude of the transmitted signal was sensitive to the allocation pattern of the aggregates. Thus, attenuation due to multiple scattering by aggregates is more dominant than the attenuation by intrinsic absorption and geometrical spreading in concrete. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Ultrasonic wave image-based modeling Finite integration technique Concrete material Multiple scattering and attenuation Simulation Validation

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Fast and scalable 3D cyber-physical modeling for high-precision mobile augmented reality systems

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PERSONAL AND UBIQUITOUS COMPUTING 2015年第8期19卷 1275-1294页

作者： Bae, Hyojoon White, Jules Golparvar-Fard, Mani Pan, Yao Sun, Yu Virginia Tech Bradley Dept Elect & Comp Engn Blacksburg VA USA Vanderbilt Univ Dept Elect Engn & Comp Sci Nashville TN 37235 USA Univ Illinois Dept Comp Sci Dept Civil & Environm Engn Urbana IL USA

Mobile augmented reality is an emerging technique which allows users to use a mobile device's camera to capture real-world imagery and view real-world physical objects and their associated cyber-information overlaid on top of imagery of them. One key challenge for mobile augmented reality is the fast and precisely localization of a user in order to determine what is visible in their camera view. Recent advances in Structure-from-Motion (SfM) enable the creation of 3D point clouds of physical objects from an unordered set of photographs taken by commodity digital cameras. The generated 3D point cloud can be used to identify the location and orientation of the camera relative to the point cloud. While this SfM-based approach provides complete pixel-accurate camera pose estimation in 3D without relying on external GPS or geomagnetic sensors, the preparation of initial 3D point cloud typically takes from hours to a day, making it difficult to use in mobile augmented reality applications. Furthermore, creating 3D cyber-information and associating it with the 3D point cloud is also a challenge of using SfM-based approach for mobile augmented reality. To overcome these challenges in 3D point cloud creation and cyber-physical content authoring, the paper presents a new SfM framework that is optimized for mobile augmented reality and rapidly generates a complete 3D point cloud of a target scene up to 28 times faster than prior approaches. Key improvements in the proposed SfM framework stem from the use of (1) state-of-the-art binary feature descriptors, (2) new filtering approach for accurate 3D modeling, (3) optimized point cloud structure for augmented reality, and (4) hardware/software parallelism. The paper also provides a new image-based 3D content authoring method designed specifically for the limited user interfaces of mobile devices. The proposed content authoring method generates 3D cyber-information from a single 2D image and automatically associates it with the 3D

关键词： Structure-from-Motion image-based modeling Mobile augmented reality

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