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international Conference on 3d Imaging, Modeling, processing, visualization and transmission (3dIMPVT)

作者： Suresh K. Lodha darren M. Fitzpatrick david P. Helmbold School of Engineering University of California Santa Cruz CA USA

We use the AdaBoost algorithm to classify 3d aerial lidar scattered height data into four categories: road, grass, buildings, and trees. To do so we use five features: height, height variation, normal variation, lidar return intensity, and image intensity. We also use only lidar-derived features to organize the data into three classes (the road and grass classes are merged). We apply and test our results using ten regions taken from lidar data collected over an area of approximately eight square miles, obtaining higher than 92% accuracy. We also apply our classifier to our entire dataset, and present visual classification results both with and without uncertainty. We implement and experiment with several variations within the AdaBoost family of algorithms. We observe that our results are robust and stable over all the various tests and algorithmic variations. We also investigate features and values that are most critical in distinguishing between the classes. This insight is important in extending the results from one geographic region to another.

关键词： Laser radar Classification tree analysis Machine learning algorithms Roads Iterative algorithms Support vector machines Support vector machine classification Testing Uncertainty data engineering

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dense 3d Reconstruction method using Coplanarities and Metric Constraints for Line Laser Scanning

Dense 3D Reconstruction method using Coplanarities and Metri...

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international Conference on 3d Imaging, Modeling, processing, visualization and transmission (3dIMPVT)

作者： Hiroshi Kawasaki Ryo Furukawa Saitama University Japan Hiroshima City University Japan

In this paper, we propose a novel method to achieve both dense 3d reconstruction of the scene and estimation of the camera intrinsic parameters by using coplanarities and other constraints (e.g. orthogonalities or parallelisms) derived from relations between planes in the scene and reflected curves of line lasers captured by a single camera. In our study, we categorize coplanarities in the scene into two types: implicit coplanarities, which can be observed as reflected curves of line lasers, and explicit coplanarities, which are, for example, observed as walls of a building. By using both types of coplanarities, we can construct simultaneous equations and can solve them up to four degrees of freedom. To upgrade the solution to the Euclidean space and estimate the camera intrinsic parameters, we can use metric constraints such as orthogonalities of the planes. Such metric constraints are given by, for example, observing the corners of rectangular boxes in the scene, or using special laser projecting device composed of two line lasers whose laser planes are configured to be perpendicular.

关键词： Reconstruction algorithms Cameras Layout Image reconstruction Nonlinear equations data mining Calibration Shape Buildings Machine vision

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Automatic Registration for Model Building using Variable dimensional Local Shape descriptors

Automatic Registration for Model Building using Variable Dim...

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international Conference on 3d Imaging, Modeling, processing, visualization and transmission (3dIMPVT)

作者： Babak Taati Michel Bondy Piotr Jasiobedzki Michael Greenspan Queen's University Faculty of Health Sciences Kingston ON CA MDA Space Missions Brampton ONT Canada School of Computing Queen''s University Kingston ONT Canada

A new set of variable dimensional local shape descriptors for 3d registration is proposed and applied to 3d model building from range images. The descriptors are based on a large set of properties represented as high dimensional histograms. The novelty of the method is two fold: first, it offers a generalized platform for a large class of local shape descriptors; second, unlike previously devised descriptors that are of low dimensionality and compact size, these descriptors are high dimensional and highly discriminating. The new approach suggests investing more into descriptor generation and comparison and in return gaining a higher percentage of inliers in the set of hypothesized point matches across the images being registered. This in turn drastically reduces the required number of RANSAC iterations for finding the alignment between two images, as is confirmed by experimentation in a 3d model building application. It is also shown that the correct choice of properties can increase the effectiveness of feature correspondences, thereby increasing the possible acquisition angle between overlapping images.

关键词： Robustness Iterative closest point algorithm Histograms Shape control data acquisition Image sensors Laser radar Bonding Space missions Automatic control

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Computational Modelling of Objects Represented in Images. Fundamentals, Methods and Applications

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2007年

作者： Tavares, Joao Manuel (EdT)/ Natal, Jorge R. M. (EdT)

ISBN: (纸本)9780415433495

This book contains keynote lectures and full papers presented at the international symposium on Computational Modelling of Objects Represented in Images (CompIMAGE), held in Coimbra, Portugal, on 20-21 October 2006. international contributions from nineteen countries provide a comprehensive coverage of the current state-of-the-art in the fields of: Image processing and Analysis; Image Segmentation; data Interpolation; Registration, Acquisition and Compression; 3d Reconstruction; Objects Tracking; Motion and deformation Analysis; Objects Simulation; Medical Imaging; and, Computational Bioimaging and visualization. Related techniques also covered in this book include the finite element method, modal analyses, stochastic methods, principal and independent components analyses and distribution models. "Computational Modelling of Objects Represented in Images" will be useful to academics, researchers and professionals in Computational Vision (image processing and analysis), Computer Sciences, and Computational Mechanics.

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A Fully Automated Method for Segmentation and Thickness Map Estimation of Femoral and Acetabular Cartilages in 3d CT Images of the Hip

A Fully Automated Method for Segmentation and Thickness Map ...

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international symposium on Image and Signal processing and Analysis

作者： Ayoub Baniasadipour Reza A. Zoroofi Yoshinobu Sato Takashi Nishii Katsuyuki Nakanishi Hisashi Tanaka Nobuhiko Sugano Hideki Yoshikawa Hironobu Nakamura Shinichi Tamura Control and Intelligent Processing Center of Excellence University of Tehran Tehran Iran Osaka University Graduate School of Medicine Osaka Japan Department of Orthopaedic Surgery Osaka University Graduate School of Medicine Osaka Japan Department of Radiology Osaka University Graduate School of Medicine Osaka Japan

ISBN: (纸本)9531841160;97

In this research, we propose a multi-step method for automatic segmentation of the hip femoral and acetabular cartilages from CT images. differentiation of the acetabular and femoral cartilages in conventional CT images due to very narrow space and low intensity of the articular space is very difficult. For this reason, MRI of the hip under continuous leg traction is the choice for assessment of the hip articular cartilage. However, this procedure is time consuming, painful, and hence inconvenient. By injecting the contrast media in the hip during data acquisition, we separated the femoral and acetabular cartilage from each other. The multi-step approach for segmentation of the femoral and acetabular cartilages is as follows. We first enhance the dynamic range and contrast of the data set by a conventional procedure. We then estimate the center of the femoral head utilizing a Hough transform. The estimated center is used as a pivotal point for beginning the process. Next, based on anatomical knowledge about the femoral head shape and size, we derive a region of interest (ROI) for further operations. In this case, by employing an Image Bottom Hat technique and anatomical knowledge about the curved shaped of the cartilages, we extract the valleys between contrast media and hip bones. The valley between the contrast media and femoral head and pelvis bone is associated with the femoral and acetabular cartilages. The anatomical assumptions we apply in this research is valid in most hip joint images. After segmentation, we present a 3d visualization and thickness map estimation of the hip femoral and acetabular cartilages. The proposed model is successfully applied to fourteen sets (3584 images) of actual in vivo hip CT data.

关键词： Image segmentation Computed tomography Hip Head Bones Magnetic resonance imaging Leg data acquisition dynamic range Shape

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Multi-View Edge-based Stereo by Incorporating Spatial Coherence

Multi-View Edge-based Stereo by Incorporating Spatial Cohere...

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international Conference on 3d Imaging, Modeling, processing, visualization and transmission (3dIMPVT)

作者： Gang Li Yakup Genc Steven W. Zucker Siemens Corporate Research Princeton NJ USA Yale University New Haven CT USA

A limitation of the state-of-art multi-view reconstruction algorithms is in their ability to handle scenes with very little texture or a lot of clutter. Texture-less scenes with clutter are traditionally difficult for dense multi-view stereo methods. Feature-based stereo algorithms, in particular, edge- based methods, are better suited for these scenes. The success of the edge-based reconstruction heavily depends on the amount of the prior information used. This paper introduces an algorithm that extends the well-known plane- sweep algorithm by incorporating spatial coherence of the scene. The method utilizes the geometric consistency derived from the continuity of three-dimensional edge points as a geometric constraint in addition to previously known multi-view image constraints. Experimental results on synthetic as well as real data are provided to demonstrate the efficacy and robustness of the proposed method.

关键词： Spatial coherence Layout Stereo vision Image reconstruction Surface reconstruction Stereo image processing Geometry Computer science Computed tomography Educational institutions

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Pose determination By PotentialWell Space Embedding

Pose Determination By PotentialWell Space Embedding

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international Conference on 3d Imaging, Modeling, processing, visualization and transmission (3dIMPVT)

作者： Limin Shang Michael Greenspan Department of Electrical & Computer Engineering Queen's University Kingston ONT Canada School of Computing Queen's University Kingston ONT Canada

A novel algorithm is introduced to estimate the pose of objects from sparse range data. Pose determination is tackled by employing the ICP algorithm to find corresponding local minima between a preprocessed model and the runtime data. Unlike other existing algorithms that try to avoid local minima, here local minima are used as effective feature vectors for generating multiple hypotheses of the pose. These hypotheses are then examined and verified using the bounded Hough transform, which is more robust than using the registration error directly. Only a small number of iterations (e.g., 5) is needed for each ICP at both preprocessing and runtime, which makes the technique efficient. The algorithm has been implemented and tested on a variety of objects, including freeform models, using both simulated and real data from Lidar and stereovision sensors. The experimental results show the technique to be both effective and efficient, executing at multiple frames per second on standard hardware. In addition, it functions well with very sparse data, possibly comprising only hundreds of points per frame, and it is also robust to measurement error and outliers.

关键词： Robustness Iterative closest point algorithm Runtime Embedded computing Impedance matching Tracking State-space methods Potential well data engineering Testing

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Broadcasting in (n, k)-arrangement graph based on an optimal spanning tree

Broadcasting in (n, k)-arrangement graph based on an optimal...

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1st Asia international Conference on Modelling and Simulation

作者： Jingli, Li Yonghong, Xiang Manli, Chen Yongheng, Zhou Yunnan Univ Sch Informat Kunming 650091 Peoples R China Yunnan Univ Sch Software Kunming 650091 Peoples R China Univ Durham Dept Comp Sci Sci Lab Durham DH1 3LE England

ISBN: (纸本)9781424403257

The tree structure has received much interest as a versatile architecture for a large class of parallel processing applications. Spanning trees in particular are essential tools for some important communication problems such as broadcasting and personalized communications. When it refers to communications, it always involves two costs. Specifically, sending a Packet of b bytes along a link takes T-s + bT(c) time, where Ts is the time to initialize (or start-up) the communication link and T-c is the latency to transmit a byte. To optimize these costs, a spanning tree is constructed to solve one-to-all broadcasting problem in an (n, k-)-arrangement graph. Since the spanning tree has an optimal height, our algorithm achieves optimal start-up cost O(d(An,k))Ts and transmission cost [Graphics] under the all-port model, and optimal transmission cost O(mTc) under the one-port model.

关键词： Broadcasting Tree graphs Cost function Electronic mail delay Computer science Tree data structures Computer architecture Parallel processing Application software

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Johnson noise thermometry near the zinc freezing point using resistance-based scaling

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international JOURNAL OF THERMOPHYSICS 2007年第2期28卷 629-645页

作者： Tew, W. L. Labenski, J. R. Nam, S. W. Benz, S. P. dresselhaus, P. d. Burroughs, C. J. NIST Proc Measurement Div Gaithersburg MD 20899 USA Natl Inst Stand & Technol Div Optoelect Boulder CO 80303 USA Natl Inst Stand & Technol Quantum Elect Metrol Div Boulder CO 80303 USA

Johnson noise thermometry (JNT) is a primary method of measuring temperature which can be applied over wide ranges. The National Institute of Standards and Technology (NIST) is currently using JNT to determine the deviations of the international Temperature Scale of 1990 (ITS-90) from the thermodynamic temperature in the range of 505-933 K, overlapping the ranges of both acoustic gas-based and radiation-based thermometry. Advances in digital electronics have now made viable the computationally intensive and data-volume-intensive processing required for JNT using noise-voltage correlation in the frequency domain. The spectral noise power, and consequently the thermodynamic temperature T, of a high-temperature JNT probe is determined relative to a known reference spectrum using a switched-input digital noise-voltage correlator and simple resistance-scaling relationships. Comparison of the JNT results with standard platinum resistance thermometers calibrated on the ITS-90 gives the deviation of the thermodynamic temperature from the temperature on the ITS-90, T - T-90. Statistical uncertainties under 50 mu K center dot K-1 are achievable in less than 1 day of integration by fitting the effects of transmission-line time constants over bandwidths of 450 kHz. The methods and results in a 3 K interval near the zinc freezing point (T (90-ZnFP) equivalent to 692.677 K) are described. Preliminary results show agreement between the JNT-derived temperatures and the ITS-90.

关键词： ITS-90 Johnson noise noise thermometry temperature

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Adaptive communications quality control for Wireless LANs

Adaptive communications quality control for Wireless LANs

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IEEE international symposium on Intelligent Signal processing and Communication Systems (ISPACS)

作者： Nari Tanabe Ken Aoki Toshihiro Furukawa Shigeo Tsujii Tokyo University of Science Nagano Chino Japan Tokyo University of Science Tokyo Shinjuku-ku Japan Institute of information Security Yokohama Kanagawa-ku Japan

This paper propose an adaptive communications quality control for Wireless LANs. This method is composed of (a) adaptive transmission frequency setting method, (b) adaptive CFP (Contention Free Period) setting method, (c) queue control method, and (d) prime slot time method. The special features of the proposed method are (1) an efficient data communication without sacrificing guarantee of the maximum delay time and the bandwidth, (2) the reduction of the buffer size, and (3) the throughput enhancement. Numerical examples show the effectiveness of the proposed method.

关键词： Programmable control Adaptive control Quality control Wireless LAN Frequency Communication system control data communication delay effects Bandwidth Throughput

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