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Sample records for based 3d surface

  1. Nonlaser-based 3D surface imaging

    SciTech Connect

    Lu, Shin-yee; Johnson, R.K.; Sherwood, R.J.

    1994-11-15

    3D surface imaging refers to methods that generate a 3D surface representation of objects of a scene under viewing. Laser-based 3D surface imaging systems are commonly used in manufacturing, robotics and biomedical research. Although laser-based systems provide satisfactory solutions for most applications, there are situations where non laser-based approaches are preferred. The issues that make alternative methods sometimes more attractive are: (1) real-time data capturing, (2) eye-safety, (3) portability, and (4) work distance. The focus of this presentation is on generating a 3D surface from multiple 2D projected images using CCD cameras, without a laser light source. Two methods are presented: stereo vision and depth-from-focus. Their applications are described.

  2. Surface topography study of prepared 3D printed moulds via 3D printer for silicone elastomer based nasal prosthesis

    NASA Astrophysics Data System (ADS)

    Abdullah, Abdul Manaf; Din, Tengku Noor Daimah Tengku; Mohamad, Dasmawati; Rahim, Tuan Noraihan Azila Tuan; Akil, Hazizan Md; Rajion, Zainul Ahmad

    2016-12-01

    Conventional prosthesis fabrication is highly depends on the hand creativity of laboratory technologist. The development in 3D printing technology offers a great help in fabricating affordable and fast yet esthetically acceptable prostheses. This study was conducted to discover the potential of 3D printed moulds for indirect silicone elastomer based nasal prosthesis fabrication. Moulds were designed using computer aided design (CAD) software (Solidworks, USA) and converted into the standard tessellation language (STL) file. Three moulds with layer thickness of 0.1, 0.2 and 0.3mm were printed utilizing polymer filament based 3D printer (Makerbot Replicator 2X, Makerbot, USA). Another one mould was printed utilizing liquid resin based 3D printer (Objet 30 Scholar, Stratasys, USA) as control. The printed moulds were then used to fabricate maxillofacial silicone specimens (n=10)/mould. Surface profilometer (Surfcom Flex, Accretech, Japan), digital microscope (KH77000, Hirox, USA) and scanning electron microscope (Quanta FEG 450, Fei, USA) were used to measure the surface roughness as well as the topological properties of fabricated silicone. Statistical analysis of One-Way ANOVA was employed to compare the surface roughness of the fabricated silicone elastomer. Result obtained demonstrated significant differences in surface roughness of the fabricated silicone (p<0.01). Further post hoc analysis also revealed significant differences in silicone fabricated using different 3D printed moulds (p<0.01). A 3D printed mould was successfully prepared and characterized. With surface topography that could be enhanced, inexpensive and rapid mould fabrication techniques, polymer filament based 3D printer is potential for indirect silicone elastomer based nasal prosthesis fabrication.

  3. Disparity pattern-based autostereoscopic 3D metrology system for in situ measurement of microstructured surfaces.

    PubMed

    Li, Da; Cheung, Chi Fai; Ren, MingJun; Whitehouse, David; Zhao, Xing

    2015-11-15

    This paper presents a disparity pattern-based autostereoscopic (DPA) 3D metrology system that makes use of a microlens array to capture raw 3D information of the measured surface in a single snapshot through a CCD camera. Hence, a 3D digital model of the target surface with the measuring data is generated through a system-associated direct extraction of disparity information (DEDI) method. The DEDI method is highly efficient for performing the direct 3D mapping of the target surface based on tomography-like operation upon every depth plane with the defocused information excluded. Precise measurement results are provided through an error-elimination process based on statistical analysis. Experimental results show that the proposed DPA 3D metrology system is capable of measuring 3D microstructured surfaces with submicrometer measuring repeatability for high precision and in situ measurement of microstructured surfaces.

  4. Surface classification and detection of latent fingerprints based on 3D surface texture parameters

    NASA Astrophysics Data System (ADS)

    Gruhn, Stefan; Fischer, Robert; Vielhauer, Claus

    2012-06-01

    In the field of latent fingerprint detection in crime scene forensics the classification of surfaces has importance. A new method for the scientific analysis of image based information for forensic science was investigated in the last years. Our image acquisition based on a sensor using Chromatic White Light (CWL) with a lateral resolution up to 2 μm. The used FRT-MicroProf 200 CWL 600 measurement device is able to capture high-resolution intensity and topography images in an optical and contact-less way. In prior work, we have suggested to use 2D surface texture parameters to classify various materials, which was a novel approach in the field of criminalistic forensic using knowledge from surface appearance and a chromatic white light sensor. A meaningful and useful classification of different crime scene specific surfaces is not existent. In this work, we want to extend such considerations by the usage of fourteen 3D surface parameters, called 'Birmingham 14'. In our experiment we define these surface texture parameters and use them to classify ten different materials in this test set-up and create specific material classes. Further it is shown in first experiments, that some surface texture parameters are sensitive to separate fingerprints from carrier surfaces. So far, the use of surface roughness is mainly known within the framework of material quality control. The analysis and classification of the captured 3D-topography images from crime scenes is important for the adaptive preprocessing depending on the surface texture. The adaptive preprocessing in dependency of surface classification is necessary for precise detection because of the wide variety of surface textures. We perform a preliminary study in usage of these 3D surface texture parameters as feature for the fingerprint detection. In combination with a reference sample we show that surface texture parameters can be an indication for a fingerprint and can be a feature in latent fingerprint detection.

  5. Fish body surface data measurement based on 3D digital image correlation

    NASA Astrophysics Data System (ADS)

    Jiang, Ming; Qian, Chen; Yang, Wenkai

    2016-01-01

    To film the moving fish in the glass tank, light will be bent at the interface of air and glass, glass and water. Based on binocular stereo vision and refraction principle, we establish a mathematical model of 3D image correlation to reconstruct the 3D coordinates of samples in the water. Marking speckle in fish surface, a series of real-time speckle images of swimming fish will be obtained by two high-speed cameras, and instantaneous 3D shape, strain, displacement etc. of fish will be reconstructed.

  6. 3D surface reconstruction based on image stitching from gastric endoscopic video sequence

    NASA Astrophysics Data System (ADS)

    Duan, Mengyao; Xu, Rong; Ohya, Jun

    2013-09-01

    This paper proposes a method for reconstructing 3D detailed structures of internal organs such as gastric wall from endoscopic video sequences. The proposed method consists of the four major steps: Feature-point-based 3D reconstruction, 3D point cloud stitching, dense point cloud creation and Poisson surface reconstruction. Before the first step, we partition one video sequence into groups, where each group consists of two successive frames (image pairs), and each pair in each group contains one overlapping part, which is used as a stitching region. Fist, the 3D point cloud of each group is reconstructed by utilizing structure from motion (SFM). Secondly, a scheme based on SIFT features registers and stitches the obtained 3D point clouds, by estimating the transformation matrix of the overlapping part between different groups with high accuracy and efficiency. Thirdly, we select the most robust SIFT feature points as the seed points, and then obtain the dense point cloud from sparse point cloud via a depth testing method presented by Furukawa. Finally, by utilizing Poisson surface reconstruction, polygonal patches for the internal organs are obtained. Experimental results demonstrate that the proposed method achieves a high accuracy and efficiency for 3D reconstruction of gastric surface from an endoscopic video sequence.

  7. Active illumination based 3D surface reconstruction and registration for image guided medialization laryngoplasty

    NASA Astrophysics Data System (ADS)

    Jin, Ge; Lee, Sang-Joon; Hahn, James K.; Bielamowicz, Steven; Mittal, Rajat; Walsh, Raymond

    2007-03-01

    The medialization laryngoplasty is a surgical procedure to improve the voice function of the patient with vocal fold paresis and paralysis. An image guided system for the medialization laryngoplasty will help the surgeons to accurately place the implant and thus reduce the failure rates of the surgery. One of the fundamental challenges in image guided system is to accurately register the preoperative radiological data to the intraoperative anatomical structure of the patient. In this paper, we present a combined surface and fiducial based registration method to register the preoperative 3D CT data to the intraoperative surface of larynx. To accurately model the exposed surface area, a structured light based stereo vision technique is used for the surface reconstruction. We combined the gray code pattern and multi-line shifting to generate the intraoperative surface of the larynx. To register the point clouds from the intraoperative stage to the preoperative 3D CT data, a shape priori based ICP method is proposed to quickly register the two surfaces. The proposed approach is capable of tracking the fiducial markers and reconstructing the surface of larynx with no damage to the anatomical structure. We used off-the-shelf digital cameras, LCD projector and rapid 3D prototyper to develop our experimental system. The final RMS error in the registration is less than 1mm.

  8. SU-F-BRF-08: Conformal Mapping-Based 3D Surface Matching and Registration

    SciTech Connect

    Song, Y; Zeng, W; Gu, X; Liu, C

    2014-06-15

    Purpose: Recently, non-rigid 3D surface matching and registration has been used extensively in engineering and medicine. However, matching 3D surfaces undergoing non-rigid deformation accurately is still a challenging mathematical problem. In this study, we present a novel algorithm to address this issue by introducing intrinsic symmetry to the registration Methods: Our computational algorithm for symmetric conformal mapping is divided into three major steps: 1) Finding the symmetric plane; 2) Finding feature points; and 3) Performing cross registration. The key strategy is to preserve the symmetry during the conformal mapping, such that the image on the parameter domain is symmetric and the area distortion factor on the parameter image is also symmetric. Several novel algorithms were developed using different conformal geometric tools. One was based on solving Riemann-Cauchy equation and the other one employed curvature flow Results: Our algorithm was implemented using generic C++ on Windows XP and used conjugate gradient search optimization for acceleration. The human face 3D surface images were acquired using a high speed 3D scanner based on the phase-shifting method. The scanning speed was 30 frames/sec. The image resolution for each frame was 640 × 480. For 3D human face surfaces with different expressions, postures, and boundaries, our algorithms were able to produce consistent result on the texture pattern on the overlapping region Conclusion: We proposed a novel algorithm to improve the robustness of conformal geometric methods by incorporating the symmetric information into the mapping process. To objectively evaluate its performance, we compared it with most existing techniques. Experimental results indicated that our method outperformed all the others in terms of robustness. The technique has a great potential in real-time patient monitoring and tracking in image-guided radiation therapy.

  9. In vivo bioluminescence tomography based on multi-view projection and 3D surface reconstruction

    NASA Astrophysics Data System (ADS)

    Zhang, Shuang; Wang, Kun; Leng, Chengcai; Deng, Kexin; Hu, Yifang; Tian, Jie

    2015-03-01

    Bioluminescence tomography (BLT) is a powerful optical molecular imaging modality, which enables non-invasive realtime in vivo imaging as well as 3D quantitative analysis in preclinical studies. In order to solve the inverse problem and reconstruct inner light sources accurately, the prior structural information is commonly necessary and obtained from computed tomography or magnetic resonance imaging. This strategy requires expensive hybrid imaging system, complicated operation protocol and possible involvement of ionizing radiation. The overall robustness highly depends on the fusion accuracy between the optical and structural information. In this study we present a pure optical bioluminescence tomographic system (POBTS) and a novel BLT method based on multi-view projection acquisition and 3D surface reconstruction. The POBTS acquired a sparse set of white light surface images and bioluminescent images of a mouse. Then the white light images were applied to an approximate surface model to generate a high quality textured 3D surface reconstruction of the mouse. After that we integrated multi-view luminescent images based on the previous reconstruction, and applied an algorithm to calibrate and quantify the surface luminescent flux in 3D.Finally, the internal bioluminescence source reconstruction was achieved with this prior information. A BALB/C mouse with breast tumor of 4T1-fLuc cells mouse model were used to evaluate the performance of the new system and technique. Compared with the conventional hybrid optical-CT approach using the same inverse reconstruction method, the reconstruction accuracy of this technique was improved. The distance error between the actual and reconstructed internal source was decreased by 0.184 mm.

  10. 3D shape measurement of optical free-form surface based on fringe projection

    NASA Astrophysics Data System (ADS)

    Li, Shaohui; Liu, Shugui; Zhang, Hongwei

    2011-05-01

    Present a novel method of 3D shape measurement of optical free-from surface based on fringe projection. A virtual reference surface is proposed which can be used to improve the detection efficiency and realize the automation of measuring process. Sinusoidal fringe patterns are projected to the high reflected surface of the measured object. The deflection fringe patterns that modulated by the object surface are captured by the CCD camera. The slope information can be obtained by analyzing the relationship between the phase deflectometry and the slope of the object surface. The wave-front reconstruction method is used to reconstruct the surface. With the application of fringe projection technology the accuracy of optical free-form surfaces measurement could reach the level of tens of micrometer or even micrometer.

  11. Automatic 3D liver segmentation based on deep learning and globally optimized surface evolution.

    PubMed

    Hu, Peijun; Wu, Fa; Peng, Jialin; Liang, Ping; Kong, Dexing

    2016-12-21

    The detection and delineation of the liver from abdominal 3D computed tomography (CT) images are fundamental tasks in computer-assisted liver surgery planning. However, automatic and accurate segmentation, especially liver detection, remains challenging due to complex backgrounds, ambiguous boundaries, heterogeneous appearances and highly varied shapes of the liver. To address these difficulties, we propose an automatic segmentation framework based on 3D convolutional neural network (CNN) and globally optimized surface evolution. First, a deep 3D CNN is trained to learn a subject-specific probability map of the liver, which gives the initial surface and acts as a shape prior in the following segmentation step. Then, both global and local appearance information from the prior segmentation are adaptively incorporated into a segmentation model, which is globally optimized in a surface evolution way. The proposed method has been validated on 42 CT images from the public Sliver07 database and local hospitals. On the Sliver07 online testing set, the proposed method can achieve an overall score of [Formula: see text], yielding a mean Dice similarity coefficient of [Formula: see text], and an average symmetric surface distance of [Formula: see text] mm. The quantitative validations and comparisons show that the proposed method is accurate and effective for clinical application.

  12. Automatic 3D liver segmentation based on deep learning and globally optimized surface evolution

    NASA Astrophysics Data System (ADS)

    Hu, Peijun; Wu, Fa; Peng, Jialin; Liang, Ping; Kong, Dexing

    2016-12-01

    The detection and delineation of the liver from abdominal 3D computed tomography (CT) images are fundamental tasks in computer-assisted liver surgery planning. However, automatic and accurate segmentation, especially liver detection, remains challenging due to complex backgrounds, ambiguous boundaries, heterogeneous appearances and highly varied shapes of the liver. To address these difficulties, we propose an automatic segmentation framework based on 3D convolutional neural network (CNN) and globally optimized surface evolution. First, a deep 3D CNN is trained to learn a subject-specific probability map of the liver, which gives the initial surface and acts as a shape prior in the following segmentation step. Then, both global and local appearance information from the prior segmentation are adaptively incorporated into a segmentation model, which is globally optimized in a surface evolution way. The proposed method has been validated on 42 CT images from the public Sliver07 database and local hospitals. On the Sliver07 online testing set, the proposed method can achieve an overall score of 80.3+/- 4.5 , yielding a mean Dice similarity coefficient of 97.25+/- 0.65 % , and an average symmetric surface distance of 0.84+/- 0.25 mm. The quantitative validations and comparisons show that the proposed method is accurate and effective for clinical application.

  13. Underwater 3D Surface Measurement Using Fringe Projection Based Scanning Devices

    PubMed Central

    Bräuer-Burchardt, Christian; Heinze, Matthias; Schmidt, Ingo; Kühmstedt, Peter; Notni, Gunther

    2015-01-01

    In this work we show the principle of optical 3D surface measurements based on the fringe projection technique for underwater applications. The challenges of underwater use of this technique are shown and discussed in comparison with the classical application. We describe an extended camera model which takes refraction effects into account as well as a proposal of an effective, low-effort calibration procedure for underwater optical stereo scanners. This calibration technique combines a classical air calibration based on the pinhole model with ray-based modeling and requires only a few underwater recordings of an object of known length and a planar surface. We demonstrate a new underwater 3D scanning device based on the fringe projection technique. It has a weight of about 10 kg and the maximal water depth for application of the scanner is 40 m. It covers an underwater measurement volume of 250 mm × 200 mm × 120 mm. The surface of the measurement objects is captured with a lateral resolution of 150 μm in a third of a second. Calibration evaluation results are presented and examples of first underwater measurements are given. PMID:26703624

  14. [3-D endocardial surface modelling based on the convex hull algorithm].

    PubMed

    Lu, Ying; Xi, Ri-hui; Shen, Hai-dong; Ye, You-li; Zhang, Yong

    2006-11-01

    In this paper, a method based on the convex hull algorithm is presented for extracting modelling data from the locations of catheter electrodes within a cardiac chamber, so as to create a 3-D model of the heart chamber during diastole and to obtain a good result in the 3-D reconstruction of the chamber based on VTK.

  15. Reliability of trunk shape measurements based on 3-D surface reconstructions

    PubMed Central

    Cheriet, Farida; Danserau, Jean; Ronsky, Janet; Zernicke, Ronald F.; Labelle, Hubert

    2007-01-01

    This study aimed to estimate the reliability of 3-D trunk surface measurements for the characterization of external asymmetry associated with scoliosis. Repeated trunk surface acquisitions using the Inspeck system (Inspeck Inc., Montreal, Canada), with two different postures A (anatomical position) and B (‘‘clavicle’’ position), were obtained from patients attending a scoliosis clinic. For each acquisition, a 3-D model of the patient’s trunk was built and a series of measurements was computed. For each measure and posture, intraclass correlation coefficients (ICC) were obtained using a bivariate analysis of variance, and the smallest detectable difference was calculated. For posture A, reliability was fair to excellent with ICC from 0.91 to 0.99 (0.85 to 0.99 for the lower bound of the 95% confidence interval). For posture B, the ICC was 0.85 to 0.98 (0.74 to 0.99 for the lower bound of the 95% confidence interval). The smallest statistically significant differences for the maximal back surface rotation was 2.5 and 1.5° for the maximal trunk rotation. Apparent global asymmetry and axial trunk rotation indices were relatively robust to changes in arm posture, both in terms of mean values and within-subject variations, and also showed a good reliability. Computing measurements from cross-sectional analysis enabled a reduction in errors compared to the measurements based on markers’ position. Although not yet sensitive enough to detect small changes for monitoring of curve natural progression, trunk surface analysis can help to document the external asymmetry associated with different types of spinal curves as well as the cosmetic improvement obtained after surgical interventions. The anatomical posture is slightly more reliable as it allows a better coverage of the trunk surface by the digitizing system. PMID:17701228

  16. 3-D micro surface profilometry employing novel Mirau-based lateral scanning interferometry

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Chia; Le, Manh-Trung; Lin, Yi-Shiuan

    2014-09-01

    An innovative 3-D surface imaging methodology for reconstructing micro surface profiles with a long depth measuring range and a nano-scale resolution was developed using the newly developed Mirau-based lateral scanning interferometry (LSI). The current measuring field of view (FOV) of conventional white light interferometers is limited by microscopic views of the existing interferometric objectives, such as those in Michelson, Mirau or Linnik designs. Moreover, the vertical scanning operation required for acquiring volumetric interferometric data is extremely time-consuming and makes white light vertical scanning interferometry (VSI) infeasible for automatic optical inspection (AOI) of micro 3-D structures. To resolve this, a newly developed white light LSI method based on Mirau’s optical configuration was developed by controlling the tilting angle of the reference mirror in the Mirau interferometric objective. With the proposed optical configuration, the surface is inspected at a tilting angle with respect to the maximum coherence plane of the interferometric system along its lateral scanning direction when the objective lies perpendicular to the tested surface. In addition, a system calibration method was developed to establish an accurate mathematical mapping model between the object depth and the lateral axis. To evaluate the feasibility of the methodology, a calibrated step height was measured for evaluating the accuracy and repeatability. Some industrial samples, such as photon spacers and other microstructures fabricated by nano-imprinting processes, were measured to verify the actual performance on real components. It was found that the measurement repeatability was controlled less than 60 nm within one standard deviation for a maximum measurable depth of 27.21 µm.

  17. Simulation of light transport in scintillators based on 3D characterization of crystal surfaces.

    PubMed

    Roncali, Emilie; Cherry, Simon R

    2013-04-07

    In the development of positron emission tomography (PET) detectors, understanding and optimizing scintillator light collection is critical for achieving high performance, particularly when the design incorporates depth-of-interaction (DOI) encoding or time-of-flight information. Monte-Carlo simulations play an important role in guiding research in detector designs and popular software such as GATE now include models of light transport in scintillators. Although current simulation toolkits are able to provide accurate models of perfectly polished surfaces, they do not successfully predict light output for other surface finishes, for example those often used in DOI-encoding detectors. The lack of accuracy of those models mainly originates from a simplified description of rough surfaces as an ensemble of micro-facets determined by the distribution of their normal, typically a gaussian distribution. The user can specify the standard deviation of this distribution, but this parameter does not provide a full description of the surface reflectance properties. We propose a different approach based on 3D measurements of the surface using atomic force microscopy. Polished and rough (unpolished) crystals were scanned to compute the surface reflectance properties. The angular distributions of reflectance and reflected rays were computed and stored in look-up tables (LUTs). The LUTs account for the effect of incidence angle and were integrated in a light transport model. Crystals of different sizes were simulated with and without reflector. The simulated maximum light output and the light output as a function of DOI showed very good agreement with experimental characterization of the crystals, indicating that our approach provides an accurate model of polished and rough surfaces and could be used to predict light collection in scintillators. This model is based on a true 3D representation of the surface, makes no assumption about the surface and provides insight on the optical

  18. Simulation of light transport in scintillators based on 3D characterization of crystal surfaces

    NASA Astrophysics Data System (ADS)

    Roncali, Emilie; Cherry, Simon R.

    2013-04-01

    In the development of positron emission tomography (PET) detectors, understanding and optimizing scintillator light collection is critical for achieving high performance, particularly when the design incorporates depth-of-interaction (DOI) encoding or time-of-flight information. Monte-Carlo simulations play an important role in guiding research in detector designs and popular software such as GATE now include models of light transport in scintillators. Although current simulation toolkits are able to provide accurate models of perfectly polished surfaces, they do not successfully predict light output for other surface finishes, for example those often used in DOI-encoding detectors. The lack of accuracy of those models mainly originates from a simplified description of rough surfaces as an ensemble of micro-facets determined by the distribution of their normal, typically a Gaussian distribution. The user can specify the standard deviation of this distribution, but this parameter does not provide a full description of the surface reflectance properties. We propose a different approach based on 3D measurements of the surface using atomic force microscopy. Polished and rough (unpolished) crystals were scanned to compute the surface reflectance properties. The angular distributions of reflectance and reflected rays were computed and stored in look-up tables (LUTs). The LUTs account for the effect of incidence angle and were integrated in a light transport model. Crystals of different sizes were simulated with and without reflector. The simulated maximum light output and the light output as a function of DOI showed very good agreement with experimental characterization of the crystals, indicating that our approach provides an accurate model of polished and rough surfaces and could be used to predict light collection in scintillators. This model is based on a true 3D representation of the surface, makes no assumption about the surface and provides insight on the optical

  19. A photogrammetry-based system for 3D surface reconstruction of prosthetics and orthotics.

    PubMed

    Li, Guang-kun; Gao, Fan; Wang, Zhi-gang

    2011-01-01

    The objective of this study is to develop an innovative close range digital photogrammetry (CRDP) system using the commercial digital SLR cameras to measure and reconstruct the 3D surface of prosthetics and orthotics. This paper describes the instrumentation, techniques and preliminary results of the proposed system. The technique works by taking pictures of the object from multiple view angles. The series of pictures were post-processed via feature point extraction, point match and 3D surface reconstruction. In comparison with the traditional method such as laser scanning, the major advantages of our instrument include the lower cost, compact and easy-to-use hardware, satisfactory measurement accuracy, and significantly less measurement time. Besides its potential applications in prosthetics and orthotics surface measurement, the simple setup and its ease of use will make it suitable for various 3D surface reconstructions.

  20. 3-D surface profilometry based on modulation measurement by applying wavelet transform method

    NASA Astrophysics Data System (ADS)

    Zhong, Min; Chen, Feng; Xiao, Chao; Wei, Yongchao

    2017-01-01

    A new analysis of 3-D surface profilometry based on modulation measurement technique by the application of Wavelet Transform method is proposed. As a tool excelling for its multi-resolution and localization in the time and frequency domains, Wavelet Transform method with good localized time-frequency analysis ability and effective de-noizing capacity can extract the modulation distribution more accurately than Fourier Transform method. Especially for the analysis of complex object, more details of the measured object can be well remained. In this paper, the theoretical derivation of Wavelet Transform method that obtains the modulation values from a captured fringe pattern is given. Both computer simulation and elementary experiment are used to show the validity of the proposed method by making a comparison with the results of Fourier Transform method. The results show that the Wavelet Transform method has a better performance than the Fourier Transform method in modulation values retrieval.

  1. Surface feature based classification of plant organs from 3D laserscanned point clouds for plant phenotyping

    PubMed Central

    2013-01-01

    Background Laserscanning recently has become a powerful and common method for plant parameterization and plant growth observation on nearly every scale range. However, 3D measurements with high accuracy, spatial resolution and speed result in a multitude of points that require processing and analysis. The primary objective of this research has been to establish a reliable and fast technique for high throughput phenotyping using differentiation, segmentation and classification of single plants by a fully automated system. In this report, we introduce a technique for automated classification of point clouds of plants and present the applicability for plant parameterization. Results A surface feature histogram based approach from the field of robotics was adapted to close-up laserscans of plants. Local geometric point features describe class characteristics, which were used to distinguish among different plant organs. This approach has been proven and tested on several plant species. Grapevine stems and leaves were classified with an accuracy of up to 98%. The proposed method was successfully transferred to 3D-laserscans of wheat plants for yield estimation. Wheat ears were separated with an accuracy of 96% from other plant organs. Subsequently, the ear volume was calculated and correlated to the ear weight, the kernel weights and the number of kernels. Furthermore the impact of the data resolution was evaluated considering point to point distances between 0.3 and 4.0 mm with respect to the classification accuracy. Conclusion We introduced an approach using surface feature histograms for automated plant organ parameterization. Highly reliable classification results of about 96% for the separation of grapevine and wheat organs have been obtained. This approach was found to be independent of the point to point distance and applicable to multiple plant species. Its reliability, flexibility and its high order of automation make this method well suited for the demands of

  2. Region-Based 3d Surface Reconstruction Using Images Acquired by Low-Cost Unmanned Aerial Systems

    NASA Astrophysics Data System (ADS)

    Lari, Z.; Al-Rawabdeh, A.; He, F.; Habib, A.; El-Sheimy, N.

    2015-08-01

    Accurate 3D surface reconstruction of our environment has become essential for an unlimited number of emerging applications. In the past few years, Unmanned Aerial Systems (UAS) are evolving as low-cost and flexible platforms for geospatial data collection that could meet the needs of aforementioned application and overcome limitations of traditional airborne and terrestrial mobile mapping systems. Due to their payload restrictions, these systems usually include consumer-grade imaging and positioning sensor which will negatively impact the quality of the collected geospatial data and reconstructed surfaces. Therefore, new surface reconstruction surfaces are needed to mitigate the impact of using low-cost sensors on the final products. To date, different approaches have been proposed to for 3D surface construction using overlapping images collected by imaging sensor mounted on moving platforms. In these approaches, 3D surfaces are mainly reconstructed based on dense matching techniques. However, generated 3D point clouds might not accurately represent the scanned surfaces due to point density variations and edge preservation problems. In order to resolve these problems, a new region-based 3D surface renostruction trchnique is introduced in this paper. This approach aims to generate a 3D photo-realistic model of individually scanned surfaces within the captured images. This approach is initiated by a Semi-Global dense Matching procedure is carried out to generate a 3D point cloud from the scanned area within the collected images. The generated point cloud is then segmented to extract individual planar surfaces. Finally, a novel region-based texturing technique is implemented for photorealistic reconstruction of the extracted planar surfaces. Experimental results using images collected by a camera mounted on a low-cost UAS demonstrate the feasibility of the proposed approach for photorealistic 3D surface reconstruction.

  3. UAV based 3D digital surface model to estimate paleolandscape in high mountainous environment

    NASA Astrophysics Data System (ADS)

    Mészáros, János; Árvai, Mátyás; Kohán, Balázs; Deák, Márton; Nagy, Balázs

    2016-04-01

    Our method to present current state of a peat bog was focused on the possible use of a UAV-system and later Structure-from-motion algorithms as processing technique. The peat bog site is located on the Vinderel Plateau, Farcǎu Massif, Maramures Mountains (Romania). The peat bog (1530 m a.s.l., N47°54'11", E24°26'37") lies below Rugasu ridge (c. 1820 m a.s.l.) and the locality serves as a conservation area for fallen down coniferous trees. Peat deposits were formed in a landslide concavity on the western slope of Farcǎu Massif. Nowadays the site is surrounded by a completely deforested landscape, and Farcǎu Massif lies above the depressed treeline. The peat bog has an extraordinary geomorphological situation, because a gully reached the bog and drained the water. In the recent past sedimentological and dendrochronological researches have been initiated. However, an accurate 3D digital surface model also needed for a complex paleoenvironmental research. Last autumn the bog and its surroundings were finally surveyed by a multirotor UAV developed in-house based on an open-source flight management unit and its firmware. During this survey a lightweight action camera (mainly to decrease payload weight) was used to take aerial photographs. While our quadcopter is capable to fly automatically on a predefined flight route, several over- and sidelapping flight lines were generated prior to the actual survey on the ground using a control software running on a notebook. Despite those precautions, limited number of batteries and severe weather affected our final flights, resulting a reduced surveyed area around peat bog. Later, during the processing we looked for a reliable tool which powerful enough to process more than 500 photos taken during flights. After testing several software Agisoft PhotoScan was used to create 3D point cloud and mesh about bog and its environment. Due to large number of photographs PhotoScan had to be configured for network processing to get

  4. Three-dimensional measurement of small inner surface profiles using feature-based 3-D panoramic registration

    NASA Astrophysics Data System (ADS)

    Gong, Yuanzheng; Seibel, Eric J.

    2017-01-01

    Rapid development in the performance of sophisticated optical components, digital image sensors, and computer abilities along with decreasing costs has enabled three-dimensional (3-D) optical measurement to replace more traditional methods in manufacturing and quality control. The advantages of 3-D optical measurement, such as noncontact, high accuracy, rapid operation, and the ability for automation, are extremely valuable for inline manufacturing. However, most of the current optical approaches are eligible for exterior instead of internal surfaces of machined parts. A 3-D optical measurement approach is proposed based on machine vision for the 3-D profile measurement of tiny complex internal surfaces, such as internally threaded holes. To capture the full topographic extent (peak to valley) of threads, a side-view commercial rigid scope is used to collect images at known camera positions and orientations. A 3-D point cloud is generated with multiview stereo vision using linear motion of the test piece, which is repeated by a rotation to form additional point clouds. Registration of these point clouds into a complete reconstruction uses a proposed automated feature-based 3-D registration algorithm. The resulting 3-D reconstruction is compared with x-ray computed tomography to validate the feasibility of our proposed method for future robotically driven industrial 3-D inspection.

  5. Three-dimensional measurement of small inner surface profiles using feature-based 3-D panoramic registration

    PubMed Central

    Gong, Yuanzheng; Seibel, Eric J.

    2017-01-01

    Rapid development in the performance of sophisticated optical components, digital image sensors, and computer abilities along with decreasing costs has enabled three-dimensional (3-D) optical measurement to replace more traditional methods in manufacturing and quality control. The advantages of 3-D optical measurement, such as noncontact, high accuracy, rapid operation, and the ability for automation, are extremely valuable for inline manufacturing. However, most of the current optical approaches are eligible for exterior instead of internal surfaces of machined parts. A 3-D optical measurement approach is proposed based on machine vision for the 3-D profile measurement of tiny complex internal surfaces, such as internally threaded holes. To capture the full topographic extent (peak to valley) of threads, a side-view commercial rigid scope is used to collect images at known camera positions and orientations. A 3-D point cloud is generated with multiview stereo vision using linear motion of the test piece, which is repeated by a rotation to form additional point clouds. Registration of these point clouds into a complete reconstruction uses a proposed automated feature-based 3-D registration algorithm. The resulting 3-D reconstruction is compared with x-ray computed tomography to validate the feasibility of our proposed method for future robotically driven industrial 3-D inspection. PMID:28286351

  6. Hierarchical PEG-Based 3D Patterns Grafting from Polymer Substrate by Surface Initiated Visible Light Photolithography.

    PubMed

    Zhao, Changwen; He, Bin; Wang, Guan; Ma, Yuhong; Yang, Wantai

    2016-10-01

    The precise construction of a hierarchical complex pattern on substrates is required for numerous applications. Here, a strategy to fabricate well-defined hierarchical three dimensional (3D) patterns on polymer substrate is developed. This technique, which combines photolithography and visible light-induced surface initiated living graft crosslinking polymerization (VSLGCP), can effectively graft 3D patterns onto polymer substrate with high fidelity and controllable height. Owing to the living nature of VSLGCP, hierarchical 3D patterns can be prepared when a sequential living graft crosslinking process is performed on the first formed patterns. As a proof-of-concept, a reactive two layer 3D pattern with a morphology of lateral stripe on vertical stripe is prepared and employed to separately immobilize model biomolecules, e.g., biotin and IgG. This two component pattern can specifically interact with corresponding target proteins successfully, indicating that this strategy has potential applications in the fabrication of polymer-based multicomponent biomolecule microarrays.

  7. Metal-mesh based transparent electrode on a 3-D curved surface by electrohydrodynamic jet printing

    NASA Astrophysics Data System (ADS)

    Seong, Baekhoon; Yoo, Hyunwoong; Dat Nguyen, Vu; Jang, Yonghee; Ryu, Changkook; Byun, Doyoung

    2014-09-01

    Invisible Ag mesh transparent electrodes (TEs), with a width of 7 μm, were prepared on a curved glass surface by electrohydrodynamic (EHD) jet printing. With a 100 μm pitch, the EHD jet printed the Ag mesh on the convex glass which had a sheet resistance of 1.49 Ω/□. The printing speed was 30 cm s-1 using Ag ink, which had a 10 000 cPs viscosity and a 70 wt% Ag nanoparticle concentration. We further showed the performance of a 3-D transparent heater using the Ag mesh transparent electrode. The EHD jet printed an invisible Ag grid transparent electrode with good electrical and optical properties with promising applications on printed optoelectronic devices.

  8. The three-dimensional elemental distribution based on the surface topography by confocal 3D-XRF analysis

    NASA Astrophysics Data System (ADS)

    Yi, Longtao; Qin, Min; Wang, Kai; Lin, Xue; Peng, Shiqi; Sun, Tianxi; Liu, Zhiguo

    2016-09-01

    Confocal three-dimensional micro-X-ray fluorescence (3D-XRF) is a good surface analysis technology widely used to analyse elements and elemental distributions. However, it has rarely been applied to analyse surface topography and 3D elemental mapping in surface morphology. In this study, a surface adaptive algorithm using the progressive approximation method was designed to obtain surface topography. A series of 3D elemental mapping analyses in surface morphology were performed in laboratories to analyse painted pottery fragments from the Majiayao Culture (3300-2900 BC). To the best of our knowledge, for the first time, sample surface topography and 3D elemental mapping were simultaneously obtained. Besides, component and depth analyses were also performed using synchrotron radiation confocal 3D-XRF and tabletop confocal 3D-XRF, respectively. The depth profiles showed that the sample has a layered structure. The 3D elemental mapping showed that the red pigment, black pigment, and pottery coat contain a large amount of Fe, Mn, and Ca, respectively. From the 3D elemental mapping analyses at different depths, a 3D rendering was obtained, clearly showing the 3D distributions of the red pigment, black pigment, and pottery coat. Compared with conventional 3D scanning, this method is time-efficient for analysing 3D elemental distributions and hence especially suitable for samples with non-flat surfaces.

  9. Structured Light Based 3d Scanning for Specular Surface by the Combination of Gray Code and Phase Shifting

    NASA Astrophysics Data System (ADS)

    Zhang, Yujia; Yilmaz, Alper

    2016-06-01

    Surface reconstruction using coded structured light is considered one of the most reliable techniques for high-quality 3D scanning. With a calibrated projector-camera stereo system, a light pattern is projected onto the scene and imaged by the camera. Correspondences between projected and recovered patterns are computed in the decoding process, which is used to generate 3D point cloud of the surface. However, the indirect illumination effects on the surface, such as subsurface scattering and interreflections, will raise the difficulties in reconstruction. In this paper, we apply maximum min-SW gray code to reduce the indirect illumination effects of the specular surface. We also analysis the errors when comparing the maximum min-SW gray code and the conventional gray code, which justifies that the maximum min-SW gray code has significant superiority to reduce the indirect illumination effects. To achieve sub-pixel accuracy, we project high frequency sinusoidal patterns onto the scene simultaneously. But for specular surface, the high frequency patterns are susceptible to decoding errors. Incorrect decoding of high frequency patterns will result in a loss of depth resolution. Our method to resolve this problem is combining the low frequency maximum min-SW gray code and the high frequency phase shifting code, which achieves dense 3D reconstruction for specular surface. Our contributions include: (i) A complete setup of the structured light based 3D scanning system; (ii) A novel combination technique of the maximum min-SW gray code and phase shifting code. First, phase shifting decoding with sub-pixel accuracy. Then, the maximum min-SW gray code is used to resolve the ambiguity resolution. According to the experimental results and data analysis, our structured light based 3D scanning system enables high quality dense reconstruction of scenes with a small number of images. Qualitative and quantitative comparisons are performed to extract the advantages of our new

  10. A cone-beam CT based technique to augment the 3D virtual skull model with a detailed dental surface.

    PubMed

    Swennen, G R J; Mommaerts, M Y; Abeloos, J; De Clercq, C; Lamoral, P; Neyt, N; Casselman, J; Schutyser, F

    2009-01-01

    Cone-beam computed tomography (CBCT) is used for maxillofacial imaging. 3D virtual planning of orthognathic and facial orthomorphic surgery requires detailed visualisation of the interocclusal relationship. This study aimed to introduce and evaluate the use of a double CBCT scan procedure with a modified wax bite wafer to augment the 3D virtual skull model with a detailed dental surface. The impressions of the dental arches and the wax bite wafer were scanned for ten patient separately using a high resolution standardized CBCT scanning protocol. Surface-based rigid registration using ICP (iterative closest points) was used to fit the virtual models on the wax bite wafer. Automatic rigid point-based registration of the wax bite wafer on the patient scan was performed to implement the digital virtual dental arches into the patient's skull model. Probability error histograms showed errors of < or =0.22 mm (25% percentile), < or =0.44 mm (50% percentile) and < or =1.09 mm (90% percentile) for ICP surface matching. The mean registration error for automatic point-based rigid registration was 0.18+/-0.10 mm (range 0.13-0.26 mm). The results show the potential for a double CBCT scan procedure with a modified wax bite wafer to set-up a 3D virtual augmented model of the skull with detailed dental surface.

  11. A 3D Optical Surface Profilometer Using a Dual-Frequency Liquid Crystal-Based Dynamic Fringe Pattern Generator

    PubMed Central

    Joo, Kyung-Il; Kim, Mugeon; Park, Min-Kyu; Park, Heewon; Kim, Byeonggon; Hahn, JoonKu; Kim, Hak-Rin

    2016-01-01

    We propose a liquid crystal (LC)-based 3D optical surface profilometer that can utilize multiple fringe patterns to extract an enhanced 3D surface depth profile. To avoid the optical phase ambiguity and enhance the 3D depth extraction, 16 interference patterns were generated by the LC-based dynamic fringe pattern generator (DFPG) using four-step phase shifting and four-step spatial frequency varying schemes. The DFPG had one common slit with an electrically controllable birefringence (ECB) LC mode and four switching slits with a twisted nematic LC mode. The spatial frequency of the projected fringe pattern could be controlled by selecting one of the switching slits. In addition, moving fringe patterns were obtainable by applying voltages to the ECB LC layer, which varied the phase difference between the common and the selected switching slits. Notably, the DFPG switching time required to project 16 fringe patterns was minimized by utilizing the dual-frequency modulation of the driving waveform to switch the LC layers. We calculated the phase modulation of the DFPG and reconstructed the depth profile of 3D objects using a discrete Fourier transform method and geometric optical parameters. PMID:27801812

  12. Efficient global optimization based 3D carotid AB-LIB MRI segmentation by simultaneously evolving coupled surfaces.

    PubMed

    Ukwatta, Eranga; Yuan, Jing; Rajchl, Martin; Fenster, Aaron

    2012-01-01

    Magnetic resonance (MR) imaging of carotid atherosclerosis biomarkers are increasingly being investigated for the risk assessment of vulnerable plaques. A fast and robust 3D segmentation of the carotid adventitia (AB) and lumen-intima (LIB) boundaries can greatly alleviate the measurement burden of generating quantitative imaging biomarkers in clinical research. In this paper, we propose a novel global optimization-based approach to segment the carotid AB and LIB from 3D T1-weighted black blood MR images, by simultaneously evolving two coupled surfaces with enforcement of anatomical consistency of the AB and LIB. We show that the evolution of two surfaces at each discrete time-frame can be optimized exactly and globally by means of convex relaxation. Our continuous max-flow based algorithm is implemented in GPUs to achieve high computational performance. The experiment results from 16 carotid MR images show that the algorithm obtained high agreement with manual segmentations and achieved high repeatability in segmentation.

  13. Surface Acoustic Waves (SAW)-Based Biosensing for Quantification of Cell Growth in 2D and 3D Cultures

    PubMed Central

    Wang, Tao; Green, Ryan; Nair, Rajesh Ramakrishnan; Howell, Mark; Mohapatra, Subhra; Guldiken, Rasim; Mohapatra, Shyam Sundar

    2015-01-01

    Detection and quantification of cell viability and growth in two-dimensional (2D) and three-dimensional (3D) cell cultures commonly involve harvesting of cells and therefore requires a parallel set-up of several replicates for time-lapse or dose–response studies. Thus, developing a non-invasive and touch-free detection of cell growth in longitudinal studies of 3D tumor spheroid cultures or of stem cell regeneration remains a major unmet need. Since surface acoustic waves (SAWs) permit mass loading-based biosensing and have been touted due to their many advantages including low cost, small size and ease of assembly, we examined the potential of SAW-biosensing to detect and quantify cell growth. Herein, we demonstrate that a shear horizontal-surface acoustic waves (SH-SAW) device comprising two pairs of resonators consisting of interdigital transducers and reflecting fingers can be used to quantify mass loading by the cells in suspension as well as within a 3D cell culture platform. A 3D COMSOL model was built to simulate the mass loading response of increasing concentrations of cells in suspension in the polydimethylsiloxane (PDMS) well in order to predict the characteristics and optimize the design of the SH-SAW biosensor. The simulated relative frequency shift from the two oscillatory circuit systems (one of which functions as control) were found to be concordant to experimental data generated with RAW264.7 macrophage and A549 cancer cells. In addition, results showed that SAW measurements per se did not affect viability of cells. Further, SH-SAW biosensing was applied to A549 cells cultured on a 3D electrospun nanofiber scaffold that generate tumor spheroids (tumoroids) and the results showed the device's ability to detect changes in tumor spheroid growth over the course of eight days. Taken together, these results demonstrate the use of SH-SAW device for detection and quantification of cell growth changes over time in 2D suspension cultures and in 3D cell

  14. Surface Acoustic Waves (SAW)-Based Biosensing for Quantification of Cell Growth in 2D and 3D Cultures.

    PubMed

    Wang, Tao; Green, Ryan; Nair, Rajesh Ramakrishnan; Howell, Mark; Mohapatra, Subhra; Guldiken, Rasim; Mohapatra, Shyam Sundar

    2015-12-19

    Detection and quantification of cell viability and growth in two-dimensional (2D) and three-dimensional (3D) cell cultures commonly involve harvesting of cells and therefore requires a parallel set-up of several replicates for time-lapse or dose-response studies. Thus, developing a non-invasive and touch-free detection of cell growth in longitudinal studies of 3D tumor spheroid cultures or of stem cell regeneration remains a major unmet need. Since surface acoustic waves (SAWs) permit mass loading-based biosensing and have been touted due to their many advantages including low cost, small size and ease of assembly, we examined the potential of SAW-biosensing to detect and quantify cell growth. Herein, we demonstrate that a shear horizontal-surface acoustic waves (SH-SAW) device comprising two pairs of resonators consisting of interdigital transducers and reflecting fingers can be used to quantify mass loading by the cells in suspension as well as within a 3D cell culture platform. A 3D COMSOL model was built to simulate the mass loading response of increasing concentrations of cells in suspension in the polydimethylsiloxane (PDMS) well in order to predict the characteristics and optimize the design of the SH-SAW biosensor. The simulated relative frequency shift from the two oscillatory circuit systems (one of which functions as control) were found to be concordant to experimental data generated with RAW264.7 macrophage and A549 cancer cells. In addition, results showed that SAW measurements per se did not affect viability of cells. Further, SH-SAW biosensing was applied to A549 cells cultured on a 3D electrospun nanofiber scaffold that generate tumor spheroids (tumoroids) and the results showed the device's ability to detect changes in tumor spheroid growth over the course of eight days. Taken together, these results demonstrate the use of SH-SAW device for detection and quantification of cell growth changes over time in 2D suspension cultures and in 3D cell

  15. Left ventricular endocardial surface detection based on real-time 3D echocardiographic data

    NASA Technical Reports Server (NTRS)

    Corsi, C.; Borsari, M.; Consegnati, F.; Sarti, A.; Lamberti, C.; Travaglini, A.; Shiota, T.; Thomas, J. D.

    2001-01-01

    OBJECTIVE: A new computerized semi-automatic method for left ventricular (LV) chamber segmentation is presented. METHODS: The LV is imaged by real-time three-dimensional echocardiography (RT3DE). The surface detection model, based on level set techniques, is applied to RT3DE data for image analysis. The modified level set partial differential equation we use is solved by applying numerical methods for conservation laws. The initial conditions are manually established on some slices of the entire volume. The solution obtained for each slice is a contour line corresponding with the boundary between LV cavity and LV endocardium. RESULTS: The mathematical model has been applied to sequences of frames of human hearts (volume range: 34-109 ml) imaged by 2D and reconstructed off-line and RT3DE data. Volume estimation obtained by this new semi-automatic method shows an excellent correlation with those obtained by manual tracing (r = 0.992). Dynamic change of LV volume during the cardiac cycle is also obtained. CONCLUSION: The volume estimation method is accurate; edge based segmentation, image completion and volume reconstruction can be accomplished. The visualization technique also allows to navigate into the reconstructed volume and to display any section of the volume.

  16. Visualization and mapping of neurosurgical functional brain data onto a 3-D MR-based model of the brain surface.

    PubMed

    Modayur, B R; Prothero, J; Rosse, C; Jakobovits, R; Brinkley, J F

    1996-01-01

    The Human Brain Project was initiated with the goal of developing methods for managing and sharing information about the brain. As a prototype Human Brain Project application we are developing a system for organizing, visualizing, integrating and sharing information about human language function. The goal of the brain mapping component of our work, described in this article, is to generate the 3D location and extent of cortical language sites with respect to a uniform, 3D patient coordinate system. The language sites of individual patients can then be combined with or related to other patient data in terms of a Talairach, surface-based, or other deformable coordinate systems. Language site mapping is done by visually comparing an intraoperative photograph with the rendered image (from MRI data). The techniques outlined in this article have been utilized to map cortical language sites of six patients. Preliminary results point to the adequacy of our volume visualizations for language mapping. The strength of the visualization scheme lies in the combination of interactive segmentation with volume and surface visualization. We are now in the process of acquiring more patient data to further validate the usefulness of our method.

  17. Methods for comparing 3D surface attributes

    NASA Astrophysics Data System (ADS)

    Pang, Alex; Freeman, Adam

    1996-03-01

    A common task in data analysis is to compare two or more sets of data, statistics, presentations, etc. A predominant method in use is side-by-side visual comparison of images. While straightforward, it burdens the user with the task of discerning the differences between the two images. The user if further taxed when the images are of 3D scenes. This paper presents several methods for analyzing the extent, magnitude, and manner in which surfaces in 3D differ in their attributes. The surface geometry are assumed to be identical and only the surface attributes (color, texture, etc.) are variable. As a case in point, we examine the differences obtained when a 3D scene is rendered progressively using radiosity with different form factor calculation methods. The comparison methods include extensions of simple methods such as mapping difference information to color or transparency, and more recent methods including the use of surface texture, perturbation, and adaptive placements of error glyphs.

  18. Protein adsorption resistant surface on polymer composite based on 2D- and 3D-controlled grafting of phospholipid moieties

    NASA Astrophysics Data System (ADS)

    Hoshi, Toru; Matsuno, Ryosuke; Sawaguchi, Takashi; Konno, Tomohiro; Takai, Madoka; Ishihara, Kazuhiko

    2008-11-01

    To prepare the biocompatible surface, a phosphorylcholine (PC) group was introduced on this hydroxyl group generated by surface hydrolysis on the polymer composite composed of polyethylene (PE) and poly (vinyl acetate) (PVAc) prepared by supercritical carbon dioxide. Two different procedures such as two-dimensional (2D) modification and three-dimensional (3D) modification were applied to obtain the steady biocompatible surface. 2D modification was that PC groups were directly anchored on the surface of the polymer composite. 3D modification was that phospholipid polymer was grafted from the surface of the polymer composite by surface-initiated atom transfer radical polymerization (SI-ATRP) of 2-methacryloyloxyethyl phosphorylcholine (MPC). The surfaces were characterized by X-ray photoelectron spectroscopy, dynamic water contact angle measurements, and atomic force microscope. The effects of the poly(MPC) chain length on the protein adsorption resistivity were investigated. The protein adsorption on the polymer composite surface with PC groups modified by 2D or 3D modification was significantly reduced as compared with that on the unmodified PE. Further, the amount of protein adsorbed on the 3D modified surface that is poly(MPC)-grafted surface decreased with an increase in the chain length of the poly(MPC). The surface with an arbitrary structure and the characteristic can be constructed by using 2D and 3D modification. We conclude that the polymer composites of PE/PVAc with PC groups on the surface are useful for fabricating biomedical devices due to their good mechanical and surface properties.

  19. A surface-based 3-D dendritic spine detection approach from confocal microscopy images.

    PubMed

    Li, Qing; Deng, Zhigang

    2012-03-01

    Determining the relationship between the dendritic spine morphology and its functional properties is a fundamental challenge in neurobiology research. In particular, how to accurately and automatically analyse meaningful structural information from a large microscopy image data set is far away from being resolved. As pointed out in existing literature, one remaining challenge in spine detection and segmentation is how to automatically separate touching spines. In this paper, based on various global and local geometric features of the dendrite structure, we propose a novel approach to detect and segment neuronal spines, in particular, a breaking-down and stitching-up algorithm to accurately separate touching spines. Extensive performance comparisons show that our approach is more accurate and robust than two state-of-the-art spine detection and segmentation algorithms.

  20. GIS based 3D visualization of subsurface and surface lineaments / faults and their geological significance, northern tamil nadu, India

    NASA Astrophysics Data System (ADS)

    Saravanavel, J.; Ramasamy, S. M.

    2014-11-01

    The study area falls in the southern part of the Indian Peninsular comprising hard crystalline rocks of Archaeozoic and Proterozoic Era. In the present study, the GIS based 3D visualizations of gravity, magnetic, resistivity and topographic datasets were made and therefrom the basement lineaments, shallow subsurface lineaments and surface lineaments/faults were interpreted. These lineaments were classified as category-1 i.e. exclusively surface lineaments, category-2 i.e. surface lineaments having connectivity with shallow subsurface lineaments and category-3 i.e. surface lineaments having connectivity with shallow subsurface lineaments and basement lineaments. These three classified lineaments were analyzed in conjunction with known mineral occurrences and historical seismicity of the study area in GIS environment. The study revealed that the category-3 NNE-SSW to NE-SW lineaments have greater control over the mineral occurrences and the N-S, NNE-SSW and NE-SW, faults/lineaments control the seismicities in the study area.

  1. Crowdsourcing Based 3d Modeling

    NASA Astrophysics Data System (ADS)

    Somogyi, A.; Barsi, A.; Molnar, B.; Lovas, T.

    2016-06-01

    Web-based photo albums that support organizing and viewing the users' images are widely used. These services provide a convenient solution for storing, editing and sharing images. In many cases, the users attach geotags to the images in order to enable using them e.g. in location based applications on social networks. Our paper discusses a procedure that collects open access images from a site frequently visited by tourists. Geotagged pictures showing the image of a sight or tourist attraction are selected and processed in photogrammetric processing software that produces the 3D model of the captured object. For the particular investigation we selected three attractions in Budapest. To assess the geometrical accuracy, we used laser scanner and DSLR as well as smart phone photography to derive reference values to enable verifying the spatial model obtained from the web-album images. The investigation shows how detailed and accurate models could be derived applying photogrammetric processing software, simply by using images of the community, without visiting the site.

  2. Determination of 3D surface displacement rates in the Upper Rhine Graben based on GURN (GNSS Upper Rhine Graben Network)

    NASA Astrophysics Data System (ADS)

    Mayer, M.; Knöpfler, A.; Masson, F.; Ulrich, P.; Heck, B.

    2012-04-01

    regional network GURN actually consists of approx. 80 permanently operating GNSS sites of different data providers in Germany, France and Switzerland. The first work steps in the context of GURN were dominated by a detailed analysis of the GNSS data base (e.g., instrumental change artefacts). This analysis included a comparison of the working group related results (EOST, GIK), where different software packages and data handling strategies were used to derive 3D coordinate time series as basis for the determination of a 3D surface displacement field. Due to very small expected velocities in the URG region, the recent GURN focus is on the reliable derivation of site velocities, therefore effects of datum realisation have to be handled with care. The presentation gives an insight into the joint venture GURN focussing on recent results (e.g., 3D surface velocity field).

  3. Vision models for 3D surfaces

    NASA Astrophysics Data System (ADS)

    Mitra, Sunanda

    1992-11-01

    Different approaches to computational stereo to represent human stereo vision have been developed over the past two decades. The Marr-Poggio theory of human stereo vision is probably the most widely accepted model of the human stereo vision. However, recently developed motion stereo models which use a sequence of images taken by either a moving camera or a moving object provide an alternative method of achieving multi-resolution matching without the use of Laplacian of Gaussian operators. While using image sequences, the baseline between two camera positions for a image pair is changed for the subsequent image pair so as to achieve different resolution for each image pair. Having different baselines also avoids the inherent occlusion problem in stereo vision models. The advantage of using multi-resolution images acquired by camera positioned at different baselines over those acquired by LOG operators is that one does not have to encounter spurious edges often created by zero-crossings in the LOG operated images. Therefore in designing a computer vision system, a motion stereo model is more appropriate than a stereo vision model. However, in some applications where only a stereo pair of images are available, recovery of 3D surfaces of natural scenes are possible in a computationally efficient manner by using cepstrum matching and regularization techniques. Section 2 of this paper describes a motion stereo model using multi-scale cepstrum matching for the detection of disparity between image pairs in a sequence of images and subsequent recovery of 3D surfaces from depth-map obtained by a non convergent triangulation technique. Section 3 presents a 3D surface recovery technique from a stereo pair using cepstrum matching for disparity detection and cubic B-splines for surface smoothing. Section 4 contains the results of 3D surface recovery using both of the techniques mentioned above. Section 5 discusses the merit of 2D cepstrum matching and cubic B

  4. PLOT3D- DRAWING THREE DIMENSIONAL SURFACES

    NASA Technical Reports Server (NTRS)

    Canright, R. B.

    1994-01-01

    PLOT3D is a package of programs to draw three-dimensional surfaces of the form z = f(x,y). The function f and the boundary values for x and y are the input to PLOT3D. The surface thus defined may be drawn after arbitrary rotations. However, it is designed to draw only functions in rectangular coordinates expressed explicitly in the above form. It cannot, for example, draw a sphere. Output is by off-line incremental plotter or online microfilm recorder. This package, unlike other packages, will plot any function of the form z = f(x,y) and portrays continuous and bounded functions of two independent variables. With curve fitting; however, it can draw experimental data and pictures which cannot be expressed in the above form. The method used is division into a uniform rectangular grid of the given x and y ranges. The values of the supplied function at the grid points (x, y) are calculated and stored; this defines the surface. The surface is portrayed by connecting successive (y,z) points with straight-line segments for each x value on the grid and, in turn, connecting successive (x,z) points for each fixed y value on the grid. These lines are then projected by parallel projection onto the fixed yz-plane for plotting. This program has been implemented on the IBM 360/67 with on-line CDC microfilm recorder.

  5. Surface Plasmons in 3D Topological Insulators

    NASA Astrophysics Data System (ADS)

    Kogar, Anshul; Vig, Sean; Cho, Gil; Thaler, Alexander; Xiao, Yiran; Hughes, Taylor; Wong, Man-Hong; Chiang, Tai-Chang; MacDougall, Greg; Abbamonte, Peter

    2015-03-01

    Most studies of three-dimensional (3D) topological insulators have concentrated on their one-electron properties as exhibited by angle-resolved photoemission spectroscopy (ARPES) or by scanning tunneling microscopy (STM). Many-body interactions are often neglected in the treatment of models of topological insulators, such as in the Kane-Mele and Bernevig-Hughes-Zhang models. Using angle-resolved inelastic electron scattering from the surface, I will present data on the collective mode that owes its existence to the presence of many-body interactions, the surface plasmon (SP), in two known 3D topological insulators, Bi2Se3 and Bi0.5Sb1.5Se1 . 5 + xTe1 . 5 - x. Surprisingly, the SP was prominent even after depressing the Fermi energy into the bulk band gap. Having studied the SP as a function of doping, momentum transfer and its aging properties, I will present evidence to suggest that bulk-surface coupling is crucial in explaining many of its properties. A simple model with dynamic bulk screening will be presented showing qualitative agreement with the observations. Lastly, the relation of the observed surface plasmon to the predicted spin-plasmon mode and to the kinks seen in the electronic dispersion as measured by ARPES will be discussed. The work was supported as part of the Center for Emergent Superconductivity, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science.

  6. Laser Based 3D Volumetric Display System

    DTIC Science & Technology

    1993-03-01

    Literature, Costa Mesa, CA July 1983. 3. "A Real Time Autostereoscopic Multiplanar 3D Display System", Rodney Don Williams, Felix Garcia, Jr., Texas...8217 .- NUMBERS LASER BASED 3D VOLUMETRIC DISPLAY SYSTEM PR: CD13 0. AUTHOR(S) PE: N/AWIU: DN303151 P. Soltan, J. Trias, W. Robinson, W. Dahlke 7...laser generated 3D volumetric images on a rotating double helix, (where the 3D displays are computer controlled for group viewing with the naked eye

  7. From Surface Data to 3D Geologic Maps

    NASA Astrophysics Data System (ADS)

    Dhont, D.; Luxey, P.; Longuesserre, V.; Monod, B.; Guillaume, B.

    2008-12-01

    New trends in earth sciences are mostly related to technologies allowing graphical representations of the geology in 3D. However, the concept of 3D geologic map is commonly misused. For instance, displays of geologic maps draped onto DEM in rotating perspective views have been misleadingly called 3D geologic maps, but this still cannot provide any volumetric underground information as a true 3D geologic map should. Here, we present a way to produce mathematically and geometrically correct 3D geologic maps constituted by the volume and shape of all geologic features of a given area. The originality of the method is that it is based on the integration of surface data only consisting of (1) geologic maps, (2) satellite images, (3) DEM and (4) bedding dips and strikes. To generate 3D geologic maps, we used a 3D geologic modeler that combines and extrapolates the surface information into a coherent 3D data set. The significance of geometrically correct 3D geologic maps is demonstrated for various geologic settings and applications. 3D models are of primarily importance for educational purposes because they reveal features that standard 2D geologic maps by themselves could not show. The 3D visualization helps in the understanding of the geometrical relationship between the different geologic features and, in turn, for the quantification of the geology at the regional scale. Furthermore, given the logistical challenges associated with modern oil and mineral exploration in remote and rugged terrain, these volume-based models can provide geological and commercial insight prior to seismic evaluation.

  8. Investigation of surface wave amplitudes in 3-D velocity and 3-D Q models

    NASA Astrophysics Data System (ADS)

    Ruan, Y.; Zhou, Y.

    2010-12-01

    It has been long recognized that seismic amplitudes depend on both wave speed structures and anelasticity (Q) structures. However, the effects of lateral heterogeneities in wave speed and Q structures on seismic amplitudes has not been well understood. We investigate the effects of 3-D wave speed and 3-D anelasticity (Q) structures on surface-wave amplitudes based upon wave propagation simulations of twelve globally-distributed earthquakes and 801 stations in Earth models with and without lateral heterogeneities in wave speed and anelasticity using a Spectral Element Method (SEM). Our tomographic-like 3-D Q models are converted from a velocity model S20RTS using a set of reasonable mineralogical parameters, assuming lateral perturbations in both velocity and Q are due to temperature perturbations. Surface-wave amplitude variations of SEM seismograms are measured in the period range of 50--200 s using boxcar taper, cosine taper and Slepian multi-tapers. We calculate ray-theoretical predictions of surface-wave amplitude perturbations due to elastic focusing, attenuation, and anelastic focusing which respectively depend upon the second spatial derivative (''roughness'') of perturbations in phase velocity, 1/Q, and the roughness of perturbations in 1/Q. Both numerical experiments and theoretical calculations show that (1) for short-period (~ 50 s) surface waves, the effects of amplitude attenuation due to 3-D Q structures are comparable with elastic focusing effects due to 3-D wave speed structures; and (2) for long-period (> 100 s) surface waves, the effects of attenuation become much weaker than elastic focusing; and (3) elastic focusing effects are correlated with anelastic focusing at all periods due to the correlation between velocity and Q models; and (4) amplitude perturbations are depend on measurement techniques and therefore cannot be directly compared with ray-theoretical predictions because ray theory does not account for the effects of measurement

  9. Volumetric and surface-based 3D MRI analyses of fetal isolated mild ventriculomegaly: brain morphometry in ventriculomegaly.

    PubMed

    Scott, Julia A; Habas, Piotr A; Rajagopalan, Vidya; Kim, Kio; Barkovich, A James; Glenn, Orit A; Studholme, Colin

    2013-05-01

    Diagnosis of fetal isolated mild ventriculomegaly (IMVM) is the most common brain abnormality on prenatal ultrasound. We have set to identify potential alterations in brain development specific to IMVM in tissue volume and cortical and ventricular local surface curvature derived from in utero magnetic resonance imaging (MRI). Multislice 2D T2-weighted MRI were acquired from 32 fetuses (16 IMVM, 16 controls) between 22 and 25.5 gestational weeks. The images were motion-corrected and reconstructed into 3D volumes for volumetric and curvature analyses. The brain images were automatically segmented into cortical plate, cerebral mantle, deep gray nuclei, and ventricles. Volumes were compared between IMVM and control subjects. Surfaces were extracted from the segmentations for local mean surface curvature measurement on the inner cortical plate and the ventricles. Linear models were estimated for age-related and ventricular volume-associated changes in local curvature in both the inner cortical plate and ventricles. While ventricular volume was enlarged in IMVM, all other tissue volumes were not different from the control group. Ventricles increased in curvature with age along the atrium and anterior body. Increasing ventricular volume was associated with reduced curvature over most of the ventricular surface. The cortical plate changed in curvature with age at multiple sites of primary sulcal formation. Reduced cortical folding was detected near the parieto-occipital sulcus in IMVM subjects. While tissue volume appears to be preserved in brains with IMVM, cortical folding may be affected in regions where ventricles are dilated.

  10. 3D surface and body documentation in forensic medicine: 3-D/CAD Photogrammetry merged with 3D radiological scanning.

    PubMed

    Thali, Michael J; Braun, Marcel; Wirth, Joachim; Vock, Peter; Dirnhofer, Richard

    2003-11-01

    A main goal of forensic medicine is to document and to translate medical findings to a language and/or visualization that is readable and understandable for judicial persons and for medical laymen. Therefore, in addition to classical methods, scientific cutting-edge technologies can and should be used. Through the use of the Forensic, 3-D/CAD-supported Photogrammetric method the documentation of so-called "morphologic fingerprints" has been realized. Forensic, 3-D/CAD-supported Photogrammetry creates morphologic data models of the injury and of the suspected injury-causing instrument allowing the evaluation of a match between the injury and the instrument. In addition to the photogrammetric body surface registration, the radiological documentation provided by a volume scan (i.e., spiral, multi-detector CT, or MRI) registers the sub-surface injury, which is not visible to Photogrammetry. The new, combined method of merging Photogrammetry and Radiology data sets creates the potential to perform many kinds of reconstructions and postprocessing of (patterned) injuries in the realm of forensic medical case work. Using this merging method of colored photogrammetric surface and gray-scale radiological internal documentation, a great step towards a new kind of reality-based, high-tech wound documentation and visualization in forensic medicine is made. The combination of the methods of 3D/CAD Photogrammetry and Radiology has the advantage of being observer-independent, non-subjective, non-invasive, digitally storable over years or decades and even transferable over the web for second opinion.

  11. 3D Human cartilage surface characterization by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Brill, Nicolai; Riedel, Jörn; Schmitt, Robert; Tingart, Markus; Truhn, Daniel; Pufe, Thomas; Jahr, Holger; Nebelung, Sven

    2015-10-01

    Early diagnosis and treatment of cartilage degeneration is of high clinical interest. Loss of surface integrity is considered one of the earliest and most reliable signs of degeneration, but cannot currently be evaluated objectively. Optical Coherence Tomography (OCT) is an arthroscopically available light-based non-destructive real-time imaging technology that allows imaging at micrometre resolutions to millimetre depths. As OCT-based surface evaluation standards remain to be defined, the present study investigated the diagnostic potential of 3D surface profile parameters in the comprehensive evaluation of cartilage degeneration. To this end, 45 cartilage samples of different degenerative grades were obtained from total knee replacements (2 males, 10 females; mean age 63.8 years), cut to standard size and imaged using a spectral-domain OCT device (Thorlabs, Germany). 3D OCT datasets of 8  ×  8, 4  ×  4 and 1  ×  1 mm (width  ×  length) were obtained and pre-processed (image adjustments, morphological filtering). Subsequent automated surface identification algorithms were used to obtain the 3D primary profiles, which were then filtered and processed using established algorithms employing ISO standards. The 3D surface profile thus obtained was used to calculate a set of 21 3D surface profile parameters, i.e. height (e.g. Sa), functional (e.g. Sk), hybrid (e.g. Sdq) and segmentation-related parameters (e.g. Spd). Samples underwent reference histological assessment according to the Degenerative Joint Disease classification. Statistical analyses included calculation of Spearman’s rho and assessment of inter-group differences using the Kruskal Wallis test. Overall, the majority of 3D surface profile parameters revealed significant degeneration-dependent differences and correlations with the exception of severe end-stage degeneration and were of distinct diagnostic value in the assessment of surface integrity. None of the 3D

  12. Optical 3D surface digitizing in forensic medicine: 3D documentation of skin and bone injuries.

    PubMed

    Thali, Michael J; Braun, Marcel; Dirnhofer, Richard

    2003-11-26

    Photography process reduces a three-dimensional (3D) wound to a two-dimensional level. If there is a need for a high-resolution 3D dataset of an object, it needs to be three-dimensionally scanned. No-contact optical 3D digitizing surface scanners can be used as a powerful tool for wound and injury-causing instrument analysis in trauma cases. The 3D skin wound and a bone injury documentation using the optical scanner Advanced TOpometric Sensor (ATOS II, GOM International, Switzerland) will be demonstrated using two illustrative cases. Using this 3D optical digitizing method the wounds (the virtual 3D computer model of the skin and the bone injuries) and the virtual 3D model of the injury-causing tool are graphically documented in 3D in real-life size and shape and can be rotated in the CAD program on the computer screen. In addition, the virtual 3D models of the bone injuries and tool can now be compared in a 3D CAD program against one another in virtual space, to see if there are matching areas. Further steps in forensic medicine will be a full 3D surface documentation of the human body and all the forensic relevant injuries using optical 3D scanners.

  13. Studies of the 3D surface roughness height

    SciTech Connect

    Avisane, Anita; Rudzitis, Janis; Kumermanis, Maris

    2013-12-16

    Nowadays nano-coatings occupy more and more significant place in technology. Innovative, functional coatings acquire new aspects from the point of view of modern technologies, considering the aggregate of physical properties that can be achieved manipulating in the production process with the properties of coatings’ surfaces on micro- and nano-level. Nano-coatings are applied on machine parts, friction surfaces, contacting parts, corrosion surfaces, transparent conducting films (TCF), etc. The equipment available at present for the production of transparent conducting oxide (TCO) coatings with highest quality is based on expensive indium tin oxide (ITO) material; therefore cheaper alternatives are being searched for. One such offered alternative is zink oxide (ZnO) nano-coatings. Evaluating the TCF physical and mechanical properties and in view of the new ISO standard (EN ISO 25178) on the introduction of surface texture (3D surface roughness) in the engineering calculations, it is necessary to examine the height of 3D surface roughness, which is one of the most significant roughness parameters. The given paper studies the average values of 3D surface roughness height and the most often applied distribution laws are as follows: the normal distribution and Rayleigh distribution. The 3D surface is simulated by a normal random field.

  14. Photonic bandgap extension of surface-disordered 3D photonic crystals based on the TiO2 inverse opal architecture.

    PubMed

    Wang, Aijun; Liu, Wenfang; Tang, Junjie; Chen, Sheng-Li; Dong, Peng

    2014-04-15

    A photonic bandgap (PBG) extension of surface-disordered 3D photonic crystals (PCs) based on the TiO2 inverse opal (TiO2-IO) architecture has been demonstrated. By using a liquid phase deposition (LPD) process based on the controlled hydrolysis of ammonium hexafluorotitanate and boric acid, an extra layer of TiO2 nanoparticles were deposited onto the internal surface of the air voids in the TiO2-IOs to increase their surface roughness, thereby introducing surface disorder in the 3D order structures. The PBG relative width of surface-disordered TiO2-IOs has been broadened significantly, and, compared to the original TiO2-IO, its largest rate of increase (27%) has been obtained. It was found that the PBG relative width increased rapidly at first and then to a much slower rate of change with increase of the duration of the LPD time. A possible cause for this finding is discussed in this Letter.

  15. 3D Surface Reconstruction and Automatic Camera Calibration

    NASA Technical Reports Server (NTRS)

    Jalobeanu, Andre

    2004-01-01

    Illustrations in this view-graph presentation are presented on a Bayesian approach to 3D surface reconstruction and camera calibration.Existing methods, surface analysis and modeling,preliminary surface reconstruction results, and potential applications are addressed.

  16. Model-based 3D SAR reconstruction

    NASA Astrophysics Data System (ADS)

    Knight, Chad; Gunther, Jake; Moon, Todd

    2014-06-01

    Three dimensional scene reconstruction with synthetic aperture radar (SAR) is desirable for target recognition and improved scene interpretability. The vertical aperture, which is critical to reconstruct 3D SAR scenes, is almost always sparsely sampled due to practical limitations, which creates an underdetermined problem. This papers explores 3D scene reconstruction using a convex model-based approach. The approach developed is demonstrated on 3D scenes, but can be extended to SAR reconstruction of sparsely sampled signals in the spatial and, or, frequency domains. The model-based approach enables knowledge-aided image formation (KAIF) by incorporating spatial, aspect, and sparsity magnitude terms into the image reconstruction. The incorporation of these terms, which are based on prior scene knowledge, will demonstrate improved results compared to traditional image formation algorithms. The SAR image formation problem is formulated as a second order cone program (SOCP) and the results are demonstrated on 3D scenes using simulated data and data from the GOTCHA data collect.1 The model-based results are contrasted against traditional backprojected images.

  17. Design Application Translates 2-D Graphics to 3-D Surfaces

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Fabric Images Inc., specializing in the printing and manufacturing of fabric tension architecture for the retail, museum, and exhibit/tradeshow communities, designed software to translate 2-D graphics for 3-D surfaces prior to print production. Fabric Images' fabric-flattening design process models a 3-D surface based on computer-aided design (CAD) specifications. The surface geometry of the model is used to form a 2-D template, similar to a flattening process developed by NASA's Glenn Research Center. This template or pattern is then applied in the development of a 2-D graphic layout. Benefits of this process include 11.5 percent time savings per project, less material wasted, and the ability to improve upon graphic techniques and offer new design services. Partners include Exhibitgroup/Giltspur (end-user client: TAC Air, a division of Truman Arnold Companies Inc.), Jack Morton Worldwide (end-user client: Nickelodeon), as well as 3D Exhibits Inc., and MG Design Associates Corp.

  18. Nanopatterning on fragile or 3D surfaces with sterol-based vapor-deposited electron beam resist

    NASA Astrophysics Data System (ADS)

    Legario, Ron R.; Kelkar, Prasad S.; Beauvais, Jacques; Lavallee, Eric; Drouin, Dominique; Cloutier, Melanie; Turcotte, David; Yang, Pan; Mun, Lau K.; Awad, Yousef; Lafrance, Pierre J.

    2004-05-01

    A novel and effective approach to nano-fabrication lithography is the vapour deposition of the negative tone electron beam resists QSR-5 and QSR-15 (Quantiscript"s sterol based resist) onto a substrate. Vapour deposition is especially conducive for patterning thin delicate membranes (e.g. advanced masks for X-ray lithography - XRL, and Low Energy Electron Proximity Projection Lithography - LEEPL), that are susceptible to breakage during the spin coating process. With the capability for depositing highly uniform thin layers (<50nm) and a demonstrated resolution better than 60nm, QSR-5 and QSR-15 have potential for the fabrication of next generation lithography masks. Optimized for low energy electron exposure where proximity effects become negligible and thus well suited for 1X lithography mask patterning, QSR-5 and QSR-15 have shown exposure doses as low as 100μC/cm2 at 3KeV. In addition to this type of application, the versatility of QSR-5 and QSR-15 have also been demonstrated by the fabrication of a Fresnel zone plate lens on the tip of an optical fibre with the goal of improving the coupling of diode laser emission into the fiber. This application clearly shows the capabilities of this process for producing nano-scale patterns on very small area surfaces that are completely unsuitable for spin-coating of the resist. A second demonstration of the resist's capabilities is the patterning of optical diffractive elements directly on the facet of a semiconductor laser. This opens the way to direct patterning on laser diode facets in order to control the emission profile from the device. It has also proven capabilities in the manufacture of delicate photo masks. In their natural state, QSR-5 and QSR-15 are solids at room temperature and are sterol based heterocyclic compounds, with unsaturated bonding capable of cross linking. On their own merit, QSR-5 and QSR-15 are capable of cross linking under electron beam exposure and are comparable in certain properties to

  19. Reconstruction and 3D visualisation based on objective real 3D based documentation.

    PubMed

    Bolliger, Michael J; Buck, Ursula; Thali, Michael J; Bolliger, Stephan A

    2012-09-01

    Reconstructions based directly upon forensic evidence alone are called primary information. Historically this consists of documentation of findings by verbal protocols, photographs and other visual means. Currently modern imaging techniques such as 3D surface scanning and radiological methods (computer tomography, magnetic resonance imaging) are also applied. Secondary interpretation is based on facts and the examiner's experience. Usually such reconstructive expertises are given in written form, and are often enhanced by sketches. However, narrative interpretations can, especially in complex courses of action, be difficult to present and can be misunderstood. In this report we demonstrate the use of graphic reconstruction of secondary interpretation with supporting pictorial evidence, applying digital visualisation (using 'Poser') or scientific animation (using '3D Studio Max', 'Maya') and present methods of clearly distinguishing between factual documentation and examiners' interpretation based on three cases. The first case involved a pedestrian who was initially struck by a car on a motorway and was then run over by a second car. The second case involved a suicidal gunshot to the head with a rifle, in which the trigger was pushed with a rod. The third case dealt with a collision between two motorcycles. Pictorial reconstruction of the secondary interpretation of these cases has several advantages. The images enable an immediate overview, give rise to enhanced clarity, and compel the examiner to look at all details if he or she is to create a complete image.

  20. 3-D model-based vehicle tracking.

    PubMed

    Lou, Jianguang; Tan, Tieniu; Hu, Weiming; Yang, Hao; Maybank, Steven J

    2005-10-01

    This paper aims at tracking vehicles from monocular intensity image sequences and presents an efficient and robust approach to three-dimensional (3-D) model-based vehicle tracking. Under the weak perspective assumption and the ground-plane constraint, the movements of model projection in the two-dimensional image plane can be decomposed into two motions: translation and rotation. They are the results of the corresponding movements of 3-D translation on the ground plane (GP) and rotation around the normal of the GP, which can be determined separately. A new metric based on point-to-line segment distance is proposed to evaluate the similarity between an image region and an instantiation of a 3-D vehicle model under a given pose. Based on this, we provide an efficient pose refinement method to refine the vehicle's pose parameters. An improved EKF is also proposed to track and to predict vehicle motion with a precise kinematics model. Experimental results with both indoor and outdoor data show that the algorithm obtains desirable performance even under severe occlusion and clutter.

  1. Image based 3D city modeling : Comparative study

    NASA Astrophysics Data System (ADS)

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-06-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can't do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city

  2. A novel method of creating a surface micromachined 3D optical assembly for MEMS-based miniaturized FTIR spectrometers

    NASA Astrophysics Data System (ADS)

    Reyes, D.; Schildkraut, E. R.; Kim, J.; Connors, R. F.; Kotidis, P.; Cavicchio, D. J.

    2008-02-01

    This paper describes design, fabrication, and characterization of a miniaturized, Fourier transform infrared (FTIR) spectrometer for the detection and identification of toxic or flammable gases. By measuring the absorption by the target material of IR radiation, unambiguous detection and identification can be achieved. The key component of the device is a micromachined Michelson interferometer capable of modulating light in the 2 - 14 μm spectral region. Two major technical achievements associated with developing a MEMS interferometer module are discussed: development of a micromirror assembly having an order of magnitude larger modulation stroke to approach laboratory instrument-grade spectral resolutions; and assembly of monolithic, millimeter-scale optical components using multi-layer surface micromachining techniques to produce an extremely low cost MEMS interferometer, which has an unprecedented optical throughput. We have manufactured and tested the device. Reported optical characterization results include a precisely aligned, static interferogram acquired from an assembled Michelson interferometer using visible light wavelengths, which promises a high sensitivity FTIR spectrometer for its size.

  3. Effective 3-D surface modeling for geographic information systems

    NASA Astrophysics Data System (ADS)

    Yüksek, K.; Alparslan, M.; Mendi, E.

    2016-01-01

    In this work, we propose a dynamic, flexible and interactive urban digital terrain platform with spatial data and query processing capabilities of geographic information systems, multimedia database functionality and graphical modeling infrastructure. A new data element, called Geo-Node, which stores image, spatial data and 3-D CAD objects is developed using an efficient data structure. The system effectively handles data transfer of Geo-Nodes between main memory and secondary storage with an optimized directional replacement policy (DRP) based buffer management scheme. Polyhedron structures are used in digital surface modeling and smoothing process is performed by interpolation. The experimental results show that our framework achieves high performance and works effectively with urban scenes independent from the amount of spatial data and image size. The proposed platform may contribute to the development of various applications such as Web GIS systems based on 3-D graphics standards (e.g., X3-D and VRML) and services which integrate multi-dimensional spatial information and satellite/aerial imagery.

  4. Nodal-line pairing with 1D-3D coupled Fermi surfaces: A model motivated by Cr-based superconductors

    NASA Astrophysics Data System (ADS)

    Wachtel, Gideon; Kim, Yong Baek

    2016-09-01

    Motivated by the recent discovery of a new family of chromium-based superconductors, we consider a two-band model, where a band of electrons dispersing only in one direction interacts with a band of electrons dispersing in all three directions. Strong 2 kf density fluctuations in the one-dimensional band induces attractive interactions between the three-dimensional electrons, which, in turn, makes the system superconducting. Solving the associated Eliashberg equations, we obtain a gap function which is peaked at the "poles" of the three-dimensional Fermi sphere, and decreases towards the "equator." When strong enough local repulsion is included, the gap actually changes sign around the equator and nodal rings are formed. These nodal rings manifest themselves in several experimentally observable quantities, some of which resemble unconventional observations in the newly discovered superconductors which motivated this work.

  5. High speed 3D surface inspection with digital holography

    NASA Astrophysics Data System (ADS)

    Brunn, Andreas; Aspert, Nicolas; Cuche, Etienne; Emery, Yves; Ettemeyer, Andreas

    2013-01-01

    Digital holography has proven its ability to acquire high accuracy full field 3D data with one single image acquisition. This means that in principle this technique offers the chance to perform 3D serial inspection processes, as well. However, one limitation in digital holography is its limited ability to measure rough surfaces. In the presence of rough surfaces, the magnification of the image has to be increased to capture the required phase information on each camera pixel. However, this leads to significant reduction of inspection speed. If low magnification is selected, the rough surface produces speckles which cannot be treated properly by digital holography algorithms. In this paper, we describe the extension of digital holography to rough surface applications using speckle interferometry technique. This technique is capable of fast inspection of rough surfaces with sub-micrometer accuracy. The principle of this approach is shown and a practical application for 3D surface inspection of wafer cutting processes is given.

  6. Conveying the 3D Shape of Transparent Surfaces Via Texture

    NASA Technical Reports Server (NTRS)

    Interrante, Victoria; Fuchs, Henry; Pizer, Stephen

    1997-01-01

    Transparency can be a useful device for depicting multiple overlapping surfaces in a single image. The challenge is to render the transparent surfaces in such a way that their three-dimensional shape can be readily understood and their depth distance from underlying structures clearly perceived. This paper describes our investigations into the use of sparsely-distributed discrete, opaque texture as an 'artistic device' for more explicitly indicating the relative depth of a transparent surface and for communicating the essential features of its 3D shape in an intuitively meaningful and minimally occluding way. The driving application for this work is the visualization of layered surfaces in radiation therapy treatment planning data, and the technique is illustrated on transparent isointensity surfaces of radiation dose. We describe the perceptual motivation and artistic inspiration for defining a stroke texture that is locally oriented in the direction of greatest normal curvature (and in which individual strokes are of a length proportional to the magnitude of the curvature in the direction they indicate), and discuss several alternative methods for applying this texture to isointensity surfaces defined in a volume. We propose an experimental paradigm for objectively measuring observers' ability to judge the shape and depth of a layered transparent surface, in the course of a task relevant to the needs of radiotherapy treatment planning, and use this paradigm to evaluate the practical effectiveness of our approach through a controlled observer experiment based on images generated from actual clinical data.

  7. Scalable 3D GIS environment managed by 3D-XML-based modeling

    NASA Astrophysics Data System (ADS)

    Shi, Beiqi; Rui, Jianxun; Chen, Neng

    2008-10-01

    Nowadays, the namely 3D GIS technologies become a key factor in establishing and maintaining large-scale 3D geoinformation services. However, with the rapidly increasing size and complexity of the 3D models being acquired, a pressing needed for suitable data management solutions has become apparent. This paper outlines that storage and exchange of geospatial data between databases and different front ends like 3D models, GIS or internet browsers require a standardized format which is capable to represent instances of 3D GIS models, to minimize loss of information during data transfer and to reduce interface development efforts. After a review of previous methods for spatial 3D data management, a universal lightweight XML-based format for quick and easy sharing of 3D GIS data is presented. 3D data management based on XML is a solution meeting the requirements as stated, which can provide an efficient means for opening a new standard way to create an arbitrary data structure and share it over the Internet. To manage reality-based 3D models, this paper uses 3DXML produced by Dassault Systemes. 3DXML uses opening XML schemas to communicate product geometry, structure and graphical display properties. It can be read, written and enriched by standard tools; and allows users to add extensions based on their own specific requirements. The paper concludes with the presentation of projects from application areas which will benefit from the functionality presented above.

  8. 3D scene reconstruction based on 3D laser point cloud combining UAV images

    NASA Astrophysics Data System (ADS)

    Liu, Huiyun; Yan, Yangyang; Zhang, Xitong; Wu, Zhenzhen

    2016-03-01

    It is a big challenge capturing and modeling 3D information of the built environment. A number of techniques and technologies are now in use. These include GPS, and photogrammetric application and also remote sensing applications. The experiment uses multi-source data fusion technology for 3D scene reconstruction based on the principle of 3D laser scanning technology, which uses the laser point cloud data as the basis and Digital Ortho-photo Map as an auxiliary, uses 3DsMAX software as a basic tool for building three-dimensional scene reconstruction. The article includes data acquisition, data preprocessing, 3D scene construction. The results show that the 3D scene has better truthfulness, and the accuracy of the scene meet the need of 3D scene construction.

  9. Derivation of 3-D surface deformation from an integration of InSAR and GNSS measurements based on Akaike's Bayesian Information Criterion

    NASA Astrophysics Data System (ADS)

    Luo, Haipeng; Liu, Yang; Chen, Ting; Xu, Caijun; Wen, Yangmao

    2016-01-01

    We present a new method to derive 3-D surface deformation from an integration of interferometric synthetic aperture radar (InSAR) images and Global Navigation Satellite System (GNSS) observations based on Akaike's Bayesian Information Criterion (ABIC), considering relationship between deformations of neighbouring locations. This method avoids interpolated errors by excluding the interpolation of GNSS into the same spatial resolution as InSAR images and harnesses the data sets and the prior smooth constraints of surface deformation objectively and simultaneously by using ABIC, which were inherently unresolved in previous studies. In particular, we define surface roughness measuring smoothing degree to evaluate the performance of the prior constraints and deduce the formula of the covariance for the estimation errors to estimate the uncertainty of modelled solution. We validate this method using synthetic tests and the 2008 Mw 7.9 Wenchuan earthquake. We find that the optimal weights associated with ABIC minimum are generally at trade-off locations that balance contributions from InSAR, GNSS data sets and the prior constraints. We use this method to evaluate the influence of the interpolated errors from the Ordinary Kriging algorithm on the derivation of surface deformation. Tests show that the interpolated errors may contribute to biasing very large weights imposed on Kriged GNSS data, suggesting that fixing the relative weights is required in this case. We also make a comparison with SISTEM method, indicating that our method allows obtaining better estimations even with sparse GNSS observations. In addition, this method can be generalized to provide a solution for situations where some types of data sets are lacking and can be exploited further to account for data sets such as the integration of displacements along radar lines and offsets along satellite tracks.

  10. Colored 3D surface reconstruction using Kinect sensor

    NASA Astrophysics Data System (ADS)

    Guo, Lian-peng; Chen, Xiang-ning; Chen, Ying; Liu, Bin

    2015-03-01

    A colored 3D surface reconstruction method which effectively fuses the information of both depth and color image using Microsoft Kinect is proposed and demonstrated by experiment. Kinect depth images are processed with the improved joint-bilateral filter based on region segmentation which efficiently combines the depth and color data to improve its quality. The registered depth data are integrated to achieve a surface reconstruction through the colored truncated signed distance fields presented in this paper. Finally, the improved ray casting for rendering full colored surface is implemented to estimate color texture of the reconstruction object. Capturing the depth and color images of a toy car, the improved joint-bilateral filter based on region segmentation is used to improve the quality of depth images and the peak signal-to-noise ratio (PSNR) is approximately 4.57 dB, which is better than 1.16 dB of the joint-bilateral filter. The colored construction results of toy car demonstrate the suitability and ability of the proposed method.

  11. Scattering of electromagnetic waves from 3D multilayer random rough surfaces based on the second-order small perturbation method: energy conservation, reflectivity, and emissivity.

    PubMed

    Sanamzadeh, Mohammadreza; Tsang, Leung; Johnson, Joel T; Burkholder, Robert J; Tan, Shurun

    2017-03-01

    A theoretical investigation of energy conservation, reflectivity, and emissivity in the scattering of electromagnetic waves from 3D multilayer media with random rough interfaces using the second-order small perturbation method (SPM2) is presented. The approach is based on the extinction theorem and develops integral equations for surface fields in the spectral domain. Using the SPM2, we calculate the scattered and transmitted coherent fields and incoherent fields. Reflected and transmitted powers are then found in the form of 2D integrations over wavenumber in the spectral domain. In the integrand, there is a summation over the spectral densities of each of the rough interfaces with each weighted by a corresponding kernel function. We show in this paper that there exists a "strong" condition of energy conservation in that the kernel functions multiplying the spectral density of each interface obey energy conservation exactly. This means that energy is conserved independent of the roughness spectral densities of the rough surfaces. Results of this strong condition are illustrated numerically for up to 50 rough interfaces without requiring specification of surface roughness properties. Two examples are illustrated. One is a multilayer configuration having weak contrasts between adjacent layers, random layer thicknesses, and randomly generated permittivity profiles. The second example is a photonic crystal of periodically alternating permittivities of larger dielectric contrast. The methodology is applied to study the effect of roughness on the brightness temperatures of the Antarctic ice sheet, which is characterized by layers of ice with permittivity fluctuations in addition to random rough interfaces. The results show that the influence of roughness can significantly increase horizontally polarized thermal emission while leaving vertically polarized emissions relatively unaffected.

  12. A 3D surface imaging system for assessing human obesity

    NASA Astrophysics Data System (ADS)

    Xu, B.; Yu, W.; Yao, M.; Yao, X.; Li, Q.; Pepper, M. R.; Freeland-Graves, J. H.

    2009-08-01

    The increasing prevalence of obesity suggests a need to develop a convenient, reliable and economical tool for assessment of this condition. Three-dimensional (3D) body surface imaging has emerged as an exciting technology for estimation of body composition. This paper presents a new 3D body imaging system, which was designed for enhanced portability, affordability, and functionality. In this system, stereo vision technology was used to satisfy the requirements for a simple hardware setup and fast image acquisitions. The portability of the system was created via a two-stand configuration, and the accuracy of body volume measurements was improved by customizing stereo matching and surface reconstruction algorithms that target specific problems in 3D body imaging. Body measurement functions dedicated to body composition assessment also were developed. The overall performance of the system was evaluated in human subjects by comparison to other conventional anthropometric methods, as well as air displacement plethysmography, for body fat assessment.

  13. Geological interpretation and analysis of surface based, spatially referenced planetary imagery data using PRoGIS 2.0 and Pro3D.

    NASA Astrophysics Data System (ADS)

    Barnes, R.; Gupta, S.; Giordano, M.; Morley, J. G.; Muller, J. P.; Tao, Y.; Sprinks, J.; Traxler, C.; Hesina, G.; Ortner, T.; Sander, K.; Nauschnegg, B.; Paar, G.; Willner, K.; Pajdla, T.

    2015-10-01

    We apply the capabilities of the geospatial environment PRoGIS 2.0 and the real time rendering viewer PRo3D to geological analysis of NASA's Mars Exploration Rover-B (MER-B Opportunity rover) and Mars Science Laboratory (MSL Curiosity rover) datasets. Short baseline and serendipitous long baseline stereo Pancam rover imagery are used to create 3D point clouds which can be combined with super-resolution images derived from Mars Reconnaissance Orbiter HiRISE orbital data, andsuper-resolution outcrop images derived from MER Pancam, as well as hand-lens scale images for geology and outcrop characterization at all scales. Data within the PRoViDE database are presented and accessed through the PRoGIS interface. Simple geological measurement tools are implemented within the PRoGIS and PRo3D web software to accurately measure the dip and strike of bedding in outcrops, create detailed stratigraphic logs for correlation between the areas investigated, and to develop realistic 3D models for the characterization of planetary surface processes. Annotation tools are being developed to aid discussion and dissemination of the observations within the planetary science community.

  14. Study of the counting efficiency of a WBC setup by using a computational 3D human body library in sitting position based on polygonal mesh surfaces.

    PubMed

    Fonseca, T C Ferreira; Bogaerts, R; Lebacq, A L; Mihailescu, C L; Vanhavere, F

    2014-04-01

    A realistic computational 3D human body library, called MaMP and FeMP (Male and Female Mesh Phantoms), based on polygonal mesh surface geometry, has been created to be used for numerical calibration of the whole body counter (WBC) system of the nuclear power plant (NPP) in Doel, Belgium. The main objective was to create flexible computational models varying in gender, body height, and mass for studying the morphology-induced variation of the detector counting efficiency (CE) and reducing the measurement uncertainties. First, the counting room and an HPGe detector were modeled using MCNPX (Monte Carlo radiation transport code). The validation of the model was carried out for different sample-detector geometries with point sources and a physical phantom. Second, CE values were calculated for a total of 36 different mesh phantoms in a seated position using the validated Monte Carlo model. This paper reports on the validation process of the in vivo whole body system and the CE calculated for different body heights and weights. The results reveal that the CE is strongly dependent on the individual body shape, size, and gender and may vary by a factor of 1.5 to 3 depending on the morphology aspects of the individual to be measured.

  15. The 3D visualization technology research of submarine pipeline based Horde3D GameEngine

    NASA Astrophysics Data System (ADS)

    Yao, Guanghui; Ma, Xiushui; Chen, Genlang; Ye, Lingjian

    2013-10-01

    With the development of 3D display and virtual reality technology, its application gets more and more widespread. This paper applies 3D display technology to the monitoring of submarine pipeline. We reconstruct the submarine pipeline and its surrounding submarine terrain in computer using Horde3D graphics rendering engine on the foundation database "submarine pipeline and relative landforms landscape synthesis database" so as to display the virtual scene of submarine pipeline based virtual reality and show the relevant data collected from the monitoring of submarine pipeline.

  16. 3D SEM for surface topography quantification - a case study on dental surfaces

    NASA Astrophysics Data System (ADS)

    Glon, F.; Flys, O.; Lööf, P.-J.; Rosén, B.-G.

    2014-03-01

    3D analysis of surface topography is becoming a more used tool for industry and research. New ISO standards are being launched to assist in quantifying engineering surfaces. The traditional optical measuring instrumentation used for 3D surface characterization has been optical interferometers and confocal based instrumentation. However, the resolution here is limited in the lateral dimension to the wavelength of visible light to about 500 nm. The great advantage using the SEM for topography measurements is the high flexibility to zoom from low magnifications and locating interesting areas to high magnification of down to nanometer large surface features within seconds. This paper presents surface characterization of dental implant micro topography. 3D topography data was created from SEM images using commercial photogrammetric software. A coherence scanning interferometer was used for reference measurements to compare with the 3D SEM measurements on relocated areas. As a result of this study, measurements emphasizes that the correlation between the accepted CSI measurements and the new technology represented by photogrammetry based on SEM images for many areal characterization parameters are around or less than 20%. The importance of selecting sampling and parameter sensitivity to varying sampling is high-lighted. Future work includes a broader study of limitations of the photogrammetry technique on certified micro-geometries and more application surfaces at different scales.

  17. Synthesizing 3D Surfaces from Parameterized Strip Charts

    NASA Technical Reports Server (NTRS)

    Robinson, Peter I.; Gomez, Julian; Morehouse, Michael; Gawdiak, Yuri

    2004-01-01

    We believe 3D information visualization has the power to unlock new levels of productivity in the monitoring and control of complex processes. Our goal is to provide visual methods to allow for rapid human insight into systems consisting of thousands to millions of parameters. We explore this hypothesis in two complex domains: NASA program management and NASA International Space Station (ISS) spacecraft computer operations. We seek to extend a common form of visualization called the strip chart from 2D to 3D. A strip chart can display the time series progression of a parameter and allows for trends and events to be identified. Strip charts can be overlayed when multiple parameters need to visualized in order to correlate their events. When many parameters are involved, the direct overlaying of strip charts can become confusing and may not fully utilize the graphing area to convey the relationships between the parameters. We provide a solution to this problem by generating 3D surfaces from parameterized strip charts. The 3D surface utilizes significantly more screen area to illustrate the differences in the parameters and the overlayed strip charts, and it can rapidly be scanned by humans to gain insight. The selection of the third dimension must be a parallel or parameterized homogenous resource in the target domain, defined using a finite, ordered, enumerated type, and not a heterogeneous type. We demonstrate our concepts with examples from the NASA program management domain (assessing the state of many plans) and the computers of the ISS (assessing the state of many computers). We identify 2D strip charts in each domain and show how to construct the corresponding 3D surfaces. The user can navigate the surface, zooming in on regions of interest, setting a mark and drilling down to source documents from which the data points have been derived. We close by discussing design issues, related work, and implementation challenges.

  18. 3D surface configuration modulates 2D symmetry detection.

    PubMed

    Chen, Chien-Chung; Sio, Lok-Teng

    2015-02-01

    We investigated whether three-dimensional (3D) information in a scene can affect symmetry detection. The stimuli were random dot patterns with 15% dot density. We measured the coherence threshold, or the proportion of dots that were the mirror reflection of the other dots in the other half of the image about a central vertical axis, at 75% accuracy with a 2AFC paradigm under various 3D configurations produced by the disparity between the left and right eye images. The results showed that symmetry detection was difficult when the corresponding dots across the symmetry axis were on different frontoparallel or inclined planes. However, this effect was not due to a difference in distance, as the observers could detect symmetry on a slanted surface, where the depth of the two sides of the symmetric axis was different. The threshold was reduced for a hinge configuration where the join of two slanted surfaces coincided with the axis of symmetry. Our result suggests that the detection of two-dimensional (2D) symmetry patterns is subject to the 3D configuration of the scene; and that coplanarity across the symmetry axis and consistency between the 2D pattern and 3D structure are important factors for symmetry detection.

  19. Objective breast symmetry evaluation using 3-D surface imaging.

    PubMed

    Eder, Maximilian; Waldenfels, Fee V; Swobodnik, Alexandra; Klöppel, Markus; Pape, Ann-Kathrin; Schuster, Tibor; Raith, Stefan; Kitzler, Elena; Papadopulos, Nikolaos A; Machens, Hans-Günther; Kovacs, Laszlo

    2012-04-01

    This study develops an objective breast symmetry evaluation using 3-D surface imaging (Konica-Minolta V910(®) scanner) by superimposing the mirrored left breast over the right and objectively determining the mean 3-D contour difference between the 2 breast surfaces. 3 observers analyzed the evaluation protocol precision using 2 dummy models (n = 60), 10 test subjects (n = 300), clinically tested it on 30 patients (n = 900) and compared it to established 2-D measurements on 23 breast reconstructive patients using the BCCT.core software (n = 690). Mean 3-D evaluation precision, expressed as the coefficient of variation (VC), was 3.54 ± 0.18 for all human subjects without significant intra- and inter-observer differences (p > 0.05). The 3-D breast symmetry evaluation is observer independent, significantly more precise (p < 0.001) than the BCCT.core software (VC = 6.92 ± 0.88) and may play a part in an objective surgical outcome analysis after incorporation into clinical practice.

  20. Pattern based 3D image Steganography

    NASA Astrophysics Data System (ADS)

    Thiyagarajan, P.; Natarajan, V.; Aghila, G.; Prasanna Venkatesan, V.; Anitha, R.

    2013-03-01

    This paper proposes a new high capacity Steganographic scheme using 3D geometric models. The novel algorithm re-triangulates a part of a triangle mesh and embeds the secret information into newly added position of triangle meshes. Up to nine bits of secret data can be embedded into vertices of a triangle without causing any changes in the visual quality and the geometric properties of the cover image. Experimental results show that the proposed algorithm is secure, with high capacity and low distortion rate. Our algorithm also resists against uniform affine transformations such as cropping, rotation and scaling. Also, the performance of the method is compared with other existing 3D Steganography algorithms. [Figure not available: see fulltext.

  1. Molecular cartography of the human skin surface in 3D.

    PubMed

    Bouslimani, Amina; Porto, Carla; Rath, Christopher M; Wang, Mingxun; Guo, Yurong; Gonzalez, Antonio; Berg-Lyon, Donna; Ackermann, Gail; Moeller Christensen, Gitte Julie; Nakatsuji, Teruaki; Zhang, Lingjuan; Borkowski, Andrew W; Meehan, Michael J; Dorrestein, Kathleen; Gallo, Richard L; Bandeira, Nuno; Knight, Rob; Alexandrov, Theodore; Dorrestein, Pieter C

    2015-04-28

    The human skin is an organ with a surface area of 1.5-2 m(2) that provides our interface with the environment. The molecular composition of this organ is derived from host cells, microbiota, and external molecules. The chemical makeup of the skin surface is largely undefined. Here we advance the technologies needed to explore the topographical distribution of skin molecules, using 3D mapping of mass spectrometry data and microbial 16S rRNA amplicon sequences. Our 3D maps reveal that the molecular composition of skin has diverse distributions and that the composition is defined not only by skin cells and microbes but also by our daily routines, including the application of hygiene products. The technological development of these maps lays a foundation for studying the spatial relationships of human skin with hygiene, the microbiota, and environment, with potential for developing predictive models of skin phenotypes tailored to individual health.

  2. Molecular cartography of the human skin surface in 3D

    PubMed Central

    Bouslimani, Amina; Porto, Carla; Rath, Christopher M.; Wang, Mingxun; Guo, Yurong; Gonzalez, Antonio; Berg-Lyon, Donna; Ackermann, Gail; Moeller Christensen, Gitte Julie; Nakatsuji, Teruaki; Zhang, Lingjuan; Borkowski, Andrew W.; Meehan, Michael J.; Dorrestein, Kathleen; Gallo, Richard L.; Bandeira, Nuno; Knight, Rob; Alexandrov, Theodore; Dorrestein, Pieter C.

    2015-01-01

    The human skin is an organ with a surface area of 1.5–2 m2 that provides our interface with the environment. The molecular composition of this organ is derived from host cells, microbiota, and external molecules. The chemical makeup of the skin surface is largely undefined. Here we advance the technologies needed to explore the topographical distribution of skin molecules, using 3D mapping of mass spectrometry data and microbial 16S rRNA amplicon sequences. Our 3D maps reveal that the molecular composition of skin has diverse distributions and that the composition is defined not only by skin cells and microbes but also by our daily routines, including the application of hygiene products. The technological development of these maps lays a foundation for studying the spatial relationships of human skin with hygiene, the microbiota, and environment, with potential for developing predictive models of skin phenotypes tailored to individual health. PMID:25825778

  3. An efficient and robust 3D mesh compression based on 3D watermarking and wavelet transform

    NASA Astrophysics Data System (ADS)

    Zagrouba, Ezzeddine; Ben Jabra, Saoussen; Didi, Yosra

    2011-06-01

    The compression and watermarking of 3D meshes are very important in many areas of activity including digital cinematography, virtual reality as well as CAD design. However, most studies on 3D watermarking and 3D compression are done independently. To verify a good trade-off between protection and a fast transfer of 3D meshes, this paper proposes a new approach which combines 3D mesh compression with mesh watermarking. This combination is based on a wavelet transformation. In fact, the used compression method is decomposed to two stages: geometric encoding and topologic encoding. The proposed approach consists to insert a signature between these two stages. First, the wavelet transformation is applied to the original mesh to obtain two components: wavelets coefficients and a coarse mesh. Then, the geometric encoding is done on these two components. The obtained coarse mesh will be marked using a robust mesh watermarking scheme. This insertion into coarse mesh allows obtaining high robustness to several attacks. Finally, the topologic encoding is applied to the marked coarse mesh to obtain the compressed mesh. The combination of compression and watermarking permits to detect the presence of signature after a compression of the marked mesh. In plus, it allows transferring protected 3D meshes with the minimum size. The experiments and evaluations show that the proposed approach presents efficient results in terms of compression gain, invisibility and robustness of the signature against of many attacks.

  4. SummitView 1.0: a code to automatically generate 3D solid models of surface micro-machining based MEMS designs.

    SciTech Connect

    McBride, Cory L. (Elemental Technologies, American Fort, UT); Yarberry, Victor R.; Schmidt, Rodney Cannon; Meyers, Ray J.

    2006-11-01

    This report describes the SummitView 1.0 computer code developed at Sandia National Laboratories. SummitView is designed to generate a 3D solid model, amenable to visualization and meshing, that represents the end state of a microsystem fabrication process such as the SUMMiT (Sandia Ultra-Planar Multilevel MEMS Technology) V process. Functionally, SummitView performs essentially the same computational task as an earlier code called the 3D Geometry modeler [1]. However, because SummitView is based on 2D instead of 3D data structures and operations, it has significant speed and robustness advantages. As input it requires a definition of both the process itself and the collection of individual 2D masks created by the designer and associated with each of the process steps. The definition of the process is contained in a special process definition file [2] and the 2D masks are contained in MEM format files [3]. The code is written in C++ and consists of a set of classes and routines. The classes represent the geometric data and the SUMMiT V process steps. Classes are provided for the following process steps: Planar Deposition, Planar Etch, Conformal Deposition, Dry Etch, Wet Etch and Release Etch. SummitView is built upon the 2D Boolean library GBL-2D [4], and thus contains all of that library's functionality.

  5. Structured Light-Based 3D Reconstruction System for Plants.

    PubMed

    Nguyen, Thuy Tuong; Slaughter, David C; Max, Nelson; Maloof, Julin N; Sinha, Neelima

    2015-07-29

    Camera-based 3D reconstruction of physical objects is one of the most popular computer vision trends in recent years. Many systems have been built to model different real-world subjects, but there is lack of a completely robust system for plants. This paper presents a full 3D reconstruction system that incorporates both hardware structures (including the proposed structured light system to enhance textures on object surfaces) and software algorithms (including the proposed 3D point cloud registration and plant feature measurement). This paper demonstrates the ability to produce 3D models of whole plants created from multiple pairs of stereo images taken at different viewing angles, without the need to destructively cut away any parts of a plant. The ability to accurately predict phenotyping features, such as the number of leaves, plant height, leaf size and internode distances, is also demonstrated. Experimental results show that, for plants having a range of leaf sizes and a distance between leaves appropriate for the hardware design, the algorithms successfully predict phenotyping features in the target crops, with a recall of 0.97 and a precision of 0.89 for leaf detection and less than a 13-mm error for plant size, leaf size and internode distance.

  6. Structured Light-Based 3D Reconstruction System for Plants

    PubMed Central

    Nguyen, Thuy Tuong; Slaughter, David C.; Max, Nelson; Maloof, Julin N.; Sinha, Neelima

    2015-01-01

    Camera-based 3D reconstruction of physical objects is one of the most popular computer vision trends in recent years. Many systems have been built to model different real-world subjects, but there is lack of a completely robust system for plants.This paper presents a full 3D reconstruction system that incorporates both hardware structures (including the proposed structured light system to enhance textures on object surfaces) and software algorithms (including the proposed 3D point cloud registration and plant feature measurement). This paper demonstrates the ability to produce 3D models of whole plants created from multiple pairs of stereo images taken at different viewing angles, without the need to destructively cut away any parts of a plant. The ability to accurately predict phenotyping features, such as the number of leaves, plant height, leaf size and internode distances, is also demonstrated. Experimental results show that, for plants having a range of leaf sizes and a distance between leaves appropriate for the hardware design, the algorithms successfully predict phenotyping features in the target crops, with a recall of 0.97 and a precision of 0.89 for leaf detection and less than a 13-mm error for plant size, leaf size and internode distance. PMID:26230701

  7. Investigation Into the Accuracy of 3D Surface Roughness Characteristics

    NASA Astrophysics Data System (ADS)

    Kumermanis, M.; Rudzitis, J.; Mozga, N.; Ancans, A.; Grislis, A.

    2014-04-01

    The existing standards for surface roughness cover only two dimensions, while in reality this is three-dimensional (3D). In particular, the 3D surface roughness parameters are important for solving the contact surface mechanics problems as related to the accuracy of 3D surface roughness characteristics. One of the most important factors for determination of 3D characteristics is the number of data points (NDP) on the x- and y-axes (i.e. in cut-off length). The NDP has a profound effect on the accuracy of measurement results, measuring time and volume of the output data (especially along the y-axis, where the NDP is identical to the number of parallel profiles). At a too small NDP the results will be incorrect and with too broad scatter, while a too large NDP - though not enlarging the range of basic information - considerably increases the measuring time. Therefore, the aim of the work was to find the optimal NDP for such surface processing methods as grinding, spark erosion and shot methods of surface treatment. Eksistējošie virsmas raupjuma standarti apskata virsmas raupjumu tikai divās dimensijās. Tomēr reālais virsmas raupjums pēc savas dabas ir trīsdimensiju (3D) objekts. Līdz ar to virsmas raupjums ir jāraksturo ar 3D parametriem. Un no šo parametru noteikšanas precizitātes ir atkarīgi tālākie virsmas aprēķini, piemēram, virsmu kontaktēšanās process. Viens no svarīgākajiem faktoriem, raksturojot virsmas raupjumu 3D, pielietojot kontakta tipa mēriekārtas, ir datu punktu skaits pa abām mērīšanas asīm x un y. Ar datu punktu skaitu mēs saprotam to skaitu mērīšanas bāzes garumā. Datu punktu skaits būtiski ietekmē sagaidāmo mērījumu rezultātu precizitāti, mērīšanai nepieciešamo laiku un izejas datu faila izmērus (sevišķi y-ass virzienā, kur katrs datu punkts ir paralēls profils). Datu punktu skaitam ir jābūt optimālam. Pārāk mazs punktu skaits noved pie neprecīziem rezultātiem un lielas to izkliedes, savuk

  8. Visualizing 3D velocity fields near contour surfaces

    SciTech Connect

    Max, N.; Crawfis, R.; Grant, C.

    1994-03-01

    Vector field rendering is difficult in 3D because the vector icons overlap and hide each other. We propose four different techniques for visualizing vector fields only near surfaces. The first uses motion blurred particles in a thickened region around the surface. The second uses a voxel grid to contain integral curves of the vector field. The third uses many antialiased lines through the surface, and the fourth uses hairs sprouting from the surface and then bending in the direction of the vector field. All the methods use the graphite pipeline, allowing real time rotation and interaction, and the first two methods can animate the texture to move in the flow determined by the velocity field.

  9. 3D Surface Topology Guides Stem Cell Adhesion and Differentiation

    PubMed Central

    Viswanathan, Priyalakshmi; Ondeck, Matthew G.; Chirasatitsin, Somyot; Nghamkham, Kamolchanok; Reilly, Gwendolen C.; Engler, Adam J.; Battaglia, Giuseppe

    2015-01-01

    Polymerized high internal phase emulsion (polyHIPE) foams are extremely versatile materials for investigating cell-substrate interactions in vitro. Foam morphologies can be controlled by polymerization conditions to result in either open or closed pore structures with different levels of connectivity, consequently enabling the comparison between 2D and 3D matrices using the same substrate with identical surface chemistry conditions. Additionally, here we achieve the control of pore surface topology (i.e. how different ligands are clustered together) using amphiphilic block copolymers as emulsion stabilisers. We demonstrate that adhesion of human mesenchymal progenitor (hES-MP) cells cultured on polyHIPE foams is dependent on foam surface topology and chemistry but is independent of porosity and interconnectivity. We also demonstrate that the interconnectivity, architecture and surface topology of the foams has an effect on the osteogenic differentiation potential of hES-MP cells. Together these data demonstrate that the adhesive heterogeneity of a 3D scaffold could regulate not only mesenchymal stem cell attachment but also cell behavior in the absence of soluble growth factors. PMID:25818420

  10. OCT 3-D surface topography of isolated human crystalline lenses

    PubMed Central

    Sun, Mengchan; Birkenfeld, Judith; de Castro, Alberto; Ortiz, Sergio; Marcos, Susana

    2014-01-01

    Quantitative 3-D Optical Coherence Tomography was used to measure surface topography of 36 isolated human lenses, and to evaluate the relationship between anterior and posterior lens surface shape and their changes with age. All lens surfaces were fitted to 6th order Zernike polynomials. Astigmatism was the predominant surface aberration in anterior and posterior lens surfaces (accounting for ~55% and ~63% of the variance respectively), followed by spherical terms, coma, trefoil and tetrafoil. The amount of anterior and posterior surface astigmatism did not vary significantly with age. The relative angle between anterior and posterior surface astigmatism axes was on average 36.5 deg, tended to decrease with age, and was >45 deg in 36.1% lenses. The anterior surface RMS spherical term, RMS coma and 3rd order RMS decreased significantly with age. In general, there was a statistically significant correlation between the 3rd and 4th order terms of the anterior and posterior surfaces. Understanding the coordination of anterior and posterior lens surface geometries and their topographical changes with age sheds light into the role of the lens in the optical properties of the eye and the lens aging mechanism. PMID:25360371

  11. 3D multifocus astigmatism and compressed sensing (3D MACS) based superresolution reconstruction

    PubMed Central

    Huang, Jiaqing; Sun, Mingzhai; Gumpper, Kristyn; Chi, Yuejie; Ma, Jianjie

    2015-01-01

    Single molecule based superresolution techniques (STORM/PALM) achieve nanometer spatial resolution by integrating the temporal information of the switching dynamics of fluorophores (emitters). When emitter density is low for each frame, they are located to the nanometer resolution. However, when the emitter density rises, causing significant overlapping, it becomes increasingly difficult to accurately locate individual emitters. This is particularly apparent in three dimensional (3D) localization because of the large effective volume of the 3D point spread function (PSF). The inability to precisely locate the emitters at a high density causes poor temporal resolution of localization-based superresolution technique and significantly limits its application in 3D live cell imaging. To address this problem, we developed a 3D high-density superresolution imaging platform that allows us to precisely locate the positions of emitters, even when they are significantly overlapped in three dimensional space. Our platform involves a multi-focus system in combination with astigmatic optics and an ℓ1-Homotopy optimization procedure. To reduce the intrinsic bias introduced by the discrete formulation of compressed sensing, we introduced a debiasing step followed by a 3D weighted centroid procedure, which not only increases the localization accuracy, but also increases the computation speed of image reconstruction. We implemented our algorithms on a graphic processing unit (GPU), which speeds up processing 10 times compared with central processing unit (CPU) implementation. We tested our method with both simulated data and experimental data of fluorescently labeled microtubules and were able to reconstruct a 3D microtubule image with 1000 frames (512×512) acquired within 20 seconds. PMID:25798314

  12. Anatomy-based 3D skeleton extraction from femur model.

    PubMed

    Gharenazifam, Mina; Arbabi, Ehsan

    2014-11-01

    Using 3D models of bones can highly improve accuracy and reliability of orthopaedic evaluation. However, it may impose excessive computational load. This article proposes a fully automatic method for extracting a compact model of the femur from its 3D model. The proposed method works by extracting a 3D skeleton based on the clinical parameters of the femur. Therefore, in addition to summarizing a 3D model of the bone, the extracted skeleton would preserve important clinical and anatomical information. The proposed method has been applied on 3D models of 10 femurs and the results have been evaluated for different resolutions of data.

  13. A flexible fast 3D profilometry based on modulation measurement

    NASA Astrophysics Data System (ADS)

    Dou, Yunfu; Su, Xianyu; Chen, Yanfei; Wang, Ying

    2011-03-01

    This paper proposes a flexible fast profilometry based on modulation measurement. Two orthogonal gratings through a beam splitter are vertically projected on an object surface, and the measured object is placed between the imaging planes of the two gratings. Then the image of the object surface modulated by the orthogonal gratings can be obtained by a CCD camera in the same direction as the grating projection. This image is processed by the operations consisting of performing the Fourier transform, spatial frequency filtering and inverse Fourier transform. Using the modulation distributions of two grating patterns, we can reconstruct the 3D shape of the object. In the measurement process, we only need to capture one fringe pattern, so it is faster than the MMP and remains the advantages of it. In the article, the principle of this method, the setup of the measurement system, some simulations and primary experiment results are given. The simulative and experimental result proves it can restore the 3D shape of the complex object fast and comparatively accurate. Because only one fringe pattern is needed in the testing, our method has a promising extensive application prospect in real-time acquiring and dynamic measurement of 3D data of complex objects.

  14. VIRTOPSY--scientific documentation, reconstruction and animation in forensic: individual and real 3D data based geo-metric approach including optical body/object surface and radiological CT/MRI scanning.

    PubMed

    Thali, Michael J; Braun, Marcel; Buck, Ursula; Aghayev, Emin; Jackowski, Christian; Vock, Peter; Sonnenschein, Martin; Dirnhofer, Richard

    2005-03-01

    Until today, most of the documentation of forensic relevant medical findings is limited to traditional 2D photography, 2D conventional radiographs, sketches and verbal description. There are still some limitations of the classic documentation in forensic science especially if a 3D documentation is necessary. The goal of this paper is to demonstrate new 3D real data based geo-metric technology approaches. This paper present approaches to a 3D geo-metric documentation of injuries on the body surface and internal injuries in the living and deceased cases. Using modern imaging methods such as photogrammetry, optical surface and radiological CT/MRI scanning in combination it could be demonstrated that a real, full 3D data based individual documentation of the body surface and internal structures is possible in a non-invasive and non-destructive manner. Using the data merging/fusing and animation possibilities, it is possible to answer reconstructive questions of the dynamic development of patterned injuries (morphologic imprints) and to evaluate the possibility, that they are matchable or linkable to suspected injury-causing instruments. For the first time, to our knowledge, the method of optical and radiological 3D scanning was used to document the forensic relevant injuries of human body in combination with vehicle damages. By this complementary documentation approach, individual forensic real data based analysis and animation were possible linking body injuries to vehicle deformations or damages. These data allow conclusions to be drawn for automobile accident research, optimization of vehicle safety (pedestrian and passenger) and for further development of crash dummies. Real 3D data based documentation opens a new horizon for scientific reconstruction and animation by bringing added value and a real quality improvement in forensic science.

  15. Depth propagation and surface construction in 3-D vision.

    PubMed

    Georgeson, Mark A; Yates, Tim A; Schofield, Andrew J

    2009-01-01

    In stereo vision, regions with ambiguous or unspecified disparity can acquire perceived depth from unambiguous regions. This has been called stereo capture, depth interpolation or surface completion. We studied some striking induced depth effects suggesting that depth interpolation and surface completion are distinct stages of visual processing. An inducing texture (2-D Gaussian noise) had sinusoidal modulation of disparity, creating a smooth horizontal corrugation. The central region of this surface was replaced by various test patterns whose perceived corrugation was measured. When the test image was horizontal 1-D noise, shown to one eye or to both eyes without disparity, it appeared corrugated in much the same way as the disparity-modulated (DM) flanking regions. But when the test image was 2-D noise, or vertical 1-D noise, little or no depth was induced. This suggests that horizontal orientation was a key factor. For a horizontal sine-wave luminance grating, strong depth was induced, but for a square-wave grating, depth was induced only when its edges were aligned with the peaks and troughs of the DM flanking surface. These and related results suggest that disparity (or local depth) propagates along horizontal 1-D features, and then a 3-D surface is constructed from the depth samples acquired. The shape of the constructed surface can be different from the inducer, and so surface construction appears to operate on the results of a more local depth propagation process.

  16. Variational approach to reconstruct surface from sparse and nonparallel contours in freehand 3D ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Deng, Shuangcheng; Jiang, Lipei; Cao, Yingyu; Zhang, Junwen; Zheng, Haiyang

    2012-01-01

    The 3D reconstruction for freehand 3D ultrasound is a challenging issue because the recorded B-scans are not only sparse, but also non-parallel (actually they may intersect each other). Conventional volume reconstruction methods can't reconstruct sparse data efficiently while not introducing geometrical artifacts, and conventional surface reconstruction methods can't reconstruct surfaces from contours that are arbitrarily oriented in 3D space. We developed a new surface reconstruction method for freehand 3D ultrasound. It is based on variational implicit function which is presented by Greg Turk for shape transformation. In the new method, we first constructed on- & off-surface constraints from the segmented contours of all recorded B-scans, then used a variational interpolation technique to get a single implicit function in 3D. Finally, the implicit function was evaluated to extract the zero-valued surface as reconstruction result. Two experiment was conducted to assess our variational surface reconstruction method, and the experiment results have shown that the new method is capable of reconstructing surface smoothly from sparse contours which can be arbitrarily oriented in 3D space.

  17. Wear Analysis of Thermal Spray Coatings on 3D Surfaces

    NASA Astrophysics Data System (ADS)

    Tillmann, W.; Luo, W.; Selvadurai, U.

    2014-01-01

    Even though the application of thermal spray coatings on complex geometries gained a greater interest in the last decade, the effect of different geometrical features on the wear behavior is still ill-defined. In this study, the wear resistance of FTC-FeCSiMn coated 3D surfaces was investigated. The wear test was carried out by means of two innovative testing procedures. The first test is a Pin-on-Tubes test where the rotating motion is realized by a lathe chuck. The specimens in the second test were fixed on the table and a robot arm operated the pin. This wear test was applied on specimens with concave or convex surfaces. The residual stresses, which were determined by means of an incremental hole-drilling method, show a dependency on the substrate geometry. The obtained stresses were put in relation to the different radii. After the wear test, a 3D-profilometer determined the wear volume and the sections of the coatings were characterized by a scanning electron microscope. The results indicate that the wear resistance is strongly influenced by the geometry of the substrate.

  18. 3D Additive Construction with Regolith for Surface Systems

    NASA Technical Reports Server (NTRS)

    Mueller, Robert P.

    2014-01-01

    Planetary surface exploration on Asteroids, the Moon, Mars and Martian Moons will require the stabilization of loose, fine, dusty regolith to avoid the effects of vertical lander rocket plume impingement, to keep abrasive and harmful dust from getting lofted and for dust free operations. In addition, the same regolith stabilization process can be used for 3 Dimensional ( 3D) printing, additive construction techniques by repeating the 2D stabilization in many vertical layers. This will allow in-situ construction with regolith so that materials will not have to be transported from Earth. Recent work in the NASA Kennedy Space Center (KSC) Surface Systems Office (NE-S) Swamp Works and at the University of Southern California (USC) under two NASA Innovative Advanced Concept (NIAC) awards have shown promising results with regolith (crushed basalt rock) materials for in-situ heat shields, bricks, landing/launch pads, berms, roads, and other structures that could be fabricated using regolith that is sintered or mixed with a polymer binder. The technical goals and objectives of this project are to prove the feasibility of 3D printing additive construction using planetary regolith simulants and to show that they have structural integrity and practical applications in space exploration.

  19. Characterisation of the surface structure of 3D printed scaffolds for cell infiltration and surgical suturing.

    PubMed

    Ruiz-Cantu, Laura; Gleadall, Andrew; Faris, Callum; Segal, Joel; Shakesheff, Kevin; Yang, Jing

    2016-03-01

    3D printing is of great interest for tissue engineering scaffolds due to the ability to form complex geometries and control internal structures, including porosity and pore size. The porous structure of scaffolds plays an important role in cell ingrowth and nutrition infusion. Although the internal porosity and pore size of 3D printed scaffolds have been frequently studied, the surface porosity and pore size, which are critical for cell infiltration and mass transport, have not been investigated. The surface geometry can differ considerably from the internal scaffold structure depending on the 3D printing process. It is vital to be able to control the surface geometry of scaffolds as well as the internal structure to fabricate optimal architectures. This work presents a method to control the surface porosity and pore size of 3D printed scaffolds. Six scaffold designs have been printed with surface porosities ranging from 3% to 21%. We have characterised the overall scaffold porosity and surface porosity using optical microscopy and microCT. It has been found that surface porosity has a significant impact on cell infiltration and proliferation. In addition, the porosity of the surface has been found to have an effect on mechanical properties and on the forces required to penetrate the scaffold with a surgical suturing needle. To the authors' knowledge, this study is the first to investigate the surface geometry of extrusion-based 3D printed scaffolds and demonstrates the importance of surface geometry in cell infiltration and clinical manipulation.

  20. Edge structure preserving 3D image denoising by local surface approximation.

    PubMed

    Qiu, Peihua; Mukherjee, Partha Sarathi

    2012-08-01

    In various applications, including magnetic resonance imaging (MRI) and functional MRI (fMRI), 3D images are becoming increasingly popular. To improve the reliability of subsequent image analyses, 3D image denoising is often a necessary preprocessing step, which is the focus of the current paper. In the literature, most existing image denoising procedures are for 2D images. Their direct extensions to 3D cases generally cannot handle 3D images efficiently because the structure of a typical 3D image is substantially more complicated than that of a typical 2D image. For instance, edge locations are surfaces in 3D cases which would be much more challenging to handle compared to edge curves in 2D cases. We propose a novel 3D image denoising procedure in this paper, based on local approximation of the edge surfaces using a set of surface templates. An important property of this method is that it can preserve edges and major edge structures (e.g., intersections of two edge surfaces and pointed corners). Numerical studies show that it works well in various applications.

  1. Frames-Based Denoising in 3D Confocal Microscopy Imaging.

    PubMed

    Konstantinidis, Ioannis; Santamaria-Pang, Alberto; Kakadiaris, Ioannis

    2005-01-01

    In this paper, we propose a novel denoising method for 3D confocal microscopy data based on robust edge detection. Our approach relies on the construction of a non-separable frame system in 3D that incorporates the Sobel operator in dual spatial directions. This multidirectional set of digital filters is capable of robustly detecting edge information by ensemble thresholding of the filtered data. We demonstrate the application of our method to both synthetic and real confocal microscopy data by comparing it to denoising methods based on separable 3D wavelets and 3D median filtering, and report very encouraging results.

  2. Automating laser scanning of 3D surfaces for reverse engineering

    NASA Astrophysics Data System (ADS)

    Chan, Vincent H.; Bradley, Colin H.; Vickers, Geoffrey W.

    1997-12-01

    Application of current 3-D laser scanning systems to reverse engineering is limited by two obstacles. The meticulous guidance of the laser scanner over the surface of the object being scanned and the segmentation of the cloud data which is collected by the laser scanner. Presently, both obstacles are being manually solved. The guidance of the laser scanning sensor at the correct surface to sensor distance is dependent on operator judgement and the segmentation of the collected data is reliant on the user to manually define surface boundaries on a computer screen. By applying a 2-D CCD camera, both of these problems can be resolved. Depth information on the location of the object surface can be derived from a pair of stereo images from the CCD camera. Using this depth information, the scanner path can be automatically calculated. Segmentation of the object surface can be accomplished by employing a Kohonen neural network into the CCD image. Successful segmentation of the image is conditional on the locations selected to start neural nodes as well as the prevention of the neuron connectors from bleeding onto neighboring patches. Thus the CCD camera allows for the automatic path planning of the laser scanner as well as the segmentation of the surface into patches defined along its natural boundaries.

  3. Review: Polymeric-Based 3D Printing for Tissue Engineering.

    PubMed

    Wu, Geng-Hsi; Hsu, Shan-Hui

    Three-dimensional (3D) printing, also referred to as additive manufacturing, is a technology that allows for customized fabrication through computer-aided design. 3D printing has many advantages in the fabrication of tissue engineering scaffolds, including fast fabrication, high precision, and customized production. Suitable scaffolds can be designed and custom-made based on medical images such as those obtained from computed tomography. Many 3D printing methods have been employed for tissue engineering. There are advantages and limitations for each method. Future areas of interest and progress are the development of new 3D printing platforms, scaffold design software, and materials for tissue engineering applications.

  4. 3D fingerprint imaging system based on full-field fringe projection profilometry

    NASA Astrophysics Data System (ADS)

    Huang, Shujun; Zhang, Zonghua; Zhao, Yan; Dai, Jie; Chen, Chao; Xu, Yongjia; Zhang, E.; Xie, Lili

    2014-01-01

    As an unique, unchangeable and easily acquired biometrics, fingerprint has been widely studied in academics and applied in many fields over the years. The traditional fingerprint recognition methods are based on the obtained 2D feature of fingerprint. However, fingerprint is a 3D biological characteristic. The mapping from 3D to 2D loses 1D information and causes nonlinear distortion of the captured fingerprint. Therefore, it is becoming more and more important to obtain 3D fingerprint information for recognition. In this paper, a novel 3D fingerprint imaging system is presented based on fringe projection technique to obtain 3D features and the corresponding color texture information. A series of color sinusoidal fringe patterns with optimum three-fringe numbers are projected onto a finger surface. From another viewpoint, the fringe patterns are deformed by the finger surface and captured by a CCD camera. 3D shape data of the finger can be obtained from the captured fringe pattern images. This paper studies the prototype of the 3D fingerprint imaging system, including principle of 3D fingerprint acquisition, hardware design of the 3D imaging system, 3D calibration of the system, and software development. Some experiments are carried out by acquiring several 3D fingerprint data. The experimental results demonstrate the feasibility of the proposed 3D fingerprint imaging system.

  5. 3D Wavelet-Based Filter and Method

    DOEpatents

    Moss, William C.; Haase, Sebastian; Sedat, John W.

    2008-08-12

    A 3D wavelet-based filter for visualizing and locating structural features of a user-specified linear size in 2D or 3D image data. The only input parameter is a characteristic linear size of the feature of interest, and the filter output contains only those regions that are correlated with the characteristic size, thus denoising the image.

  6. Representation of 3-D surface orientation by velocity and disparity gradient cues in area MT.

    PubMed

    Sanada, Takahisa M; Nguyenkim, Jerry D; Deangelis, Gregory C

    2012-04-01

    Neural coding of the three-dimensional (3-D) orientation of planar surface patches may be an important intermediate step in constructing representations of complex 3-D surface structure. Spatial gradients of binocular disparity, image velocity, and texture provide potent cues to the 3-D orientation (tilt and slant) of planar surfaces. Previous studies have described neurons in both dorsal and ventral stream areas that are selective for surface tilt based on one or more of these gradient cues. However, relatively little is known about whether single neurons provide consistent information about surface orientation from multiple gradient cues. Moreover, it is unclear how neural responses to combinations of surface orientation cues are related to responses to the individual cues. We measured responses of middle temporal (MT) neurons to random dot stimuli that simulated planar surfaces at a variety of tilts and slants. Four cue conditions were tested: disparity, velocity, and texture gradients alone, as well as all three gradient cues combined. Many neurons showed robust tuning for surface tilt based on disparity and velocity gradients, with relatively little selectivity for texture gradients. Some neurons showed consistent tilt preferences for disparity and velocity cues, whereas others showed large discrepancies. Responses to the combined stimulus were generally well described as a weighted linear sum of responses to the individual cues, even when disparity and velocity preferences were discrepant. These findings suggest that area MT contains a rudimentary representation of 3-D surface orientation based on multiple cues, with single neurons implementing a simple cue integration rule.

  7. Design of 3D scanner for surface contour mapping by ultrasonic sensor

    NASA Astrophysics Data System (ADS)

    Munir, Muhammad Miftahul; Billah, Mohammad Aziz; Surachman, Arif; Budiman, Maman; Khairurrijal

    2015-04-01

    Surface mapping systems have attracted great attention due to their potential applications in many areas. In this paper, a simple 3D scanner based on ultrasonic sensor was designed for mapping a contour of object surface. The scanner using an SRF02 ultrasonic sensor, a microcontroller and radio frequency (RF) module to collect coordinates of object surface (point cloud), and sent data to computer. The point cloud collection process was performed by moving two ultrasonic sensors in y and x directions. Both sensors measure a distance from an object surface to a reference point of each sensor. The measurement results represent the point cloud of object surface and the data will be sent to computer via RF module. The point cloud then converted to 3D model using MATLAB. It was found that the object contours can be reconstructed very well by the developed 3D scanner system.

  8. Modelling of facial growth in Czech children based on longitudinal data: Age progression from 12 to 15 years using 3D surface models.

    PubMed

    Koudelová, Jana; Dupej, Ján; Brůžek, Jaroslav; Sedlak, Petr; Velemínská, Jana

    2015-03-01

    Dealing with the increasing number of long-term missing children and juveniles requires more precise and objective age progression techniques for the prediction of their current appearance. Our contribution includes detailed and real facial growth information used for modelling age progression during adolescence. This study was based on an evaluation of the overall 180 three-dimensional (3D) facial scans of Czech children (23 boys, 22 girls), which were longitudinally studied from 12 to 15 years of age and thus revealed the real growth-related changes. The boys underwent more marked changes compared with the girls, especially in the regions of the eyebrow ridges, nose and chin. Using modern geometric morphometric methods, together with their applications, we modelled the ageing and allometric trajectories for both sexes and simulated the age-progressed effects on facial scans. The facial parts that are important for facial recognition (eyes, nose, mouth and chin) all deviated less than 0.75mm, whereas the areas with the largest deviations were situated on the marginal parts of the face. The mean error between the predicted and real facial morphology obtained by modelling the children from 12 to 15 years of age was 1.92mm in girls and 1.86mm in boys. This study is beneficial for forensic artists as it reduces the subjectivity of age progression methods.

  9. NoSQL Based 3D City Model Management System

    NASA Astrophysics Data System (ADS)

    Mao, B.; Harrie, L.; Cao, J.; Wu, Z.; Shen, J.

    2014-04-01

    To manage increasingly complicated 3D city models, a framework based on NoSQL database is proposed in this paper. The framework supports import and export of 3D city model according to international standards such as CityGML, KML/COLLADA and X3D. We also suggest and implement 3D model analysis and visualization in the framework. For city model analysis, 3D geometry data and semantic information (such as name, height, area, price and so on) are stored and processed separately. We use a Map-Reduce method to deal with the 3D geometry data since it is more complex, while the semantic analysis is mainly based on database query operation. For visualization, a multiple 3D city representation structure CityTree is implemented within the framework to support dynamic LODs based on user viewpoint. Also, the proposed framework is easily extensible and supports geoindexes to speed up the querying. Our experimental results show that the proposed 3D city management system can efficiently fulfil the analysis and visualization requirements.

  10. Surgeon-Based 3D Printing for Microvascular Bone Flaps.

    PubMed

    Taylor, Erin M; Iorio, Matthew L

    2017-03-04

    Background Three-dimensional (3D) printing has developed as a revolutionary technology with the capacity to design accurate physical models in preoperative planning. We present our experience in surgeon-based design of 3D models, using home 3D software and printing technology for use as an adjunct in vascularized bone transfer. Methods Home 3D printing techniques were used in the design and execution of vascularized bone flap transfers to the upper extremity. Open source imaging software was used to convert preoperative computed tomography scans and create 3D models. These were printed in the surgeon's office as 3D models for the planned reconstruction. Vascularized bone flaps were designed intraoperatively based on the 3D printed models. Results Three-dimensional models were created for intraoperative use in vascularized bone flaps, including (1) medial femoral trochlea (MFT) flap for scaphoid avascular necrosis and nonunion, (2) MFT flap for lunate avascular necrosis and nonunion, (3) medial femoral condyle (MFC) flap for wrist arthrodesis, and (4) free fibula osteocutaneous flap for distal radius septic nonunion. Templates based on the 3D models allowed for the precise and rapid contouring of well-vascularized bone flaps in situ, prior to ligating the donor pedicle. Conclusions Surgeon-based 3D printing is a feasible, innovative technology that allows for the precise and rapid contouring of models that can be created in various configurations for pre- and intraoperative planning. The technology is easy to use, convenient, and highly economical as compared with traditional send-out manufacturing. Surgeon-based 3D printing is a useful adjunct in vascularized bone transfer. Level of Evidence Level IV.

  11. Tropospheric ozone in the western Pacific Rim: Analysis of satellite and surface-based observations along with comprehensive 3-D model simulations

    NASA Technical Reports Server (NTRS)

    Young, Sun-Woo; Carmichael, Gregory R.

    1994-01-01

    Tropospheric ozone production and transport in mid-latitude eastern Asia is studied. Data analysis of surface-based ozone measurements in Japan and satellite-based tropospheric column measurements of the entire western Pacific Rim are combined with results from three-dimensional model simulations to investigate the diurnal, seasonal and long-term variations of ozone in this region. Surface ozone measurements from Japan show distinct seasonal variation with a spring peak and summer minimum. Satellite studies of the entire tropospheric column of ozone show high concentrations in both the spring and summer seasons. Finally, preliminary model simulation studies show good agreement with observed values.

  12. 3D Printing of Carbon Nanotubes-Based Microsupercapacitors.

    PubMed

    Yu, Wei; Zhou, Han; Li, Ben Q; Ding, Shujiang

    2017-02-08

    A novel 3D printing procedure is presented for fabricating carbon-nanotubes (CNTs)-based microsupercapacitors. The 3D printer uses a CNTs ink slurry with a moderate solid content and prints a stream of continuous droplets. Appropriate control of a heated base is applied to facilitate the solvent removal and adhesion between printed layers and to improve the structure integrity without structure delamination or distortion upon drying. The 3D-printed electrodes for microsupercapacitors are characterized by SEM, laser scanning confocal microscope, and step profiler. Effect of process parameters on 3D printing is also studied. The final solid-state microsupercapacitors are assembled with the printed multilayer CNTs structures and poly(vinyl alcohol)-H3PO4 gel as the interdigitated microelectrodes and electrolyte. The electrochemical performance of 3D printed microsupercapacitors is also tested, showing a significant areal capacitance and excellent cycle stability.

  13. Reconstruction-based 3D/2D image registration.

    PubMed

    Tomazevic, Dejan; Likar, Bostjan; Pernus, Franjo

    2005-01-01

    In this paper we present a novel 3D/2D registration method, where first, a 3D image is reconstructed from a few 2D X-ray images and next, the preoperative 3D image is brought into the best possible spatial correspondence with the reconstructed image by optimizing a similarity measure. Because the quality of the reconstructed image is generally low, we introduce a novel asymmetric mutual information similarity measure, which is able to cope with low image quality as well as with different imaging modalities. The novel 3D/2D registration method has been evaluated using standardized evaluation methodology and publicly available 3D CT, 3DRX, and MR and 2D X-ray images of two spine phantoms, for which gold standard registrations were known. In terms of robustness, reliability and capture range the proposed method outperformed the gradient-based method and the method based on digitally reconstructed radiographs (DRRs).

  14. 3D face recognition by projection-based methods

    NASA Astrophysics Data System (ADS)

    Dutagaci, Helin; Sankur, Bülent; Yemez, Yücel

    2006-02-01

    In this paper, we investigate recognition performances of various projection-based features applied on registered 3D scans of faces. Some features are data driven, such as ICA-based features or NNMF-based features. Other features are obtained using DFT or DCT-based schemes. We apply the feature extraction techniques to three different representations of registered faces, namely, 3D point clouds, 2D depth images and 3D voxel. We consider both global and local features. Global features are extracted from the whole face data, whereas local features are computed over the blocks partitioned from 2D depth images. The block-based local features are fused both at feature level and at decision level. The resulting feature vectors are matched using Linear Discriminant Analysis. Experiments using different combinations of representation types and feature vectors are conducted on the 3D-RMA dataset.

  15. 3D Printed Graphene Based Energy Storage Devices.

    PubMed

    Foster, Christopher W; Down, Michael P; Zhang, Yan; Ji, Xiaobo; Rowley-Neale, Samuel J; Smith, Graham C; Kelly, Peter J; Banks, Craig E

    2017-03-03

    3D printing technology provides a unique platform for rapid prototyping of numerous applications due to its ability to produce low cost 3D printed platforms. Herein, a graphene-based polylactic acid filament (graphene/PLA) has been 3D printed to fabricate a range of 3D disc electrode (3DE) configurations using a conventional RepRap fused deposition moulding (FDM) 3D printer, which requires no further modification/ex-situ curing step. To provide proof-of-concept, these 3D printed electrode architectures are characterised both electrochemically and physicochemically and are advantageously applied as freestanding anodes within Li-ion batteries and as solid-state supercapacitors. These freestanding anodes neglect the requirement for a current collector, thus offering a simplistic and cheaper alternative to traditional Li-ion based setups. Additionally, the ability of these devices' to electrochemically produce hydrogen via the hydrogen evolution reaction (HER) as an alternative to currently utilised platinum based electrodes (with in electrolysers) is also performed. The 3DE demonstrates an unexpectedly high catalytic activity towards the HER (-0.46 V vs. SCE) upon the 1000th cycle, such potential is the closest observed to the desired value of platinum at (-0.25 V vs. SCE). We subsequently suggest that 3D printing of graphene-based conductive filaments allows for the simple fabrication of energy storage devices with bespoke and conceptual designs to be realised.

  16. 3D Printed Graphene Based Energy Storage Devices

    PubMed Central

    Foster, Christopher W.; Down, Michael P.; Zhang, Yan; Ji, Xiaobo; Rowley-Neale, Samuel J.; Smith, Graham C.; Kelly, Peter J.; Banks, Craig E.

    2017-01-01

    3D printing technology provides a unique platform for rapid prototyping of numerous applications due to its ability to produce low cost 3D printed platforms. Herein, a graphene-based polylactic acid filament (graphene/PLA) has been 3D printed to fabricate a range of 3D disc electrode (3DE) configurations using a conventional RepRap fused deposition moulding (FDM) 3D printer, which requires no further modification/ex-situ curing step. To provide proof-of-concept, these 3D printed electrode architectures are characterised both electrochemically and physicochemically and are advantageously applied as freestanding anodes within Li-ion batteries and as solid-state supercapacitors. These freestanding anodes neglect the requirement for a current collector, thus offering a simplistic and cheaper alternative to traditional Li-ion based setups. Additionally, the ability of these devices’ to electrochemically produce hydrogen via the hydrogen evolution reaction (HER) as an alternative to currently utilised platinum based electrodes (with in electrolysers) is also performed. The 3DE demonstrates an unexpectedly high catalytic activity towards the HER (−0.46 V vs. SCE) upon the 1000th cycle, such potential is the closest observed to the desired value of platinum at (−0.25 V vs. SCE). We subsequently suggest that 3D printing of graphene-based conductive filaments allows for the simple fabrication of energy storage devices with bespoke and conceptual designs to be realised. PMID:28256602

  17. 3D Printed Graphene Based Energy Storage Devices

    NASA Astrophysics Data System (ADS)

    Foster, Christopher W.; Down, Michael P.; Zhang, Yan; Ji, Xiaobo; Rowley-Neale, Samuel J.; Smith, Graham C.; Kelly, Peter J.; Banks, Craig E.

    2017-03-01

    3D printing technology provides a unique platform for rapid prototyping of numerous applications due to its ability to produce low cost 3D printed platforms. Herein, a graphene-based polylactic acid filament (graphene/PLA) has been 3D printed to fabricate a range of 3D disc electrode (3DE) configurations using a conventional RepRap fused deposition moulding (FDM) 3D printer, which requires no further modification/ex-situ curing step. To provide proof-of-concept, these 3D printed electrode architectures are characterised both electrochemically and physicochemically and are advantageously applied as freestanding anodes within Li-ion batteries and as solid-state supercapacitors. These freestanding anodes neglect the requirement for a current collector, thus offering a simplistic and cheaper alternative to traditional Li-ion based setups. Additionally, the ability of these devices’ to electrochemically produce hydrogen via the hydrogen evolution reaction (HER) as an alternative to currently utilised platinum based electrodes (with in electrolysers) is also performed. The 3DE demonstrates an unexpectedly high catalytic activity towards the HER (‑0.46 V vs. SCE) upon the 1000th cycle, such potential is the closest observed to the desired value of platinum at (‑0.25 V vs. SCE). We subsequently suggest that 3D printing of graphene-based conductive filaments allows for the simple fabrication of energy storage devices with bespoke and conceptual designs to be realised.

  18. 3D object recognition based on local descriptors

    NASA Astrophysics Data System (ADS)

    Jakab, Marek; Benesova, Wanda; Racev, Marek

    2015-01-01

    In this paper, we propose an enhanced method of 3D object description and recognition based on local descriptors using RGB image and depth information (D) acquired by Kinect sensor. Our main contribution is focused on an extension of the SIFT feature vector by the 3D information derived from the depth map (SIFT-D). We also propose a novel local depth descriptor (DD) that includes a 3D description of the key point neighborhood. Thus defined the 3D descriptor can then enter the decision-making process. Two different approaches have been proposed, tested and evaluated in this paper. First approach deals with the object recognition system using the original SIFT descriptor in combination with our novel proposed 3D descriptor, where the proposed 3D descriptor is responsible for the pre-selection of the objects. Second approach demonstrates the object recognition using an extension of the SIFT feature vector by the local depth description. In this paper, we present the results of two experiments for the evaluation of the proposed depth descriptors. The results show an improvement in accuracy of the recognition system that includes the 3D local description compared with the same system without the 3D local description. Our experimental system of object recognition is working near real-time.

  19. Constructing topologically connected surfaces for the comprehensive analysis of 3-D medical structures

    NASA Astrophysics Data System (ADS)

    Kalvin, Alan D.; Cutting, Court B.; Haddad, Betsy; Noz, Marilyn E.

    1991-06-01

    Three-dimensional (3D) medical imaging deals with the visualization, manipulation, and measuring of objects in 3D medical images. So far, research efforts have concentrated primarily on visualization, using well-developed methods from computer graphics. Very little has been achieved in developing techniques for manipulating medical objects, or for extracting quantitative measurements from them beyond volume calculation (by counting voxels), and computing distances and angles between manually located surface points. A major reason for the slow pace in the development of manipulation and quantification methods lies with the limitations of current algorithms for constructing surfaces from 3D solid objects. We show that current surface construction algorithms either (a) do not construct valid surface descriptions of solid objects or (b) produce surface representations that are not particularly suitable for anything other than visualization. We present ALLIGATOR, a new surface construction algorithm that produces valid, topologically connected surface representations of solid objects. We have developed a modeling system based on the surface representations created by ALLIGATOR that is suitable for developing algorithms to visualize, manipulate, and quantify 3D medical objects. Using this modeling system we have developed a method for efficiently computing principle curvatures and directions on surfaces. These measurements form the basis for a new metric system being developed for morphometrics. The modeling system is also being used in the development of systems for quantitative pre-surgical planning and surgical augmentation.

  20. 3D Printing of Molecular Potential Energy Surface Models

    ERIC Educational Resources Information Center

    Lolur, Phalgun; Dawes, Richard

    2014-01-01

    Additive manufacturing, commonly known as 3D printing, is gaining popularity in a variety of applications and has recently become routinely available. Today, 3D printing services are not only found in engineering design labs and through online companies, but also in university libraries offering student access. In addition, affordable options for…

  1. Tracking tissue section surfaces for automated 3D confocal cytometry

    NASA Astrophysics Data System (ADS)

    Agustin, Ramses; Price, Jeffrey H.

    2002-05-01

    Three-dimensional cytometry, whereby large volumes of tissue would be measured automatically, requires a computerized method for detecting the upper and lower tissue boundaries. In conventional confocal microscopy, the user interactively sets limits for axial scanning for each field-of-view. Biological specimens vary in section thickness, thereby driving the requirement for setting vertical scan limits. Limits could be set arbitrarily large to ensure the entire tissue is scanned, but automatic surface identification would eliminate storing undue numbers of empty optical sections and forms the basis for incorporating lateral microscope stage motion to collect unlimited numbers of stacks. This walk-away automation of 3D confocal scanning for biological imaging is the first sep towards practical, computerized statistical sampling from arbitrarily large tissue volumes. Preliminary results for automatic tissue surface tracking were obtained for phase-contrast microscopy by measuring focus sharpness (previously used for high-speed autofocus by our group). Measurements were taken from 5X5 fields-of-view from hamster liver sections, varying from five to twenty microns in thickness, then smoothed to lessen variations of in-focus information at each axial position. Because image sharpness (as the power of high spatial frequency components) drops across the axial boundaries of a tissue section, mathematical quantities including the full-width at half-maximum, extrema in the first derivative, and second derivative were used to locate the proximal and distal surfaces of a tissue. Results from these tests were evaluated against manual (i.e., visual) determination of section boundaries.

  2. Surface modified alginate microcapsules for 3D cell culture

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Wen; Kuo, Chiung Wen; Chueh, Di-Yen; Chen, Peilin

    2016-06-01

    Culture as three dimensional cell aggregates or spheroids can offer an ideal platform for tissue engineering applications and for pharmaceutical screening. Such 3D culture models, however, may suffer from the problems such as immune response and ineffective and cumbersome culture. This paper describes a simple method for producing microcapsules with alginate cores and a thin shell of poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) to encapsulate mouse induced pluripotent stem (miPS) cells, generating a non-fouling surface as an effective immunoisolation barrier. We demonstrated the trapping of the alginate microcapsules in a microwell array for the continuous observation and culture of a large number of encapsulated miPS cells in parallel. miPS cells cultured in the microcapsules survived well and proliferated to form a single cell aggregate. Droplet formation of monodisperse microcapsules with controlled size combined with flow cytometry provided an efficient way to quantitatively analyze the growth of encapsulated cells in a high-throughput manner. The simple and cost-effective coating technique employed to produce the core-shell microcapsules could be used in the emerging field of cell therapy. The microwell array would provide a convenient, user friendly and high-throughput platform for long-term cell culture and monitoring.

  3. Multiframe image point matching and 3-d surface reconstruction.

    PubMed

    Tsai, R Y

    1983-02-01

    This paper presents two new methods, the Joint Moment Method (JMM) and the Window Variance Method (WVM), for image matching and 3-D object surface reconstruction using multiple perspective views. The viewing positions and orientations for these perspective views are known a priori, as is usually the case for such applications as robotics and industrial vision as well as close range photogrammetry. Like the conventional two-frame correlation method, the JMM and WVM require finding the extrema of 1-D curves, which are proved to theoretically approach a delta function exponentially as the number of frames increases for the JMM and are much sharper than the two-frame correlation function for both the JMM and the WVM, even when the image point to be matched cannot be easily distinguished from some of the other points. The theoretical findings have been supported by simulations. It is also proved that JMM and WVM are not sensitive to certain radiometric effects. If the same window size is used, the computational complexity for the proposed methods is about n - 1 times that for the two-frame method where n is the number of frames. Simulation results show that the JMM and WVM require smaller windows than the two-frame correlation method with better accuracy, and therefore may even be more computationally feasible than the latter since the computational complexity increases quadratically as a function of the window size.

  4. Powder-based 3D printing for bone tissue engineering.

    PubMed

    Brunello, G; Sivolella, S; Meneghello, R; Ferroni, L; Gardin, C; Piattelli, A; Zavan, B; Bressan, E

    2016-01-01

    Bone tissue engineered 3-D constructs customized to patient-specific needs are emerging as attractive biomimetic scaffolds to enhance bone cell and tissue growth and differentiation. The article outlines the features of the most common additive manufacturing technologies (3D printing, stereolithography, fused deposition modeling, and selective laser sintering) used to fabricate bone tissue engineering scaffolds. It concentrates, in particular, on the current state of knowledge concerning powder-based 3D printing, including a description of the properties of powders and binder solutions, the critical phases of scaffold manufacturing, and its applications in bone tissue engineering. Clinical aspects and future applications are also discussed.

  5. Visual Semantic Based 3D Video Retrieval System Using HDFS

    PubMed Central

    Kumar, C.Ranjith; Suguna, S.

    2016-01-01

    This paper brings out a neoteric frame of reference for visual semantic based 3d video search and retrieval applications. Newfangled 3D retrieval application spotlight on shape analysis like object matching, classification and retrieval not only sticking up entirely with video retrieval. In this ambit, we delve into 3D-CBVR (Content Based Video Retrieval) concept for the first time. For this purpose, we intent to hitch on BOVW and Mapreduce in 3D framework. Instead of conventional shape based local descriptors, we tried to coalesce shape, color and texture for feature extraction. For this purpose, we have used combination of geometric & topological features for shape and 3D co-occurrence matrix for color and texture. After thriving extraction of local descriptors, TB-PCT (Threshold Based- Predictive Clustering Tree) algorithm is used to generate visual codebook and histogram is produced. Further, matching is performed using soft weighting scheme with L2 distance function. As a final step, retrieved results are ranked according to the Index value and acknowledged to the user as a feedback .In order to handle prodigious amount of data and Efficacious retrieval, we have incorporated HDFS in our Intellection. Using 3D video dataset, we future the performance of our proposed system which can pan out that the proposed work gives meticulous result and also reduce the time intricacy. PMID:28003793

  6. Visual Semantic Based 3D Video Retrieval System Using HDFS.

    PubMed

    Kumar, C Ranjith; Suguna, S

    2016-08-01

    This paper brings out a neoteric frame of reference for visual semantic based 3d video search and retrieval applications. Newfangled 3D retrieval application spotlight on shape analysis like object matching, classification and retrieval not only sticking up entirely with video retrieval. In this ambit, we delve into 3D-CBVR (Content Based Video Retrieval) concept for the first time. For this purpose, we intent to hitch on BOVW and Mapreduce in 3D framework. Instead of conventional shape based local descriptors, we tried to coalesce shape, color and texture for feature extraction. For this purpose, we have used combination of geometric & topological features for shape and 3D co-occurrence matrix for color and texture. After thriving extraction of local descriptors, TB-PCT (Threshold Based- Predictive Clustering Tree) algorithm is used to generate visual codebook and histogram is produced. Further, matching is performed using soft weighting scheme with L2 distance function. As a final step, retrieved results are ranked according to the Index value and acknowledged to the user as a feedback .In order to handle prodigious amount of data and Efficacious retrieval, we have incorporated HDFS in our Intellection. Using 3D video dataset, we future the performance of our proposed system which can pan out that the proposed work gives meticulous result and also reduce the time intricacy.

  7. Macroporous hydrogels based on 2-hydroxyethyl methacrylate. Part 6: 3D hydrogels with positive and negative surface charges and polyelectrolyte complexes in spinal cord injury repair.

    PubMed

    Hejcl, A; Lesný, P; Prádný, M; Sedý, J; Zámecník, J; Jendelová, P; Michálek, J; Syková, E

    2009-07-01

    Macroporous hydrogels are artificial biomaterials commonly used in tissue engineering, including central nervous system (CNS) repair. Their physical properties may be modified to improve their adhesion properties and promote tissue regeneration. We implanted four types of hydrogels based on 2-hydroxyethyl methacrylate (HEMA) with different surface charges inside a spinal cord hemisection cavity at the Th8 level in rats. The spinal cords were processed 1 and 6 months after implantation and histologically evaluated. Connective tissue deposition was most abundant in the hydrogels with positively-charged functional groups. Axonal regeneration was promoted in hydrogels carrying charged functional groups; hydrogels with positively charged functional groups showed increased axonal ingrowth into the central parts of the implant. Few astrocytes grew into the hydrogels. Our study shows that HEMA-based hydrogels carrying charged functional groups improve axonal ingrowth inside the implants compared to implants without any charge. Further, positively charged functional groups promote connective tissue infiltration and extended axonal regeneration inside a hydrogel bridge.

  8. 3D model retrieval method based on mesh segmentation

    NASA Astrophysics Data System (ADS)

    Gan, Yuanchao; Tang, Yan; Zhang, Qingchen

    2012-04-01

    In the process of feature description and extraction, current 3D model retrieval algorithms focus on the global features of 3D models but ignore the combination of global and local features of the model. For this reason, they show less effective performance to the models with similar global shape and different local shape. This paper proposes a novel algorithm for 3D model retrieval based on mesh segmentation. The key idea is to exact the structure feature and the local shape feature of 3D models, and then to compares the similarities of the two characteristics and the total similarity between the models. A system that realizes this approach was built and tested on a database of 200 objects and achieves expected results. The results show that the proposed algorithm improves the precision and the recall rate effectively.

  9. Uniform Surface Modification of 3D Bioglass®-Based Scaffolds with Mesoporous Silica Particles (MCM-41) for Enhancing Drug Delivery Capability

    PubMed Central

    Boccardi, Elena; Philippart, Anahí; Juhasz-Bortuzzo, Judith A.; Beltrán, Ana M.; Novajra, Giorgia; Vitale-Brovarone, Chiara; Spiecker, Erdmann; Boccaccini, Aldo R.

    2015-01-01

    The design and characterization of a new family of multifunctional scaffolds based on bioactive glass (BG) of 45S5 composition for bone tissue engineering and drug delivery applications are presented. These BG-based scaffolds are developed via a replication method of polyurethane packaging foam. In order to increase the therapeutic functionality, the scaffolds were coated with mesoporous silica particles (MCM-41), which act as an in situ drug delivery system. These sub-micron spheres are characterized by large surface area and pore volume with a narrow pore diameter distribution. The solution used for the synthesis of the silica mesoporous particles was designed to obtain a high-ordered mesoporous structure and spherical shape – both are key factors for achieving the desired controlled drug release. The MCM-41 particles were synthesized directly inside the BG-based scaffolds, and the drug-release capability of this combined system was evaluated. Moreover, the effect of MCM-41 particle coating on the bioactivity of the BG-based scaffolds was assessed. The results indicate that it is possible to obtain a multifunctional scaffold system characterized by high and interconnected porosity, high bioactivity, and sustained drug delivery capability. PMID:26594642

  10. 3D microstructure modeling of compressed fiber-based materials

    NASA Astrophysics Data System (ADS)

    Gaiselmann, Gerd; Tötzke, Christian; Manke, Ingo; Lehnert, Werner; Schmidt, Volker

    2014-07-01

    A novel parametrized model that describes the 3D microstructure of compressed fiber-based materials is introduced. It allows to virtually generate the microstructure of realistically compressed gas-diffusion layers (GDL). Given the input of a 3D microstructure of some fiber-based material, the model compresses the system of fibers in a uniaxial direction for arbitrary compression rates. The basic idea is to translate the fibers in the direction of compression according to a vector field which depends on the rate of compression and on the locations of fibers within the material. In order to apply the model to experimental 3D image data of fiber-based materials given for several compression states, an optimal vector field is estimated by simulated annealing. The model is applied to 3D image data of non-woven GDL in PEMFC gained by synchrotron tomography for different compression rates. The compression model is validated by comparing structural characteristics computed for experimentally compressed and virtually compressed microstructures, where two kinds of compression - using a flat stamp and a stamp with a flow-field profile - are applied. For both stamps types, a good agreement is found. Furthermore, the compression model is combined with a stochastic 3D microstructure model for uncompressed fiber-based materials. This allows to efficiently generate compressed fiber-based microstructures in arbitrary volumes.

  11. 3D ear identification based on sparse representation.

    PubMed

    Zhang, Lin; Ding, Zhixuan; Li, Hongyu; Shen, Ying

    2014-01-01

    Biometrics based personal authentication is an effective way for automatically recognizing, with a high confidence, a person's identity. Recently, 3D ear shape has attracted tremendous interests in research field due to its richness of feature and ease of acquisition. However, the existing ICP (Iterative Closet Point)-based 3D ear matching methods prevalent in the literature are not quite efficient to cope with the one-to-many identification case. In this paper, we aim to fill this gap by proposing a novel effective fully automatic 3D ear identification system. We at first propose an accurate and efficient template-based ear detection method. By utilizing such a method, the extracted ear regions are represented in a common canonical coordinate system determined by the ear contour template, which facilitates much the following stages of feature extraction and classification. For each extracted 3D ear, a feature vector is generated as its representation by making use of a PCA-based local feature descriptor. At the stage of classification, we resort to the sparse representation based classification approach, which actually solves an l1-minimization problem. To the best of our knowledge, this is the first work introducing the sparse representation framework into the field of 3D ear identification. Extensive experiments conducted on a benchmark dataset corroborate the effectiveness and efficiency of the proposed approach. The associated Matlab source code and the evaluation results have been made publicly online available at http://sse.tongji.edu.cn/linzhang/ear/srcear/srcear.htm.

  12. 3D surface reconstruction of apples from 2D NIR images

    NASA Astrophysics Data System (ADS)

    Zhu, Bin; Jiang, Lu; Cheng, Xuemei; Tao, Yang

    2005-11-01

    Machine vision methods are widely used in apple defect detection and quality grading applications. Currently, 2D near-infrared (NIR) imaging of apples is often used to detect apple defects because the image intensity of defects is different from normal apple parts. However, a drawback of this method is that the apple calyx also exhibits similar image intensity to the apple defects. Since an apple calyx often appears in the NIR image, the false alarm rate is high with the 2D NIR imaging method. In this paper, a 2D NIR imaging method is extended to a 3D reconstruction so that the apple calyx can be differentiated from apple defects according to their different 3D depth information. The Lambertian model is used to evaluate the reflectance map of the apple surface, and then Pentland's Shape-From-Shading (SFS) method is applied to reconstruct the 3D surface information of the apple based on Fast Fourier Transform (FFT). Pentland's method is directly derived from human perception properties, making it close to the way human eyes recover 3D information from a 2D scene. In addition, the FFT reduces the computation time significantly. The reconstructed 3D apple surface maps are shown in the results, and different depths of apple calyx and defects are obtained correctly.

  13. Recursive estimation of 3D motion and surface structure from local affine flow parameters.

    PubMed

    Calway, Andrew

    2005-04-01

    A recursive structure from motion algorithm based on optical flow measurements taken from an image sequence is described. It provides estimates of surface normals in addition to 3D motion and depth. The measurements are affine motion parameters which approximate the local flow fields associated with near-planar surface patches in the scene. These are integrated over time to give estimates of the 3D parameters using an extended Kalman filter. This also estimates the camera focal length and, so, the 3D estimates are metric. The use of parametric measurements means that the algorithm is computationally less demanding than previous optical flow approaches and the recursive filter builds in a degree of noise robustness. Results of experiments on synthetic and real image sequences demonstrate that the algorithm performs well.

  14. Modeling Images of Natural 3D Surfaces: Overview and Potential Applications

    NASA Technical Reports Server (NTRS)

    Jalobeanu, Andre; Kuehnel, Frank; Stutz, John

    2004-01-01

    Generative models of natural images have long been used in computer vision. However, since they only describe the of 2D scenes, they fail to capture all the properties of the underlying 3D world. Even though such models are sufficient for many vision tasks a 3D scene model is when it comes to inferring a 3D object or its characteristics. In this paper, we present such a generative model, incorporating both a multiscale surface prior model for surface geometry and reflectance, and an image formation process model based on realistic rendering, the computation of the posterior model parameter densities, and on the critical aspects of the rendering. We also how to efficiently invert the model within a Bayesian framework. We present a few potential applications, such as asteroid modeling and Planetary topography recovery, illustrated by promising results on real images.

  15. DCT and DST Based Image Compression for 3D Reconstruction

    NASA Astrophysics Data System (ADS)

    Siddeq, Mohammed M.; Rodrigues, Marcos A.

    2017-03-01

    This paper introduces a new method for 2D image compression whose quality is demonstrated through accurate 3D reconstruction using structured light techniques and 3D reconstruction from multiple viewpoints. The method is based on two discrete transforms: (1) A one-dimensional Discrete Cosine Transform (DCT) is applied to each row of the image. (2) The output from the previous step is transformed again by a one-dimensional Discrete Sine Transform (DST), which is applied to each column of data generating new sets of high-frequency components followed by quantization of the higher frequencies. The output is then divided into two parts where the low-frequency components are compressed by arithmetic coding and the high frequency ones by an efficient minimization encoding algorithm. At decompression stage, a binary search algorithm is used to recover the original high frequency components. The technique is demonstrated by compressing 2D images up to 99% compression ratio. The decompressed images, which include images with structured light patterns for 3D reconstruction and from multiple viewpoints, are of high perceptual quality yielding accurate 3D reconstruction. Perceptual assessment and objective quality of compression are compared with JPEG and JPEG2000 through 2D and 3D RMSE. Results show that the proposed compression method is superior to both JPEG and JPEG2000 concerning 3D reconstruction, and with equivalent perceptual quality to JPEG2000.

  16. 3D display based on parallax barrier with multiview zones.

    PubMed

    Lv, Guo-Jiao; Wang, Qiong-Hua; Zhao, Wu-Xiang; Wang, Jun

    2014-03-01

    A 3D display based on a parallax barrier with multiview zones is proposed. This display consists of a 2D display panel and a parallax barrier. The basic element of the parallax barrier has three narrow slits. They can show three columns of subpixels on the 2D display panel and form 3D pixels. The parallax barrier can provide multiview zones. In these multiview zones, the proposed 3D display can use a small number of views to achieve a high density of views. Therefore, the distance between views is the same as the conventional ones with more views. Considering the proposed display has fewer views, which bring more 3D pixels in the 3D images, the resolution and brightness will be higher than the conventional ones. A 12-view prototype of the proposed 3D display is developed, and it provides the same density of views as a conventional one with 28 views. Experimental results show the proposed display has higher resolution and brightness than the conventional one. The cross talk is also limited at a low level.

  17. 3D surface reconstruction and visualization of the Drosophila wing imaginal disc at cellular resolution

    NASA Astrophysics Data System (ADS)

    Bai, Linge; Widmann, Thomas; Jülicher, Frank; Dahmann, Christian; Breen, David

    2013-01-01

    Quantifying and visualizing the shape of developing biological tissues provide information about the morphogenetic processes in multicellular organisms. The size and shape of biological tissues depend on the number, size, shape, and arrangement of the constituting cells. To better understand the mechanisms that guide tissues into their final shape, it is important to investigate the cellular arrangement within tissues. Here we present a data processing pipeline to generate 3D volumetric surface models of epithelial tissues, as well as geometric descriptions of the tissues' apical cell cross-sections. The data processing pipeline includes image acquisition, editing, processing and analysis, 2D cell mesh generation, 3D contourbased surface reconstruction, cell mesh projection, followed by geometric calculations and color-based visualization of morphological parameters. In their first utilization we have applied these procedures to construct a 3D volumetric surface model at cellular resolution of the wing imaginal disc of Drosophila melanogaster. The ultimate goal of the reported effort is to produce tools for the creation of detailed 3D geometric models of the individual cells in epithelial tissues. To date, 3D volumetric surface models of the whole wing imaginal disc have been created, and the apicolateral cell boundaries have been identified, allowing for the calculation and visualization of cell parameters, e.g. apical cross-sectional area of cells. The calculation and visualization of morphological parameters show position-dependent patterns of cell shape in the wing imaginal disc. Our procedures should offer a general data processing pipeline for the construction of 3D volumetric surface models of a wide variety of epithelial tissues.

  18. Generation of 3-D surface maps in waste storage silos using a structured light source

    NASA Technical Reports Server (NTRS)

    Burks, B. L.; Rowe, J. C.; Dinkins, M. A.; Christensen, B.; Selleck, C.; Jacoboski, D.; Markus, R.

    1992-01-01

    Surface contours inside the large waste storage tanks typical of the Department of Energy (DOE) complex are, in general, highly irregular. In addition to pipes and other pieces of equipment in the tanks, the surfaces may have features such as mounds, fissures, crystalline structures, and mixed solid and liquid forms. Prior to remediation activities, it will be necessary to characterize the waste to determine the most effective remediation approaches. Surface contour data will be required both prior to and during remediation. The use is described of a structured light source to generate 3-D surface contour maps of the interior of waste storage silos at the Feed Materials Production Center at Fernald, OH. The landscape inside these large waste storage tanks bears a strong resemblance to some of the landscapes that might be encountered during lunar or planetary exploration. Hence, these terrestrial 3-D mapping techniques may be directly applicable to extraterrestrial exploration. In further development, it will be demonstrated that these 3-D data can be used for robotic task planning just as 3-D surface contour data of a satellite could be used to plan maintenance tasks for a space-based servicing robot.

  19. Axisymmetric Implementation for 3D-Based DSMC Codes

    NASA Technical Reports Server (NTRS)

    Stewart, Benedicte; Lumpkin, F. E.; LeBeau, G. J.

    2011-01-01

    The primary objective in developing NASA s DSMC Analysis Code (DAC) was to provide a high fidelity modeling tool for 3D rarefied flows such as vacuum plume impingement and hypersonic re-entry flows [1]. The initial implementation has been expanded over time to offer other capabilities including a novel axisymmetric implementation. Because of the inherently 3D nature of DAC, this axisymmetric implementation uses a 3D Cartesian domain and 3D surfaces. Molecules are moved in all three dimensions but their movements are limited by physical walls to a small wedge centered on the plane of symmetry (Figure 1). Unfortunately, far from the axis of symmetry, the cell size in the direction perpendicular to the plane of symmetry (the Z-direction) may become large compared to the flow mean free path. This frequently results in inaccuracies in these regions of the domain. A new axisymmetric implementation is presented which aims to solve this issue by using Bird s approach for the molecular movement while preserving the 3D nature of the DAC software [2]. First, the computational domain is similar to that previously used such that a wedge must still be used to define the inflow surface and solid walls within the domain. As before molecules are created inside the inflow wedge triangles but they are now rotated back to the symmetry plane. During the move step, molecules are moved in 3D but instead of interacting with the wedge walls, the molecules are rotated back to the plane of symmetry at the end of the move step. This new implementation was tested for multiple flows over axisymmetric shapes, including a sphere, a cone, a double cone and a hollow cylinder. Comparisons to previous DSMC solutions and experiments, when available, are made.

  20. 3D measurement system based on computer-generated gratings

    NASA Astrophysics Data System (ADS)

    Zhu, Yongjian; Pan, Weiqing; Luo, Yanliang

    2010-08-01

    A new kind of 3D measurement system has been developed to achieve the 3D profile of complex object. The principle of measurement system is based on the triangular measurement of digital fringe projection, and the fringes are fully generated from computer. Thus the computer-generated four fringes form the data source of phase-shifting 3D profilometry. The hardware of system includes the computer, video camera, projector, image grabber, and VGA board with two ports (one port links to the screen, another to the projector). The software of system consists of grating projection module, image grabbing module, phase reconstructing module and 3D display module. A software-based synchronizing method between grating projection and image capture is proposed. As for the nonlinear error of captured fringes, a compensating method is introduced based on the pixel-to-pixel gray correction. At the same time, a least square phase unwrapping is used to solve the problem of phase reconstruction by using the combination of Log Modulation Amplitude and Phase Derivative Variance (LMAPDV) as weight. The system adopts an algorithm from Matlab Tool Box for camera calibration. The 3D measurement system has an accuracy of 0.05mm. The execution time of system is 3~5s for one-time measurement.

  1. Voice and gesture-based 3D multimedia presentation tool

    NASA Astrophysics Data System (ADS)

    Fukutake, Hiromichi; Akazawa, Yoshiaki; Okada, Yoshihiro

    2007-09-01

    This paper proposes a 3D multimedia presentation tool that allows the user to manipulate intuitively only through the voice input and the gesture input without using a standard keyboard or a mouse device. The authors developed this system as a presentation tool to be used in a presentation room equipped a large screen like an exhibition room in a museum because, in such a presentation environment, it is better to use voice commands and the gesture pointing input rather than using a keyboard or a mouse device. This system was developed using IntelligentBox, which is a component-based 3D graphics software development system. IntelligentBox has already provided various types of 3D visible, reactive functional components called boxes, e.g., a voice input component and various multimedia handling components. IntelligentBox also provides a dynamic data linkage mechanism called slot-connection that allows the user to develop 3D graphics applications by combining already existing boxes through direct manipulations on a computer screen. Using IntelligentBox, the 3D multimedia presentation tool proposed in this paper was also developed as combined components only through direct manipulations on a computer screen. The authors have already proposed a 3D multimedia presentation tool using a stage metaphor and its voice input interface. This time, we extended the system to make it accept the user gesture input besides voice commands. This paper explains details of the proposed 3D multimedia presentation tool and especially describes its component-based voice and gesture input interfaces.

  2. 3D surface imaging for guidance in breast cancer radiotherapy: organs at risk

    NASA Astrophysics Data System (ADS)

    Alderliesten, Tanja; Betgen, Anja; van Vliet-Vroegindeweij, Corine; Remeijer, Peter

    2013-03-01

    Purpose: To evaluate the variability in heart position in deep-inspiration breath-hold (DIBH) radiotherapy for breast cancer when 3D surface imaging would be used for monitoring the depth of the breath hold during treatment. Materials and Methods: Ten patients who received DIBH radiotherapy after breast-conserving surgery (BCS) were included. Retrospectively, heart-based registrations were performed for cone-beam computed tomography (CBCT) to planning CT and breast surface registrations were performed for a 3D surface (two different regions of interest [ROIs]), captured concurrently with CBCT, to planning CT. The resulting setup errors were compared with linear regression analysis and receiver operating characteristic (ROC) analysis was performed to investigate the prediction quality of 3D surface imaging for 3D heart displacement. Further, the residual setup errors (systematic [Σ] and random [σ]) of the heart were estimated relative to the surface registrations. Results: When surface imaging [ROIleft-side;ROIboth-sides] would be used for monitoring, the residual errors of the heart position are in left-right: Σ=[0.360.12], σ=[0.160.14] cranio-caudal: Σ=[0.540.54], σ=[0.280.31] and in anteriorposterior: Σ=[0.180.14], σ=[0.200.19] cm. Correlations between setup errors were: R2 = [0.23;0.73], [0.67;0.65], [0.65;0.73] in left-right, cranio-caudal, and anterior-posterior direction, respectively. ROC analysis resulted in an area under the ROC curve of [0.82;0.78]. Conclusion: The use of ROIboth-sides provided promising results. However, considerable variability in the heart position, particularly in CC direction, is observed when 3D surface imaging would be used for guidance in DIBH radiotherapy after BCS. Planning organ at risk volume margins should be used to take into account the heart-position variability.

  3. Highly-Sensitive Surface-Enhanced Raman Spectroscopy (SERS)-based Chemical Sensor using 3D Graphene Foam Decorated with Silver Nanoparticles as SERS substrate

    PubMed Central

    Srichan, Chavis; Ekpanyapong, Mongkol; Horprathum, Mati; Eiamchai, Pitak; Nuntawong, Noppadon; Phokharatkul, Ditsayut; Danvirutai, Pobporn; Bohez, Erik; Wisitsoraat, Anurat; Tuantranont, Adisorn

    2016-01-01

    In this work, a novel platform for surface-enhanced Raman spectroscopy (SERS)-based chemical sensors utilizing three-dimensional microporous graphene foam (GF) decorated with silver nanoparticles (AgNPs) is developed and applied for methylene blue (MB) detection. The results demonstrate that silver nanoparticles significantly enhance cascaded amplification of SERS effect on multilayer graphene foam (GF). The enhancement factor of AgNPs/GF sensor is found to be four orders of magnitude larger than that of AgNPs/Si substrate. In addition, the sensitivity of the sensor could be tuned by controlling the size of silver nanoparticles. The highest SERS enhancement factor of ∼5 × 104 is achieved at the optimal nanoparticle size of 50 nm. Moreover, the sensor is capable of detecting MB over broad concentration ranges from 1 nM to 100 μM. Therefore, AgNPs/GF is a highly promising SERS substrate for detection of chemical substances with ultra-low concentrations. PMID:27020705

  4. Hough transform-based 3D mesh retrieval

    NASA Astrophysics Data System (ADS)

    Zaharia, Titus; Preteux, Francoise J.

    2001-11-01

    This papre addresses the issue of 3D mesh indexation by using shape descriptors (SDs) under constraints of geometric and topological invariance. A new shape descriptor, the Optimized 3D Hough Transform Descriptor (O3HTD) is here proposed. Intrinsically topologically stable, the O3DHTD is not invariant to geometric transformations. Nevertheless, we show mathematically how the O3DHTD can be optimally associated (in terms of compactness of representation and computational complexity) with a spatial alignment procedure which leads to a geometric invariant behavior. Experimental results have been carried out upon the MPEG-7 3D model database consisting of about 1300 meshes in VRML 2.0 format. Objective retrieval results, based upon the definition of a categorized ground truth subset, are reported in terms of Bull Eye Percentage (BEP) score and compared to those obtained by applying the MPEg-7 3D SD. It is shown that the O3DHTD outperforms the MPEg-7 3D SD of up to 28%.

  5. Optical 3D watermark based digital image watermarking for telemedicine

    NASA Astrophysics Data System (ADS)

    Li, Xiao Wei; Kim, Seok Tae

    2013-12-01

    Region of interest (ROI) of a medical image is an area including important diagnostic information and must be stored without any distortion. This algorithm for application of watermarking technique for non-ROI of the medical image preserving ROI. The paper presents a 3D watermark based medical image watermarking scheme. In this paper, a 3D watermark object is first decomposed into 2D elemental image array (EIA) by a lenslet array, and then the 2D elemental image array data is embedded into the host image. The watermark extraction process is an inverse process of embedding. The extracted EIA through the computational integral imaging reconstruction (CIIR) technique, the 3D watermark can be reconstructed. Because the EIA is composed of a number of elemental images possesses their own perspectives of a 3D watermark object. Even though the embedded watermark data badly damaged, the 3D virtual watermark can be successfully reconstructed. Furthermore, using CAT with various rule number parameters, it is possible to get many channels for embedding. So our method can recover the weak point having only one transform plane in traditional watermarking methods. The effectiveness of the proposed watermarking scheme is demonstrated with the aid of experimental results.

  6. Full-field 3D shape measurement of specular surfaces by direct phase to depth relationship

    NASA Astrophysics Data System (ADS)

    Zhang, Zonghua; Liu, Yue; Huang, Shujun; Niu, Zhenqi; Guo, Jiao; Gao, Nan; Gao, Feng; Jiang, Xiangqian

    2016-11-01

    This paper presents a new Phase Measuring Deflectometry (PMD) method to measure specular object having discontinuous surfaces. A mathematical model is established to directly relate absolute phase and depth, instead of phase and gradient. Based on the model, a hardware measuring system has been set up, which consists of a beam splitter to change the optical path, and two LCD screens to display the same sinusoidal fringe patterns. By using model-based and machine vision method, system calibration is accomplished to provide the required parameters and conditions. The verification tests are given to evaluate the effectiveness of the developed system. The 3D shape of an artificial step having multiple specular surfaces and a concave mirror has been measured. Initial experimental results show that the proposed measurement method can obtain 3D shape of specular objects with discontinuous surface effectively.

  7. Applications of Alginate-Based Bioinks in 3D Bioprinting

    PubMed Central

    Axpe, Eneko; Oyen, Michelle L.

    2016-01-01

    Three-dimensional (3D) bioprinting is on the cusp of permitting the direct fabrication of artificial living tissue. Multicellular building blocks (bioinks) are dispensed layer by layer and scaled for the target construct. However, only a few materials are able to fulfill the considerable requirements for suitable bioink formulation, a critical component of efficient 3D bioprinting. Alginate, a naturally occurring polysaccharide, is clearly the most commonly employed material in current bioinks. Here, we discuss the benefits and disadvantages of the use of alginate in 3D bioprinting by summarizing the most recent studies that used alginate for printing vascular tissue, bone and cartilage. In addition, other breakthroughs in the use of alginate in bioprinting are discussed, including strategies to improve its structural and degradation characteristics. In this review, we organize the available literature in order to inspire and accelerate novel alginate-based bioink formulations with enhanced properties for future applications in basic research, drug screening and regenerative medicine. PMID:27898010

  8. Perception-based shape retrieval for 3D building models

    NASA Astrophysics Data System (ADS)

    Zhang, Man; Zhang, Liqiang; Takis Mathiopoulos, P.; Ding, Yusi; Wang, Hao

    2013-01-01

    With the help of 3D search engines, a large number of 3D building models can be retrieved freely online. A serious disadvantage of most rotation-insensitive shape descriptors is their inability to distinguish between two 3D building models which are different at their main axes, but appear similar when one of them is rotated. To resolve this problem, we present a novel upright-based normalization method which not only correctly rotates such building models, but also greatly simplifies and accelerates the abstraction and the matching of building models' shape descriptors. Moreover, the abundance of architectural styles significantly hinders the effective shape retrieval of building models. Our research has shown that buildings with different designs are not well distinguished by the widely recognized shape descriptors for general 3D models. Motivated by this observation and to further improve the shape retrieval quality, a new building matching method is introduced and analyzed based on concepts found in the field of perception theory and the well-known Light Field descriptor. The resulting normalized building models are first classified using the qualitative shape descriptors of Shell and Unevenness which outline integral geometrical and topological information. These models are then put in on orderly fashion with the help of an improved quantitative shape descriptor which we will term as Horizontal Light Field Descriptor, since it assembles detailed shape characteristics. To accurately evaluate the proposed methodology, an enlarged building shape database which extends previous well-known shape benchmarks was implemented as well as a model retrieval system supporting inputs from 2D sketches and 3D models. Various experimental performance evaluation results have shown that, as compared to previous methods, retrievals employing the proposed matching methodology are faster and more consistent with human recognition of spatial objects. In addition these performance

  9. Binary 3D image interpolation algorithm based global information and adaptive curves fitting

    NASA Astrophysics Data System (ADS)

    Zhang, Tian-yi; Zhang, Jin-hao; Guan, Xiang-chen; Li, Qiu-ping; He, Meng

    2013-08-01

    Interpolation is a necessary processing step in 3-D reconstruction because of the non-uniform resolution. Conventional interpolation methods simply use two slices to obtain the missing slices between the two slices .when the key slice is missing, those methods may fail to recover it only employing the local information .And the surface of 3D object especially for the medical tissues may be highly complicated, so a single interpolation can hardly get high-quality 3D image. We propose a novel binary 3D image interpolation algorithm. The proposed algorithm takes advantages of the global information. It chooses the best curve adaptively from lots of curves based on the complexity of the surface of 3D object. The results of this algorithm are compared with other interpolation methods on artificial objects and real breast cancer tumor to demonstrate the excellent performance.

  10. A monthly quality assurance procedure for 3D surface imaging.

    PubMed

    Wooten, H Omar; Klein, Eric E; Gokhroo, Garima; Santanam, Lakshmi

    2010-12-21

    A procedure for periodic quality assurance of a video surface imaging system is introduced. AlignRT is a video camera-based patient localization system that captures and compares images of a patient's topography to a DICOM-formatted external contour, then calculates shifts required to accurately reposition the patient. This technical note describes the tools and methods implemented in our department to verify correct and accurate operation of the AlignRT hardware and software components. The procedure described is performed monthly and complements a daily calibration of the system.

  11. 3D Ear Identification Based on Sparse Representation

    PubMed Central

    Zhang, Lin; Ding, Zhixuan; Li, Hongyu; Shen, Ying

    2014-01-01

    Biometrics based personal authentication is an effective way for automatically recognizing, with a high confidence, a person’s identity. Recently, 3D ear shape has attracted tremendous interests in research field due to its richness of feature and ease of acquisition. However, the existing ICP (Iterative Closet Point)-based 3D ear matching methods prevalent in the literature are not quite efficient to cope with the one-to-many identification case. In this paper, we aim to fill this gap by proposing a novel effective fully automatic 3D ear identification system. We at first propose an accurate and efficient template-based ear detection method. By utilizing such a method, the extracted ear regions are represented in a common canonical coordinate system determined by the ear contour template, which facilitates much the following stages of feature extraction and classification. For each extracted 3D ear, a feature vector is generated as its representation by making use of a PCA-based local feature descriptor. At the stage of classification, we resort to the sparse representation based classification approach, which actually solves an l1-minimization problem. To the best of our knowledge, this is the first work introducing the sparse representation framework into the field of 3D ear identification. Extensive experiments conducted on a benchmark dataset corroborate the effectiveness and efficiency of the proposed approach. The associated Matlab source code and the evaluation results have been made publicly online available at http://sse.tongji.edu.cn/linzhang/ear/srcear/srcear.htm. PMID:24740247

  12. Optimal Image Stitching for Concrete Bridge Bottom Surfaces Aided by 3d Structure Lines

    NASA Astrophysics Data System (ADS)

    Liu, Yahui; Yao, Jian; Liu, Kang; Lu, Xiaohu; Xia, Menghan

    2016-06-01

    Crack detection for bridge bottom surfaces via remote sensing techniques is undergoing a revolution in the last few years. For such applications, a large amount of images, acquired with high-resolution industrial cameras close to the bottom surfaces with some mobile platform, are required to be stitched into a wide-view single composite image. The conventional idea of stitching a panorama with the affine model or the homographic model always suffers a series of serious problems due to poor texture and out-of-focus blurring introduced by depth of field. In this paper, we present a novel method to seamlessly stitch these images aided by 3D structure lines of bridge bottom surfaces, which are extracted from 3D camera data. First, we propose to initially align each image in geometry based on its rough position and orientation acquired with both a laser range finder (LRF) and a high-precision incremental encoder, and these images are divided into several groups with the rough position and orientation data. Secondly, the 3D structure lines of bridge bottom surfaces are extracted from the 3D cloud points acquired with 3D cameras, which impose additional strong constraints on geometrical alignment of structure lines in adjacent images to perform a position and orientation optimization in each group to increase the local consistency. Thirdly, a homographic refinement between groups is applied to increase the global consistency. Finally, we apply a multi-band blending algorithm to generate a large-view single composite image as seamlessly as possible, which greatly eliminates both the luminance differences and the color deviations between images and further conceals image parallax. Experimental results on a set of representative images acquired from real bridge bottom surfaces illustrate the superiority of our proposed approaches.

  13. The effect of near-infrared laser beam on the surface modification of metal complex based on 3D laser scanning system

    NASA Astrophysics Data System (ADS)

    Zhao, Mali; Liu, Tiegen; Jiang, Junfeng; Wang, Meng

    2014-11-01

    High-precision 3-dimensional metallization is difficult to realize in specific nonmetallic areas by using the traditional methods such as wet-chemical and mechanical methods because of the disadvantage that usually they cannot achieve selective modification. In this paper, 3-dimensional laser scanning system was applied to achieve the modification of specific regions of the sample surface. In 3-dimensional laser scanning system, the laser beam, after going through dynamic focusing system, was reflected by galvanometers and then focused by f-theta lens on the sample surface. The changes in surface characteristics of the blends of polycarbonate and acrylonitrile butadiene styrene copolymers (PC/ABS) mixed with Cu-Cr complex by the laser irradiation with the wavelength of 1064nm were investigated. Through analysis it was found that the smooth surface of the original samples was changed to a micro-hole structure accompanied by an increased surface roughness as well as an increased water contact angle. The chemical composition percentage had changed and the metal components of copper and chromium were detected after the laser irradiation. The irradiated areas were degraded into organic ligand fragments, volatile gas and reducing metal ions of copper and chromium. Besides, the thickness of the deposited metal layer and the adhesive force between the metal layer and the substrate after electroless plating varied according to the laser parameters such as frequency and scanning speed. As shown in the experiment, the thickness of deposited copper layer exceeded 11μm and the deposited nickel layer exceeded 2μm respectively.

  14. Strain-Initialized Robust Bone Surface Detection in 3-D Ultrasound.

    PubMed

    Hussain, Mohammad Arafat; Hodgson, Antony J; Abugharbieh, Rafeef

    2017-03-01

    Three-dimensional ultrasound has been increasingly considered as a safe radiation-free alternative to radiation-based fluoroscopic imaging for surgical guidance during computer-assisted orthopedic interventions, but because ultrasound images contain significant artifacts, it is challenging to automatically extract bone surfaces from these images. We propose an effective way to extract 3-D bone surfaces using a surface growing approach that is seeded from 2-D bone contours. The initial 2-D bone contours are estimated from a combination of ultrasound strain images and envelope power images. Novel features of the proposed method include: (i) improvement of a previously reported 2-D strain imaging-based bone segmentation method by incorporation of a depth-dependent cumulative power of the envelope into the elastographic data; (ii) incorporation of an echo decorrelation measure-based weight to fuse the strain and envelope maps; (iii) use of local statistics of the bone surface candidate points to detect the presence of any bone discontinuity; and (iv) an extension of our 2-D bone contour into a 3-D bone surface by use of an effective surface growing approach. Our new method produced average improvements in the mean absolute error of 18% and 23%, respectively, on 2-D and 3-D experimental phantom data, compared with those of two state-of-the-art bone segmentation methods. Validation on 2-D and 3-D clinical in vivo data also reveals, respectively, an average improvement in the mean absolute fitting error of 55% and an 18-fold improvement in the computation time.

  15. Optical 3D shape, surface, and material analysis

    NASA Astrophysics Data System (ADS)

    Tiziani, Hans J.

    2001-06-01

    Different techniques are available for macro- and micro- topometry. The methods are basically known but their industrial implementation requires robust measuring systems, where calibration is an important necessity. Different techniques will be presented. New elements such as liquid crystal displays and micromirror devices are available leading to new applications to be discussed. Combinative methods and integration in measuring systems becomes interesting. The state of the art and new developments will be presented. Together with calibration for 3D-shock or vibration analysis an object shape measuring systems will be directly combined with a vibration measuring system.

  16. A new approach towards image based virtual 3D city modeling by using close range photogrammetry

    NASA Astrophysics Data System (ADS)

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-05-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing day to day for various engineering and non-engineering applications. Generally three main image based approaches are using for virtual 3D city models generation. In first approach, researchers used Sketch based modeling, second method is Procedural grammar based modeling and third approach is Close range photogrammetry based modeling. Literature study shows that till date, there is no complete solution available to create complete 3D city model by using images. These image based methods also have limitations This paper gives a new approach towards image based virtual 3D city modeling by using close range photogrammetry. This approach is divided into three sections. First, data acquisition process, second is 3D data processing, and third is data combination process. In data acquisition process, a multi-camera setup developed and used for video recording of an area. Image frames created from video data. Minimum required and suitable video image frame selected for 3D processing. In second section, based on close range photogrammetric principles and computer vision techniques, 3D model of area created. In third section, this 3D model exported to adding and merging of other pieces of large area. Scaling and alignment of 3D model was done. After applying the texturing and rendering on this model, a final photo-realistic textured 3D model created. This 3D model transferred into walk-through model or in movie form. Most of the processing steps are automatic. So this method is cost effective and less laborious. Accuracy of this model is good. For this research work, study area is the campus of department of civil engineering, Indian Institute of Technology, Roorkee. This campus acts as a prototype for city. Aerial photography is restricted in many country

  17. NDE of a 3-D surface crack using closely coupled probes for DCPD technique

    SciTech Connect

    Saka, M.; Abe, H.; Hirota, D.; Komura, I.

    1998-11-01

    A procedure of applying the d-c potential drop technique using the closely coupled probes to NDE of a 3-D surface crack is newly developed. The calibration equation for three sensors which differ in the distance between the probes is derived. Experiments validated the use of the calibration equation for the NDE of cracks. The method to use the three sensors properly based on the measuring sensitivity is shown.

  18. Evolution of 3D surface imaging systems in facial plastic surgery.

    PubMed

    Tzou, Chieh-Han John; Frey, Manfred

    2011-11-01

    Recent advancements in computer technologies have propelled the development of 3D imaging systems. 3D surface-imaging is taking surgeons to a new level of communication with patients; moreover, it provides quick and standardized image documentation. This article recounts the chronologic evolution of 3D surface imaging, and summarizes the current status of today's facial surface capturing technology. This article also discusses current 3D surface imaging hardware and software, and their different techniques, technologies, and scientific validation, which provides surgeons with the background information necessary for evaluating the systems and knowledge about the systems they might incorporate into their own practice.

  19. A continuous surface reconstruction method on point cloud captured from a 3D surface photogrammetry system

    SciTech Connect

    Liu, Wenyang; Cheung, Yam; Sabouri, Pouya; Arai, Tatsuya J.; Sawant, Amit; Ruan, Dan

    2015-11-15

    achieved submillimeter reconstruction RMSE under different configurations, demonstrating quantitatively the faith of the proposed method in preserving local structural properties of the underlying surface in the presence of noise and missing measurements, and its robustness toward variations of such characteristics. On point clouds from the human subject, the proposed method successfully reconstructed all patient surfaces, filling regions where raw point coordinate readings were missing. Within two comparable regions of interest in the chest area, similar mean curvature distributions were acquired from both their reconstructed surface and CT surface, with mean and standard deviation of (μ{sub recon} = − 2.7 × 10{sup −3} mm{sup −1}, σ{sub recon} = 7.0 × 10{sup −3} mm{sup −1}) and (μ{sub CT} = − 2.5 × 10{sup −3} mm{sup −1}, σ{sub CT} = 5.3 × 10{sup −3} mm{sup −1}), respectively. The agreement of local geometry properties between the reconstructed surfaces and the CT surface demonstrated the ability of the proposed method in faithfully representing the underlying patient surface. Conclusions: The authors have integrated and developed an accurate level-set based continuous surface reconstruction method on point clouds acquired by a 3D surface photogrammetry system. The proposed method has generated a continuous representation of the underlying phantom and patient surfaces with good robustness against noise and missing measurements. It serves as an important first step for further development of motion tracking methods during radiotherapy.

  20. A continuous surface reconstruction method on point cloud captured from a 3D surface photogrammetry system

    PubMed Central

    Liu, Wenyang; Cheung, Yam; Sabouri, Pouya; Arai, Tatsuya J.; Sawant, Amit; Ruan, Dan

    2015-01-01

    achieved submillimeter reconstruction RMSE under different configurations, demonstrating quantitatively the faith of the proposed method in preserving local structural properties of the underlying surface in the presence of noise and missing measurements, and its robustness toward variations of such characteristics. On point clouds from the human subject, the proposed method successfully reconstructed all patient surfaces, filling regions where raw point coordinate readings were missing. Within two comparable regions of interest in the chest area, similar mean curvature distributions were acquired from both their reconstructed surface and CT surface, with mean and standard deviation of (μrecon = − 2.7 × 10−3 mm−1, σrecon = 7.0 × 10−3 mm−1) and (μCT = − 2.5 × 10−3 mm−1, σCT = 5.3 × 10−3 mm−1), respectively. The agreement of local geometry properties between the reconstructed surfaces and the CT surface demonstrated the ability of the proposed method in faithfully representing the underlying patient surface. Conclusions: The authors have integrated and developed an accurate level-set based continuous surface reconstruction method on point clouds acquired by a 3D surface photogrammetry system. The proposed method has generated a continuous representation of the underlying phantom and patient surfaces with good robustness against noise and missing measurements. It serves as an important first step for further development of motion tracking methods during radiotherapy. PMID:26520747

  1. 3D geometry-based quantification of colocalizations in multichannel 3D microscopy images of human soft tissue tumors.

    PubMed

    Wörz, Stefan; Sander, Petra; Pfannmöller, Martin; Rieker, Ralf J; Joos, Stefan; Mechtersheimer, Gunhild; Boukamp, Petra; Lichter, Peter; Rohr, Karl

    2010-08-01

    We introduce a new model-based approach for automatic quantification of colocalizations in multichannel 3D microscopy images. The approach uses different 3D parametric intensity models in conjunction with a model fitting scheme to localize and quantify subcellular structures with high accuracy. The central idea is to determine colocalizations between different channels based on the estimated geometry of the subcellular structures as well as to differentiate between different types of colocalizations. A statistical analysis was performed to assess the significance of the determined colocalizations. This approach was used to successfully analyze about 500 three-channel 3D microscopy images of human soft tissue tumors and controls.

  2. 3D-shape-based retrieval within the MPEG-7 framework

    NASA Astrophysics Data System (ADS)

    Zaharia, Titus; Preteux, Francoise J.

    2001-05-01

    Because of the continuous development of multimedia technologies, virtual worlds and augmented reality, 3D contents become a common feature of the today information systems. Hence, standardizing tools for content-based indexing of visual data is a key issue for computer vision related applications. Within the framework of the future MPEG-7 standard, tools for intelligent content-based access to 3D information, targeting applications such as search and retrieval and browsing of 3D model databases, have been recently considered and evaluated. In this paper, we present the 3D Shape Spectrum Descriptor (3D SSD), recently adopted within the current MPEG-7 Committee Draft (CD). The proposed descriptor aims at providing an intrinsic shape description of a 3D mesh and is defined as the distribution of the shape index over the entire mesh. The shape index is a local geometric attribute of a 3D surface, expressed as the angular coordinate of a polar representation of the principal curvature vector. Experimental results have been carried out upon the MPEG-7 3D model database consisting of about 1300 meshes in VRML 2.0 format. Objective retrieval results, based upon the definition of a ground truth subset, are reported in terms of Bull Eye Percentage (BEP) score.

  3. Importance of a 3D forward modeling tool for surface wave analysis methods

    NASA Astrophysics Data System (ADS)

    Pageot, Damien; Le Feuvre, Mathieu; Donatienne, Leparoux; Philippe, Côte; Yann, Capdeville

    2016-04-01

    Since a few years, seismic surface waves analysis methods (SWM) have been widely developed and tested in the context of subsurface characterization and have demonstrated their effectiveness for sounding and monitoring purposes, e.g., high-resolution tomography of the principal geological units of California or real time monitoring of the Piton de la Fournaise volcano. Historically, these methods are mostly developed under the assumption of semi-infinite 1D layered medium without topography. The forward modeling is generally based on Thomson-Haskell matrix based modeling algorithm and the inversion is driven by Monte-Carlo sampling. Given their efficiency, SWM have been transfered to several scale of which civil engineering structures in order to, e.g., determine the so-called V s30 parameter or assess other critical constructional parameters in pavement engineering. However, at this scale, many structures may often exhibit 3D surface variations which drastically limit the efficiency of SWM application. Indeed, even in the case of an homogeneous structure, 3D geometry can bias the dispersion diagram of Rayleigh waves up to obtain discontinuous phase velocity curves which drastically impact the 1D mean velocity model obtained from dispersion inversion. Taking advantages of high-performance computing center accessibility and wave propagation modeling algorithm development, it is now possible to consider the use of a 3D elastic forward modeling algorithm instead of Thomson-Haskell method in the SWM inversion process. We use a parallelized 3D elastic modeling code based on the spectral element method which allows to obtain accurate synthetic data with very low numerical dispersion and a reasonable numerical cost. In this study, we choose dike embankments as an illustrative example. We first show that their longitudinal geometry may have a significant effect on dispersion diagrams of Rayleigh waves. Then, we demonstrate the necessity of 3D elastic modeling as a forward

  4. Evaluation Model for Pavement Surface Distress on 3d Point Clouds from Mobile Mapping System

    NASA Astrophysics Data System (ADS)

    Aoki, K.; Yamamoto, K.; Shimamura, H.

    2012-07-01

    This paper proposes a methodology to evaluate the pavement surface distress for maintenance planning of road pavement using 3D point clouds from Mobile Mapping System (MMS). The issue on maintenance planning of road pavement requires scheduled rehabilitation activities for damaged pavement sections to keep high level of services. The importance of this performance-based infrastructure asset management on actual inspection data is globally recognized. Inspection methodology of road pavement surface, a semi-automatic measurement system utilizing inspection vehicles for measuring surface deterioration indexes, such as cracking, rutting and IRI, have already been introduced and capable of continuously archiving the pavement performance data. However, any scheduled inspection using automatic measurement vehicle needs much cost according to the instruments' specification or inspection interval. Therefore, implementation of road maintenance work, especially for the local government, is difficult considering costeffectiveness. Based on this background, in this research, the methodologies for a simplified evaluation for pavement surface and assessment of damaged pavement section are proposed using 3D point clouds data to build urban 3D modelling. The simplified evaluation results of road surface were able to provide useful information for road administrator to find out the pavement section for a detailed examination and for an immediate repair work. In particular, the regularity of enumeration of 3D point clouds was evaluated using Chow-test and F-test model by extracting the section where the structural change of a coordinate value was remarkably achieved. Finally, the validity of the current methodology was investigated by conducting a case study dealing with the actual inspection data of the local roads.

  5. Visual fatigue evaluation based on depth in 3D videos

    NASA Astrophysics Data System (ADS)

    Wang, Feng-jiao; Sang, Xin-zhu; Liu, Yangdong; Shi, Guo-zhong; Xu, Da-xiong

    2013-08-01

    In recent years, 3D technology has become an emerging industry. However, visual fatigue always impedes the development of 3D technology. In this paper we propose some factors affecting human perception of depth as new quality metrics. These factors are from three aspects of 3D video--spatial characteristics, temporal characteristics and scene movement characteristics. They play important roles for the viewer's visual perception. If there are many objects with a certain velocity and the scene changes fast, viewers will feel uncomfortable. In this paper, we propose a new algorithm to calculate the weight values of these factors and analyses their effect on visual fatigue.MSE (Mean Square Error) of different blocks is taken into consideration from the frame and inter-frame for 3D stereoscopic videos. The depth frame is divided into a number of blocks. There are overlapped and sharing pixels (at half of the block) in the horizontal and vertical direction. Ignoring edge information of objects in the image can be avoided. Then the distribution of all these data is indicated by kurtosis with regard of regions which human eye may mainly gaze at. Weight values can be gotten by the normalized kurtosis. When the method is used for individual depth, spatial variation can be achieved. When we use it in different frames between current and previous one, we can get temporal variation and scene movement variation. Three factors above are linearly combined, so we can get objective assessment value of 3D videos directly. The coefficients of three factors can be estimated based on the liner regression. At last, the experimental results show that the proposed method exhibits high correlation with subjective quality assessment results.

  6. 3-D model-based tracking for UAV indoor localization.

    PubMed

    Teulière, Céline; Marchand, Eric; Eck, Laurent

    2015-05-01

    This paper proposes a novel model-based tracking approach for 3-D localization. One main difficulty of standard model-based approach lies in the presence of low-level ambiguities between different edges. In this paper, given a 3-D model of the edges of the environment, we derive a multiple hypotheses tracker which retrieves the potential poses of the camera from the observations in the image. We also show how these candidate poses can be integrated into a particle filtering framework to guide the particle set toward the peaks of the distribution. Motivated by the UAV indoor localization problem where GPS signal is not available, we validate the algorithm on real image sequences from UAV flights.

  7. Robust Locally Weighted Regression For Ground Surface Extraction In Mobile Laser Scanning 3D Data

    NASA Astrophysics Data System (ADS)

    Nurunnabi, A.; West, G.; Belton, D.

    2013-10-01

    A new robust way for ground surface extraction from mobile laser scanning 3D point cloud data is proposed in this paper. Fitting polynomials along 2D/3D points is one of the well-known methods for filtering ground points, but it is evident that unorganized point clouds consist of multiple complex structures by nature so it is not suitable for fitting a parametric global model. The aim of this research is to develop and implement an algorithm to classify ground and non-ground points based on statistically robust locally weighted regression which fits a regression surface (line in 2D) by fitting without any predefined global functional relation among the variables of interest. Afterwards, the z (elevation)-values are robustly down weighted based on the residuals for the fitted points. The new set of down weighted z-values along with x (or y) values are used to get a new fit of the (lower) surface (line). The process of fitting and down-weighting continues until the difference between two consecutive fits is insignificant. Then the final fit represents the ground level of the given point cloud and the ground surface points can be extracted. The performance of the new method has been demonstrated through vehicle based mobile laser scanning 3D point cloud data from urban areas which include different problematic objects such as short walls, large buildings, electric poles, sign posts and cars. The method has potential in areas like building/construction footprint determination, 3D city modelling, corridor mapping and asset management.

  8. Construction of Extended 3D Field of Views of the Internal Bladder Wall Surface: A Proof of Concept

    NASA Astrophysics Data System (ADS)

    Ben-Hamadou, Achraf; Daul, Christian; Soussen, Charles

    2016-09-01

    3D extended field of views (FOVs) of the internal bladder wall facilitate lesion diagnosis, patient follow-up and treatment traceability. In this paper, we propose a 3D image mosaicing algorithm guided by 2D cystoscopic video-image registration for obtaining textured FOV mosaics. In this feasibility study, the registration makes use of data from a 3D cystoscope prototype providing, in addition to each small FOV image, some 3D points located on the surface. This proof of concept shows that textured surfaces can be constructed with minimally modified cystoscopes. The potential of the method is demonstrated on numerical and real phantoms reproducing various surface shapes. Pig and human bladder textures are superimposed on phantoms with known shape and dimensions. These data allow for quantitative assessment of the 3D mosaicing algorithm based on the registration of images simulating bladder textures.

  9. 3D Building Models Segmentation Based on K-Means++ Cluster Analysis

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Mao, B.

    2016-10-01

    3D mesh model segmentation is drawing increasing attentions from digital geometry processing field in recent years. The original 3D mesh model need to be divided into separate meaningful parts or surface patches based on certain standards to support reconstruction, compressing, texture mapping, model retrieval and etc. Therefore, segmentation is a key problem for 3D mesh model segmentation. In this paper, we propose a method to segment Collada (a type of mesh model) 3D building models into meaningful parts using cluster analysis. Common clustering methods segment 3D mesh models by K-means, whose performance heavily depends on randomized initial seed points (i.e., centroid) and different randomized centroid can get quite different results. Therefore, we improved the existing method and used K-means++ clustering algorithm to solve this problem. Our experiments show that K-means++ improves both the speed and the accuracy of K-means, and achieve good and meaningful results.

  10. Pluto: Modeling of 3-D Atmosphere-Surface Interactions

    NASA Astrophysics Data System (ADS)

    Michaels, Timothy I.

    2015-11-01

    Atmosphere-surface interactions on Pluto are of great importance to creating and maintaining the atmospheric variations and heterogeneous surface that have been observed by New Horizons and two decades' prior work. Publicly released images/data from New Horizons contain numerous fascinating surface features and constrasts. Insights into their origin, maintenance, and/or evolution may be gleaned through multidisciplinary climate modeling. Some results from such modeling will be presented, with an emphasis on shorter-timescale interactions.

  11. 3-D measuring of engine camshaft based on machine vision

    NASA Astrophysics Data System (ADS)

    Qiu, Jianxin; Tan, Liang; Xu, Xiaodong

    2008-12-01

    The non-touch 3D measuring based on machine vision is introduced into camshaft precise measuring. Currently, because CCD 3-dimensional measuring can't meet requirements for camshaft's measuring precision, it's necessary to improve its measuring precision. In this paper, we put forward a method to improve the measuring method. A Multi-Character Match method based on the Polygonal Non-regular model is advanced with the theory of Corner Extraction and Corner Matching .This method has solved the problem of the matching difficulty and a low precision. In the measuring process, the use of the Coded marked Point method and Self-Character Match method can bring on this problem. The 3D measuring experiment on camshaft, which based on the Multi-Character Match method of the Polygonal Non-regular model, proves that the normal average measuring precision is increased to a new level less than 0.04mm in the point-clouds photo merge. This measuring method can effectively increase the 3D measuring precision of the binocular CCD.

  12. Midsagittal plane extraction from brain images based on 3D SIFT

    NASA Astrophysics Data System (ADS)

    Wu, Huisi; Wang, Defeng; Shi, Lin; Wen, Zhenkun; Ming, Zhong

    2014-03-01

    Midsagittal plane (MSP) extraction from 3D brain images is considered as a promising technique for human brain symmetry analysis. In this paper, we present a fast and robust MSP extraction method based on 3D scale-invariant feature transform (SIFT). Unlike the existing brain MSP extraction methods, which mainly rely on the gray similarity, 3D edge registration or parameterized surface matching to determine the fissure plane, our proposed method is based on distinctive 3D SIFT features, in which the fissure plane is determined by parallel 3D SIFT matching and iterative least-median of squares plane regression. By considering the relative scales, orientations and flipped descriptors between two 3D SIFT features, we propose a novel metric to measure the symmetry magnitude for 3D SIFT features. By clustering and indexing the extracted SIFT features using a k-dimensional tree (KD-tree) implemented on graphics processing units, we can match multiple pairs of 3D SIFT features in parallel and solve the optimal MSP on-the-fly. The proposed method is evaluated by synthetic and in vivo datasets, of normal and pathological cases, and validated by comparisons with the state-of-the-art methods. Experimental results demonstrated that our method has achieved a real-time performance with better accuracy yielding an average yaw angle error below 0.91° and an average roll angle error no more than 0.89°.

  13. A Generalized Approach to the Modeling and Analysis of 3D Surface Morphology in Organisms

    PubMed Central

    Pappas, Janice L.; Miller, Daniel J.

    2013-01-01

    The surface geometry of an organism represents the boundary of its three-dimensional (3D) form and can be used as a proxy for the phenotype. A mathematical approach is presented that describes surface morphology using parametric 3D equations with variables expressed as x, y, z in terms of parameters u, v. Partial differentiation of variables with respect to parameters yields elements of the Jacobian representing tangent lines and planes of every point on the surface. Jacobian elements provide a compact size-free summary of the entire surface, and can be used as variables in principal components analysis to produce a morphospace. Mollusk and echinoid models are generated to demonstrate that whole organisms can be represented in a common morphospace, regardless of differences in size, geometry, and taxonomic affinity. Models can be used to simulate theoretical forms, novel morphologies, and patterns of phenotypic variation, and can also be empirically-based by designing them with reference to actual forms using reverse engineering principles. Although this study uses the Jacobian to summarize models, they can also be analyzed with 3D methods such as eigensurface, spherical harmonics, wavelet analysis, and geometric morphometrics. This general approach should prove useful for exploring broad questions regarding morphological evolution and variation. PMID:24204866

  14. Projection-slice theorem based 2D-3D registration

    NASA Astrophysics Data System (ADS)

    van der Bom, M. J.; Pluim, J. P. W.; Homan, R.; Timmer, J.; Bartels, L. W.

    2007-03-01

    In X-ray guided procedures, the surgeon or interventionalist is dependent on his or her knowledge of the patient's specific anatomy and the projection images acquired during the procedure by a rotational X-ray source. Unfortunately, these X-ray projections fail to give information on the patient's anatomy in the dimension along the projection axis. It would be very profitable to provide the surgeon or interventionalist with a 3D insight of the patient's anatomy that is directly linked to the X-ray images acquired during the procedure. In this paper we present a new robust 2D-3D registration method based on the Projection-Slice Theorem. This theorem gives us a relation between the pre-operative 3D data set and the interventional projection images. Registration is performed by minimizing a translation invariant similarity measure that is applied to the Fourier transforms of the images. The method was tested by performing multiple exhaustive searches on phantom data of the Circle of Willis and on a post-mortem human skull. Validation was performed visually by comparing the test projections to the ones that corresponded to the minimal value of the similarity measure. The Projection-Slice Theorem Based method was shown to be very effective and robust, and provides capture ranges up to 62 degrees. Experiments have shown that the method is capable of retrieving similar results when translations are applied to the projection images.

  15. 3D shape measurement with phase correlation based fringe projection

    NASA Astrophysics Data System (ADS)

    Kühmstedt, Peter; Munckelt, Christoph; Heinze, Matthias; Bräuer-Burchardt, Christian; Notni, Gunther

    2007-06-01

    Here we propose a method for 3D shape measurement by means of phase correlation based fringe projection in a stereo arrangement. The novelty in the approach is characterized by following features. Correlation between phase values of the images of two cameras is used for the co-ordinate calculation. This work stands in contrast to the sole usage of phase values (phasogrammetry) or classical triangulation (phase values and image co-ordinates - camera raster values) for the determination of the co-ordinates. The method's main advantage is the insensitivity of the 3D-coordinates from the absolute phase values. Thus it prevents errors in the determination of the co-ordinates and improves robustness in areas with interreflections artefacts and inhomogeneous regions of intensity. A technical advantage is the fact that the accuracy of the 3D co-ordinates does not depend on the projection resolution. Thus the achievable quality of the 3D co-ordinates can be selectively improved by the use of high quality camera lenses and can participate in improvements in modern camera technologies. The presented new solution of the stereo based fringe projection with phase correlation makes a flexible, errortolerant realization of measuring systems within different applications like quality control, rapid prototyping, design and CAD/CAM possible. In the paper the phase correlation method will be described in detail. Furthermore, different realizations will be shown, i.e. a mobile system for the measurement of large objects and an endoscopic like system for CAD/CAM in dental industry.

  16. Abdominal aortic aneurysm imaging with 3-D ultrasound: 3-D-based maximum diameter measurement and volume quantification.

    PubMed

    Long, A; Rouet, L; Debreuve, A; Ardon, R; Barbe, C; Becquemin, J P; Allaire, E

    2013-08-01

    The clinical reliability of 3-D ultrasound imaging (3-DUS) in quantification of abdominal aortic aneurysm (AAA) was evaluated. B-mode and 3-DUS images of AAAs were acquired for 42 patients. AAAs were segmented. A 3-D-based maximum diameter (Max3-D) and partial volume (Vol30) were defined and quantified. Comparisons between 2-D (Max2-D) and 3-D diameters and between orthogonal acquisitions were performed. Intra- and inter-observer reproducibility was evaluated. Intra- and inter-observer coefficients of repeatability (CRs) were less than 5.18 mm for Max3-D. Intra-observer and inter-observer CRs were respectively less than 6.16 and 8.71 mL for Vol30. The mean of normalized errors of Vol30 was around 7%. Correlation between Max2-D and Max3-D was 0.988 (p < 0.0001). Max3-D and Vol30 were not influenced by a probe rotation of 90°. Use of 3-DUS to quantify AAA is a new approach in clinical practice. The present study proposed and evaluated dedicated parameters. Their reproducibility makes the technique clinically reliable.

  17. New algorithms to map asymmetries of 3D surfaces.

    PubMed

    Combès, Benoît; Prima, Sylvain

    2008-01-01

    In this paper, we propose a set of new generic automated processing tools to characterise the local asymmetries of anatomical structures (represented by surfaces) at an individual level, and within/between populations. The building bricks of this toolbox are: (1) a new algorithm for robust, accurate, and fast estimation of the symmetry plane of grossly symmetrical surfaces, and (2) a new algorithm for the fast, dense, nonlinear matching of surfaces. This last algorithm is used both to compute dense individual asymmetry maps on surfaces, and to register these maps to a common template for population studies. We show these two algorithms to be mathematically well-grounded, and provide some validation experiments. Then we propose a pipeline for the statistical evaluation of local asymmetries within and between populations. Finally we present some results on real data.

  18. 3D precision measurements of meter sized surfaces using low cost illumination and camera techniques

    NASA Astrophysics Data System (ADS)

    Ekberg, Peter; Daemi, Bita; Mattsson, Lars

    2017-04-01

    Using dedicated stereo camera systems and structured light is a well-known method for measuring the 3D shape of large surfaces. However the problem is not trivial when high accuracy, in the range of few tens of microns, is needed. Many error sources need to be handled carefully in order to obtain high quality results. In this study, we present a measurement method based on low-cost camera and illumination solutions combined with high-precision image analysis and a new approach in camera calibration and 3D reconstruction. The setup consists of two ordinary digital cameras and a Gobo projector as a structured light source. A matrix of dots is projected onto the target area. The two cameras capture the images of the projected pattern on the object. The images are processed by advanced subpixel resolution algorithms prior to the application of the 3D reconstruction technique. The strength of the method lays in a different approach for calibration, 3D reconstruction, and high-precision image analysis algorithms. Using a 10 mm pitch pattern of the light dots, the method is capable of reconstructing the 3D shape of surfaces. The precision (1σ repeatability) in the measurements is  <10 µm over a volume of 60  ×  50  ×  10 cm3 at a hardware cost of ~2% of available advanced measurement techniques. The expanded uncertainty (95% confidence level) is estimated to be 83 µm, with the largest uncertainty contribution coming from the absolute length of the metal ruler used as reference.

  19. The design and implementation of stereoscopic 3D scalable vector graphics based on WebKit

    NASA Astrophysics Data System (ADS)

    Liu, Zhongxin; Wang, Wenmin; Wang, Ronggang

    2014-03-01

    Scalable Vector Graphics (SVG), which is a language designed based on eXtensible Markup Language (XML), is used to describe basic shapes embedded in webpages, such as circles and rectangles. However, it can only depict 2D shapes. As a consequence, web pages using classical SVG can only display 2D shapes on a screen. With the increasing development of stereoscopic 3D (S3D) technology, binocular 3D devices have been widely used. Under this circumstance, we intend to extend the widely used web rendering engine WebKit to support the description and display of S3D webpages. Therefore, the extension of SVG is of necessity. In this paper, we will describe how to design and implement SVG shapes with stereoscopic 3D mode. Two attributes representing the depth and thickness are added to support S3D shapes. The elimination of hidden lines and hidden surfaces, which is an important process in this project, is described as well. The modification of WebKit is also discussed, which is made to support the generation of both left view and right view at the same time. As is shown in the result, in contrast to the 2D shapes generated by the Google Chrome web browser, the shapes got from our modified browser are in S3D mode. With the feeling of depth and thickness, the shapes seem to be real 3D objects away from the screen, rather than simple curves and lines as before.

  20. Visual Short-Term Memory Benefit for Objects on Different 3-D Surfaces

    ERIC Educational Resources Information Center

    Xu, Yaoda; Nakayama, Ken

    2007-01-01

    Visual short-term memory (VSTM) plays an important role in visual cognition. Although objects are located on different 3-dimensional (3-D) surfaces in the real world, how VSTM capacity may be influenced by the presence of multiple 3-D surfaces has never been examined. By manipulating binocular disparities of visual displays, the authors found that…

  1. A Hierarchical Building Segmentation in Digital Surface Models for 3D Reconstruction

    PubMed Central

    Yan, Yiming; Gao, Fengjiao; Deng, Shupei; Su, Nan

    2017-01-01

    In this study, a hierarchical method for segmenting buildings in a digital surface model (DSM), which is used in a novel framework for 3D reconstruction, is proposed. Most 3D reconstructions of buildings are model-based. However, the limitations of these methods are overreliance on completeness of the offline-constructed models of buildings, and the completeness is not easily guaranteed since in modern cities buildings can be of a variety of types. Therefore, a model-free framework using high precision DSM and texture-images buildings was introduced. There are two key problems with this framework. The first one is how to accurately extract the buildings from the DSM. Most segmentation methods are limited by either the terrain factors or the difficult choice of parameter-settings. A level-set method are employed to roughly find the building regions in the DSM, and then a recently proposed ‘occlusions of random textures model’ are used to enhance the local segmentation of the buildings. The second problem is how to generate the facades of buildings. Synergizing with the corresponding texture-images, we propose a roof-contour guided interpolation of building facades. The 3D reconstruction results achieved by airborne-like images and satellites are compared. Experiments show that the segmentation method has good performance, and 3D reconstruction is easily performed by our framework, and better visualization results can be obtained by airborne-like images, which can be further replaced by UAV images. PMID:28125018

  2. Neuromorphic Event-Based 3D Pose Estimation

    PubMed Central

    Reverter Valeiras, David; Orchard, Garrick; Ieng, Sio-Hoi; Benosman, Ryad B.

    2016-01-01

    Pose estimation is a fundamental step in many artificial vision tasks. It consists of estimating the 3D pose of an object with respect to a camera from the object's 2D projection. Current state of the art implementations operate on images. These implementations are computationally expensive, especially for real-time applications. Scenes with fast dynamics exceeding 30–60 Hz can rarely be processed in real-time using conventional hardware. This paper presents a new method for event-based 3D object pose estimation, making full use of the high temporal resolution (1 μs) of asynchronous visual events output from a single neuromorphic camera. Given an initial estimate of the pose, each incoming event is used to update the pose by combining both 3D and 2D criteria. We show that the asynchronous high temporal resolution of the neuromorphic camera allows us to solve the problem in an incremental manner, achieving real-time performance at an update rate of several hundreds kHz on a conventional laptop. We show that the high temporal resolution of neuromorphic cameras is a key feature for performing accurate pose estimation. Experiments are provided showing the performance of the algorithm on real data, including fast moving objects, occlusions, and cases where the neuromorphic camera and the object are both in motion. PMID:26834547

  3. An endoscopic 3D scanner based on structured light.

    PubMed

    Schmalz, Christoph; Forster, Frank; Schick, Anton; Angelopoulou, Elli

    2012-07-01

    We present a new endoscopic 3D scanning system based on Single Shot Structured Light. The proposed design makes it possible to build an extremely small scanner. The sensor head contains a catadioptric camera and a pattern projection unit. The paper describes the working principle and calibration procedure of the sensor. The prototype sensor head has a diameter of only 3.6mm and a length of 14mm. It is mounted on a flexible shaft. The scanner is designed for tubular cavities and has a cylindrical working volume of about 30mm length and 30mm diameter. It acquires 3D video at 30 frames per second and typically generates approximately 5000 3D points per frame. By design, the resolution varies over the working volume, but is generally better than 200μm. A prototype scanner has been built and is evaluated in experiments with phantoms and biological samples. The recorded average error on a known test object was 92μm.

  4. 3D surface scan of biological samples with a Push-broom Imaging Spectrometer

    NASA Astrophysics Data System (ADS)

    Yao, Haibo; Kincaid, Russell; Hruska, Zuzana; Brown, Robert L.; Bhatnagar, Deepak; Cleveland, Thomas E.

    2013-08-01

    The food industry is always on the lookout for sensing technologies for rapid and nondestructive inspection of food products. Hyperspectral imaging technology integrates both imaging and spectroscopy into unique imaging sensors. Its application for food safety and quality inspection has made significant progress in recent years. Specifically, hyperspectral imaging has shown its potential for surface contamination detection in many food related applications. Most existing hyperspectral imaging systems use pushbroom scanning which is generally used for flat surface inspection. In some applications it is desirable to be able to acquire hyperspectral images on circular objects such as corn ears, apples, and cucumbers. Past research describes inspection systems that examine all surfaces of individual objects. Most of these systems did not employ hyperspectral imaging. These systems typically utilized a roller to rotate an object, such as an apple. During apple rotation, the camera took multiple images in order to cover the complete surface of the apple. The acquired image data lacked the spectral component present in a hyperspectral image. This paper discusses the development of a hyperspectral imaging system for a 3-D surface scan of biological samples. The new instrument is based on a pushbroom hyperspectral line scanner using a rotational stage to turn the sample. The system is suitable for whole surface hyperspectral imaging of circular objects. In addition to its value to the food industry, the system could be useful for other applications involving 3-D surface inspection.

  5. Facial-paralysis diagnostic system based on 3D reconstruction

    NASA Astrophysics Data System (ADS)

    Khairunnisaa, Aida; Basah, Shafriza Nisha; Yazid, Haniza; Basri, Hassrizal Hassan; Yaacob, Sazali; Chin, Lim Chee

    2015-05-01

    The diagnostic process of facial paralysis requires qualitative assessment for the classification and treatment planning. This result is inconsistent assessment that potential affect treatment planning. We developed a facial-paralysis diagnostic system based on 3D reconstruction of RGB and depth data using a standard structured-light camera - Kinect 360 - and implementation of Active Appearance Models (AAM). We also proposed a quantitative assessment for facial paralysis based on triangular model. In this paper, we report on the design and development process, including preliminary experimental results. Our preliminary experimental results demonstrate the feasibility of our quantitative assessment system to diagnose facial paralysis.

  6. 3D digitization methods based on laser excitation and active triangulation: a comparison

    NASA Astrophysics Data System (ADS)

    Aubreton, Olivier; Mériaudeau, Fabrice; Truchetet, Frédéric

    2016-04-01

    3D reconstruction of surfaces is an important topic in computer vision and corresponds to a large field of applications: industrial inspection, reverse engineering, object recognition, biometry, archeology… Because of the large varieties of applications, one can find in the literature a lot of approaches which can be classified into two families: passive and active [1]. Certainly because of their reliability, active approaches, using imaging system with an additional controlled light source, seem to be the most commonly used in the industrial field. In this domain, the 3D digitization approach based on active 3D triangulation has had important developments during the last ten years [2] and seems to be mature today if considering the important number of systems proposed by manufacturers. Unfortunately, the performances of active 3D scanners depend on the optical properties of the surface to digitize. As an example, on Fig 1.a, a 3D shape with a diffuse surface has been digitized with Comet V scanner (Steinbichler). The 3D reconstruction is presented on Fig 1.b. The same experiment was carried out on a similar object (same shape) but presenting a specular surface (Fig 1.c and Fig 1.d) ; it can clearly be observed, that the specularity influences of the performance of the digitization.

  7. Direct ambient noise tomography for 3-D near surface shear velocity structure: methodology and applications

    NASA Astrophysics Data System (ADS)

    Yao, H.; Fang, H.; Li, C.; Liu, Y.; Zhang, H.; van der Hilst, R. D.; Huang, Y. C.

    2014-12-01

    Ambient noise tomography has provided essential constraints on crustal and uppermost mantle shear velocity structure in global seismology. Recent studies demonstrate that high frequency (e.g., ~ 1 Hz) surface waves between receivers at short distances can be successfully retrieved from ambient noise cross-correlation and then be used for imaging near surface or shallow crustal shear velocity structures. This approach provides important information for strong ground motion prediction in seismically active area and overburden structure characterization in oil and gas fields. Here we propose a new tomographic method to invert all surface wave dispersion data for 3-D variations of shear wavespeed without the intermediate step of phase or group velocity maps.The method uses frequency-dependent propagation paths and a wavelet-based sparsity-constrained tomographic inversion. A fast marching method is used to compute, at each period, surface wave traveltimes and ray paths between sources and receivers. This avoids the assumption of great-circle propagation that is used in most surface wave tomographic studies, but which is not appropriate in complex media. The wavelet coefficients of the velocity model are estimated with an iteratively reweighted least squares (IRLS) algorithm, and upon iterations the surface wave ray paths and the data sensitivity matrix are updated from the newly obtained velocity model. We apply this new method to determine the 3-D near surface wavespeed variations in the Taipei basin of Taiwan, Hefei urban area and a shale and gas production field in China using the high-frequency interstation Rayleigh wave dispersion data extracted from ambient noisecross-correlation. The results reveal strong effects of off-great-circle propagation of high-frequency surface waves in these regions with above 30% shear wavespeed variations. The proposed approach is more efficient and robust than the traditional two-step surface wave tomography for imaging complex

  8. Sensitivity Analysis of the Scattering-Based SARBM3D Despeckling Algorithm

    PubMed Central

    Di Simone, Alessio

    2016-01-01

    Synthetic Aperture Radar (SAR) imagery greatly suffers from multiplicative speckle noise, typical of coherent image acquisition sensors, such as SAR systems. Therefore, a proper and accurate despeckling preprocessing step is almost mandatory to aid the interpretation and processing of SAR data by human users and computer algorithms, respectively. Very recently, a scattering-oriented version of the popular SAR Block-Matching 3D (SARBM3D) despeckling filter, named Scattering-Based (SB)-SARBM3D, was proposed. The new filter is based on the a priori knowledge of the local topography of the scene. In this paper, an experimental sensitivity analysis of the above-mentioned despeckling algorithm is carried out, and the main results are shown and discussed. In particular, the role of both electromagnetic and geometrical parameters of the surface and the impact of its scattering behavior are investigated. Furthermore, a comprehensive sensitivity analysis of the SB-SARBM3D filter against the Digital Elevation Model (DEM) resolution and the SAR image-DEM coregistration step is also provided. The sensitivity analysis shows a significant robustness of the algorithm against most of the surface parameters, while the DEM resolution plays a key role in the despeckling process. Furthermore, the SB-SARBM3D algorithm outperforms the original SARBM3D in the presence of the most realistic scattering behaviors of the surface. An actual scenario is also presented to assess the DEM role in real-life conditions. PMID:27347971

  9. Sensitivity Analysis of the Scattering-Based SARBM3D Despeckling Algorithm.

    PubMed

    Di Simone, Alessio

    2016-06-25

    Synthetic Aperture Radar (SAR) imagery greatly suffers from multiplicative speckle noise, typical of coherent image acquisition sensors, such as SAR systems. Therefore, a proper and accurate despeckling preprocessing step is almost mandatory to aid the interpretation and processing of SAR data by human users and computer algorithms, respectively. Very recently, a scattering-oriented version of the popular SAR Block-Matching 3D (SARBM3D) despeckling filter, named Scattering-Based (SB)-SARBM3D, was proposed. The new filter is based on the a priori knowledge of the local topography of the scene. In this paper, an experimental sensitivity analysis of the above-mentioned despeckling algorithm is carried out, and the main results are shown and discussed. In particular, the role of both electromagnetic and geometrical parameters of the surface and the impact of its scattering behavior are investigated. Furthermore, a comprehensive sensitivity analysis of the SB-SARBM3D filter against the Digital Elevation Model (DEM) resolution and the SAR image-DEM coregistration step is also provided. The sensitivity analysis shows a significant robustness of the algorithm against most of the surface parameters, while the DEM resolution plays a key role in the despeckling process. Furthermore, the SB-SARBM3D algorithm outperforms the original SARBM3D in the presence of the most realistic scattering behaviors of the surface. An actual scenario is also presented to assess the DEM role in real-life conditions.

  10. Using 3D Printers to Model Earth Surface Topography for Increased Student Understanding and Retention

    NASA Astrophysics Data System (ADS)

    Thesenga, David; Town, James

    2014-05-01

    In February 2000, the Space Shuttle Endeavour flew a specially modified radar system during an 11-day mission. The purpose of the multinational Shuttle Radar Topography Mission (SRTM) was to "obtain elevation data on a near-global scale to generate the most complete high-resolution digital topographic database of Earth" by using radar interferometry. The data and resulting products are now publicly available for download and give a view of the landscape removed of vegetation, buildings, and other structures. This new view of the Earth's topography allows us to see previously unmapped or poorly mapped regions of the Earth as well as providing a level of detail that was previously unknown using traditional topographic mapping techniques. Understanding and appreciating the geographic terrain is a complex but necessary requirement for middle school aged (11-14yo) students. Abstract in nature, topographic maps and other 2D renderings of the Earth's surface and features do not address the inherent spatial challenges of a concrete-learner and traditional methods of teaching can at times exacerbate the problem. Technological solutions such as 3D-imaging in programs like Google Earth are effective but lack the tactile realness that can make a large difference in learning comprehension and retention for these young students. First developed in the 1980's, 3D printers were not commercial reality until recently and the rapid rise in interest has driven down the cost. With the advent of sub US1500 3D printers, this technology has moved out of the high-end marketplace and into the local office supply store. Schools across the US and elsewhere in the world are adding 3D printers to their technological workspaces and students have begun rapid-prototyping and manufacturing a variety of projects. This project attempted to streamline the process of transforming SRTM data from a GeoTIFF format by way of Python code. The resulting data was then inputted into a CAD-based program for

  11. Comparison Between Two Generic 3d Building Reconstruction Approaches - Point Cloud Based VS. Image Processing Based

    NASA Astrophysics Data System (ADS)

    Dahlke, D.; Linkiewicz, M.

    2016-06-01

    This paper compares two generic approaches for the reconstruction of buildings. Synthesized and real oblique and vertical aerial imagery is transformed on the one hand into a dense photogrammetric 3D point cloud and on the other hand into photogrammetric 2.5D surface models depicting a scene from different cardinal directions. One approach evaluates the 3D point cloud statistically in order to extract the hull of structures, while the other approach makes use of salient line segments in 2.5D surface models, so that the hull of 3D structures can be recovered. With orders of magnitudes more analyzed 3D points, the point cloud based approach is an order of magnitude more accurate for the synthetic dataset compared to the lower dimensioned, but therefor orders of magnitude faster, image processing based approach. For real world data the difference in accuracy between both approaches is not significant anymore. In both cases the reconstructed polyhedra supply information about their inherent semantic and can be used for subsequent and more differentiated semantic annotations through exploitation of texture information.

  12. 3-D world modeling based on combinatorial geometry for autonomous robot navigation

    SciTech Connect

    Goldstein, M.; Pin, F.G.; de Saussure, G.; Weisbin, C.R.

    1987-01-01

    In applications of robotics to surveillance and mapping at nuclear facilities, the scene to be described is fundamentally three-dimensional. Usually, only partial information concerning the 3-D environment is known a-priori. Using an autonomous robot, this information may be updated using range data to provide an accurate model of the environment. Range data quantify the distances from the sensor focal plane to the object surface. In other words, the 3-D coordinates of discrete points on the object surface are known. The approach proposed herein for 3-D world modeling is based on the Combinatorial Geometry (C.G.) Method which is widely used in Monte Carlo particle transport calculations. First, each measured point on the object surface is surrounded by a small solid sphere with a radius determined by the range to that point. Then, the 3-D shapes of the visible surfaces are obtained by taking the (Boolean) union of all the spheres. The result is a concise and unambiguous representation of the object's boundary surfaces. The distances from discrete points on the robot's boundary surface to various objects are calculated effectively using the C.G. type of representation. This feature is particularly useful for navigation purposes. The efficiency of the proposed approach is illustrated by a simulation of a spherical robot navigating in a 3-D room with several static obstacles.

  13. 3-D Surface Visualization of pH Titration "Topos": Equivalence Point Cliffs, Dilution Ramps, and Buffer Plateaus

    ERIC Educational Resources Information Center

    Smith, Garon C.; Hossain, Md Mainul; MacCarthy, Patrick

    2014-01-01

    3-D topographic surfaces ("topos") can be generated to visualize how pH behaves during titration and dilution procedures. The surfaces are constructed by plotting computed pH values above a composition grid with volume of base added in one direction and overall system dilution on the other. What emerge are surface features that…

  14. Modeling approaches for ligand-based 3D similarity.

    PubMed

    Tresadern, Gary; Bemporad, Daniele

    2010-10-01

    3D ligand-based similarity approaches are widely used in the early phases of drug discovery for tasks such as hit finding by virtual screening or compound design with quantitative structure-activity relationships. Here in we review widely used software for performing such tasks. Some techniques are based on relatively mature technology, shape-based similarity for instance. Typically, these methods remained in the realm of the expert user, the experienced modeler. However, advances in implementation and speed have improved usability and allow these methods to be applied to databases comprising millions of compounds. There are now many reports of such methods impacting drug-discovery projects. As such, the medicinal chemistry community has become the intended market for some of these new tools, yet they may consider the wide array and choice of approaches somewhat disconcerting. Each method has subtle differences and is better suited to certain tasks than others. In this article we review some of the widely used computational methods via application, provide straightforward background on the underlying theory and provide examples for the interested reader to pursue in more detail. In the new era of preclinical drug discovery there will be ever more pressure to move faster and more efficiently, and computational approaches based on 3D ligand similarity will play an increasing role in in this process.

  15. To 3D or Not to 3D, That Is the Question: Do 3D Surface Analyses Improve the Ecomorphological Power of the Distal Femur in Placental Mammals?

    PubMed Central

    Gould, Francois D. H.

    2014-01-01

    Improvements in three-dimensional imaging technologies have renewed interest in the study of functional and ecological morphology. Quantitative approaches to shape analysis are used increasingly to study form-function relationships. These methods are computationally intensive, technically demanding, and time-consuming, which may limit sampling potential. There have been few side-by-side comparisons of the effectiveness of such approaches relative to more traditional analyses using linear measurements and ratios. Morphological variation in the distal femur of mammals has been shown to reflect differences in locomotor modes across clades. Thus I tested whether a geometric morphometric analysis of surface shape was superior to a multivariate analysis of ratios for describing ecomorphological patterns in distal femoral variation. A sample of 164 mammalian specimens from 44 genera was assembled. Each genus was assigned to one of six locomotor categories. The same hypotheses were tested using two methods. Six linear measurements of the distal femur were taken with calipers, from which four ratios were calculated. A 3D model was generated with a laser scanner, and analyzed using three dimensional geometric morphometrics. Locomotor category significantly predicted variation in distal femoral morphology in both analyses. Effect size was larger in the geometric morphometric analysis than in the analysis of ratios. Ordination reveals a similar pattern with arboreal and cursorial taxa as extremes on a continuum of morphologies in both analyses. Discriminant functions calculated from the geometric morphometric analysis were more accurate than those calculated from ratios. Both analysis of ratios and geometric morphometric surface analysis reveal similar, biologically meaningful relationships between distal femoral shape and locomotor mode. The functional signal from the morphology is slightly higher in the geometric morphometric analysis. The practical costs of conducting these

  16. Virtual reality 3D headset based on DMD light modulators

    SciTech Connect

    Bernacki, Bruce E.; Evans, Allan; Tang, Edward

    2014-06-13

    We present the design of an immersion-type 3D headset suitable for virtual reality applications based upon digital micro-mirror devices (DMD). Our approach leverages silicon micro mirrors offering 720p resolution displays in a small form-factor. Supporting chip sets allow rapid integration of these devices into wearable displays with high resolution and low power consumption. Applications include night driving, piloting of UAVs, fusion of multiple sensors for pilots, training, vision diagnostics and consumer gaming. Our design is described in which light from the DMD is imaged to infinity and the user’s own eye lens forms a real image on the user’s retina.

  17. Defining an optimal surface chemistry for pluripotent stem cell culture in 2D and 3D

    NASA Astrophysics Data System (ADS)

    Zonca, Michael R., Jr.

    Surface chemistry is critical for growing pluripotent stem cells in an undifferentiated state. There is great potential to engineer the surface chemistry at the nanoscale level to regulate stem cell adhesion. However, the challenge is to identify the optimal surface chemistry of the substrata for ES cell attachment and maintenance. Using a high-throughput polymerization and screening platform, a chemically defined, synthetic polymer grafted coating that supports strong attachment and high expansion capacity of pluripotent stem cells has been discovered using mouse embryonic stem (ES) cells as a model system. This optimal substrate, N-[3-(Dimethylamino)propyl] methacrylamide (DMAPMA) that is grafted on 2D synthetic poly(ether sulfone) (PES) membrane, sustains the self-renewal of ES cells (up to 7 passages). DMAPMA supports cell attachment of ES cells through integrin beta1 in a RGD-independent manner and is similar to another recently reported polymer surface. Next, DMAPMA has been able to be transferred to 3D by grafting to synthetic, polymeric, PES fibrous matrices through both photo-induced and plasma-induced polymerization. These 3D modified fibers exhibited higher cell proliferation and greater expression of pluripotency markers of mouse ES cells than 2D PES membranes. Our results indicated that desirable surfaces in 2D can be scaled to 3D and that both surface chemistry and structural dimension strongly influence the growth and differentiation of pluripotent stem cells. Lastly, the feasibility of incorporating DMAPMA into a widely used natural polymer, alginate, has been tested. Novel adhesive alginate hydrogels have been successfully synthesized by either direct polymerization of DMAPMA and methacrylic acid blended with alginate, or photo-induced DMAPMA polymerization on alginate nanofibrous hydrogels. In particular, DMAPMA-coated alginate hydrogels support strong ES cell attachment, exhibiting a concentration dependency of DMAPMA. This research provides a

  18. Handheld underwater 3D sensor based on fringe projection technique

    NASA Astrophysics Data System (ADS)

    Bräuer-Burchardt, Christian; Heinze, Matthias; Schmidt, Ingo; Meng, Lichun; Ramm, Roland; Kühmstedt, Peter; Notni, Gunther

    2015-05-01

    A new, handheld 3D surface scanner was developed especially for underwater use until a diving depth of about 40 meters. Additionally, the sensor is suitable for the outdoor use under bad weather circumstance like splashing water, wind, and bad illumination conditions. The optical components of the sensor are two cameras and one projector. The measurement field is about 250 mm x 200 mm. The depth resolution is about 50 μm and the lateral resolution is approximately 150 μm. The weight of the scanner is about 10 kg. The housing was produced of synthetic powder using a 3D printing technique. The measurement time for one scan is between a third and a half second. The computer for measurement control and data analysis is already integrated into the housing of the scanner. A display on the backside presents the results of each measurement graphically for a real-time evaluation of the user during the recording of the measurement data.

  19. Improving segmentation of 3D touching cell nuclei using flow tracking on surface meshes.

    PubMed

    Li, Gang; Guo, Lei

    2012-01-01

    Automatic segmentation of touching cell nuclei in 3D microscopy images is of great importance in bioimage informatics and computational biology. This paper presents a novel method for improving 3D touching cell nuclei segmentation. Given binary touching nuclei by the method in Li et al. (2007), our method herein consists of several steps: surface mesh reconstruction and curvature information estimation; direction field diffusion on surface meshes; flow tracking on surface meshes; and projection of surface mesh segmentation to volumetric images. The method is validated on both synthesised and real 3D touching cell nuclei images, demonstrating its validity and effectiveness.

  20. A 3D optical study of Low Surface Brightness galaxies

    NASA Astrophysics Data System (ADS)

    Chemin, L.; Amram, P.; Carignan, C.; Balkowski, C.; van Driel, W.; Cayatte, V.; Hernandez, O.

    2004-12-01

    Integral field spectroscopy observations of the ionized gas in Low Surface Brightness Galaxies (LSBs) are presented. The goal of this study is to map their kinematics at high angular resolution and to study their dark matter (DM) distribution. For that purpose, we have used Fabry-Perot observations obtained at the CFH and ESO 3.6m telescopes. The new contribution of highly resolved velocity fields is crucial to study the role of non-circular motions on the dynamics of LSBs, and particularly on the shape of their DM halo profile (cusp- or core- dominated halo). Here are shown some examples of galaxies in which such motions exist in their central parts and prevent from determining the accurate shape of their DM halo.

  1. Evaluation of precision and accuracy assessment of different 3-D surface imaging systems for biomedical purposes.

    PubMed

    Eder, Maximilian; Brockmann, Gernot; Zimmermann, Alexander; Papadopoulos, Moschos A; Schwenzer-Zimmerer, Katja; Zeilhofer, Hans Florian; Sader, Robert; Papadopulos, Nikolaos A; Kovacs, Laszlo

    2013-04-01

    Three-dimensional (3-D) surface imaging has gained clinical acceptance, especially in the field of cranio-maxillo-facial and plastic, reconstructive, and aesthetic surgery. Six scanners based on different scanning principles (Minolta Vivid 910®, Polhemus FastSCAN™, GFM PRIMOS®, GFM TopoCAM®, Steinbichler Comet® Vario Zoom 250, 3dMD DSP 400®) were used to measure five sheep skulls of different sizes. In three areas with varying anatomical complexity (areas, 1 = high; 2 = moderate; 3 = low), 56 distances between 20 landmarks are defined on each skull. Manual measurement (MM), coordinate machine measurements (CMM) and computer tomography (CT) measurements were used to define a reference method for further precision and accuracy evaluation of different 3-D scanning systems. MM showed high correlation to CMM and CT measurements (both r = 0.987; p < 0.001) and served as the reference method. TopoCAM®, Comet® and Vivid 910® showed highest measurement precision over all areas of complexity; Vivid 910®, the Comet® and the DSP 400® demonstrated highest accuracy over all areas with Vivid 910® being most accurate in areas 1 and 3, and the DSP 400® most accurate in area 2. In accordance to the measured distance length, most 3-D devices present higher measurement precision and accuracy for large distances and lower degrees of precision and accuracy for short distances. In general, higher degrees of complexity are associated with lower 3-D assessment accuracy, suggesting that for optimal results, different types of scanners should be applied to specific clinical applications and medical problems according to their special construction designs and characteristics.

  2. Fast vision-based catheter 3D reconstruction.

    PubMed

    Moradi Dalvand, Mohsen; Nahavandi, Saeid; Howe, Robert D

    2016-07-21

    Continuum robots offer better maneuverability and inherent compliance and are well-suited for surgical applications as catheters, where gentle interaction with the environment is desired. However, sensing their shape and tip position is a challenge as traditional sensors can not be employed in the way they are in rigid robotic manipulators. In this paper, a high speed vision-based shape sensing algorithm for real-time 3D reconstruction of continuum robots based on the views of two arbitrary positioned cameras is presented. The algorithm is based on the closed-form analytical solution of the reconstruction of quadratic curves in 3D space from two arbitrary perspective projections. High-speed image processing algorithms are developed for the segmentation and feature extraction from the images. The proposed algorithms are experimentally validated for accuracy by measuring the tip position, length and bending and orientation angles for known circular and elliptical catheter shaped tubes. Sensitivity analysis is also carried out to evaluate the robustness of the algorithm. Experimental results demonstrate good accuracy (maximum errors of  ±0.6 mm and  ±0.5 deg), performance (200 Hz), and robustness (maximum absolute error of 1.74 mm, 3.64 deg for the added noises) of the proposed high speed algorithms.

  3. Fast vision-based catheter 3D reconstruction

    NASA Astrophysics Data System (ADS)

    Moradi Dalvand, Mohsen; Nahavandi, Saeid; Howe, Robert D.

    2016-07-01

    Continuum robots offer better maneuverability and inherent compliance and are well-suited for surgical applications as catheters, where gentle interaction with the environment is desired. However, sensing their shape and tip position is a challenge as traditional sensors can not be employed in the way they are in rigid robotic manipulators. In this paper, a high speed vision-based shape sensing algorithm for real-time 3D reconstruction of continuum robots based on the views of two arbitrary positioned cameras is presented. The algorithm is based on the closed-form analytical solution of the reconstruction of quadratic curves in 3D space from two arbitrary perspective projections. High-speed image processing algorithms are developed for the segmentation and feature extraction from the images. The proposed algorithms are experimentally validated for accuracy by measuring the tip position, length and bending and orientation angles for known circular and elliptical catheter shaped tubes. Sensitivity analysis is also carried out to evaluate the robustness of the algorithm. Experimental results demonstrate good accuracy (maximum errors of  ±0.6 mm and  ±0.5 deg), performance (200 Hz), and robustness (maximum absolute error of 1.74 mm, 3.64 deg for the added noises) of the proposed high speed algorithms.

  4. Automatic feature detection for 3D surface reconstruction from HDTV endoscopic videos

    NASA Astrophysics Data System (ADS)

    Groch, Anja; Baumhauer, Matthias; Meinzer, Hans-Peter; Maier-Hein, Lena

    2010-02-01

    A growing number of applications in the field of computer-assisted laparoscopic interventions depend on accurate and fast 3D surface acquisition. The most commonly applied methods for 3D reconstruction of organ surfaces from 2D endoscopic images involve establishment of correspondences in image pairs to allow for computation of 3D point coordinates via triangulation. The popular feature-based approach for correspondence search applies a feature descriptor to compute high-dimensional feature vectors describing the characteristics of selected image points. Correspondences are established between image points with similar feature vectors. In a previous study, the performance of a large set of state-of-the art descriptors for the use in minimally invasive surgery was assessed. However, standard Phase Alternating Line (PAL) endoscopic images were utilized for this purpose. In this paper, we apply some of the best performing feature descriptors to in-vivo PAL endoscopic images as well as to High Definition Television (HDTV) endoscopic images of the same scene and show that the quality of the correspondences can be increased significantly when using high resolution images.

  5. Searching surface orientation of microscopic objects for accurate 3D shape recovery.

    PubMed

    Shim, Seong-O; Mahmood, Muhammad Tariq; Choi, Tae-Sun

    2012-05-01

    In this article, we propose a new shape from focus (SFF) method to estimate 3D shape of microscopic objects using surface orientation cue of each object patch. Most of the SFF algorithms compute the focus value of a pixel from the information of neighboring pixels lying on the same image frame based on an assumption that the small object patch corresponding to the small neighborhood of a pixel is a plane parallel to the focal plane. However, this assumption fails in the optics with limited depth of field where the neighboring pixels of an image have different degree of focus. To overcome this problem, we try to search the surface orientation of the small object patch corresponding to each pixel in the image sequence. Searching of the surface orientation is done indirectly by principal component analysis. Then, the focus value of each pixel is computed from the neighboring pixels lying on the surface perpendicular to the corresponding surface orientation. Experimental results on synthetic and real microscopic objects show that the proposed method produces more accurate 3D shape in comparison to the existing techniques.

  6. Maximum likelihood estimation of parameterized 3-D surfaces using a moving camera

    NASA Technical Reports Server (NTRS)

    Hung, Y.; Cernuschi-Frias, B.; Cooper, D. B.

    1987-01-01

    A new approach is introduced to estimating object surfaces in three-dimensional space from a sequence of images. A surface of interest here is modeled as a 3-D function known up to the values of a few parameters. The approach will work with any parameterization. However, in work to date researchers have modeled objects as patches of spheres, cylinders, and planes - primitive objects. These primitive surfaces are special cases of 3-D quadric surfaces. Primitive surface estimation is treated as the general problem of maximum likelihood parameter estimation based on two or more functionally related data sets. In the present case, these data sets constitute a sequence of images taken at different locations and orientations. A simple geometric explanation is given for the estimation algorithm. Though various techniques can be used to implement this nonlinear estimation, researches discuss the use of gradient descent. Experiments are run and discussed for the case of a sphere of unknown location. These experiments graphically illustrate the various advantages of using as many images as possible in the estimation and of distributing camera positions from first to last over as large a baseline as possible. Researchers introduce the use of asymptotic Bayesian approximations in order to summarize the useful information in a sequence of images, thereby drastically reducing both the storage and amount of processing required.

  7. Integral imaging based 3D display of holographic data.

    PubMed

    Yöntem, Ali Özgür; Onural, Levent

    2012-10-22

    We propose a method and present applications of this method that converts a diffraction pattern into an elemental image set in order to display them on an integral imaging based display setup. We generate elemental images based on diffraction calculations as an alternative to commonly used ray tracing methods. Ray tracing methods do not accommodate the interference and diffraction phenomena. Our proposed method enables us to obtain elemental images from a holographic recording of a 3D object/scene. The diffraction pattern can be either numerically generated data or digitally acquired optical data. The method shows the connection between a hologram (diffraction pattern) and an elemental image set of the same 3D object. We showed three examples, one of which is the digitally captured optical diffraction tomography data of an epithelium cell. We obtained optical reconstructions with our integral imaging display setup where we used a digital lenslet array. We also obtained numerical reconstructions, again by using the diffraction calculations, for comparison. The digital and optical reconstruction results are in good agreement.

  8. Luminance binocular disparity for 3D surface simulation

    NASA Astrophysics Data System (ADS)

    Paille, Damien; Monot, Annie; Dumont-Becle, Patricia; Kemeny, Andras

    2001-06-01

    Different stereoscopic effects, base don 100 percent binocular luminance contrast have been described previously: the 'sieve' effect, the 'binocular lustre' effect, the 'floating' effect and the rivaldepth' effect. By mean of a dichoptic set-up, we have measured the detection thresholds for these different effects in function of binocular luminance contrast. Psychometric data have ben recorded using a Yes-No paradigm, a spatial 2AFC paradigm and a temporal 2AFC paradigm. Our results show that even for small contrast all these stereoscopic effects are perceived. We have noticed an increase of the detection thresholds in the following order: 'sieve', 'binocular lustre', 'rivaldepth' and 'floating' effect. Two groups have been distinguished.

  9. EEG-based usability assessment of 3D shutter glasses

    NASA Astrophysics Data System (ADS)

    Wenzel, Markus A.; Schultze-Kraft, Rafael; Meinecke, Frank C.; Cardinaux, Fabien; Kemp, Thomas; Müller, Klaus-Robert; Curio, Gabriel; Blankertz, Benjamin

    2016-02-01

    Objective. Neurotechnology can contribute to the usability assessment of products by providing objective measures of neural workload and can uncover usability impediments that are not consciously perceived by test persons. In this study, the neural processing effort imposed on the viewer of 3D television by shutter glasses was quantified as a function of shutter frequency. In particular, we sought to determine the critical shutter frequency at which the ‘neural flicker’ vanishes, such that visual fatigue due to this additional neural effort can be prevented by increasing the frequency of the system. Approach. Twenty-three participants viewed an image through 3D shutter glasses, while multichannel electroencephalogram (EEG) was recorded. In total ten shutter frequencies were employed, selected individually for each participant to cover the range below, at and above the threshold of flicker perception. The source of the neural flicker correlate was extracted using independent component analysis and the flicker impact on the visual cortex was quantified by decoding the state of the shutter from the EEG. Main Result. Effects of the shutter glasses were traced in the EEG up to around 67 Hz—about 20 Hz over the flicker perception threshold—and vanished at the subsequent frequency level of 77 Hz. Significance. The impact of the shutter glasses on the visual cortex can be detected by neurotechnology even when a flicker is not reported by the participants. Potential impact. Increasing the shutter frequency from the usual 50 Hz or 60 Hz to 77 Hz reduces the risk of visual fatigue and thus improves shutter-glass-based 3D usability.

  10. Performance assessment of 3D surface imaging technique for medical imaging applications

    NASA Astrophysics Data System (ADS)

    Li, Tuotuo; Geng, Jason; Li, Shidong

    2013-03-01

    Recent development in optical 3D surface imaging technologies provide better ways to digitalize the 3D surface and its motion in real-time. The non-invasive 3D surface imaging approach has great potential for many medical imaging applications, such as motion monitoring of radiotherapy, pre/post evaluation of plastic surgery and dermatology, to name a few. Various commercial 3D surface imaging systems have appeared on the market with different dimension, speed and accuracy. For clinical applications, the accuracy, reproducibility and robustness across the widely heterogeneous skin color, tone, texture, shape properties, and ambient lighting is very crucial. Till now, a systematic approach for evaluating the performance of different 3D surface imaging systems still yet exist. In this paper, we present a systematic performance assessment approach to 3D surface imaging system assessment for medical applications. We use this assessment approach to exam a new real-time surface imaging system we developed, dubbed "Neo3D Camera", for image-guided radiotherapy (IGRT). The assessments include accuracy, field of view, coverage, repeatability, speed and sensitivity to environment, texture and color.

  11. Mapping gray-scale image to 3D surface scanning data by ray tracing

    NASA Astrophysics Data System (ADS)

    Li, Peng; Jones, Peter R. M.

    1997-03-01

    The extraction and location of feature points from range imaging is an important but difficult task in machine vision based measurement systems. There exist some feature points which are not able to be detected from pure geometric characteristics, particularly in those measurement tasks related to the human body. The Loughborough Anthropometric Shadow Scanner (LASS) is a whole body surface scanner based on structured light technique. Certain applications of LASS require accurate location of anthropometric landmarks from the scanned data. This is sometimes impossible from existing raw data because some landmarks do not appear in the scanned data. Identification of these landmarks has to resort to surface texture of the scanned object. Modifications to LASS were made to allow gray-scale images to be captured before or after the object was scanned. Two-dimensional gray-scale image must be mapped to the scanned data to acquire the 3D coordinates of a landmark. The method to map 2D images to the scanned data is based on the colinearity conditions and ray-tracing method. If the camera center and image coordinates are known, the corresponding object point must lie on a ray starting from the camera center and connecting to the image coordinate. By intersecting the ray with the scanned surface of the object, the 3D coordinates of a point can be solved. Experimentation has demonstrated the feasibility of the method.

  12. Review of three-dimensional (3D) surface imaging for oncoplastic, reconstructive and aesthetic breast surgery.

    PubMed

    O'Connell, Rachel L; Stevens, Roger J G; Harris, Paul A; Rusby, Jennifer E

    2015-08-01

    Three-dimensional surface imaging (3D-SI) is being marketed as a tool in aesthetic breast surgery. It has recently also been studied in the objective evaluation of cosmetic outcome of oncological procedures. The aim of this review is to summarise the use of 3D-SI in oncoplastic, reconstructive and aesthetic breast surgery. An extensive literature review was undertaken to identify published studies. Two reviewers independently screened all abstracts and selected relevant articles using specific inclusion criteria. Seventy two articles relating to 3D-SI for breast surgery were identified. These covered endpoints such as image acquisition, calculations and data obtainable, comparison of 3D and 2D imaging and clinical research applications of 3D-SI. The literature provides a favourable view of 3D-SI. However, evidence of its superiority over current methods of clinical decision making, surgical planning, communication and evaluation of outcome is required before it can be accepted into mainstream practice.

  13. Appearance-based color face recognition with 3D model

    NASA Astrophysics Data System (ADS)

    Wang, Chengzhang; Bai, Xiaoming

    2013-03-01

    Appearance-based face recognition approaches explore color cues of face images, i.e. grey or color information for recognition task. They first encode color face images, and then extract facial features for classification. Similar to conventional singular value decomposition, hypercomplex matrix also exists singular value decomposition on hypercomplex field. In this paper, a novel color face recognition approach based on hypercomplex singular value decomposition is proposed. The approach employs hypercomplex to encode color face information of different channels simultaneously. Hypercomplex singular value decomposition is utilized then to compute the basis vectors of the color face subspace. To improve learning efficiency of the algorithm, 3D active deformable model is exploited to generate virtual face images. Color face samples are projected onto the subspace and projection coefficients are utilized as facial features. Experimental results on CMU PIE face database verify the effectiveness of the proposed approach.

  14. Improving 3D Wavelet-Based Compression of Hyperspectral Images

    NASA Technical Reports Server (NTRS)

    Klimesh, Matthew; Kiely, Aaron; Xie, Hua; Aranki, Nazeeh

    2009-01-01

    Two methods of increasing the effectiveness of three-dimensional (3D) wavelet-based compression of hyperspectral images have been developed. (As used here, images signifies both images and digital data representing images.) The methods are oriented toward reducing or eliminating detrimental effects of a phenomenon, referred to as spectral ringing, that is described below. In 3D wavelet-based compression, an image is represented by a multiresolution wavelet decomposition consisting of several subbands obtained by applying wavelet transforms in the two spatial dimensions corresponding to the two spatial coordinate axes of the image plane, and by applying wavelet transforms in the spectral dimension. Spectral ringing is named after the more familiar spatial ringing (spurious spatial oscillations) that can be seen parallel to and near edges in ordinary images reconstructed from compressed data. These ringing phenomena are attributable to effects of quantization. In hyperspectral data, the individual spectral bands play the role of edges, causing spurious oscillations to occur in the spectral dimension. In the absence of such corrective measures as the present two methods, spectral ringing can manifest itself as systematic biases in some reconstructed spectral bands and can reduce the effectiveness of compression of spatially-low-pass subbands. One of the two methods is denoted mean subtraction. The basic idea of this method is to subtract mean values from spatial planes of spatially low-pass subbands prior to encoding, because (a) such spatial planes often have mean values that are far from zero and (b) zero-mean data are better suited for compression by methods that are effective for subbands of two-dimensional (2D) images. In this method, after the 3D wavelet decomposition is performed, mean values are computed for and subtracted from each spatial plane of each spatially-low-pass subband. The resulting data are converted to sign-magnitude form and compressed in a

  15. Relevance of PEG in PLA-based blends for tissue engineering 3D-printed scaffolds.

    PubMed

    Serra, Tiziano; Ortiz-Hernandez, Monica; Engel, Elisabeth; Planell, Josep A; Navarro, Melba

    2014-05-01

    Achieving high quality 3D-printed structures requires establishing the right printing conditions. Finding processing conditions that satisfy both the fabrication process and the final required scaffold properties is crucial. This work stresses the importance of studying the outcome of the plasticizing effect of PEG on PLA-based blends used for the fabrication of 3D-direct-printed scaffolds for tissue engineering applications. For this, PLA/PEG blends with 5, 10 and 20% (w/w) of PEG and PLA/PEG/bioactive CaP glass composites were processed in the form of 3D rapid prototyping scaffolds. Surface analysis and differential scanning calorimetry revealed a rearrangement of polymer chains and a topography, wettability and elastic modulus increase of the studied surfaces as PEG was incorporated. Moreover, addition of 10 and 20% PEG led to non-uniform 3D structures with lower mechanical properties. In vitro degradation studies showed that the inclusion of PEG significantly accelerated the degradation rate of the material. Results indicated that the presence of PEG not only improves PLA processing but also leads to relevant surface, geometrical and structural changes including modulation of the degradation rate of PLA-based 3D printed scaffolds.

  16. 3D modeling based on CityEngine

    NASA Astrophysics Data System (ADS)

    Jia, Guangyin; Liao, Kaiju

    2017-03-01

    Currently, there are many 3D modeling softwares, like 3DMAX, AUTOCAD, and more populous BIM softwares represented by REVIT. CityEngine modeling software introduced in this paper can fully utilize the existing GIS data and combine other built models to make 3D modeling on internal and external part of buildings in a rapid and batch manner, so as to improve the 3D modeling efficiency.

  17. An adaptive learning approach for 3-D surface reconstruction from point clouds.

    PubMed

    Junior, Agostinho de Medeiros Brito; Neto, Adrião Duarte Dória; de Melo, Jorge Dantas; Goncalves, Luiz Marcos Garcia

    2008-06-01

    In this paper, we propose a multiresolution approach for surface reconstruction from clouds of unorganized points representing an object surface in 3-D space. The proposed method uses a set of mesh operators and simple rules for selective mesh refinement, with a strategy based on Kohonen's self-organizing map (SOM). Basically, a self-adaptive scheme is used for iteratively moving vertices of an initial simple mesh in the direction of the set of points, ideally the object boundary. Successive refinement and motion of vertices are applied leading to a more detailed surface, in a multiresolution, iterative scheme. Reconstruction was experimented on with several point sets, including different shapes and sizes. Results show generated meshes very close to object final shapes. We include measures of performance and discuss robustness.

  18. 3D Gabor wavelet based vessel filtering of photoacoustic images.

    PubMed

    Haq, Israr Ul; Nagoaka, Ryo; Makino, Takahiro; Tabata, Takuya; Saijo, Yoshifumi

    2016-08-01

    Filtering and segmentation of vasculature is an important issue in medical imaging. The visualization of vasculature is crucial for the early diagnosis and therapy in numerous medical applications. This paper investigates the use of Gabor wavelet to enhance the effect of vasculature while eliminating the noise due to size, sensitivity and aperture of the detector in 3D Optical Resolution Photoacoustic Microscopy (OR-PAM). A detailed multi-scale analysis of wavelet filtering and Hessian based method is analyzed for extracting vessels of different sizes since the blood vessels usually vary with in a range of radii. The proposed algorithm first enhances the vasculature in the image and then tubular structures are classified by eigenvalue decomposition of the local Hessian matrix at each voxel in the image. The algorithm is tested on non-invasive experiments, which shows appreciable results to enhance vasculature in photo-acoustic images.

  19. 3D reconstruction of light flux distribution on arbitrary surfaces from 2D multi-photographic images.

    PubMed

    Chen, Xueli; Gao, Xinbo; Chen, Duofang; Ma, Xiaopeng; Zhao, Xiaohui; Shen, Man; Li, Xiangsi; Qu, Xiaochao; Liang, Jimin; Ripoll, Jorge; Tian, Jie

    2010-09-13

    Optical tomography can demonstrate accurate three-dimensional (3D) imaging that recovers the 3D spatial distribution and concentration of the luminescent probes in biological tissues, compared with planar imaging. However, the tomographic approach is extremely difficult to implement due to the complexity in the reconstruction of 3D surface flux distribution from multi-view two dimensional (2D) measurements on the subject surface. To handle this problem, a novel and effective method is proposed in this paper to determine the surface flux distribution from multi-view 2D photographic images acquired by a set of non-contact detectors. The method is validated with comparison experiments involving both regular and irregular surfaces. Reconstruction of the inside probes based on the reconstructed surface flux distribution further demonstrates the potential of the proposed method in its application in optical tomography.

  20. Visualization of Buffer Capacity with 3-D "Topo" Surfaces: Buffer Ridges, Equivalence Point Canyons and Dilution Ramps

    ERIC Educational Resources Information Center

    Smith, Garon C.; Hossain, Md Mainul

    2016-01-01

    BufCap TOPOS is free software that generates 3-D topographical surfaces ("topos") for acid-base equilibrium studies. It portrays pH and buffer capacity behavior during titration and dilution procedures. Topo surfaces are created by plotting computed pH and buffer capacity values above a composition grid with volume of NaOH as the x axis…

  1. Semiautomatic approaches to account for 3-D distortion of the electric field from local, near-surface structures in 3-D resistivity inversions of 3-D regional magnetotelluric data

    USGS Publications Warehouse

    Rodriguez, Brian D.

    2017-03-31

    This report summarizes the results of three-dimensional (3-D) resistivity inversion simulations that were performed to account for local 3-D distortion of the electric field in the presence of 3-D regional structure, without any a priori information on the actual 3-D distribution of the known subsurface geology. The methodology used a 3-D geologic model to create a 3-D resistivity forward (“known”) model that depicted the subsurface resistivity structure expected for the input geologic configuration. The calculated magnetotelluric response of the modeled resistivity structure was assumed to represent observed magnetotelluric data and was subsequently used as input into a 3-D resistivity inverse model that used an iterative 3-D algorithm to estimate 3-D distortions without any a priori geologic information. A publicly available inversion code, WSINV3DMT, was used for all of the simulated inversions, initially using the default parameters, and subsequently using adjusted inversion parameters. A semiautomatic approach of accounting for the static shift using various selections of the highest frequencies and initial models was also tested. The resulting 3-D resistivity inversion simulation was compared to the “known” model and the results evaluated. The inversion approach that produced the lowest misfit to the various local 3-D distortions was an inversion that employed an initial model volume resistivity that was nearest to the maximum resistivities in the near-surface layer.

  2. Extended volume and surface scatterometer for optical characterization of 3D-printed elements

    NASA Astrophysics Data System (ADS)

    Dannenberg, Florian; Uebeler, Denise; Weiß, Jürgen; Pescoller, Lukas; Weyer, Cornelia; Hahlweg, Cornelius

    2015-09-01

    The use of 3d printing technology seems to be a promising way for low cost prototyping, not only of mechanical, but also of optical components or systems. It is especially useful in applications where customized equipment repeatedly is subject to immediate destruction, as in experimental detonics and the like. Due to the nature of the 3D-printing process, there is a certain inner texture and therefore inhomogeneous optical behaviour to be taken into account, which also indicates mechanical anisotropy. Recent investigations are dedicated to quantification of optical properties of such printed bodies and derivation of corresponding optimization strategies for the printing process. Beside mounting, alignment and illumination means, also refractive and reflective elements are subject to investigation. The proposed measurement methods are based on an imaging nearfield scatterometer for combined volume and surface scatter measurements as proposed in previous papers. In continuation of last year's paper on the use of near field imaging, which basically is a reflective shadowgraph method, for characterization of glossy surfaces like printed matter or laminated material, further developments are discussed. The device has been extended for observation of photoelasticity effects and therefore homogeneity of polarization behaviour. A refined experimental set-up is introduced. Variation of plane of focus and incident angle are used for separation of various the images of the layers of the surface under test, cross and parallel polarization techniques are applied. Practical examples from current research studies are included.

  3. Construction of 3D micropatterned surfaces with wormlike and superhydrophilic PEG brushes to detect dysfunctional cells.

    PubMed

    Hou, Jianwen; Shi, Qiang; Ye, Wei; Fan, Qunfu; Shi, Hengchong; Wong, Shing-Chung; Xu, Xiaodong; Yin, Jinghua

    2014-12-10

    Detection of dysfunctional and apoptotic cells plays an important role in clinical diagnosis and therapy. To develop a portable and user-friendly platform for dysfunctional and aging cell detection, we present a facile method to construct 3D patterns on the surface of styrene-b-(ethylene-co-butylene)-b-styrene elastomer (SEBS) with poly(ethylene glycol) brushes. Normal red blood cells (RBCs) and lysed RBCs (dysfunctional cells) are used as model cells. The strategy is based on the fact that poly(ethylene glycol) brushes tend to interact with phosphatidylserine, which is in the inner leaflet of normal cell membranes but becomes exposed in abnormal or apoptotic cell membranes. We demonstrate that varied patterned surfaces can be obtained by selectively patterning atom transfer radical polymerization (ATRP) initiators on the SEBS surface via an aqueous-based method and growing PEG brushes through surface-initiated atom transfer radical polymerization. The relatively high initiator density and polymerization temperature facilitate formation of PEG brushes in high density, which gives brushes worm-like morphology and superhydrophilic property; the tendency of dysfunctional cells adhered on the patterned surfaces is completely different from well-defined arrays of normal cells on the patterned surfaces, providing a facile method to detect dysfunctional cells effectively. The PEG-patterned surfaces are also applicable to detect apoptotic HeLa cells. The simplicity and easy handling of the described technique shows the potential application in microdiagnostic devices.

  4. Real-time 3D surface-image-guided beam setup in radiotherapy of breast cancer

    SciTech Connect

    Djajaputra, David; Li Shidong

    2005-01-01

    We describe an approach for external beam radiotherapy of breast cancer that utilizes the three-dimensional (3D) surface information of the breast. The surface data of the breast are obtained from a 3D optical camera that is rigidly mounted on the ceiling of the treatment vault. This 3D camera utilizes light in the visible range therefore it introduces no ionization radiation to the patient. In addition to the surface topographical information of the treated area, the camera also captures gray-scale information that is overlaid on the 3D surface image. This allows us to visualize the skin markers and automatically determine the isocenter position and the beam angles in the breast tangential fields. The field sizes and shapes of the tangential, supraclavicular, and internal mammary gland fields can all be determined according to the 3D surface image of the target. A least-squares method is first introduced for the tangential-field setup that is useful for compensation of the target shape changes. The entire process of capturing the 3D surface data and subsequent calculation of beam parameters typically requires less than 1 min. Our tests on phantom experiments and patient images have achieved the accuracy of 1 mm in shift and 0.5 deg. in rotation. Importantly, the target shape and position changes in each treatment session can both be corrected through this real-time image-guided system.

  5. Feature-constrained surface reconstruction approach for point cloud data acquired with 3D laser scanner

    NASA Astrophysics Data System (ADS)

    Wang, Yongbo; Sheng, Yehua; Lu, Guonian; Tian, Peng; Zhang, Kai

    2008-04-01

    Surface reconstruction is an important task in the field of 3d-GIS, computer aided design and computer graphics (CAD & CG), virtual simulation and so on. Based on available incremental surface reconstruction methods, a feature-constrained surface reconstruction approach for point cloud is presented. Firstly features are extracted from point cloud under the rules of curvature extremes and minimum spanning tree. By projecting local sample points to the fitted tangent planes and using extracted features to guide and constrain the process of local triangulation and surface propagation, topological relationship among sample points can be achieved. For the constructed models, a process named consistent normal adjustment and regularization is adopted to adjust normal of each face so that the correct surface model is achieved. Experiments show that the presented approach inherits the convenient implementation and high efficiency of traditional incremental surface reconstruction method, meanwhile, it avoids improper propagation of normal across sharp edges, which means the applicability of incremental surface reconstruction is greatly improved. Above all, appropriate k-neighborhood can help to recognize un-sufficient sampled areas and boundary parts, the presented approach can be used to reconstruct both open and close surfaces without additional interference.

  6. Hydrogel-based reinforcement of 3D bioprinted constructs

    PubMed Central

    Levato, R; Peiffer, Q C; de Ruijter, M; Hennink, W E; Vermonden, T; Malda, J

    2016-01-01

    Progress within the field of biofabrication is hindered by a lack of suitable hydrogel formulations. Here, we present a novel approach based on a hybrid printing technique to create cellularized 3D printed constructs. The hybrid bioprinting strategy combines a reinforcing gel for mechanical support with a bioink to provide a cytocompatible environment. In comparison with thermoplastics such as є-polycaprolactone, the hydrogel-based reinforcing gel platform enables printing at cell-friendly temperatures, targets the bioprinting of softer tissues and allows for improved control over degradation kinetics. We prepared amphiphilic macromonomers based on poloxamer that form hydrolysable, covalently cross-linked polymer networks. Dissolved at a concentration of 28.6%w/w in water, it functions as reinforcing gel, while a 5%w/w gelatin-methacryloyl based gel is utilized as bioink. This strategy allows for the creation of complex structures, where the bioink provides a cytocompatible environment for encapsulated cells. Cell viability of equine chondrocytes encapsulated within printed constructs remained largely unaffected by the printing process. The versatility of the system is further demonstrated by the ability to tune the stiffness of printed constructs between 138 and 263 kPa, as well as to tailor the degradation kinetics of the reinforcing gel from several weeks up to more than a year. PMID:27431861

  7. A Secret 3D Model Sharing Scheme with Reversible Data Hiding Based on Space Subdivision

    NASA Astrophysics Data System (ADS)

    Tsai, Yuan-Yu

    2016-03-01

    Secret sharing is a highly relevant research field, and its application to 2D images has been thoroughly studied. However, secret sharing schemes have not kept pace with the advances of 3D models. With the rapid development of 3D multimedia techniques, extending the application of secret sharing schemes to 3D models has become necessary. In this study, an innovative secret 3D model sharing scheme for point geometries based on space subdivision is proposed. Each point in the secret point geometry is first encoded into a series of integer values that fall within [0, p - 1], where p is a predefined prime number. The share values are derived by substituting the specified integer values for all coefficients of the sharing polynomial. The surface reconstruction and the sampling concepts are then integrated to derive a cover model with sufficient model complexity for each participant. Finally, each participant has a separate 3D stego model with embedded share values. Experimental results show that the proposed technique supports reversible data hiding and the share values have higher levels of privacy and improved robustness. This technique is simple and has proven to be a feasible secret 3D model sharing scheme.

  8. New 3-D microarray platform based on macroporous polymer monoliths.

    PubMed

    Rober, M; Walter, J; Vlakh, E; Stahl, F; Kasper, C; Tennikova, T

    2009-06-30

    Polymer macroporous monoliths are widely used as efficient sorbents in different, mostly dynamic, interphase processes. In this paper, monolithic materials strongly bound to the inert glass surface are suggested as operative matrices at the development of three-dimensional (3-D) microarrays. For this purpose, several rigid macroporous copolymers differed by reactivity and hydrophobic-hydrophilic properties were synthesized and tested: (1) glycidyl methacrylate-co-ethylene dimethacrylate (poly(GMA-co-EDMA)), (2) glycidyl methacrylate-co-glycerol dimethacrylate (poly(GMA-co-GDMA)), (3) N-hydroxyphthalimide ester of acrylic acid-co-glycidyl methacrylate-co-ethylene dimethacrylate (poly(HPIEAA-co-GMA-co-EDMA)), (4) 2-cyanoethyl methacrylate-co-ethylene dimethacrylate (poly(CEMA-co-EDMA)), and (5) 2-cyanoethyl methacrylate-co-2-hydroxyethyl methacrylate-co-ethylene dimethacrylate (poly(CEMA-co-HEMA-co-EDMA)). The constructed devices were used as platforms for protein microarrays construction and model mouse IgG-goat anti-mouse IgG affinity pair was used to demonstrate the potential of developed test-systems, as well as to optimize microanalytical conditions. The offered microarray platforms were applied to detect the bone tissue marker osteopontin directly in cell culture medium.

  9. Energy harvesting “3-D knitted spacer” based piezoelectric textiles

    NASA Astrophysics Data System (ADS)

    Anand, S.; Soin, N.; Shah, T. H.; Siores, E.

    2016-07-01

    The piezoelectric effect in Poly(vinylidene fluoride), PVDF, was discovered over four decades ago and since then, significant work has been carried out aiming at the production of high p-phase fibres and their integration into fabric structures for energy harvesting. However, little work has been done in the area of production of “true piezoelectric fabric structures” based on flexible polymeric materials such as PVDF. In this work, we demonstrate “3-D knitted spacer” technology based all-fibre piezoelectric fabrics as power generators and energy harvesters. The knitted single-structure piezoelectric generator consists of high p-phase (~80%) piezoelectric PVDF monofilaments as the spacer yarn interconnected between silver (Ag) coated polyamide multifilament yarn layers acting as the top and bottom electrodes. The novel and unique textile structure provides an output power density in the range of 1.105.10 gWcm-2 at applied impact pressures in the range of 0.02-0.10 MPa, thus providing significantly higher power outputs and efficiencies over the existing 2-D woven and nonwoven piezoelectric structures. The high energy efficiency, mechanical durability and comfort of the soft, flexible and all-fibre based power generator is highly attractive for a variety of potential applications such as wearable electronic systems and energy harvesters charged from ambient environment or by human movement.

  10. Cloud Based Web 3d GIS Taiwan Platform

    NASA Astrophysics Data System (ADS)

    Tsai, W.-F.; Chang, J.-Y.; Yan, S. Y.; Chen, B.

    2011-09-01

    This article presents the status of the web 3D GIS platform, which has been developed in the National Applied Research Laboratories. The purpose is to develop a global earth observation 3D GIS platform for applications to disaster monitoring and assessment in Taiwan. For quick response to preliminary and detailed assessment after a natural disaster occurs, the web 3D GIS platform is useful to access, transfer, integrate, display and analyze the multi-scale huge data following the international OGC standard. The framework of cloud service for data warehousing management and efficiency enhancement using VMWare is illustrated in this article.

  11. Effects of 3D Toroidally Asymmetric Magnetic Field on Tokamak Magnetic Surfaces

    NASA Astrophysics Data System (ADS)

    Lao, L. L.

    2005-10-01

    The effects of 3D error magnetic field on magnetic surfaces are investigated using the DIII-D internal coils (I-Coils). Slowly rotating n=1 traveling waves at 5 Hz and various amplitudes were applied to systematically perturb the edge surfaces by programming the I-Coil currents. The vertical separatrix location difference between EFIT magnetic reconstructions that assumes toroidal symmetry and Thomson scattering Te measurements responds in phase to the applied perturbed field. The oscillation amplitudes increase with the strength of the applied field but are much smaller than those expected from the applied field alone. The results indicate that plasma response is important. Various plasma response models based on results from the MHD codes MARS and GATO are being developed and compared to the experimental observations. To more accurately evaluate the effects of magnetic measurement errors, a new form of the magnetic uncertainty matrix is also being implemented into EFIT. Details will be presented.

  12. Numerical and experimental investigation of the 3D free surface flow in a model Pelton turbine

    NASA Astrophysics Data System (ADS)

    Fiereder, R.; Riemann, S.; Schilling, R.

    2010-08-01

    This investigation focuses on the numerical and experimental analysis of the 3D free surface flow in a Pelton turbine. In particular, two typical flow conditions occurring in a full scale Pelton turbine - a configuration with a straight inlet as well as a configuration with a 90 degree elbow upstream of the nozzle - are considered. Thereby, the effect of secondary flow due to the 90 degree bending of the upstream pipe on the characteristics of the jet is explored. The hybrid flow field consists of pure liquid flow within the conduit and free surface two component flow of the liquid jet emerging out of the nozzle into air. The numerical results are validated against experimental investigations performed in the laboratory of the Institute of Fluid Mechanics (FLM). For the numerical simulation of the flow the in-house unstructured fully parallelized finite volume solver solver3D is utilized. An advanced interface capturing model based on the classic Volume of Fluid method is applied. In order to ensure sharp interface resolution an additional convection term is added to the transport equation of the volume fraction. A collocated variable arrangement is used and the set of non-linear equations, containing fluid conservation equations and model equations for turbulence and volume fraction, are solved in a segregated manner. For pressure-velocity coupling the SIMPLE and PISO algorithms are implemented. Detailed analysis of the observed flow patterns in the jet and of the jet geometry are presented.

  13. Surface rippling during solidification of binary polycrystalline alloy: Insights from 3-D phase-field simulations

    NASA Astrophysics Data System (ADS)

    Ankit, Kumar; Xing, Hui; Selzer, Michael; Nestler, Britta; Glicksman, Martin E.

    2017-01-01

    The mechanisms by which crystalline imperfections initiate breakdown of a planar front during directional solidification remain a topic of longstanding interest. Previous experimental findings show that the solid-liquid interface adjacent to a grain boundary provides a potential site where morphological instabilities initiate. However, interpretation of experimental data is difficult for complex 3-D diffusion fields that develop around grain multi-junctions and boundary ridges. We apply a phase-field approach to investigate factors that induce interfacial instabilities during directional solidification of a binary polycrystalline alloy. Using 2-D simulations, we establish the influence of solid-liquid interfacial energies on the spatial localization of initial interfacial perturbations. Based on parametric studies, we predict that grain misorientation and supersaturation in the melt provide major crystal growth factors determining solute segregation responsible for surface rippling. Subsequent breakdown of boundary ridges into periodic rows of hills, as simulated in 3-D, conform well with experiments. Finally, the significance of crystal misorientation relationships is elucidated in inducing spatial alignment of surface ripples.

  14. Extracting valley-ridge lines from point-cloud-based 3D fingerprint models.

    PubMed

    Pang, Xufang; Song, Zhan; Xie, Wuyuan

    2013-01-01

    3D fingerprinting is an emerging technology with the distinct advantage of touchless operation. More important, 3D fingerprint models contain more biometric information than traditional 2D fingerprint images. However, current approaches to fingerprint feature detection usually must transform the 3D models to a 2D space through unwrapping or other methods, which might introduce distortions. A new approach directly extracts valley-ridge features from point-cloud-based 3D fingerprint models. It first applies the moving least-squares method to fit a local paraboloid surface and represent the local point cloud area. It then computes the local surface's curvatures and curvature tensors to facilitate detection of the potential valley and ridge points. The approach projects those points to the most likely valley-ridge lines, using statistical means such as covariance analysis and cross correlation. To finally extract the valley-ridge lines, it grows the polylines that approximate the projected feature points and removes the perturbations between the sampled points. Experiments with different 3D fingerprint models demonstrate this approach's feasibility and performance.

  15. Lithologic identification & mapping test based on 3D inversion of magnetic and gravity

    NASA Astrophysics Data System (ADS)

    Yan, Jiayong; Lv, Qingtian; Qi, Guang; Zhao, Jinhua; Zhang, Yongqian

    2016-04-01

    Though lithologic identification & mapping to achieve ore concentration district transparent within 5km depth is the main way to realize deep fine structures study, to explore deep mineral resources and to reveal metallogenic regularity of large-scale ore district . Owing to the wide covered area, high sampling density and mature three-dimensional inversion algorithm of gravity and magnetic data, so gravity and magnetic inversion become the most likely way to achieve three-dimensional lithologic mapping at the present stage. In this paper, we take Lu-zong(Lujiang county to Zongyang county in Anhui province ,east China) ore district as a case, we proposed lithologic mapping flow based 3D inversion of gravity magnetic and then carry out the lithologic mapping test. Lithologic identification & mapping flow is as follows: 1. Analysis relations between lithology and density and magnetic susceptibility by cross plot. 2.Extracting appropriate residual anomalies from high-precision Bourger gravity and aeromagnetic. 3.Use same mesh, do 3D magnetic and gravity inversion respectively under prior information constrained, and then invert susceptibility and density 3D model. 4. According setp1, construct logical topology operations between density 3D model and susceptibility. 5.Use the logical operations, identify lithogies cell by cell in 3D mesh, and then get 3D lithological model. According this flow, we obtained three-dimensional distribution of five main type lithologies in the Lu-Zong ore district within 5km depth. The result of lithologic mapping not only showed that the shallow characteristics and surface geological mapping are basically Coincide,more importantly ,it reveals the deeper lithologic changes.The lithlogical model make up the insufficient of surface geological mapping. The lithologic mapping test results in Lu-Zong ore concentration district showed that lithological mapping using 3D inversion of gravity and magnetic is a effective method to reveal the

  16. Gis-Based Smart Cartography Using 3d Modeling

    NASA Astrophysics Data System (ADS)

    Malinverni, E. S.; Tassetti, A. N.

    2013-08-01

    3D City Models have evolved to be important tools for urban decision processes and information systems, especially in planning, simulation, analysis, documentation and heritage management. On the other hand existing and in use numerical cartography is often not suitable to be used in GIS because not geometrically and topologically correctly structured. The research aim is to 3D structure and organize a numeric cartography for GIS and turn it into CityGML standardized features. The work is framed around a first phase of methodological analysis aimed to underline which existing standard (like ISO and OGC rules) can be used to improve the quality requirement of a cartographic structure. Subsequently, from this technical specifics, it has been investigated the translation in formal contents, using an owner interchange software (SketchUp), to support some guide lines implementations to generate a GIS3D structured in GML3. It has been therefore predisposed a test three-dimensional numerical cartography (scale 1:500, generated from range data captured by 3D laser scanner), tested on its quality according to the previous standard and edited when and where necessary. Cad files and shapefiles are converted into a final 3D model (Google SketchUp model) and then exported into a 3D city model (CityGML LoD1/LoD2). The GIS3D structure has been managed in a GIS environment to run further spatial analysis and energy performance estimate, not achievable in a 2D environment. In particular geometrical building parameters (footprint, volume etc.) are computed and building envelop thermal characteristics are derived from. Lastly, a simulation is carried out to deal with asbestos and home renovating charges and show how the built 3D city model can support municipal managers with risk diagnosis of the present situation and development of strategies for a sustainable redevelop.

  17. Combination of 3D skin surface texture features and 2D ABCD features for improved melanoma diagnosis.

    PubMed

    Ding, Yi; John, Nigel W; Smith, Lyndon; Sun, Jiuai; Smith, Melvyn

    2015-10-01

    Two-dimensional asymmetry, border irregularity, colour variegation and diameter (ABCD) features are important indicators currently used for computer-assisted diagnosis of malignant melanoma (MM); however, they often prove to be insufficient to make a convincing diagnosis. Previous work has demonstrated that 3D skin surface normal features in the form of tilt and slant pattern disruptions are promising new features independent from the existing 2D ABCD features. This work investigates that whether improved lesion classification can be achieved by combining the 3D features with the 2D ABCD features. Experiments using a nonlinear support vector machine classifier show that many combinations of the 2D ABCD features and the 3D features can give substantially better classification accuracy than using (1) single features and (2) many combinations of the 2D ABCD features. The best 2D and 3D feature combination includes the overall 3D skin surface disruption, the asymmetry and all the three colour channel features. It gives an overall 87.8 % successful classification, which is better than the best single feature with 78.0 % and the best 2D feature combination with 83.1 %. These demonstrate that (1) the 3D features have additive values to improve the existing lesion classification and (2) combining the 3D feature with all the 2D features does not lead to the best lesion classification. The two ABCD features not selected by the best 2D and 3D combination, namely (1) the border feature and (2) the diameter feature, were also studied in separate experiments. It found that inclusion of either feature in the 2D and 3D combination can successfully classify 3 out of 4 lesion groups. The only one group not accurately classified by either feature can be classified satisfactorily by the other. In both cases, they have shown better classification performances than those without the 3D feature in the combinations. This further demonstrates that (1) the 3D feature can be used to

  18. Open-GL-based stereo system for 3D measurements

    NASA Astrophysics Data System (ADS)

    Boochs, Frank; Gehrhoff, Anja; Neifer, Markus

    2000-05-01

    A stereo system designed and used for the measurement of 3D- coordinates within metric stereo image pairs will be presented. First, the motivation for the development is shown, allowing to evaluate stereo images. As the use and availability of metric images of digital type rapidly increases corresponding equipment for the measuring process is needed. Systems which have been developed up to now are either very special ones, founded on high end graphics workstations with an according pricing or simple ones with restricted measuring functionality. A new conception will be shown, avoiding special high end graphics hardware but providing the measuring functionality required. The presented stereo system is based on PC-hardware equipped with a graphic board and uses an object oriented programming technique. The specific needs of a measuring system are shown and the corresponding requirements which have to be met by the system. The key role of OpenGL is described, which supplies some elementary graphic functions, being directly supported by graphic boards and thus provides the performance needed. Further important aspects as modularity and hardware independence and their value for the solution are shown. Finally some sample functions concerned with image display and handling are presented in more detail.

  19. SU-E-T-04: 3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions

    SciTech Connect

    Cumming, I; Lasso, A; Rankin, A; Fichtinger, G; Joshi, C P; Falkson, C; Schreiner, L John

    2014-06-01

    Purpose: Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions. Methods: We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer ( http://www.slicer.org ) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement. A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material. Results: The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm. Conclusion: Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required

  20. Poly(acrylic acid) brushes pattern as a 3D functional biosensor surface for microchips

    NASA Astrophysics Data System (ADS)

    Wang, Yan-Mei; Cui, Yi; Cheng, Zhi-Qiang; Song, Lu-Sheng; Wang, Zhi-You; Han, Bao-Hang; Zhu, Jin-Song

    2013-02-01

    Poly(acrylic acid) (PAA) brushes, a novel three dimensional (3D) precursor layer of biosensor or protein microarrays, possess high protein loading level and low non-specific protein adsorption. In this article, we describe a simple and convenient way to fabricate 3D PAA brushes pattern by microcontact printing (μCP) and characterize it with FT-IR and optical microscopy. The carboxyl groups of PAA brushes can be applied to covalently immobilize protein for immunoassay. Thriving 3D space made by patterning PAA brushes thin film is available to enhance protein immobilization, which is confirmed by measuring model protein interaction between human immunoglobulin G (H-IgG) and goat anti-H-IgG (G-H-IgG) with fluorescence microscopy and surface plasmon resonance imaging (SPRi). As expected, the SPRi signals of H-IgG coating on 3D PAA brushes pattern and further measuring specific binding with G-H-IgG are all larger than that of 3D PAA brushes without pattern and 2D bare gold surface. We further revealed that this surface can be used for high-throughput screening and clinical diagnosis by label-free assaying of Hepatitis-B-Virus surface antibody (HBsAb) with Hepatitis-B-Virus surface antigen (HBsAg) concentration array chip. The linearity range for HBsAb assay is wider than that of conventional ELISA method.

  1. A Simple Quality Assessment Index for Stereoscopic Images Based on 3D Gradient Magnitude

    PubMed Central

    Wang, Shanshan; Shao, Feng; Li, Fucui; Yu, Mei; Jiang, Gangyi

    2014-01-01

    We present a simple quality assessment index for stereoscopic images based on 3D gradient magnitude. To be more specific, we construct 3D volume from the stereoscopic images across different disparity spaces and calculate pointwise 3D gradient magnitude similarity (3D-GMS) along three horizontal, vertical, and viewpoint directions. Then, the quality score is obtained by averaging the 3D-GMS scores of all points in the 3D volume. Experimental results on four publicly available 3D image quality assessment databases demonstrate that, in comparison with the most related existing methods, the devised algorithm achieves high consistency alignment with subjective assessment. PMID:25133265

  2. Automated 3D renal segmentation based on image partitioning

    NASA Astrophysics Data System (ADS)

    Yeghiazaryan, Varduhi; Voiculescu, Irina D.

    2016-03-01

    Despite several decades of research into segmentation techniques, automated medical image segmentation is barely usable in a clinical context, and still at vast user time expense. This paper illustrates unsupervised organ segmentation through the use of a novel automated labelling approximation algorithm followed by a hypersurface front propagation method. The approximation stage relies on a pre-computed image partition forest obtained directly from CT scan data. We have implemented all procedures to operate directly on 3D volumes, rather than slice-by-slice, because our algorithms are dimensionality-independent. The results picture segmentations which identify kidneys, but can easily be extrapolated to other body parts. Quantitative analysis of our automated segmentation compared against hand-segmented gold standards indicates an average Dice similarity coefficient of 90%. Results were obtained over volumes of CT data with 9 kidneys, computing both volume-based similarity measures (such as the Dice and Jaccard coefficients, true positive volume fraction) and size-based measures (such as the relative volume difference). The analysis considered both healthy and diseased kidneys, although extreme pathological cases were excluded from the overall count. Such cases are difficult to segment both manually and automatically due to the large amplitude of Hounsfield unit distribution in the scan, and the wide spread of the tumorous tissue inside the abdomen. In the case of kidneys that have maintained their shape, the similarity range lies around the values obtained for inter-operator variability. Whilst the procedure is fully automated, our tools also provide a light level of manual editing.

  3. Fluorescent stereo microscopy for 3D surface profilometry and deformation mapping.

    PubMed

    Hu, Zhenxing; Luo, Huiyang; Du, Yingjie; Lu, Hongbing

    2013-05-20

    Recently, mechanobiology has received increased attention. For investigation of biofilm and cellular tissue, measurements of the surface topography and deformation in real-time are a pre-requisite for understanding the growth mechanisms. In this paper, a novel three-dimensional (3D) fluorescent microscopic method for surface profilometry and deformation measurements is developed. In this technique a pair of cameras are connected to a binocular fluorescent microscope to acquire micrographs from two different viewing angles of a sample surface doped or sprayed with fluorescent microparticles. Digital image correlation technique is used to search for matching points in the pairing fluorescence micrographs. After calibration of the system, the 3D surface topography is reconstructed from the pair of planar images. When the deformed surface topography is compared with undeformed topography using fluorescent microparticles for movement tracking of individual material points, the full field deformation of the surface is determined. The technique is demonstrated on topography measurement of a biofilm, and also on surface deformation measurement of the biofilm during growth. The use of 3D imaging of the fluorescent microparticles eliminates the formation of bright parts in an image caused by specular reflections. The technique is appropriate for non-contact, full-field and real-time 3D surface profilometry and deformation measurements of materials and structures at the microscale.

  4. 3-D Acoustic Scattering from 2-D Rough Surfaces Using A Parabolic Equation Model

    DTIC Science & Technology

    2013-12-01

    acoustic propagation signals, especially at mid- frequencies and higher (e.g., acoustic communications systems). For many years, the effects of rough...of the effect of surface scattering on 3-D propagation , which is critical in evaluating the variability in underwater acoustic propagation . Results...14. SUBJECT TERMS Acoustic Propagation , Acoustic Scattering, Sea Surface Perturbations, Split- Step Fourier Algorithm, Finite Difference Algorithm

  5. Automatic system for 3D reconstruction of the chick eye based on digital photographs.

    PubMed

    Wong, Alexander; Genest, Reno; Chandrashekar, Naveen; Choh, Vivian; Irving, Elizabeth L

    2012-01-01

    The geometry of anatomical specimens is very complex and accurate 3D reconstruction is important for morphological studies, finite element analysis (FEA) and rapid prototyping. Although magnetic resonance imaging, computed tomography and laser scanners can be used for reconstructing biological structures, the cost of the equipment is fairly high and specialised technicians are required to operate the equipment, making such approaches limiting in terms of accessibility. In this paper, a novel automatic system for 3D surface reconstruction of the chick eye from digital photographs of a serially sectioned specimen is presented as a potential cost-effective and practical alternative. The system is designed to allow for automatic detection of the external surface of the chick eye. Automatic alignment of the photographs is performed using a combination of coloured markers and an algorithm based on complex phase order likelihood that is robust to noise and illumination variations. Automatic segmentation of the external boundaries of the eye from the aligned photographs is performed using a novel level-set segmentation approach based on a complex phase order energy functional. The extracted boundaries are sampled to construct a 3D point cloud, and a combination of Delaunay triangulation and subdivision surfaces is employed to construct the final triangular mesh. Experimental results using digital photographs of the chick eye show that the proposed system is capable of producing accurate 3D reconstructions of the external surface of the eye. The 3D model geometry is similar to a real chick eye and could be used for morphological studies and FEA.

  6. Comparison of two different surfaces for 3d model abstraction in support of remote sensing simulations

    SciTech Connect

    Pope, Paul A; Ranken, Doug M

    2010-01-01

    A method for abstracting a 3D model by shrinking a triangular mesh, defined upon a best fitting ellipsoid surrounding the model, onto the model's surface has been previously described. This ''shrinkwrap'' process enables a semi-regular mesh to be defined upon an object's surface. This creates a useful data structure for conducting remote sensing simulations and image processing. However, using a best fitting ellipsoid having a graticule-based tessellation to seed the shrinkwrap process suffers from a mesh which is too dense at the poles. To achieve a more regular mesh, the use of a best fitting, subdivided icosahedron was tested. By subdividing each of the twenty facets of the icosahedron into regular triangles of a predetermined size, arbitrarily dense, highly-regular starting meshes can be created. Comparisons of the meshes resulting from these two seed surfaces are described. Use of a best fitting icosahedron-based mesh as the seed surface in the shrinkwrap process is preferable to using a best fitting ellipsoid. The impacts to remote sensing simulations, specifically generation of synthetic imagery, is illustrated.

  7. Collaboration on Scene Graph Based 3D Data

    NASA Astrophysics Data System (ADS)

    Ammon, Lorenz; Bieri, Hanspeter

    Professional 3D digital content creation tools, like Alias Maya or discreet 3ds max, offer only limited support for a team of artists to work on a 3D model collaboratively. We present a scene graph repository system that enables fine-grained collaboration on scenes built using standard 3D DCC tools by applying the concept of collaborative versions to a general attributed scene graph. Artists can work on the same scene in parallel without locking out each other. The artists' changes to a scene are regularly merged to ensure that all artists can see each others progress and collaborate on current data. We introduce the concept of indirect changes and indirect conflicts to systematically inspect the effects that collaborative changes have on a scene. Inspecting indirect conflicts helps maintaining scene consistency by systematically looking for inconsistencies at the right places.

  8. 3-dimensional (3D) fabricated polymer based drug delivery systems.

    PubMed

    Moulton, Simon E; Wallace, Gordon G

    2014-11-10

    Drug delivery from 3-dimensional (3D) structures is a rapidly growing area of research. It is essential to achieve structures wherein drug stability is ensured, the drug loading capacity is appropriate and the desired controlled release profile can be attained. Attention must also be paid to the development of appropriate fabrication machinery that allows 3D drug delivery systems (DDS) to be produced in a simple, reliable and reproducible manner. The range of fabrication methods currently being used to form 3D DDSs include electrospinning (solution and melt), wet-spinning and printing (3-dimensional). The use of these techniques enables production of DDSs from the macro-scale down to the nano-scale. This article reviews progress in these fabrication techniques to form DDSs that possess desirable drug delivery kinetics for a wide range of applications.

  9. Structure light telecentric stereoscopic vision 3D measurement system based on Scheimpflug condition

    NASA Astrophysics Data System (ADS)

    Mei, Qing; Gao, Jian; Lin, Hui; Chen, Yun; Yunbo, He; Wang, Wei; Zhang, Guanjin; Chen, Xin

    2016-11-01

    We designed a new three-dimensional (3D) measurement system for micro components: a structure light telecentric stereoscopic vision 3D measurement system based on the Scheimpflug condition. This system creatively combines the telecentric imaging model and the Scheimpflug condition on the basis of structure light stereoscopic vision, having benefits of a wide measurement range, high accuracy, fast speed, and low price. The system measurement range is 20 mm×13 mm×6 mm, the lateral resolution is 20 μm, and the practical vertical resolution reaches 2.6 μm, which is close to the theoretical value of 2 μm and well satisfies the 3D measurement needs of micro components such as semiconductor devices, photoelectron elements, and micro-electromechanical systems. In this paper, we first introduce the principle and structure of the system and then present the system calibration and 3D reconstruction. We then present an experiment that was performed for the 3D reconstruction of the surface topography of a wafer, followed by a discussion. Finally, the conclusions are presented.

  10. 3D Clumped Cell Segmentation Using Curvature Based Seeded Watershed

    PubMed Central

    Atta-Fosu, Thomas; Guo, Weihong; Jeter, Dana; Mizutani, Claudia M.; Stopczynski, Nathan; Sousa-Neves, Rui

    2017-01-01

    Image segmentation is an important process that separates objects from the background and also from each other. Applied to cells, the results can be used for cell counting which is very important in medical diagnosis and treatment, and biological research that is often used by scientists and medical practitioners. Segmenting 3D confocal microscopy images containing cells of different shapes and sizes is still challenging as the nuclei are closely packed. The watershed transform provides an efficient tool in segmenting such nuclei provided a reasonable set of markers can be found in the image. In the presence of low-contrast variation or excessive noise in the given image, the watershed transform leads to over-segmentation (a single object is overly split into multiple objects). The traditional watershed uses the local minima of the input image and will characteristically find multiple minima in one object unless they are specified (marker-controlled watershed). An alternative to using the local minima is by a supervised technique called seeded watershed, which supplies single seeds to replace the minima for the objects. Consequently, the accuracy of a seeded watershed algorithm relies on the accuracy of the predefined seeds. In this paper, we present a segmentation approach based on the geometric morphological properties of the ‘landscape’ using curvatures. The curvatures are computed as the eigenvalues of the Shape matrix, producing accurate seeds that also inherit the original shape of their respective cells. We compare with some popular approaches and show the advantage of the proposed method. PMID:28280723

  11. Microseismic network design assessment based on 3D ray tracing

    NASA Astrophysics Data System (ADS)

    Näsholm, Sven Peter; Wuestefeld, Andreas; Lubrano-Lavadera, Paul; Lang, Dominik; Kaschwich, Tina; Oye, Volker

    2016-04-01

    There is increasing demand on the versatility of microseismic monitoring networks. In early projects, being able to locate any triggers was considered a success. These early successes led to a better understanding of how to extract value from microseismic results. Today operators, regulators, and service providers work closely together in order to find the optimum network design to meet various requirements. In the current study we demonstrate an integrated and streamlined network capability assessment approach. It is intended for use during the microseismic network design process prior to installation. The assessments are derived from 3D ray tracing between a grid of event points and the sensors. Three aspects are discussed: 1) Magnitude of completeness or detection limit; 2) Event location accuracy; and 3) Ground-motion hazard. The network capability parameters 1) and 2) are estimated at all hypothetic event locations and are presented in the form of maps given a seismic sensor coordinate scenario. In addition, the ray tracing traveltimes permit to estimate the point-spread-functions (PSFs) at the event grid points. PSFs are useful in assessing the resolution and focusing capability of the network for stacking-based event location and imaging methods. We estimate the performance for a hypothetical network case with 11 sensors. We consider the well-documented region around the San Andreas Fault Observatory at Depth (SAFOD) located north of Parkfield, California. The ray tracing is done through a detailed velocity model which covers a 26.2 by 21.2 km wide area around the SAFOD drill site with a resolution of 200 m both for the P-and S-wave velocities. Systematic network capability assessment for different sensor site scenarios prior to installation facilitates finding a final design which meets the survey objectives.

  12. 3D surface measurements with isogeometric stereocorrelation-Application to complex shapes

    NASA Astrophysics Data System (ADS)

    Dufour, John-Eric; Leclercq, Sylvain; Schneider, Julien; Roux, Stéphane; Hild, François

    2016-12-01

    The aim of the present study is to measure complex shapes of tested objects by using a priori information given by their CAD model via stereocorrelation. To follow a 3D object during its deformation and to determine 3D surface displacement fields, a first measurement of the object shape is necessary. It is achieved by updating the CAD reference via a global approach to stereocorrelation. Once the 3D shape has been determined, the next step is to measure 3D displacement fields during loading. The kinematics of the deformed shape is assumed to be written within the same isogeometric framework. Isogeometric stereocorrelation is applied to analyze a compression test on a ribbed cylinder in two different configurations of the stereo rig.

  13. 3D numerical simulation analysis of passive drag near free surface in swimming

    NASA Astrophysics Data System (ADS)

    Zhan, Jie-min; Li, Tian-zeng; Chen, Xue-bin; Li, Yok-sheung; Wai, Wing-hong Onyx

    2015-04-01

    The aim of this work is to build a 3D numerical model to study the characteristics of passive drag on competitive swimmers taking into account the impact of the free surface. This model solves the 3D incompressible Navier-Stokes equations using RNG k- ɛ turbulence closure. The volume of fluid (VOF) method is used to locate the free surface. The 3D virtual model is created by Computer Aided Industrial Design (CAID) software, Rhinoceros. Firstly, a specific posture of swimming is studied. The simulation results are in good agreement with the data from mannequin towing experiments. The effects of a swimmer's arms and legs positions on swimming performance are then studied. Finally, it is demonstrated that the present method is capable of simulating gliding near the free surface.

  14. Numerical Investigation of 3D multichannel analysis of surface wave method

    NASA Astrophysics Data System (ADS)

    Wang, Limin; Xu, Yixian; Luo, Yinhe

    2015-08-01

    Multichannel analysis of surface wave (MASW) method is an efficient tool to obtain near-surface S-wave velocity, and it has gained popularity in engineering practice. Up to now, most examples of using the MASW technique are focused on 2D models or data from a 1D linear receiver spread. We propose a 3D MASW scheme. A finite-difference (FD) method is used to investigate the method using linear and fan-shaped receiver spreads. Results show that the 3D topography strongly affects propagation of Rayleigh waves. The energy concentration of dispersion image is distorted and bifurcated because of the influence of free-surface topography. These effects are reduced with the 3D MASW method. Lastly we investigate the relation between the array size and the resolution of dispersion measurement.

  15. 3D Surface Reconstruction of Rills in a Spanish Olive Grove

    NASA Astrophysics Data System (ADS)

    Brings, Christine; Gronz, Oliver; Seeger, Manuel; Wirtz, Stefan; Taguas, Encarnación; Ries, Johannes B.

    2016-04-01

    The low-cost, user-friendly photogrammetric Structure from Motion (SfM) technique is used for 3D surface reconstruction and difference calculation of an 18 meter long rill in South Spain (Andalusia, Puente Genil). The images were taken with a Canon HD video camera before and after a rill experiment in an olive grove. Recording with a video camera has compared to a photo camera a huge time advantage and the method also guarantees more than adequately overlapping sharp images. For each model, approximately 20 minutes of video were taken. As SfM needs single images, the sharpest image was automatically selected from 8 frame intervals. The sharpness was estimated using a derivative-based metric. Then, VisualSfM detects feature points in each image, searches matching feature points in all image pairs and recovers the camera and feature positions. Finally, by triangulation of camera positions and feature points the software reconstructs a point cloud of the rill surface. From the point cloud, 3D surface models (meshes) are created and via difference calculations of the pre and post model a visualization of the changes (erosion and accumulation areas) and quantification of erosion volumes are possible. The calculated volumes are presented in spatial units of the models and so real values must be converted via references. The results show that rills in olive groves have a high dynamic due to the lack of vegetation cover under the trees, so that the rill can incise until the bedrock. Another reason for the high activity is the intensive employment of machinery.

  16. Design of a 3D surface scanner prototype suitable for MR.

    PubMed

    Cavalleri, M; Romei, M; Reni, G

    2010-01-01

    The detection of body movements during MR examination could help in reducing motion artifacts or to get patient responses during functional magnetic resonance. It can be supported by a slit scanner, that combines a camera with a light stripe projector to obtain 3D coordinates of points forming the external surface of the body. In this work we propose a slit scanner prototype based on a miniaturized projector without moving parts. Just small sized hardware is required to analyze the video signal, operating in time domain instead of spatial domain. To accomplish this, the camera is placed with its pixel columns as more parallel as possible to the projected light stripes and the camera video signal is analyzed by a resistor transistor logic after analog processing.

  17. An efficient solid modeling system based on a hand-held 3D laser scan device

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Xu, Jun; Xu, Chenxi; Pan, Ming

    2014-12-01

    The hand-held 3D laser scanner sold in the market is appealing for its port and convenient to use, but price is expensive. To develop such a system based cheap devices using the same principles as the commercial systems is impossible. In this paper, a simple hand-held 3D laser scanner is developed based on a volume reconstruction method using cheap devices. Unlike convenient laser scanner to collect point cloud of an object surface, the proposed method only scan few key profile curves on the surface. Planar section curve network can be generated from these profile curves to construct a volume model of the object. The details of design are presented, and illustrated by the example of a complex shaped object.

  18. surf3d: A 3-D finite-element program for the analysis of surface and corner cracks in solids subjected to mode-1 loadings

    NASA Technical Reports Server (NTRS)

    Raju, I. S.; Newman, J. C., Jr.

    1993-01-01

    A computer program, surf3d, that uses the 3D finite-element method to calculate the stress-intensity factors for surface, corner, and embedded cracks in finite-thickness plates with and without circular holes, was developed. The cracks are assumed to be either elliptic or part eliptic in shape. The computer program uses eight-noded hexahedral elements to model the solid. The program uses a skyline storage and solver. The stress-intensity factors are evaluated using the force method, the crack-opening displacement method, and the 3-D virtual crack closure methods. In the manual the input to and the output of the surf3d program are described. This manual also demonstrates the use of the program and describes the calculation of the stress-intensity factors. Several examples with sample data files are included with the manual. To facilitate modeling of the user's crack configuration and loading, a companion program (a preprocessor program) that generates the data for the surf3d called gensurf was also developed. The gensurf program is a three dimensional mesh generator program that requires minimal input and that builds a complete data file for surf3d. The program surf3d is operational on Unix machines such as CRAY Y-MP, CRAY-2, and Convex C-220.

  19. Complete calibration of a phase-based 3D imaging system based on fringe projection technique

    NASA Astrophysics Data System (ADS)

    Meng, Shasha; Ma, Haiyan; Zhang, Zonghua; Guo, Tong; Zhang, Sixiang; Hu, Xiaotang

    2011-11-01

    Phase calculation-based 3D imaging systems have been widely studied because of the advantages of non-contact operation, full-field, fast acquisition and automatic data processing. A vital step is calibration, which builds up the relationship between phase map and range image. The existing calibration methods are complicated because of using a precise translating stage or a 3D gauge block. Recently, we presented a simple method to convert phase into depth data by using a polynomial function and a plate having discrete markers on the surface with known distance in between. However, the initial position of all the markers needs to be determined manually and the X, Y coordinates are not calibrated. This paper presents a complete calibration method of phase calculation-based 3D imaging systems by using a plate having discrete markers on the surface with known distance in between. The absolute phase of each pixel can be calculated by projecting fringe pattern onto the plate. Each marker position can be determined by an automatic extraction algorithm, so the relative depth of each pixel to a chosen reference plane can be obtained. Therefore, coefficient set of the polynomial function for each pixel are determined by using the obtained absolute phase and depth data. In the meanwhile, pixel positions and the X, Y coordinates can be established by the parameters of the CCD camera. Experimental results and performance evaluation show that the proposed calibration method can easily build up the relationship between absolute phase map and range image in a simple way.

  20. Cold atmospheric plasma (CAP) surface nanomodified 3D printed polylactic acid (PLA) scaffolds for bone regeneration.

    PubMed

    Wang, Mian; Favi, Pelagie; Cheng, Xiaoqian; Golshan, Negar H; Ziemer, Katherine S; Keidar, Michael; Webster, Thomas J

    2016-12-01

    Three-dimensional (3D) printing is a new fabrication method for tissue engineering which can precisely control scaffold architecture at the micron-scale. However, scaffolds not only need 3D biocompatible structures that mimic the micron structure of natural tissues, they also require mimicking of the nano-scale extracellular matrix properties of the tissue they intend to replace. In order to achieve this, the objective of the present in vitro study was to use cold atmospheric plasma (CAP) as a quick and inexpensive way to modify the nano-scale roughness and chemical composition of a 3D printed scaffold surface. Water contact angles of a normal 3D printed poly-lactic-acid (PLA) scaffold dramatically dropped after CAP treatment from 70±2° to 24±2°. In addition, the nano-scale surface roughness (Rq) of the untreated 3D PLA scaffolds drastically increased (up to 250%) after 1, 3, and 5min of CAP treatment from 1.20nm to 10.50nm, 22.90nm, and 27.60nm, respectively. X-ray photoelectron spectroscopy (XPS) analysis showed that the ratio of oxygen to carbon significantly increased after CAP treatment, which indicated that the CAP treatment of PLA not only changed nano-scale roughness but also chemistry. Both changes in hydrophilicity and nano-scale roughness demonstrated a very efficient plasma treatment, which in turn significantly promoted both osteoblast (bone forming cells) and mesenchymal stem cell attachment and proliferation. These promising results suggest that CAP surface modification may have potential applications for enhancing 3D printed PLA bone tissue engineering materials (and all 3D printed materials) in a quick and an inexpensive manner and, thus, should be further studied.

  1. Automated 3D Damaged Cavity Model Builder for Lower Surface Acreage Tile on Orbiter

    NASA Technical Reports Server (NTRS)

    Belknap, Shannon; Zhang, Michael

    2013-01-01

    The 3D Automated Thermal Tool for Damaged Acreage Tile Math Model builder was developed to perform quickly and accurately 3D thermal analyses on damaged lower surface acreage tiles and structures beneath the damaged locations on a Space Shuttle Orbiter. The 3D model builder created both TRASYS geometric math models (GMMs) and SINDA thermal math models (TMMs) to simulate an idealized damaged cavity in the damaged tile(s). The GMMs are processed in TRASYS to generate radiation conductors between the surfaces in the cavity. The radiation conductors are inserted into the TMMs, which are processed in SINDA to generate temperature histories for all of the nodes on each layer of the TMM. The invention allows a thermal analyst to create quickly and accurately a 3D model of a damaged lower surface tile on the orbiter. The 3D model builder can generate a GMM and the correspond ing TMM in one or two minutes, with the damaged cavity included in the tile material. A separate program creates a configuration file, which would take a couple of minutes to edit. This configuration file is read by the model builder program to determine the location of the damage, the correct tile type, tile thickness, structure thickness, and SIP thickness of the damage, so that the model builder program can build an accurate model at the specified location. Once the models are built, they are processed by the TRASYS and SINDA.

  2. 3D scanning electron microscopy applied to surface characterization of fluorosed dental enamel.

    PubMed

    Limandri, Silvina; Galván Josa, Víctor; Valentinuzzi, María Cecilia; Chena, María Emilia; Castellano, Gustavo

    2016-05-01

    The enamel surfaces of fluorotic teeth were studied by scanning electron stereomicroscopy. Different whitening treatments were applied to 25 pieces to remove stains caused by fluorosis and their surfaces were characterized by stereomicroscopy in order to obtain functional and amplitude parameters. The topographic features resulting for each treatment were determined through these parameters. The results obtained show that the 3D reconstruction achieved from the SEM stereo pairs is a valuable potential alternative for the surface characterization of this kind of samples.

  3. 3D shape reconstruction of specular surfaces by using phase measuring deflectometry

    NASA Astrophysics Data System (ADS)

    Zhou, Tian; Chen, Kun; Wei, Haoyun; Li, Yan

    2016-10-01

    The existing estimation methods for recovering height information from surface gradient are mainly divided into Modal and Zonal techniques. Since specular surfaces used in the industry always have complex and large areas, considerations must be given to both the improvement of measurement accuracy and the acceleration of on-line processing speed, which beyond the capacity of existing estimations. Incorporating the Modal and Zonal approaches into a unifying scheme, we introduce an improved 3D shape reconstruction version of specular surfaces based on Phase Measuring Deflectometry in this paper. The Modal estimation is firstly implemented to derive the coarse height information of the measured surface as initial iteration values. Then the real shape can be recovered utilizing a modified Zonal wave-front reconstruction algorithm. By combining the advantages of Modal and Zonal estimations, the proposed method simultaneously achieves consistently high accuracy and dramatically rapid convergence. Moreover, the iterative process based on an advanced successive overrelaxation technique shows a consistent rejection of measurement errors, guaranteeing the stability and robustness in practical applications. Both simulation and experimentally measurement demonstrate the validity and efficiency of the proposed improved method. According to the experimental result, the computation time decreases approximately 74.92% in contrast to the Zonal estimation and the surface error is about 6.68 μm with reconstruction points of 391×529 pixels of an experimentally measured sphere mirror. In general, this method can be conducted with fast convergence speed and high accuracy, providing an efficient, stable and real-time approach for the shape reconstruction of specular surfaces in practical situations.

  4. Cranial Base Superimposition for 3D Evaluation of Soft Tissue Changes

    PubMed Central

    Cevidanes, Lucia H.C.; Motta, Alexandre; Proffit, William R.; Ackerman, James L.; Styner, Martin

    2009-01-01

    The recent emphasis on soft tissues as the limiting factor in treatment and on soft tissue relationships in establishing the goals of treatment has made 3D analysis of soft tissues more important in diagnosis and treatment planning. It is equally important to be able to detect changes in the facial soft tissues produced by growth and/or treatment. This requires structures of reference for superimposition, and a way to display the changes with quantitative information. This paper outlines a technique for quantifying facial soft tissue changes as viewed in CBCT data, using fully-automated voxel-wise registration of the cranial base surface. The assessment of change of soft tissues is done via calculation of the Euclidean surface distances between the 3D models. Color maps are used for visual assessment of the location and quantification of changes. This methodology allows a detailed examination of soft tissue changes with growth and/or treatment. Because of the lack of stable references with 3D photogrammetry, 3D photography and laser scanning, soft tissue changes cannot be accurately quantified by these methods. PMID:20381752

  5. Impact of 3-D printed PLA- and chitosan-based scaffolds on human monocyte/macrophage responses: unraveling the effect of 3-D structures on inflammation.

    PubMed

    Almeida, Catarina R; Serra, Tiziano; Oliveira, Marta I; Planell, Josep A; Barbosa, Mário A; Navarro, Melba

    2014-02-01

    Recent studies have pointed towards a decisive role of inflammation in triggering tissue repair and regeneration, while at the same time it is accepted that an exacerbated inflammatory response may lead to rejection of an implant. Within this context, understanding and having the capacity to regulate the inflammatory response elicited by 3-D scaffolds aimed for tissue regeneration is crucial. This work reports on the analysis of the cytokine profile of human monocytes/macrophages in contact with biodegradable 3-D scaffolds with different surface properties, architecture and controlled pore geometry, fabricated by 3-D printing technology. Fabrication processes were optimized to create four different 3-D platforms based on polylactic acid (PLA), PLA/calcium phosphate glass or chitosan. Cytokine secretion and cell morphology of human peripheral blood monocytes allowed to differentiate on the different matrices were analyzed. While all scaffolds supported monocyte/macrophage adhesion and stimulated cytokine production, striking differences between PLA-based and chitosan scaffolds were found, with chitosan eliciting increased secretion of tumor necrosis factor (TNF)-α, while PLA-based scaffolds induced higher production of interleukin (IL)-6, IL-12/23 and IL-10. Even though the material itself induced the biggest differences, the scaffold geometry also impacted on TNF-α and IL-12/23 production, with chitosan scaffolds having larger pores and wider angles leading to a higher secretion of these pro-inflammatory cytokines. These findings strengthen the appropriateness of these 3-D platforms to study modulation of macrophage responses by specific parameters (chemistry, topography, scaffold architecture).

  6. Assessment of Iterative Closest Point Registration Accuracy for Different Phantom Surfaces Captured by an Optical 3D Sensor in Radiotherapy

    PubMed Central

    Walke, Mathias; Gademann, Günther

    2017-01-01

    An optical 3D sensor provides an additional tool for verification of correct patient settlement on a Tomotherapy treatment machine. The patient's position in the actual treatment is compared with the intended position defined in treatment planning. A commercially available optical 3D sensor measures parts of the body surface and estimates the deviation from the desired position without markers. The registration precision of the in-built algorithm and of selected ICP (iterative closest point) algorithms is investigated on surface data of specially designed phantoms captured by the optical 3D sensor for predefined shifts of the treatment table. A rigid body transform is compared with the actual displacement to check registration reliability for predefined limits. The curvature type of investigated phantom bodies has a strong influence on registration result which is more critical for surfaces of low curvature. We investigated the registration accuracy of the optical 3D sensor for the chosen phantoms and compared the results with selected unconstrained ICP algorithms. Safe registration within the clinical limits is only possible for uniquely shaped surface regions, but error metrics based on surface normals improve translational registration. Large registration errors clearly hint at setup deviations, whereas small values do not guarantee correct positioning. PMID:28163773

  7. Understanding surface processes 3D imaging from micro-scale to regional scale

    NASA Astrophysics Data System (ADS)

    Jaboyedoff, Michel; Abellan, Antonio; Carrea, Dario; Derron, Marc-Henri; Franz, Martin; Guerin, Antoine; Humair, Florian; Matasci, Battista; Michoud, Clément; Nicolet, Pierrick; Penna, Ivanna; Rudaz, Benjamin; Voumard, Jeremie; Wyser, Emmanuel

    2015-04-01

    The production of topography using remote sensing techniques has considerably been improved during the last fifteen years due to the advances in electronics and to the increase of computing power. The earth surface is monitored at all the scales using Space Shuttle Missions (SRTM) digital elevation model (DEM), or using laser scanner (LS), both terrestrial (TLS) and airborne (ALS), with accuracies that can reach up to less than 50 microns for observations of objects at meter scale. Recently, photogrammetry has been pushed by the progress of LiDAR and thanks to the advance in image recognition. It led to the development of new techniques such as structure-from-motion (SFM), which allows obtaining 3D point cloud based on several pictures of the same object taken from several point of views. Both LiDAR and Photogrammetry produce 3D point clouds. One of the current 3D applications is the surface changes, which is often based simply on the subtraction of DEM at different time intervals, leading to a simple superficial description of the natural processes without information on the mass transport. However, a point cloud has much more information than a simple surface. For instance, shape recognition can be used to track objects or deformations such as a rock mass toppling, either using the shape of the point cloud or a specific moving element. Such method permits, for instance, to study in detail pre-failure accelerations, and are now routinely used in mining industry. Other methods are coupling images and DEMs and are used, for example, to capture the surface vectors of displacements in order to deduce the surface deformations of landslides. These types of surveys have now broad applications to all kinds of erosional processes. The coastal retreat can be monitored, and it displays in some places several centimetres per year of retreat on average. The sediment transports in torrent are now better constraint showing clearly pulses. The seasonal cycles can as well be

  8. Design of a 3-D surface scanner for lower limb prosthetics: a technical note.

    PubMed

    Commean, P K; Smith, K E; Vannier, M W

    1996-07-01

    A three-dimensional (3-D) noncontact optical surface range sensing imaging system that captures the entire circumferential and distal end surfaces of lower limb residua in less than 1 second has been developed. The optical surface scanner (OSS) consists of four charge injection device (CID) cameras and three white light projectors, mounted on a rigid frame surrounding the subject's residuum, allowing 360 degrees surface coverage of the lower residual limb. Anatomic 3-D computer graphics reconstruction of a residuum surface, recorded with the OSS imaging system, is used for visualization and measurement. One cubical and two spherical calibration test objects were used to obtain a system precision of less than 1 mm. In a study conducted with 13 persons with below knee (BK) amputation, the OSS system was compared to calipers, electromagnetic digitizer, and volumetric computed tomography with better than 1 mm precision on plaster positive casts and approximately 2 mm on the residual limbs.

  9. Two-dimensional evaluation of 3D needled Cf/SiC composite fiber bundle surface

    NASA Astrophysics Data System (ADS)

    Wei, Jinhua; Lin, Bin; Cao, Xiaoyan; Zhang, Xiaofeng; Fang, Sheng

    2015-11-01

    The variations of fiber bundle surface microstructure have direct influence on the material performance, especially the friction and wear properties. Therefore, fiber bundle is the smallest evaluation unit of Cf/SiC composite surface. However, due to the anisotropy and inhomogeneity of Cf/SiC composite, it is difficult to evaluate the surface characteristics. Researchers think that two-dimensional evaluation is not suitable for the composites surface assessment any more because of its complex composition and varied surface structure. In this paper, a novel method is introduced for the evaluation of 3D needled Cf/SiC composite fiber bundle surface. On the level of Cf/SiC composite fiber bundle surface, two-dimensional evaluation method is adopted, with which the fiber bundle surface quality can be quantitatively evaluated by the two-dimensional surface roughness Ra. As long as the extracted surface profiles averagely distributed on Cf/SiC composite fiber bundle surface, with appropriate sampling length and sampling number, the mean value of Ra can estimate the whole surface roughness, thus reflecting the roughness degree of surface accurately. This study not only benefits the detection of 3D needled Cf/SiC composite fiber bundle surface quality, and lays a foundation on the evaluation of material functional features in further. And it corresponds to the convenient application in engineering practice.

  10. Controlled surface topography regulates collective 3D migration by epithelial-mesenchymal composite embryonic tissues.

    PubMed

    Song, Jiho; Shawky, Joseph H; Kim, YongTae; Hazar, Melis; LeDuc, Philip R; Sitti, Metin; Davidson, Lance A

    2015-07-01

    Cells in tissues encounter a range of physical cues as they migrate. Probing single cell and collective migratory responses to physically defined three-dimensional (3D) microenvironments and the factors that modulate those responses are critical to understanding how tissue migration is regulated during development, regeneration, and cancer. One key physical factor that regulates cell migration is topography. Most studies on surface topography and cell mechanics have been carried out with single migratory cells, yet little is known about the spreading and motility response of 3D complex multi-cellular tissues to topographical cues. Here, we examine the response to complex topographical cues of microsurgically isolated tissue explants composed of epithelial and mesenchymal cell layers from naturally 3D organized embryos of the aquatic frog Xenopus laevis. We control topography using fabricated micropost arrays (MPAs) and investigate the collective 3D migration of these multi-cellular systems in these MPAs. We find that the topography regulates both collective and individual cell migration and that dense MPAs reduce but do not eliminate tissue spreading. By modulating cell size through the cell cycle inhibitor Mitomycin C or the spacing of the MPAs we uncover how 3D topographical cues disrupt collective cell migration. We find surface topography can direct both single cell motility and tissue spreading, altering tissue-scale processes that enable efficient conversion of single cell motility into collective movement.

  11. 3D-modeling of Callisto's sputtered surface-exosphere environment

    NASA Astrophysics Data System (ADS)

    Lammer, Helmut; Pfleger, Martin; Lindqvist, Jesper; Lichtenegger, Herbert; Holmström, Mats; Vorburger, Audrey; Wurz, Peter; Barabash, Stas

    2016-04-01

    We study the stoichiometrical release of various surface elements caused by plasma sputtering from an assumed icy and non-icy (i.e., chondritic) surface into the exosphere of the Jovian satellite Callisto. We apply a 3D plasma planetary interaction hybrid model that is used for the evaluation of precipitation maps of magnetospheric H+, O+ and S+ sputter agents onto Callisto's surface. The obtained precipitation maps are then applied to the assumed surface compositions where the related sputter yields are calculated by means of the 2013 SRIM code and are coupled with a 3D exosphere model. Sputtered surface particles are followed on their individual trajectories until they either escape Callisto's gravitational attraction or return to the surface. We study also the effect of collisions between sputter species and ambient O2 molecules which form a tiny atmosphere near the satellite's surface and compare the exosphere densities that are obtained from the 3D model with and without a background gaseous envelope with recent 1D model results. Finally we discuss if the Neutral gas and Ion Mass (NIM) spectrometer, that is part of the Particle Environment Package (PEP) on board of the JUICE mission will be able to detect sputtered particles from Callisto's icy and non-icy surface.

  12. Face recognition based on matching of local features on 3D dynamic range sequences

    NASA Astrophysics Data System (ADS)

    Echeagaray-Patrón, B. A.; Kober, Vitaly

    2016-09-01

    3D face recognition has attracted attention in the last decade due to improvement of technology of 3D image acquisition and its wide range of applications such as access control, surveillance, human-computer interaction and biometric identification systems. Most research on 3D face recognition has focused on analysis of 3D still data. In this work, a new method for face recognition using dynamic 3D range sequences is proposed. Experimental results are presented and discussed using 3D sequences in the presence of pose variation. The performance of the proposed method is compared with that of conventional face recognition algorithms based on descriptors.

  13. Triangular mesh establishment of 3D laser scanning data based on ellipsoidal projection

    NASA Astrophysics Data System (ADS)

    Zheng, De-hua; Xu, Jia; Li, Jia; Wang, Xin-sen

    2011-10-01

    The establishment of high quality triangular mesh is one of the key steps in 3D laser scanning data processing. Traditional triangulation algorithms have been proposed directly on the basis of adjacency relation between points in 3D space. However, when the point density is non-uniform or the noise exists, the problems such as surface hole, dough sheet overlapping and inconsistent normal appear easily. In this paper, a triangular mesh establishing algorithm based on ellipsoidal projection is proposed. After comparing the theory of ellipsoidal projection and cylindrical projection, the proposed triangular mesh establishing algorithm is analyzed in detail including basic idea and implementation method. To evaluate the performance and efficiency of the proposed algorithm, two experiments are then carried out on the 3D point cloud data of a foundation pit. The results indicate that though the computational efficiency of proposed algorithm is a little inferior to the algorithm based on cylindrical projection, the proposed algorithm is more effective for establishing point cloud of both top and bottom of the object and the original topological relation of 3D scanning points can be maintained better.

  14. The use of 3D surface scanning for the measurement and assessment of the human foot

    PubMed Central

    2010-01-01

    Background A number of surface scanning systems with the ability to quickly and easily obtain 3D digital representations of the foot are now commercially available. This review aims to present a summary of the reported use of these technologies in footwear development, the design of customised orthotics, and investigations for other ergonomic purposes related to the foot. Methods The PubMed and ScienceDirect databases were searched. Reference lists and experts in the field were also consulted to identify additional articles. Studies in English which had 3D surface scanning of the foot as an integral element of their protocol were included in the review. Results Thirty-eight articles meeting the search criteria were included. Advantages and disadvantages of using 3D surface scanning systems are highlighted. A meta-analysis of studies using scanners to investigate the changes in foot dimensions during varying levels of weight bearing was carried out. Conclusions Modern 3D surface scanning systems can obtain accurate and repeatable digital representations of the foot shape and have been successfully used in medical, ergonomic and footwear development applications. The increasing affordability of these systems presents opportunities for researchers investigating the foot and for manufacturers of foot related apparel and devices, particularly those interested in producing items that are customised to the individual. Suggestions are made for future areas of research and for the standardization of the protocols used to produce foot scans. PMID:20815914

  15. In situ fabrication of 3D Ag@ZnO nanostructures for microfluidic surface-enhanced Raman scattering systems.

    PubMed

    Xie, Yuliang; Yang, Shikuan; Mao, Zhangming; Li, Peng; Zhao, Chenglong; Cohick, Zane; Huang, Po-Hsun; Huang, Tony Jun

    2014-12-23

    In this work, we develop an in situ method to grow highly controllable, sensitive, three-dimensional (3D) surface-enhanced Raman scattering (SERS) substrates via an optothermal effect within microfluidic devices. Implementing this approach, we fabricate SERS substrates composed of Ag@ZnO structures at prescribed locations inside microfluidic channels, sites within which current fabrication of SERS structures has been arduous. Conveniently, properties of the 3D Ag@ZnO nanostructures such as length, packing density, and coverage can also be adjusted by tuning laser irradiation parameters. After exploring the fabrication of the 3D nanostructures, we demonstrate a SERS enhancement factor of up to ∼2×10(6) and investigate the optical properties of the 3D Ag@ZnO structures through finite-difference time-domain simulations. To illustrate the potential value of our technique, low concentrations of biomolecules in the liquid state are detected. Moreover, an integrated cell-trapping function of the 3D Ag@ZnO structures records the surface chemical fingerprint of a living cell. Overall, our optothermal-effect-based fabrication technique offers an effective combination of microfluidics with SERS, resolving problems associated with the fabrication of SERS substrates in microfluidic channels. With its advantages in functionality, simplicity, and sensitivity, the microfluidic-SERS platform presented should be valuable in many biological, biochemical, and biomedical applications.

  16. In Situ Fabrication of 3D Ag@ZnO Nanostructures for Microfluidic Surface-Enhanced Raman Scattering Systems

    PubMed Central

    2015-01-01

    In this work, we develop an in situ method to grow highly controllable, sensitive, three-dimensional (3D) surface-enhanced Raman scattering (SERS) substrates via an optothermal effect within microfluidic devices. Implementing this approach, we fabricate SERS substrates composed of Ag@ZnO structures at prescribed locations inside microfluidic channels, sites within which current fabrication of SERS structures has been arduous. Conveniently, properties of the 3D Ag@ZnO nanostructures such as length, packing density, and coverage can also be adjusted by tuning laser irradiation parameters. After exploring the fabrication of the 3D nanostructures, we demonstrate a SERS enhancement factor of up to ∼2 × 106 and investigate the optical properties of the 3D Ag@ZnO structures through finite-difference time-domain simulations. To illustrate the potential value of our technique, low concentrations of biomolecules in the liquid state are detected. Moreover, an integrated cell-trapping function of the 3D Ag@ZnO structures records the surface chemical fingerprint of a living cell. Overall, our optothermal-effect-based fabrication technique offers an effective combination of microfluidics with SERS, resolving problems associated with the fabrication of SERS substrates in microfluidic channels. With its advantages in functionality, simplicity, and sensitivity, the microfluidic-SERS platform presented should be valuable in many biological, biochemical, and biomedical applications. PMID:25402207

  17. Incorporating 3D body motions into large-sized freeform surface conceptual design.

    PubMed

    Qin, Shengfeng; Wright, David K; Kang, Jingsheng; Prieto, P A

    2005-01-01

    Large-sized free-form surface design presents some challenges in practice. Especially at the conceptual design stage, sculpting physical models is still essential for surface development, because CAD models are less intuitive for designers to design and modify them. These sculpted physical models can be then scanned and converted into CAD models. However, if the physical models are too big, designers may have problems in finding a suitable position to conduct their operations or simply the models are difficult to be scanned in. We investigated a novel surface modelling approach by utilising a 3D motion capture system. For designing a large-sized surface, a network of splines is initially set up. Artists or designers wearing motion marks on their hands can then change shapes of the splines with their hands. Literarily they can move their body freely to any positions to perform their tasks. They can also move their hands in 3D free space to detail surface characteristics by their gestures. All their design motions are recorded in the motion capturing system and transferred into 3D curves and surfaces correspondingly. This paper reports this novel surface design method associated with some case studies.

  18. 3D surface topography of cylinder liner forecasting during plateau honing process

    NASA Astrophysics Data System (ADS)

    Reizer, R.; Pawlus, P.

    2011-08-01

    Areal surface topographies after plateau honing process were measured. A correlation analysis of surface texture parameters was then carried out. As the results, the following parameters describing plateau honed cylinder 3D surface topography were selected: amplitude Sq, Sz, spatial: Str, Std, hybrid SΔq as well as functional: Spq, Svq and Smq. 3D surface topographies were modeled. The modeled surface topographies were correctly matched to measured ones in 77% of all analyzed cases. The plateau honing experiment was then carried out using an orthogonal selective research plan. Two machining parameters were input variables: coarse honing pressure pv and plateau honing time t. Chosen cylinder liners texture parameters were output values. As the result of the experiment, regression equations connecting plateau honing process parameters pv and t with recommended 3D surface topography parameters were obtained. Finally, cylinder liner surface topographies were predicted for various values of machining parameters. Proper matching accuracy of modeled to measured textures was assured in 67% of analyzed cases.

  19. Correlations of Surface Deformation and 3D Flow Field in a Compliant Wall Turbulent Channel Flow.

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Zhang, Cao; Katz, Joseph

    2015-11-01

    This study focuses on the correlations between surface deformation and flow features, including velocity, vorticity and pressure, in a turbulent channel flow over a flat, compliant Polydimethylsiloxane (PDMS) wall. The channel centerline velocity is 2.5 m/s, and the friction Reynolds number is 2.3x103. Analysis is based on simultaneous measurements of the time resolved 3D velocity and surface deformation using tomographic PIV and Mach-Zehnder Interferometry. The volumetric pressure distribution is calculated plane by plane by spatially integrating the material acceleration using virtual boundary, omni-directional method. Conditional sampling based on local high/low pressure and deformation events reveals the primary flow structures causing the deformation. High pressure peaks appear at the interface between sweep and ejection, whereas the negative deformations peaks (dent) appear upstream, under the sweeps. The persistent phase lag between flow and deformations are presumably caused by internal damping within the PDMS. Some of the low pressure peaks and strong ejections are located under the head of hairpin vortices, and accordingly, are associated with positive deformation (bump). Others bumps and dents are correlated with some spanwise offset large inclined quasi-streamwise vortices that are not necessarily associated with hairpins. Sponsored by ONR.

  20. OB3D, a new set of 3D objects available for research: a web-based study

    PubMed Central

    Buffat, Stéphane; Chastres, Véronique; Bichot, Alain; Rider, Delphine; Benmussa, Frédéric; Lorenceau, Jean

    2014-01-01

    Studying object recognition is central to fundamental and clinical research on cognitive functions but suffers from the limitations of the available sets that cannot always be modified and adapted to meet the specific goals of each study. We here present a new set of 3D scans of real objects available on-line as ASCII files, OB3D. These files are lists of dots, each defined by a triplet of spatial coordinates and their normal that allow simple and highly versatile transformations and adaptations. We performed a web-based experiment to evaluate the minimal number of dots required for the denomination and categorization of these objects, thus providing a reference threshold. We further analyze several other variables derived from this data set, such as the correlations with object complexity. This new stimulus set, which was found to activate the Lower Occipital Complex (LOC) in another study, may be of interest for studies of cognitive functions in healthy participants and patients with cognitive impairments, including visual perception, language, memory, etc. PMID:25339920

  1. Silk-based anisotropical 3D biotextiles for bone regeneration.

    PubMed

    Ribeiro, Viviana P; Silva-Correia, Joana; Nascimento, Ana I; da Silva Morais, Alain; Marques, Alexandra P; Ribeiro, Ana S; Silva, Carla J; Bonifácio, Graça; Sousa, Rui A; Oliveira, Joaquim M; Oliveira, Ana L; Reis, Rui L

    2017-04-01

    Bone loss in the craniofacial complex can been treated using several conventional therapeutic strategies that face many obstacles and limitations. In this work, novel three-dimensional (3D) biotextile architectures were developed as a possible strategy for flat bone regeneration applications. As a fully automated processing route, this strategy as potential to be easily industrialized. Silk fibroin (SF) yarns were processed into weft-knitted fabrics spaced by a monofilament of polyethylene terephthalate (PET). A comparative study with a similar 3D structure made entirely of PET was established. Highly porous scaffolds with homogeneous pore distribution were observed using micro-computed tomography analysis. The wet state dynamic mechanical analysis revealed a storage modulus In the frequency range tested, the storage modulus values obtained for SF-PET scaffolds were higher than for the PET scaffolds. Human adipose-derived stem cells (hASCs) cultured on the SF-PET spacer structures showed the typical pattern for ALP activity under osteogenic culture conditions. Osteogenic differentiation of hASCs on SF-PET and PET constructs was also observed by extracellular matrix mineralization and expression of osteogenic-related markers (osteocalcin, osteopontin and collagen type I) after 28 days of osteogenic culture, in comparison to the control basal medium. The quantification of convergent macroscopic blood vessels toward the scaffolds by a chick chorioallantoic membrane assay, showed higher angiogenic response induced by the SF-PET textile scaffolds than PET structures and gelatin sponge controls. Subcutaneous implantation in CD-1 mice revealed tissue ingrowth's accompanied by blood vessels infiltration in both spacer constructs. The structural adaptability of textile structures combined to the structural similarities of the 3D knitted spacer fabrics to craniofacial bone tissue and achieved biological performance, make these scaffolds a possible solution for tissue

  2. Development and Implementation of a Web-Enabled 3D Consultation Tool for Breast Augmentation Surgery Based on 3D-Image Reconstruction of 2D Pictures

    PubMed Central

    Garcia, Jaime; Olariu, Radu; Dindoyal, Irving; Le Huu, Serge

    2012-01-01

    Background Producing a rich, personalized Web-based consultation tool for plastic surgeons and patients is challenging. Objective (1) To develop a computer tool that allows individual reconstruction and simulation of 3-dimensional (3D) soft tissue from ordinary digital photos of breasts, (2) to implement a Web-based, worldwide-accessible preoperative surgical planning platform for plastic surgeons, and (3) to validate this tool through a quality control analysis by comparing 3D laser scans of the patients with the 3D reconstructions with this tool from original 2-dimensional (2D) pictures of the same patients. Methods The proposed system uses well-established 2D digital photos for reconstruction into a 3D torso, which is then available to the user for interactive planning. The simulation is performed on dedicated servers, accessible via Internet. It allows the surgeon, together with the patient, to previsualize the impact of the proposed breast augmentation directly during the consultation before a surgery is decided upon. We retrospectively conduced a quality control assessment of available anonymized pre- and postoperative 2D digital photographs of patients undergoing breast augmentation procedures. The method presented above was used to reconstruct 3D pictures from 2D digital pictures. We used a laser scanner capable of generating a highly accurate surface model of the patient’s anatomy to acquire ground truth data. The quality of the computed 3D reconstructions was compared with the ground truth data used to perform both qualitative and quantitative evaluations. Results We evaluated the system on 11 clinical cases for surface reconstructions and 4 clinical cases of postoperative simulations, using laser surface scan technologies showing a mean reconstruction error between 2 and 4 mm and a maximum outlier error of 16 mm. Qualitative and quantitative analyses from plastic surgeons demonstrate the potential of these new emerging technologies. Conclusions We

  3. Controlled implant/soft tissue interaction by nanoscale surface modifications of 3D porous titanium implants.

    PubMed

    Rieger, Elisabeth; Dupret-Bories, Agnès; Salou, Laetitia; Metz-Boutigue, Marie-Helene; Layrolle, Pierre; Debry, Christian; Lavalle, Philippe; Vrana, Nihal Engin

    2015-06-07

    Porous titanium implants are widely employed in the orthopaedics field to ensure good bone fixation. Recently, the use of porous titanium implants has also been investigated in artificial larynx development in a clinical setting. Such uses necessitate a better understanding of the interaction of soft tissues with porous titanium structures. Moreover, surface treatments of titanium have been generally evaluated in planar structures, while the porous titanium implants have complex 3 dimensional (3D) architectures. In this study, the determining factors for soft tissue integration of 3D porous titanium implants were investigated as a function of surface treatments via quantification of the interaction of serum proteins and cells with single titanium microbeads (300-500 μm in diameter). Samples were either acid etched or nanostructured by anodization. When the samples are used in 3D configuration (porous titanium discs of 2 mm thickness) in vivo (in subcutis of rats for 2 weeks), a better integration was observed for both anodized and acid etched samples compared to the non-treated implants. If the implants were also pre-treated with rat serum before implantation, the integration was further facilitated. In order to understand the underlying reasons for this effect, human fibroblast cell culture tests under several conditions (directly on beads, beads in suspension, beads encapsulated in gelatin hydrogels) were conducted to mimic the different interactions of cells with Ti implants in vivo. Physical characterization showed that surface treatments increased hydrophilicity, protein adsorption and roughness. Surface treatments also resulted in improved adsorption of serum albumin which in turn facilitated the adsorption of other proteins such as apolipoprotein as quantified by protein sequencing. The cellular response to the beads showed considerable difference with respect to the cell culture configuration. When the titanium microbeads were entrapped in cell

  4. Sensitivity study of 3-D modeling for multi-D inversion of surface NMR

    NASA Astrophysics Data System (ADS)

    Warsa, Grandis, Hendra

    2012-06-01

    Geophysical field method of surface nuclear magnetic resonance (SNMR) allows a direct determination of hydrogeological parameters of the subsurface. The amplitude of the SNMR signal is directly linked to the amount of mobile water. The relaxation behaviour of the signal correlates with pore sizes and hydraulic conductivities of an aquifer. For improving capability and reliability of SNMR method we have presented a forward modeling scheme of 3-D water content and decay time structures that can be used for multi-D interpretation. Currently SNMR is carried out mainly with a 1-D working scheme using coinciding loops. For each sounding point using a coincident circular loop antenna, the amplitudes and decay times of the SNMR signal are the product of a three dimensional distribution of the water content and decay time in the subsurface and their sensitivity to the receiver. The antenna is moved at the surface and the SNMR relaxation signal are plotted as a function of the pulse moment and sounding point. The errors might be very large by neglecting the 2-D or even 3-D geometry of the structures which have to be considered in the analysis and inversion in the future. The results show that the 3-D modeling is reliable and flexible to be integrated into the 2-D/3-D inversion scheme for inverting surface NMR data to recover a multi-D distribution of water content and decay time of an aquifer.

  5. Developed Design for Humeral Head Replacement Using 3D Surface Mapping

    NASA Astrophysics Data System (ADS)

    Salah, H. R.

    2014-12-01

    Assessment of dimensional and geometrical data on the humeral head replacement (HHR) objects is essential for solving the relevant designing problems in the physics of reverse engineering (RE). In this work, 2D-assessment for human humerus was performed using the computed tomography (CT) technique within the RE plan, after which the 2D images of humeral objects were converted into 3D images. The conversion was successful and indicated a clear difference in the 2D and 3D estimates of sizes and geometry of the humerus. The authors have analyzed and confirmed experimentally the statistical information on the relevant anatomical objects. The results of finite-element simulation of the compressive stresses affecting the geometry of 3D surface mapping were analyzed using SolidWorks software. For developing the biomechanical design of an HHR object suitable biomaterials were selected, and different metal-based biomaterials are discussed as applied at various loads. New methodology is presented for the size estimation of humeral head - both anatomical and artificial - in 3D-shape. A detailed interpretation is given for the results of CT D-measurements. Izmēru un ģeometrisko datu novērtējums, kas attiecas uz pleca kaula galviņas nomaiņas (PKGN) objektiem, nepieciešams, lai risinātu virkni reversīvās inženierijas (RI) problēmu. Šajā darbā cilvēka pleca kaula galviņas divdimensiju novērtējums tika veikts ar datortomogrāfijas palīdzību (RI) ietvaros, un pēc tam objekta divdimensiju attēlojums tika pārveidots trīsdimensiju. Pārveidojums bija sekmīgs, parādot pleca kaula galviņas izmēru un ģeometrijas atšķirības starp 2D un 3D novērtējumiem. Autori izanalizēja un eksperimentāli apstiprināja statistisko informāciju pēc dotā veida anatomiskiem objektiem. Saspiešanas sasprindzinājumi, kuri ietekmē trīsdimensiju virsmas attēlojuma ģeometriju, tika analizēti ar gala-elementu simulācijas metodi, lietojot programmu Solid

  6. Variation in the measurement of cranial volume and surface area using 3D laser scanning technology.

    PubMed

    Sholts, Sabrina B; Wärmländer, Sebastian K T S; Flores, Louise M; Miller, Kevin W P; Walker, Phillip L

    2010-07-01

    Three-dimensional (3D) laser scanner models of human crania can be used for forensic facial reconstruction, and for obtaining craniometric data useful for estimating age, sex, and population affinity of unidentified human remains. However, the use of computer-generated measurements in a casework setting requires the measurement precision to be known. Here, we assess the repeatability and precision of cranial volume and surface area measurements using 3D laser scanner models created by different operators using different protocols for collecting and processing data. We report intraobserver measurement errors of 0.2% and interobserver errors of 2% of the total area and volume values, suggesting that observer-related errors do not pose major obstacles for sharing, combining, or comparing such measurements. Nevertheless, as no standardized procedure exists for area or volume measurements from 3D models, it is imperative to report the scanning and postscanning protocols employed when such measurements are conducted in a forensic setting.

  7. 3D Surface Reconstruction of Plant Seeds by Volume Carving: Performance and Accuracies

    PubMed Central

    Roussel, Johanna; Geiger, Felix; Fischbach, Andreas; Jahnke, Siegfried; Scharr, Hanno

    2016-01-01

    We describe a method for 3D reconstruction of plant seed surfaces, focusing on small seeds with diameters as small as 200 μm. The method considers robotized systems allowing single seed handling in order to rotate a single seed in front of a camera. Even though such systems feature high position repeatability, at sub-millimeter object scales, camera pose variations have to be compensated. We do this by robustly estimating the tool center point from each acquired image. 3D reconstruction can then be performed by a simple shape-from-silhouette approach. In experiments we investigate runtimes, theoretically achievable accuracy, experimentally achieved accuracy, and show as a proof of principle that the proposed method is well sufficient for 3D seed phenotyping purposes. PMID:27375628

  8. 3D reconstruction of a patient-specific surface model of the proximal femur from calibrated x-ray radiographs: A validation study

    SciTech Connect

    Zheng Guoyan; Schumann, Steffen

    2009-04-15

    Twenty-three femurs (one plastic bone and twenty-two cadaver bones) with both nonpathologic and pathologic cases were considered to validate a statistical shape model based technique for three-dimensional (3D) reconstruction of a patient-specific surface model from calibrated x-ray radiographs. The 3D reconstruction technique is based on an iterative nonrigid registration of the features extracted from a statistically instantiated 3D surface model to those interactively identified from the radiographs. The surface models reconstructed from the radiographs were compared to the associated ground truths derived either from a 3D CT-scan reconstruction method or from a 3D laser-scan reconstruction method and an average error distance of 0.95 mm were found. Compared to the existing works, our approach has the advantage of seamlessly handling both nonpathologic and pathologic cases even when the statistical shape model that we used was constructed from surface models of nonpathologic bones.

  9. 3D printed PLA-based scaffolds: a versatile tool in regenerative medicine.

    PubMed

    Serra, Tiziano; Mateos-Timoneda, Miguel A; Planell, Josep A; Navarro, Melba

    2013-10-01

    Rapid prototyping (RP), also known as additive manufacturing (AM), has been well received and adopted in the biomedical field. The capacity of this family of techniques to fabricate customized 3D structures with complex geometries and excellent reproducibility has revolutionized implantology and regenerative medicine. In particular, nozzle-based systems allow the fabrication of high-resolution polylactic acid (PLA) structures that are of interest in regenerative medicine. These 3D structures find interesting applications in the regenerative medicine field where promising applications including biodegradable templates for tissue regeneration purposes, 3D in vitro platforms for studying cell response to different scaffolds conditions and for drug screening are considered among others. Scaffolds functionality depends not only on the fabrication technique, but also on the material used to build the 3D structure, the geometry and inner architecture of the structure, and the final surface properties. All being crucial parameters affecting scaffolds success. This Commentary emphasizes the importance of these parameters in scaffolds' fabrication and also draws the attention toward the versatility of these PLA scaffolds as a potential tool in regenerative medicine and other medical fields.

  10. Image-Based Airborne LiDAR Point Cloud Encoding for 3d Building Model Retrieval

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Chen; Lin, Chao-Hung

    2016-06-01

    With the development of Web 2.0 and cyber city modeling, an increasing number of 3D models have been available on web-based model-sharing platforms with many applications such as navigation, urban planning, and virtual reality. Based on the concept of data reuse, a 3D model retrieval system is proposed to retrieve building models similar to a user-specified query. The basic idea behind this system is to reuse these existing 3D building models instead of reconstruction from point clouds. To efficiently retrieve models, the models in databases are compactly encoded by using a shape descriptor generally. However, most of the geometric descriptors in related works are applied to polygonal models. In this study, the input query of the model retrieval system is a point cloud acquired by Light Detection and Ranging (LiDAR) systems because of the efficient scene scanning and spatial information collection. Using Point clouds with sparse, noisy, and incomplete sampling as input queries is more difficult than that by using 3D models. Because that the building roof is more informative than other parts in the airborne LiDAR point cloud, an image-based approach is proposed to encode both point clouds from input queries and 3D models in databases. The main goal of data encoding is that the models in the database and input point clouds can be consistently encoded. Firstly, top-view depth images of buildings are generated to represent the geometry surface of a building roof. Secondly, geometric features are extracted from depth images based on height, edge and plane of building. Finally, descriptors can be extracted by spatial histograms and used in 3D model retrieval system. For data retrieval, the models are retrieved by matching the encoding coefficients of point clouds and building models. In experiments, a database including about 900,000 3D models collected from the Internet is used for evaluation of data retrieval. The results of the proposed method show a clear superiority

  11. Euro-Maps 3D- A Transnational, High-Resolution Digital Surface Model For Europe

    NASA Astrophysics Data System (ADS)

    Uttenthaler, A.; Barner, F.; Hass, T.; Makiola, J.; d'Angelo, P.; Reinartz, P.; Carl, S.; Steiner, K.

    2013-12-01

    Euro-Maps 3D is a homogeneous 5 m spaced digital surface model (DSM) semi-automatically derived by Euromap from 2.5 m in-flight stereo data provided by the Indian IRS-P5 Cartosat-1 satellite. This new and innovative product has been developed in close co- operation with the Remote Sensing Technology Institute (IMF) of the German Aerospace Center (DLR) and is being jointly exploited. The very detailed and accurate representation of the surface is achieved by using a sophisticated and well adapted algorithm implemented on the basis of the Semi-Global Matching approach. In addition, the final product includes detailed flanking information consisting of several pixel-based quality and traceability layers also including an ortho layer. The product is believed to provide maximum accuracy and transparency. The DSM product meets and exceeds HRE80 qualification standards. The DSM product will be made available transnational in a homogeneous quality for most parts of Europe, North Africa and Turkey by Euromap step-by-step. Other areas around the world are processed on demand.

  12. Robust ego-motion estimation and 3-D model refinement using surface parallax.

    PubMed

    Agrawal, Amit; Chellappa, Rama

    2006-05-01

    We present an iterative algorithm for robustly estimating the ego-motion and refining and updating a coarse depth map using parametric surface parallax models and brightness derivatives extracted from an image pair. Given a coarse depth map acquired by a range-finder or extracted from a digital elevation map (DEM), ego-motion is estimated by combining a global ego-motion constraint and a local brightness constancy constraint. Using the estimated camera motion and the available depth estimate, motion of the three-dimensional (3-D) points is compensated. We utilize the fact that the resulting surface parallax field is an epipolar field, and knowing its direction from the previous motion estimates, estimate its magnitude and use it to refine the depth map estimate. The parallax magnitude is estimated using a constant parallax model (CPM) which assumes a smooth parallax field and a depth based parallax model (DBPM), which models the parallax magnitude using the given depth map. We obtain confidence measures for determining the accuracy of the estimated depth values which are used to remove regions with potentially incorrect depth estimates for robustly estimating ego-motion in subsequent iterations. Experimental results using both synthetic and real data (both indoor and outdoor sequences) illustrate the effectiveness of the proposed algorithm.

  13. Generating 3D and 3D-like animations of strongly uneven surface microareas of bloodstains from small series of partially out-of-focus digital SEM micrographs.

    PubMed

    Hortolà, Policarp

    2010-01-01

    When dealing with microscopic still images of some kinds of samples, the out-of-focus problem represents a particularly serious limiting factor for the subsequent generation of fully sharp 3D animations. In order to produce fully-focused 3D animations of strongly uneven surface microareas, a vertical stack of six digital secondary-electron SEM micrographs of a human bloodstain microarea was acquired. Afterwards, single combined images were generated using a macrophotography and light microscope image post-processing software. Subsequently, 3D animations of texture and topography were obtained in different formats using a combination of software tools. Finally, a 3D-like animation of a texture-topography composite was obtained in different formats using another combination of software tools. By one hand, results indicate that the use of image post-processing software not concerned primarily with electron micrographs allows to obtain, in an easy way, fully-focused images of strongly uneven surface microareas of bloodstains from small series of partially out-of-focus digital SEM micrographs. On the other hand, results also indicate that such small series of electron micrographs can be utilized for generating 3D and 3D-like animations that can subsequently be converted into different formats, by using certain user-friendly software facilities not originally designed for use in SEM, that are easily available from Internet. Although the focus of this study was on bloodstains, the methods used in it well probably are also of relevance for studying the surface microstructures of other organic or inorganic materials whose sharp displaying is difficult of obtaining from a single SEM micrograph.

  14. 3D Micropatterned Surface Inspired by Salvinia molesta via Direct Laser Lithography

    PubMed Central

    2015-01-01

    Biomimetic functional surfaces are attracting increasing attention for their relevant technological applications. Despite these efforts, inherent limitations of microfabrication techniques prevent the replication of complex hierarchical microstructures. Using a 3D laser lithography technique, we fabricated a 3D patterned surface bioinspired to Salvinia molesta leaves. The artificial hairs, with crownlike heads, were reproduced by scaling down (ca. 100 times smaller) the dimensions of natural features, so that microscale hairs with submicrometric resolution were attained. The micropatterned surface, in analogy with the natural model, shows interesting properties in terms of hydrophobicity and air retention when submerged by water, even if realized with a hydrophilic material. Furthermore, we successfully demonstrated the capability to promote localized condensation of water droplets from moisture in the atmosphere. PMID:26558410

  15. 3D Micropatterned Surface Inspired by Salvinia molesta via Direct Laser Lithography.

    PubMed

    Tricinci, Omar; Terencio, Tercio; Mazzolai, Barbara; Pugno, Nicola M; Greco, Francesco; Mattoli, Virgilio

    2015-11-25

    Biomimetic functional surfaces are attracting increasing attention for their relevant technological applications. Despite these efforts, inherent limitations of microfabrication techniques prevent the replication of complex hierarchical microstructures. Using a 3D laser lithography technique, we fabricated a 3D patterned surface bioinspired to Salvinia molesta leaves. The artificial hairs, with crownlike heads, were reproduced by scaling down (ca. 100 times smaller) the dimensions of natural features, so that microscale hairs with submicrometric resolution were attained. The micropatterned surface, in analogy with the natural model, shows interesting properties in terms of hydrophobicity and air retention when submerged by water, even if realized with a hydrophilic material. Furthermore, we successfully demonstrated the capability to promote localized condensation of water droplets from moisture in the atmosphere.

  16. Anomalous Surface Deformation of Sapphire Clarified by 3D-FEM Simulation of the Nanoindentation

    NASA Astrophysics Data System (ADS)

    Nowak, Roman; Manninen, Timo; Li, Chunliang; Heiskanen, Kari; Hannula, Simo-Pekka; Lindroos, Veikko; Soga, Tetsuo; Yoshida, Fusahito

    This work clarifies the origin of anomalous surface deformation reflected by peculiar surface patterns around indentation impressions on various crystallographic planes of sapphire. The three-dimensional finite element simulation (3D-FEM) of nanoindentation in Al2O3 crystal allowed the authors to localize the regions in which various kinds of twinning and slip are most prone to be activated. The work provides a novel approach to the “hardness anisotropy”, which was modeled so far using a modified uniaxial-stress approximation of this essentially 3D, non-isotropic contact problem. The calculated results enabled the authors to unravel the asymmetric surface deformation detected on prismatic planes by the high-resolution microscopy, which cannot be explained using simple crystallographic considerations.

  17. Reliability of a 3D surface laser scanner for orthodontic applications.

    PubMed

    Kusnoto, Budi; Evans, Carla A

    2002-10-01

    A device for recreating three-dimensional (3D) objects on a computer is the surface laser scanner. By triangulating distances between the reflecting laser beam and the scanned surface, the surface laser scanner can detect not only an object's length and width but also its depth. The scanner's ease of use has opened various possibilities in laboratory research and clinical investigation. We assessed the reliability of generating 3D object reconstructions using the Minolta Vivid700 3D surface laser scanner (Minolta USA, Ramsey, NJ). Accuracy and reproducibility were tested on a geometrical calibrated cylinder, a dental study model, and a plaster facial model. Tests were conducted at varying distances between the object and the scanner. It was found that (1) in the calibrated cylinder tests, spatial distance measurement was accurate to 0.5 mm (+/- 0.1 mm) in the vertical dimension and 0.3 mm (+/- 0.3 mm) in the horizontal dimension; (2) in the study model test, molar width was accurate to 0.2 mm (+/- 0.1 mm, P >.05), and palatal vault depth could be measured to 0.7 mm (+/- 0.2 mm, P > 0.05); and (3) for the facial model, an accuracy of 1.9 +/- 0.8 mm was obtained. The findings suggest that the surface laser scanner has great research potential because of its accuracy and ease of use. Treatment changes, growth, surgical simulations, and many other orthodontic applications can be approached 3-dimensionally with this device.

  18. Coniferous Canopy BRF Simulation Based on 3-D Realistic Scene

    NASA Technical Reports Server (NTRS)

    Wang, Xin-yun; Guo, Zhi-feng; Qin, Wen-han; Sun, Guo-qing

    2011-01-01

    It is difficulties for the computer simulation method to study radiation regime at large-scale. Simplified coniferous model was investigate d in the present study. It makes the computer simulation methods such as L-systems and radiosity-graphics combined method (RGM) more powerf ul in remote sensing of heterogeneous coniferous forests over a large -scale region. L-systems is applied to render 3-D coniferous forest scenarios: and RGM model was used to calculate BRF (bidirectional refle ctance factor) in visible and near-infrared regions. Results in this study show that in most cases both agreed well. Meanwhiie at a tree and forest level. the results are also good.

  19. SU-E-J-209: Verification of 3D Surface Registration Between Stereograms and CT Images

    SciTech Connect

    Han, T; Gifford, K; Smith, B; Salehpour, M

    2014-06-01

    Purpose: Stereography can provide a visualization of the skin surface for radiation therapy patients. The aim of this study was to verify the registration algorithm in a commercial image analysis software, 3dMDVultus, for the fusion of stereograms and CT images. Methods: CT and stereographic scans were acquired of a head phantom and a deformable phantom. CT images were imported in 3dMDVultus and the surface contours were generated by threshold segmentation. Stereograms were reconstructed in 3dMDVultus. The resulting surfaces were registered with Vultus algorithm and then exported to in-house registration software and compared with four algorithms: rigid, affine, non-rigid iterative closest point (ICP) and b-spline algorithm. RMS (root-mean-square residuals of the surface point distances) error between the registered CT and stereogram surfaces was calculated and analyzed. Results: For the head phantom, the maximum RMS error between registered CT surfaces to stereogram was 6.6 mm for Vultus algorithm, whereas the mean RMS error was 0.7 mm. For the deformable phantom, the maximum RMS error was 16.2 mm for Vultus algorithm, whereas the mean RMS error was 4.4 mm. Non-rigid ICP demonstrated the best registration accuracy, as the mean of RMS errors were both within 1 mm. Conclusion: The accuracy of registration algorithm in 3dMDVultus was verified and exceeded RMS of 2 mm for deformable cases. Non-rigid ICP and b-spline algorithms improve the registration accuracy for both phantoms, especially in deformable one. For those patients whose body habitus deforms during radiation therapy, more advanced nonrigid algorithms need to be used.

  20. The 3D scanner for measuring body surface area: a simplified calculation in the Chinese adult.

    PubMed

    Yu, Chi-Yuan; Lo, Yu-Hung; Chiou, Wen-Ko

    2003-05-01

    Three-dimensional (3D) surface anthropometry enables us to extend the study to 3D geometry and morphology of mainly external human body tissues. A model is presented for estimation of human body surface area (BSA), which is identical in form to the one proposed in 1916 by DuBois and DuBois is presented. The purpose of this study is to measure BSA, using 3D scanner, and to derive a simple BSA estimation formula for the Chinese adults. In as little as 12s, the Chang Gung Whole-Body Scanner (CGWBS) allows you to capture the shape of the entire human body. The total error in BSA measurement due to scanning measurement and software computational error is less than 1%. The 3D anthropometric measures in a healthy population (n=3951) were investigated, and the results were used to derive a BSA estimation formula. The results seem to be comparable to previous data that measured BSA using traditional methods. The BSA estimation model of this study also validated using 300 new measurements along with the formulae proposed in previous researches. The result suggests that our formula better fits our adults.

  1. 3-D Adaptive Sparsity Based Image Compression with Applications to Optical Coherence Tomography

    PubMed Central

    Fang, Leyuan; Li, Shutao; Kang, Xudong; Izatt, Joseph A.; Farsiu, Sina

    2015-01-01

    We present a novel general-purpose compression method for tomographic images, termed 3D adaptive sparse representation based compression (3D-ASRC). In this paper, we focus on applications of 3D-ASRC for the compression of ophthalmic 3D optical coherence tomography (OCT) images. The 3D-ASRC algorithm exploits correlations among adjacent OCT images to improve compression performance, yet is sensitive to preserving their differences. Due to the inherent denoising mechanism of the sparsity based 3D-ASRC, the quality of the compressed images are often better than the raw images they are based on. Experiments on clinical-grade retinal OCT images demonstrate the superiority of the proposed 3D-ASRC over other well-known compression methods. PMID:25561591

  2. Controlled implant/soft tissue interaction by nanoscale surface modifications of 3D porous titanium implants

    NASA Astrophysics Data System (ADS)

    Rieger, Elisabeth; Dupret-Bories, Agnès; Salou, Laetitia; Metz-Boutigue, Marie-Helene; Layrolle, Pierre; Debry, Christian; Lavalle, Philippe; Engin Vrana, Nihal

    2015-05-01

    Porous titanium implants are widely employed in the orthopaedics field to ensure good bone fixation. Recently, the use of porous titanium implants has also been investigated in artificial larynx development in a clinical setting. Such uses necessitate a better understanding of the interaction of soft tissues with porous titanium structures. Moreover, surface treatments of titanium have been generally evaluated in planar structures, while the porous titanium implants have complex 3 dimensional (3D) architectures. In this study, the determining factors for soft tissue integration of 3D porous titanium implants were investigated as a function of surface treatments via quantification of the interaction of serum proteins and cells with single titanium microbeads (300-500 μm in diameter). Samples were either acid etched or nanostructured by anodization. When the samples are used in 3D configuration (porous titanium discs of 2 mm thickness) in vivo (in subcutis of rats for 2 weeks), a better integration was observed for both anodized and acid etched samples compared to the non-treated implants. If the implants were also pre-treated with rat serum before implantation, the integration was further facilitated. In order to understand the underlying reasons for this effect, human fibroblast cell culture tests under several conditions (directly on beads, beads in suspension, beads encapsulated in gelatin hydrogels) were conducted to mimic the different interactions of cells with Ti implants in vivo. Physical characterization showed that surface treatments increased hydrophilicity, protein adsorption and roughness. Surface treatments also resulted in improved adsorption of serum albumin which in turn facilitated the adsorption of other proteins such as apolipoprotein as quantified by protein sequencing. The cellular response to the beads showed considerable difference with respect to the cell culture configuration. When the titanium microbeads were entrapped in cell

  3. Perception of 3D shape from homogeneous and nonhomogeneous surface textures

    NASA Astrophysics Data System (ADS)

    Li, Andrea; Zaidi, Qasim

    2004-06-01

    When a textured 3-dimensional surface is projected in perspective, the statistics of the texture in the image change with the shape of the surface. Most shape-from-texture models assume that these changes are due solely to the projection of non-fronto-parallel portions of the surface. This is true for developable surfaces, which are formed by bending or curving flat, textured sheets without tearing or stretching. However, for other surfaces such as those carved from solids or formed by stretched materials, the texture on the surface is generally not homogenous. If the perspective image is parsed into local Fourier spectra, we find that signature patterns of orientation flows occur at locations corresponding to specific 3-D shapes. These patterns occur generically for developable, carved and stretched surfaces and when they are visible, observers make veridical shape judgments. In contrast, frequency modulations vary systematically for different types of surfaces, and often lead to non-veridical percepts when they are caused by changes in slant (e.g. isotropically textured developable surfaces). Our results suggest that in the extraction of 3-D shape, the visual system can generically employ a limited number of neural mechanisms to extract the signature orientation flows from the image regardless of homogeneity.

  4. Excitation of anti-symmetric coupled spoof SPPs in 3D SIS waveguides based on coupling

    NASA Astrophysics Data System (ADS)

    Li-li, Tian; Yang, Chen; Jian-long, Liu; Kai, Guo; Ke-ya, Zhou; Yang, Gao; Shu-tian, Liu

    2016-07-01

    According to the electromagnetic field distributions, there exist two kinds of coupled spoof surface plasmon polaritons (SSPPs), the symmetric and anti-symmetric modes, in the three-dimensional (3D) subwavelength spoof-insulator-spoof (SIS) waveguide. We study the dispersion and excitation of the two kinds of coupled SSPPs supported by the 3D SIS waveguide. The evolution of the dispersion with the thickness and gap width of the waveguide is numerically investigated, and we give a theoretical analysis according to the coupling mechanism. Specially, based on the coupling mechanism, we design a zipper structure, through which the excitation and propagation of the anti-symmetric coupled modes can be realized effectively. Project supported by the National Basic Research Program of China (Grant No. 2013CBA01702) and the National Natural Science Foundation of China (Grant Nos. 61377016, 61575055, 10974039, 61307072, 61308017, and 61405056).

  5. Illustrating Surface Shape in Volume Data via Principal Direction-Driven 3D Line Integral Convolution

    NASA Technical Reports Server (NTRS)

    Interrante, Victoria

    1997-01-01

    The three-dimensional shape and relative depth of a smoothly curving layered transparent surface may be communicated particularly effectively when the surface is artistically enhanced with sparsely distributed opaque detail. This paper describes how the set of principal directions and principal curvatures specified by local geometric operators can be understood to define a natural 'flow' over the surface of an object, and can be used to guide the placement of the lines of a stroke texture that seeks to represent 3D shape information in a perceptually intuitive way. The driving application for this work is the visualization of layered isovalue surfaces in volume data, where the particular identity of an individual surface is not generally known a priori and observers will typically wish to view a variety of different level surfaces from the same distribution, superimposed over underlying opaque structures. By advecting an evenly distributed set of tiny opaque particles, and the empty space between them, via 3D line integral convolution through the vector field defined by the principal directions and principal curvatures of the level surfaces passing through each gridpoint of a 3D volume, it is possible to generate a single scan-converted solid stroke texture that may intuitively represent the essential shape information of any level surface in the volume. To generate longer strokes over more highly curved areas, where the directional information is both most stable and most relevant, and to simultaneously downplay the visual impact of directional information in the flatter regions, one may dynamically redefine the length of the filter kernel according to the magnitude of the maximum principal curvature of the level surface at the point around which it is applied.

  6. On the evaluation of photogrammetric methods for dense 3D surface reconstruction in a metrological context

    NASA Astrophysics Data System (ADS)

    Toschi, I.; Capra, A.; De Luca, L.; Beraldin, J.-A.; Cournoyer, L.

    2014-05-01

    This paper discusses a methodology to evaluate the accuracy of recently developed image-based 3D modelling techniques. So far, the emergence of these novel methods has not been supported by the definition of an internationally recognized standard which is fundamental for user confidence and market growth. In order to provide an element of reflection and solution to the different communities involved in 3D imaging, a promising approach is presented in this paper for the assessment of both metric quality and limitations of an open-source suite of tools (Apero/MicMac), developed for the extraction of dense 3D point clouds from a set of unordered 2D images. The proposed procedural workflow is performed within a metrological context, through inter-comparisons with "reference" data acquired with two hemispherical laser scanners, one total station, and one laser tracker. The methodology is applied to two case studies, designed in order to analyse the software performances in dealing with both outdoor and environmentally controlled conditions, i.e. the main entrance of Cathédrale de la Major (Marseille, France) and a custom-made scene located at National Research Council of Canada 3D imaging Metrology Laboratory (Ottawa). Comparative data and accuracy evidence produced for both tests allow the study of some key factors affecting 3D model accuracy.

  7. Voxel-Based 3-D Tree Modeling from Lidar Images for Extracting Tree Structual Information

    NASA Astrophysics Data System (ADS)

    Hosoi, F.

    2014-12-01

    Recently, lidar (light detection and ranging) has been used to extracting tree structural information. Portable scanning lidar systems can capture the complex shape of individual trees as a 3-D point-cloud image. 3-D tree models reproduced from the lidar-derived 3-D image can be used to estimate tree structural parameters. We have proposed the voxel-based 3-D modeling for extracting tree structural parameters. One of the tree parameters derived from the voxel modeling is leaf area density (LAD). We refer to the method as the voxel-based canopy profiling (VCP) method. In this method, several measurement points surrounding the canopy and optimally inclined laser beams are adopted for full laser beam illumination of whole canopy up to the internal. From obtained lidar image, the 3-D information is reproduced as the voxel attributes in the 3-D voxel array. Based on the voxel attributes, contact frequency of laser beams on leaves is computed and LAD in each horizontal layer is obtained. This method offered accurate LAD estimation for individual trees and woody canopy trees. For more accurate LAD estimation, the voxel model was constructed by combining airborne and portable ground-based lidar data. The profiles obtained by the two types of lidar complemented each other, thus eliminating blind regions and yielding more accurate LAD profiles than could be obtained by using each type of lidar alone. Based on the estimation results, we proposed an index named laser beam coverage index, Ω, which relates to the lidar's laser beam settings and a laser beam attenuation factor. It was shown that this index can be used for adjusting measurement set-up of lidar systems and also used for explaining the LAD estimation error using different types of lidar systems. Moreover, we proposed a method to estimate woody material volume as another application of the voxel tree modeling. In this method, voxel solid model of a target tree was produced from the lidar image, which is composed of

  8. Hybrid atlas-based and image-based approach for segmenting 3D brain MRIs

    NASA Astrophysics Data System (ADS)

    Bueno, Gloria; Musse, Olivier; Heitz, Fabrice; Armspach, Jean-Paul

    2001-07-01

    This work is a contribution to the problem of localizing key cerebral structures in 3D MRIs and its quantitative evaluation. In pursuing it, the cooperation between an image-based segmentation method and a hierarchical deformable registration approach has been considered. The segmentation relies on two main processes: homotopy modification and contour decision. The first one is achieved by a marker extraction stage where homogeneous 3D regions of an image, I(s), from the data set are identified. These regions, M(I), are obtained combining information from deformable atlas, achieved by the warping of eight previous labeled maps on I(s). Then, the goal of the decision stage is to precisely locate the contours of the 3D regions set by the markers. This contour decision is performed by a 3D extension of the watershed transform. The anatomical structures taken into consideration and embedded into the atlas are brain, ventricles, corpus callosum, cerebellum, right and left hippocampus, medulla and midbrain. The hybrid method operates fully automatically and in 3D, successfully providing segmented brain structures. The quality of the segmentation has been studied in terms of the detected volume ratio by using kappa statistic and ROC analysis. Results of the method are shown and validated on a 3D MRI phantom. This study forms part of an on-going long term research aiming at the creation of a 3D probabilistic multi-purpose anatomical brain atlas.

  9. Contactless operating table control based on 3D image processing.

    PubMed

    Schröder, Stephan; Loftfield, Nina; Langmann, Benjamin; Frank, Klaus; Reithmeier, Eduard

    2014-01-01

    Interaction with mobile consumer devices leads to a higher acceptance and affinity of persons to natural user interfaces and perceptional interaction possibilities. New interaction modalities become accessible and are capable to improve human machine interaction even in complex and high risk environments, like the operation room. Here, manifold medical disciplines cause a great variety of procedures and thus staff and equipment. One universal challenge is to meet the sterility requirements, for which common contact-afflicted remote interfaces always pose a potential risk causing a hazard for the process. The proposed operating table control system overcomes this process risk and thus improves the system usability significantly. The 3D sensor system, the Microsoft Kinect, captures the motion of the user, allowing a touchless manipulation of an operating table. Three gestures enable the user to select, activate and manipulate all segments of the motorised system in a safe and intuitive way. The gesture dynamics are synchronised with the table movement. In a usability study, 15 participants evaluated the system with a system usability score by Broke of 79. This states a high potential for implementation and acceptance in interventional environments. In the near future, even processes with higher risks could be controlled with the proposed interface, while interfaces become safer and more direct.

  10. MIMO based 3D imaging system at 360 GHz

    NASA Astrophysics Data System (ADS)

    Herschel, R.; Nowok, S.; Zimmermann, R.; Lang, S. A.; Pohl, N.

    2016-05-01

    A MIMO radar imaging system at 360 GHz is presented as a part of the comprehensive approach of the European FP7 project TeraSCREEN, using multiple frequency bands for active and passive imaging. The MIMO system consists of 16 transmitter and 16 receiver antennas within one single array. Using a bandwidth of 30 GHz, a range resolution up to 5 mm is obtained. With the 16×16 MIMO system 256 different azimuth bins can be distinguished. Mechanical beam steering is used to measure 130 different elevation angles where the angular resolution is obtained by a focusing elliptical mirror. With this system a high resolution 3D image can be generated with 4 frames per second, each containing 16 million points. The principle of the system is presented starting from the functional structure, covering the hardware design and including the digital image generation. This is supported by simulated data and discussed using experimental results from a preliminary 90 GHz system underlining the feasibility of the approach.

  11. Research of Fast 3D Imaging Based on Multiple Mode

    NASA Astrophysics Data System (ADS)

    Chen, Shibing; Yan, Huimin; Ni, Xuxiang; Zhang, Xiuda; Wang, Yu

    2016-02-01

    Three-dimensional (3D) imaging has received increasingly extensive attention and has been widely used currently. Lots of efforts have been put on three-dimensional imaging method and system study, in order to meet fast and high accurate requirement. In this article, we realize a fast and high quality stereo matching algorithm on field programmable gate array (FPGA) using the combination of time-of-flight (TOF) camera and binocular camera. Images captured from the two cameras own a same spatial resolution, letting us use the depth maps taken by the TOF camera to figure initial disparity. Under the constraint of the depth map as the stereo pairs when comes to stereo matching, expected disparity of each pixel is limited within a narrow search range. In the meanwhile, using field programmable gate array (FPGA, altera cyclone IV series) concurrent computing we can configure multi core image matching system, thus doing stereo matching on embedded system. The simulation results demonstrate that it can speed up the process of stereo matching and increase matching reliability and stability, realize embedded calculation, expand application range.

  12. A global model simulation for 3-D radiative transfer impact on surface hydrology over the Sierra Nevada and Rocky Mountains

    DOE PAGES

    Lee, W.-L.; Gu, Y.; Liou, K. N.; ...

    2015-05-19

    We investigate 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the western United States, specifically the Rocky Mountains and the Sierra Nevada, using the global CCSM4 (Community Climate System Model version 4; Community Atmosphere Model/Community Land Model – CAM4/CLM4) with a 0.23° × 0.31° resolution for simulations over 6 years. In a 3-D radiative transfer parameterization, we have updated surface topography data from a resolution of 1 km to 90 m to improve parameterization accuracy. In addition, we have also modified the upward-flux deviation (3-D–PP (plane-parallel)) adjustment to ensure that the energy balance atmore » the surface is conserved in global climate simulations based on 3-D radiation parameterization. We show that deviations in the net surface fluxes are not only affected by 3-D mountains but also influenced by feedbacks of cloud and snow in association with the long-term simulations. Deviations in sensible heat and surface temperature generally follow the patterns of net surface solar flux. The monthly snow water equivalent (SWE) deviations show an increase in lower elevations due to reduced snowmelt, leading to a reduction in cumulative runoff. Over higher-elevation areas, negative SWE deviations are found because of increased solar radiation available at the surface. Simulated precipitation increases for lower elevations, while it decreases for higher elevations, with a minimum in April. Liquid runoff significantly decreases at higher elevations after April due to reduced SWE and precipitation.« less

  13. A global model simulation for 3-D radiative transfer impact on surface hydrology over the Sierra Nevada and Rocky Mountains

    SciTech Connect

    Lee, W. -L.; Gu, Y.; Liou, K. N.; Leung, L. R.; Hsu, H. -H.

    2015-05-19

    We investigate 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the western United States, specifically the Rocky Mountains and the Sierra Nevada, using the global CCSM4 (Community Climate System Model version 4; Community Atmosphere Model/Community Land Model – CAM4/CLM4) with a 0.23° × 0.31° resolution for simulations over 6 years. In a 3-D radiative transfer parameterization, we have updated surface topography data from a resolution of 1 km to 90 m to improve parameterization accuracy. In addition, we have also modified the upward-flux deviation (3-D–PP (plane-parallel)) adjustment to ensure that the energy balance at the surface is conserved in global climate simulations based on 3-D radiation parameterization. We show that deviations in the net surface fluxes are not only affected by 3-D mountains but also influenced by feedbacks of cloud and snow in association with the long-term simulations. Deviations in sensible heat and surface temperature generally follow the patterns of net surface solar flux. The monthly snow water equivalent (SWE) deviations show an increase in lower elevations due to reduced snowmelt, leading to a reduction in cumulative runoff. Over higher-elevation areas, negative SWE deviations are found because of increased solar radiation available at the surface. Simulated precipitation increases for lower elevations, while it decreases for higher elevations, with a minimum in April. Liquid runoff significantly decreases at higher elevations after April due to reduced SWE and precipitation.

  14. Parallel Imaging of 3D Surface Profile with Space-Division Multiplexing

    PubMed Central

    Lee, Hyung Seok; Cho, Soon-Woo; Kim, Gyeong Hun; Jeong, Myung Yung; Won, Young Jae; Kim, Chang-Seok

    2016-01-01

    We have developed a modified optical frequency domain imaging (OFDI) system that performs parallel imaging of three-dimensional (3D) surface profiles by using the space division multiplexing (SDM) method with dual-area swept sourced beams. We have also demonstrated that 3D surface information for two different areas could be well obtained in a same time with only one camera by our method. In this study, double field of views (FOVs) of 11.16 mm × 5.92 mm were achieved within 0.5 s. Height range for each FOV was 460 µm and axial and transverse resolutions were 3.6 and 5.52 µm, respectively. PMID:26805840

  15. 3d-transition metal induced enhancement of molecular hydrogen adsorption on Mg(0001) surface: An Ab-initio study

    NASA Astrophysics Data System (ADS)

    Banerjee, Paramita; Das, G. P.

    2016-05-01

    In our effort to do first principles design of suitable materials for hydrogen storage, we have explored the interaction characteristics of a hydrogen molecule with pure as well as a 3d-transition metal (TM) atom doped Mg(0001) surface using density functional theory (DFT) based approach. Doping of a 3d-TM atom by creating a vacancy on the top most layer of Mg(0001) surface, enhances the molecular hydrogen adsorption efficiency of this surface by ~ 6 times. The TM atom gains some charge from the defected site of the Mg(0001) surface, becomes anionic and adsorbs the hydrogen molecule via Anti Kubas-type interaction. The interaction energy of this H2 molecule, including van der Waals dispersion correction, turns out to be ~ 0.4 eV, which falls in the right energy window between physisorption and chemisorption. On full coverage of this 3d-TM atom doped Mg(0001) surface with hydrogen molecules, the gravimetric density of hydrogen has been estimated to be ~ 5.6 wt %, thereby satisfying the criteria set by the department of energy (DOE) for efficient hydrogen storage.

  16. 3D-SURFER 2.0: web platform for real-time search and characterization of protein surfaces.

    PubMed

    Xiong, Yi; Esquivel-Rodriguez, Juan; Sael, Lee; Kihara, Daisuke

    2014-01-01

    The increasing number of uncharacterized protein structures necessitates the development of computational approaches for function annotation using the protein tertiary structures. Protein structure database search is the basis of any structure-based functional elucidation of proteins. 3D-SURFER is a web platform for real-time protein surface comparison of a given protein structure against the entire PDB using 3D Zernike descriptors. It can smoothly navigate the protein structure space in real-time from one query structure to another. A major new feature of Release 2.0 is the ability to compare the protein surface of a single chain, a single domain, or a single complex against databases of protein chains, domains, complexes, or a combination of all three in the latest PDB. Additionally, two types of protein structures can now be compared: all-atom-surface and backbone-atom-surface. The server can also accept a batch job for a large number of database searches. Pockets in protein surfaces can be identified by VisGrid and LIGSITE (csc) . The server is available at http://kiharalab.org/3d-surfer/.

  17. 3D surface imaging of the human female torso in upright to supine positions.

    PubMed

    Reece, Gregory P; Merchant, Fatima; Andon, Johnny; Khatam, Hamed; Ravi-Chandar, K; Weston, June; Fingeret, Michelle C; Lane, Chris; Duncan, Kelly; Markey, Mia K

    2015-04-01

    Three-dimensional (3D) surface imaging of breasts is usually done with the patient in an upright position, which does not permit comparison of changes in breast morphology with changes in position of the torso. In theory, these limitations may be eliminated if the 3D camera system could remain fixed relative to the woman's torso as she is tilted from 0 to 90°. We mounted a 3dMDtorso imaging system onto a bariatric tilt table to image breasts at different tilt angles. The images were validated using a rigid plastic mannequin and the metrics compared to breast metrics obtained from five subjects with diverse morphology. The differences between distances between the same fiducial marks differed between the supine and upright positions by less than 1% for the mannequin, whereas the differences for distances between the same fiducial marks on the breasts of the five subjects differed significantly and could be correlated with body mass index and brassiere cup size for each position change. We show that a tilt table-3D imaging system can be used to determine quantitative changes in the morphology of ptotic breasts when the subject is tilted to various angles.

  18. State of the art of 3D scanning systems and inspection of textile surfaces

    NASA Astrophysics Data System (ADS)

    Montilla, M.; Orjuela-Vargas, S. A.; Philips, W.

    2014-02-01

    The rapid development of hardware and software in the digital image processing field has boosted research in computer vision for applications in industry. The development of new electronic devices and the tendency to decrease their prices makes possible new developments that few decades ago were possible only in the imagination. This is the case of 3D imaging technology which permits to detect failures in industrial products by inspecting aspects on their 3D surface. In search of an optimal solution for scanning textiles we present in this paper a review of existing techniques for digitizing 3D surfaces. Topographic details of textiles can be obtained by digitizing surfaces using laser line triangulation, phase shifting optical triangulation, projected-light, stereo-vision systems and silhouette analysis. Although we are focused on methods that have been used in the textile industry, we also consider potential mechanisms used for other applications. We discuss the advantages and disadvantages of the evaluated methods and state a summary of potential implementations for the textile industry.

  19. Assessment of Ulcer Wounds Size Using 3D Skin Surface Imaging

    NASA Astrophysics Data System (ADS)

    Hani, Ahmad Fadzil M.; Eltegani, Nejood M.; Hussein, Suraiya H.; Jamil, Adawiyah; Gill, Priya

    In this work 3D surface scans of wounds are used to obtain several measurement including wound top area, true surface area (rue area), depth, and volume for the purpose of assessing the progress of ulcer wounds throughout treatment. KONICA MINOLTA 910 laser scanner is used to obtain the surface scans. The algorithm for estimating top area and true surface area from surface scan can reduce the inaccuracy that might result when using manual method. Two methods for solid construction and volume computation were considered; namely mid-point projection and convex hull approximation (Delaunay tetrahedralization). The performance of convex hull approximation method for volume estimation is improved by performing surface subdivision prior to the approximation. The performance of these algorithms on different patterns of simulated wound models is presented. Furthermore the algorithms are tested in two molded wounds printed using rapid prototyping (RP) technique.

  20. Combining scale-space and similarity-based aspect graphs for fast 3D object recognition.

    PubMed

    Ulrich, Markus; Wiedemann, Christian; Steger, Carsten

    2012-10-01

    This paper describes an approach for recognizing instances of a 3D object in a single camera image and for determining their 3D poses. A hierarchical model is generated solely based on the geometry information of a 3D CAD model of the object. The approach does not rely on texture or reflectance information of the object's surface, making it useful for a wide range of industrial and robotic applications, e.g., bin-picking. A hierarchical view-based approach that addresses typical problems of previous methods is applied: It handles true perspective, is robust to noise, occlusions, and clutter to an extent that is sufficient for many practical applications, and is invariant to contrast changes. For the generation of this hierarchical model, a new model image generation technique by which scale-space effects can be taken into account is presented. The necessary object views are derived using a similarity-based aspect graph. The high robustness of an exhaustive search is combined with an efficient hierarchical search. The 3D pose is refined by using a least-squares adjustment that minimizes geometric distances in the image, yielding a position accuracy of up to 0.12 percent with respect to the object distance, and an orientation accuracy of up to 0.35 degree in our tests. The recognition time is largely independent of the complexity of the object, but depends mainly on the range of poses within which the object may appear in front of the camera. For efficiency reasons, the approach allows the restriction of the pose range depending on the application. Typical runtimes are in the range of a few hundred ms.

  1. Vision-Based 3D Motion Estimation for On-Orbit Proximity Satellite Tracking and Navigation

    DTIC Science & Technology

    2015-06-01

    printed using the Fortus 400mc 3D rapid- prototyping printer of the NPS Space Systems Academic Group, while the internal structure is made of aluminum...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited VISION-BASED 3D ...REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE VISION-BASED 3D MOTION ESTIMATION FOR ON-ORBIT PROXIMITY SATELLITE TRACKING

  2. [Investigation of the surface layer of 3D-matrices for tissue engineering].

    PubMed

    Chernonosova, V S; Kvon, R I; Kiseleva, E V; Stepanova, A O; Laktionov, P P

    2017-01-01

    Electrospinning is a convenient and promising manufacturing method a variety of materials for tissue engineering. 3D matrices fabricated by electrospinning from solutions of polycaprolactone with human serum albumin or gelatin in 1,1,1,3,3,3-hexafluoroisopropanol were studied. The microstructure of the 3D matrices and surface of the fibers were investigated using scanning electron microscopy. Protein distribution in the surface layer was studied by modification of protein amino groups with N-(2-hydroxyethyl)phenazine and X-ray photoelectron spectroscopy. It was shown, that concentration of the proteins in the surface layer of fibers exceeded their concentration in the initial electrospun solution up to 12 times and the surface layer was enriched in the protein inversely to the concentration of the protein in solution. The minor part of the proteins was released from fibers during first 30-60 min after swelling in water. Treatment of matrices with proteinase K hydrolyzed about 1/3 of the surface exposed human serum albumin. Thus, both methods can be used to study the surface content of the materials produced by electrospinning from blends of synthetic and natural polymers, however X-ray photoelectron spectroscopy appears to be more convenient and informative.

  3. 3D-2D ultrasound feature-based registration for navigated prostate biopsy: a feasibility study.

    PubMed

    Selmi, Sonia Y; Promayon, Emmanuel; Troccaz, Jocelyne

    2016-08-01

    The aim of this paper is to describe a 3D-2D ultrasound feature-based registration method for navigated prostate biopsy and its first results obtained on patient data. A system combining a low-cost tracking system and a 3D-2D registration algorithm was designed. The proposed 3D-2D registration method combines geometric and image-based distances. After extracting features from ultrasound images, 3D and 2D features within a defined distance are matched using an intensity-based function. The results are encouraging and show acceptable errors with simulated transforms applied on ultrasound volumes from real patients.

  4. Surface states in a 3D topological insulator: The role of hexagonal warping and curvature

    SciTech Connect

    Repin, E. V.; Burmistrov, I. S.

    2015-09-15

    We explore a combined effect of hexagonal warping and a finite effective mass on both the tunneling density of electronic surface states and the structure of Landau levels of 3D topological insulators. We find the increasing warping to transform the square-root van Hove singularity into a logarithmic one. For moderate warping, an additional logarithmic singularity and a jump in the tunneling density of surface states appear. By combining the perturbation theory and the WKB approximation, we calculate the Landau levels in the presence of hexagonal warping. We predict that due to the degeneracy removal, the evolution of Landau levels in the magnetic field is drastically modified.

  5. Surface strain-field determination of tympanic membrane using 3D-digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Hernandez-Montes, María del S.; Mendoza Santoyo, Fernando; Muñoz, Silvino; Perez, Carlos; de la Torre, Manuel; Flores, Mauricio; Alvarez, Luis

    2015-08-01

    In order to increase the understanding of soft tissues mechanical properties, 3D Digital Holographic Interferometry (3D-DHI) was used to quantify the strain-field on a cat tympanic membrane (TM) surface. The experiments were carried out applying a constant sound-stimuli pressure of 90 dB SPL (0.632 Pa) on the TM at 1.2 kHz. The technique allows the accurate acquisition of the micro-displacement data along the x, y and z directions, which is a must for a full characterization of the tissue mechanical behavior under load, and for the calculation of the strain-field in situ. The displacements repeatability in z direction shows a standard deviation of 0.062 μm at 95% confidence level. In order to realize the full 3D characterization correctly the contour of the TM surface was measured employing the optically non-contact two-illumination positions contouring method. The x, y and z displacements combined with the TM contour data allow the evaluation its strain-field by spatially differentiating the u(m,n), v(m,n), and w(m,n) deformation components. The accurate and correct determination of the TM strain-field leads to describing its elasticity, which is an important parameter needed to improve ear biomechanics studies, audition processes and TM mobility in both experimental measurements and theoretical analysis of ear functionality and its modeling.

  6. Volatile transport on inhomogeneous surfaces: II. Numerical calculations (VT3D)

    NASA Astrophysics Data System (ADS)

    Young, Leslie A.

    2017-03-01

    Several distant icy worlds have atmospheres that are in vapor-pressure equilibrium with their surface volatiles, including Pluto, Triton, and, probably, several large KBOs near perihelion. Studies of the volatile and thermal evolution of these have been limited by computational speed, especially for models that treat surfaces that vary with both latitude and longitude. In order to expedite such work, I present a new numerical model for the seasonal behavior of Pluto and Triton which (i) uses initial conditions that improve convergence, (ii) uses an expedient method for handling the transition between global and non-global atmospheres, (iii) includes local conservation of energy and global conservation of mass to partition energy between heating, conduction, and sublimation or condensation, (iv) uses time-stepping algorithms that ensure stability while allowing larger timesteps, and (v) can include longitudinal variability. This model, called VT3D, has been used in Young (2012a, 2012b), Young (2013), Olkin et al. (2015), Young and McKinnon (2013), and French et al. (2015). Many elements of VT3D can be used independently. For example, VT3D can also be used to speed up thermophysical models (Spencer et al., 1989) for bodies without volatiles. Code implementation is included in the supplemental materials and is available from the author.

  7. Magellan 3D perspective of Venus surface in western Eistla Regio

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Magellan synthetic aperture radar data was used to create this three- dimensional (3D) perspective view of Venus' western Eistla Regio. This viewpoint is located at 1,310 kilometers (812 miles) southwest of Gula Mons at an elevation of 0.178 kilometers (0.48 miles). The view is of the northeast with Gula Mons appearing on the horizon. Gula Mons, a 3 kilometer (1.86 mile) high volcano, is located at approximately 22 degrees north latitude, 359 degrees east longitude. The impact crater Cunitz, named for the astronomer and mathematician Maria Cunitz, is visible in the center of the image. The crater is 48.5 kilometers (30 miles) in diameter and is 215 kilometers (133 miles) from the viewer's position. Magellan synthetic aperture radar data is combined with radar altimetry to develop a 3D map of the surface. Rays cast in a computer intersect the surface to create a 3D view. Simulated color and a digital elevation map developed by the United States (U.S.) Geological Survey is used to enhanc

  8. SU-E-J-128: 3D Surface Reconstruction of a Patient Using Epipolar Geometry

    SciTech Connect

    Kotoku, J; Nakabayashi, S; Kumagai, S; Ishibashi, T; Kobayashi, T; Haga, A; Saotome, N; Arai, N

    2014-06-01

    Purpose: To obtain a 3D surface data of a patient in a non-invasive way can substantially reduce the effort for the registration of patient in radiation therapy. To achieve this goal, we introduced the multiple view stereo technique, which is known to be used in a 'photo tourism' on the internet. Methods: 70 Images were taken with a digital single-lens reflex camera from different angles and positions. The camera positions and angles were inferred later in the reconstruction step. A sparse 3D reconstruction model was locating by SIFT features, which is robust for rotation and shift variance, in each image. We then found a set of correspondences between pairs of images by computing the fundamental matrix using the eight-point algorithm with RANSAC. After the pair matching, we optimized the parameter including camera positions to minimize the reprojection error by use of bundle adjustment technique (non-linear optimization). As a final step, we performed dense reconstruction and associate a color with each point using the library of PMVS. Results: Surface data were reconstructed well by visual inspection. The human skin is reconstructed well, althogh the reconstruction was time-consuming for direct use in daily clinical practice. Conclusion: 3D reconstruction using multi view stereo geometry is a promising tool for reducing the effort of patient setup. This work was supported by JSPS KAKENHI(25861128)

  9. Modeling of 3d Space-time Surface of Potential Fields and Hydrogeologic Modeling of Nuclear Waste Disposal Sites

    NASA Astrophysics Data System (ADS)

    Shestopalov, V.; Bondarenko, Y.; Zayonts, I.; Rudenko, Y.

    Introduction After the Chernobyl Nuclear Power Plant (CNPP) disaster (04.26.1986) a huge amount (over 2000 sq. km) of nuclear wastes appeared within so-called "Cher- nobyl Exclusion Zone" (CEZ). At present there are not enough storage facilities in the Ukraine for safe disposal of nuclear wastes and hazardous chemical wastes. The urgent problem now is safe isolation of these dangerous wastes. According to the developed state program of radioactive waste management, the construction of a na- tional storage facility of nuclear wastes is planned. It is also possible to create regional storage facilities for hazardous chemical wastes. The region of our exploration cov- ers the eastern part of the Korosten Plutone and its slope, reaching the CNPP. 3D Space-Time Surface Imaging of Geophysical Fields. There are only three direct meth- ods of stress field reconstruction in present practice, namely the field investigations based on the large-scale fracturing tests, petrotectonic and optical polarization meth- ods. Unfortunately, all these methods are extremely laborious and need the regular field tests, which is difficult to conduct in the areas of anisotropic rock outcrops. A compilation of magnetic and gravity data covering the CNPP area was carried out as a prelude to an interpretation study. More than thirty map products were generated from magnetic, gravity and geodesy data to prepare the 3D Space-Time Surface Images (3D STSI). Multi-layer topography and geophysic surfaces included: total magnetic intensity, isostatically-corrected Bouguer gravity, aspect and slope, first and second derivatives, vertical and horizontal curvature, histogram characteristics and space cor- relation coefficients between the gradient fields. Many maps shows the first and sec- ond derivatives of the potential fields, with the results of lineament (edge) structure detection superimposed. The lineament or edges of the potential fields are located from maximal gradient in many directions

  10. A primitive-based 3D object recognition system

    NASA Technical Reports Server (NTRS)

    Dhawan, Atam P.

    1988-01-01

    An intermediate-level knowledge-based system for decomposing segmented data into three-dimensional primitives was developed to create an approximate three-dimensional description of the real world scene from a single two-dimensional perspective view. A knowledge-based approach was also developed for high-level primitive-based matching of three-dimensional objects. Both the intermediate-level decomposition and the high-level interpretation are based on the structural and relational matching; moreover, they are implemented in a frame-based environment.

  11. 3D nanostructure reconstruction based on the SEM imaging principle, and applications.

    PubMed

    Zhu, Fu-Yun; Wang, Qi-Qi; Zhang, Xiao-Sheng; Hu, Wei; Zhao, Xin; Zhang, Hai-Xia

    2014-05-09

    This paper addresses a novel 3D reconstruction method for nanostructures based on the scanning electron microscopy (SEM) imaging principle. In this method, the shape from shading (SFS) technique is employed, to analyze the gray-scale information of a single top-view SEM image which contains all the visible surface information, and finally to reconstruct the 3D surface morphology. It offers not only unobstructed observation from various angles but also the exact physical dimensions of nanostructures. A convenient and commercially available tool (NanoViewer) is developed based on this method for nanostructure analysis and characterization of properties. The reconstruction result coincides well with the SEM nanostructure image and is verified in different ways. With the extracted structure information, subsequent research of the nanostructure can be carried out, such as roughness analysis, optimizing properties by structure improvement and performance simulation with a reconstruction model. Efficient, practical and non-destructive, the method will become a powerful tool for nanostructure surface observation and characterization.

  12. 3D transient model to predict temperature and ablated areas during laser processing of metallic surfaces

    NASA Astrophysics Data System (ADS)

    Naghshine, Babak. B.; Kiani, Amirkianoosh

    2017-02-01

    Laser processing is one of the most popular small-scale patterning methods and has many applications in semiconductor device fabrication and biomedical engineering. Numerical modelling of this process can be used for better understanding of the process, optimization, and predicting the quality of the final product. An accurate 3D model is presented here for short laser pulses that can predict the ablation depth and temperature distribution on any section of the material in a minimal amount of time. In this transient model, variations of thermal properties, plasma shielding, and phase change are considered. Ablation depth was measured using a 3D optical profiler. Calculated depths are in good agreement with measured values on laser treated titanium surfaces. The proposed model can be applied to a wide range of materials and laser systems.

  13. Simultaneous calculation of three optical surfaces in the 3D SMS freeform RXI optic

    NASA Astrophysics Data System (ADS)

    Sorgato, Simone; Chaves, Julio; Mohedano, Rubén.; Hernández, Maikel; Blen, José; Benitez, Pablo; Miñano, Juan C.; Grabovickic, Dejan; Thienpont, Hugo; Duerr, Fabian

    2016-09-01

    The Freeform RXI collimator is a remarkable example of advanced nonimaging device designed with the 3D Simultaneous Multiple Surface (SMS) Method. In the original design, two (the front refracting surface and the back mirror) of the three optical surfaces of the RXI are calculated simultaneously and one (the cavity surrounding the source) is fixed by the designer. As a result, the RXI perfectly couples two input wavefronts (coming from the edges of the extended LED source) with two output wavefronts (defining the output beam). This allows for LED lamps able to produce controlled intensity distributions, which can and have been successfully applied to demanding applications like high- and low-beams for Automotive Lighting. Nevertheless, current trends in this field are moving towards smaller headlamps with more shape constraints driven by car design. We present an improved version of the 3D RXI in which also the cavity surface is computed during the design, so that there are three freeform surfaces calculated simultaneously and an additional degree of freedom for controlling the light emission: now the RXI can perfectly couple three input wavefronts with three output wavefronts. The enhanced control over ray beams allows for improved light homogeneity and better pattern definition.

  14. Elastic shape analysis of cylindrical surfaces for 3D/2D registration in endometrial tissue characterization.

    PubMed

    Samir, Chafik; Kurtek, Sebastian; Srivastava, Anuj; Canis, Michel

    2014-05-01

    We study the problem of joint registration and deformation analysis of endometrial tissue using 3D magnetic resonance imaging (MRI) and 2D trans-vaginal ultrasound (TVUS) measurements. In addition to the different imaging techniques involved in the two modalities, this problem is complicated due to: 1) different patient pose during MRI and TVUS observations, 2) the 3D nature of MRI and 2D nature of TVUS measurements, 3) the unknown intersecting plane for TVUS in MRI volume, and 4) the potential deformation of endometrial tissue during TVUS measurement process. Focusing on the shape of the tissue, we use expert manual segmentation of its boundaries in the two modalities and apply, with modification, recent developments in shape analysis of parametric surfaces to this problem. First, we extend the 2D TVUS curves to generalized cylindrical surfaces through replication, and then we compare them with MRI surfaces using elastic shape analysis. This shape analysis provides a simultaneous registration (optimal reparameterization) and deformation (geodesic) between any two parametrized surfaces. Specifically, it provides optimal curves on MRI surfaces that match with the original TVUS curves. This framework results in an accurate quantification and localization of the deformable endometrial cells for radiologists, and growth characterization for gynecologists and obstetricians. We present experimental results using semi-synthetic data and real data from patients to illustrate these ideas.

  15. PACS-based interface for 3D anatomical structure visualization and surgical planning

    NASA Astrophysics Data System (ADS)

    Koehl, Christophe; Soler, Luc; Marescaux, Jacques

    2002-05-01

    The interpretation of radiological image is routine but it remains a rather difficult task for physicians. It requires complex mental processes, that permit translation from 2D slices into 3D localization and volume determination of visible diseases. An easier and more extensive visualization and exploitation of medical images can be reached through the use of computer-based systems that provide real help from patient admission to post-operative followup. In this way, we have developed a 3D visualization interface linked to a PACS database that allows manipulation and interaction on virtual organs delineated from CT-scan or MRI. This software provides the 3D real-time surface rendering of anatomical structures, an accurate evaluation of volumes and distances and the improvement of radiological image analysis and exam annotation through a negatoscope tool. It also provides a tool for surgical planning allowing the positioning of an interactive laparoscopic instrument and the organ resection. The software system could revolutionize the field of computerized imaging technology. Indeed, it provides a handy and portable tool for pre-operative and intra-operative analysis of anatomy and pathology in various medical fields. This constitutes the first step of the future development of augmented reality and surgical simulation systems.

  16. Scientific rotoscoping: a morphology-based method of 3-D motion analysis and visualization.

    PubMed

    Gatesy, Stephen M; Baier, David B; Jenkins, Farish A; Dial, Kenneth P

    2010-06-01

    Three-dimensional skeletal movement is often impossible to accurately quantify from external markers. X-ray imaging more directly visualizes moving bones, but extracting 3-D kinematic data is notoriously difficult from a single perspective. Stereophotogrammetry is extremely powerful if bi-planar fluoroscopy is available, yet implantation of three radio-opaque markers in each segment of interest may be impractical. Herein we introduce scientific rotoscoping (SR), a new method of motion analysis that uses articulated bone models to simultaneously animate and quantify moving skeletons without markers. The three-step process is described using examples from our work on pigeon flight and alligator walking. First, the experimental scene is reconstructed in 3-D using commercial animation software so that frames of undistorted fluoroscopic and standard video can be viewed in their correct spatial context through calibrated virtual cameras. Second, polygonal models of relevant bones are created from CT or laser scans and rearticulated into a hierarchical marionette controlled by virtual joints. Third, the marionette is registered to video images by adjusting each of its degrees of freedom over a sequence of frames. SR outputs high-resolution 3-D kinematic data for multiple, unmarked bones and anatomically accurate animations that can be rendered from any perspective. Rather than generating moving stick figures abstracted from the coordinates of independent surface points, SR is a morphology-based method of motion analysis deeply rooted in osteological and arthrological data.

  17. Optimizing visual comfort for stereoscopic 3D display based on color-plus-depth signals.

    PubMed

    Shao, Feng; Jiang, Qiuping; Fu, Randi; Yu, Mei; Jiang, Gangyi

    2016-05-30

    Visual comfort is a long-facing problem in stereoscopic 3D (S3D) display. In this paper, targeting to produce S3D content based on color-plus-depth signals, a general framework for depth mapping to optimize visual comfort for S3D display is proposed. The main motivation of this work is to remap the depth range of color-plus-depth signals to a new depth range that is suitable to comfortable S3D display. Towards this end, we first remap the depth range globally based on the adjusted zero disparity plane, and then present a two-stage global and local depth optimization solution to solve the visual comfort problem. The remapped depth map is used to generate the S3D output. We demonstrate the power of our approach on perceptually uncomfortable and comfortable stereoscopic images.

  18. A Tetraperylene Diimides Based 3D Nonfullerene Acceptor for Efficient Organic Photovoltaics.

    PubMed

    Liu, Shi-Yong; Wu, Chen-Hao; Li, Chang-Zhi; Liu, Sheng-Qiang; Wei, Kung-Hwa; Chen, Hong-Zheng; Jen, Alex K-Y

    2015-04-01

    A nonfullerene acceptor based on a 3D tetraperylene diimide is developed for bulk heterojunction organic photovoltaics. The disruption of perylene diimide planarity with a 3D framework suppresses the self-aggregation of perylene diimide and inhibits excimer formation. From planar monoperylene diimide to 3D tetraperylene diimide, a significant improvement of power conversion efficiency from 0.63% to 3.54% can be achieved.

  19. Exploring the surface reactivity of 3d metal endofullerenes: a density-functional theory study.

    PubMed

    Estrada-Salas, Rubén E; Valladares, Ariel A

    2009-09-24

    Changes in the preferential sites of electrophilic, nucleophilic, and radical attacks on the pristine C60 surface with endohedral doping using 3d transition metal atoms were studied via two useful reactivity indices, namely the Fukui functions and the molecular electrostatic potential. Both of these were calculated at the density functional BPW91 level of theory with the DNP basis set. Our results clearly show changes in the preferential reactivity sites on the fullerene surface when it is doped with Mn, Fe, Co, or Ni atoms, whereas there are no significant changes in the preferential reactivity sites on the C60 surface upon endohedral doping with Cu and Zn atoms. Electron affinities (EA), ionization potentials (IP), and HOMO-LUMO gaps (Eg) were also calculated to complete the study of the endofullerene's surface reactivity. These findings provide insight into endofullerene functionalization, an important issue in their application.

  20. Assessment of engineered surfaces roughness by high-resolution 3D SEM photogrammetry.

    PubMed

    Gontard, L C; López-Castro, J D; González-Rovira, L; Vázquez-Martínez, J M; Varela-Feria, F M; Marcos, M; Calvino, J J

    2017-03-07

    We describe a methodology to obtain three-dimensional models of engineered surfaces using scanning electron microscopy and multi-view photogrammetry (3DSEM). For the reconstruction of the 3D models of the surfaces we used freeware available in the cloud. The method was applied to study the surface roughness of metallic samples patterned with parallel grooves by means of laser. The results are compared with measurements obtained using stylus profilometry (PR) and SEM stereo-photogrammetry (SP). The application of 3DSEM is more time demanding than PR or SP, but it provides a more accurate representation of the surfaces. The results obtained with the three techniques are compared by investigating the influence of sampling step on roughness parameters.

  1. How to select the most relevant 3D roughness parameters of a surface.

    PubMed

    Deltombe, R; Kubiak, K J; Bigerelle, M

    2014-01-01

    In order to conduct a comprehensive roughness analysis, around sixty 3D roughness parameters are created to describe most of the surface morphology with regard to specific functions, properties or applications. In this paper, a multiscale surface topography decomposition method is proposed with application to stainless steel (AISI 304), which is processed by rolling at different fabrication stages and by electrical discharge tool machining. Fifty-six 3D-roughness parameters defined in ISO, EUR, and ASME standards are calculated for the measured surfaces. Then, expert software "MesRug" is employed to perform statistical analysis on acquired data in order to find the most relevant parameters characterizing the effect of both processes (rolling and machining), and to determine the most appropriate scale of analysis. For the rolling process: The parameter Vmc (the Core Material Volume--defined as volume of material comprising the texture between heights corresponding to the material ratio values of p = 10% and q = 80%) computed at the scale of 3 µm is the most relevant parameter to characterize the cold rolling process. For the EDM Process, the best roughness parameter is SPD that represents the number of peaks per unit area after segmentation of a surface into motifs computed at the scale of 8 µm.

  2. Synthesis and 3D printing of biodegradable polyurethane elastomer by a water-based process for cartilage tissue engineering applications.

    PubMed

    Hung, Kun-Che; Tseng, Ching-Shiow; Hsu, Shan-Hui

    2014-10-01

    Biodegradable materials that can undergo degradation in vivo are commonly employed to manufacture tissue engineering scaffolds, by techniques including the customized 3D printing. Traditional 3D printing methods involve the use of heat, toxic organic solvents, or toxic photoinitiators for fabrication of synthetic scaffolds. So far, there is no investigation on water-based 3D printing for synthetic materials. In this study, the water dispersion of elastic and biodegradable polyurethane (PU) nanoparticles is synthesized, which is further employed to fabricate scaffolds by 3D printing using polyethylene oxide (PEO) as a viscosity enhancer. The surface morphology, degradation rate, and mechanical properties of the water-based 3D-printed PU scaffolds are evaluated and compared with those of polylactic-co-glycolic acid (PLGA) scaffolds made from the solution in organic solvent. These scaffolds are seeded with chondrocytes for evaluation of their potential as cartilage scaffolds. Chondrocytes in 3D-printed PU scaffolds have excellent seeding efficiency, proliferation, and matrix production. Since PU is a category of versatile materials, the aqueous 3D printing process developed in this study is a platform technology that can be used to fabricate devices for biomedical applications.

  3. Advantages and drawbacks of Thiol-ene based resins for 3D-printing

    NASA Astrophysics Data System (ADS)

    Leonards, Holger; Engelhardt, Sascha; Hoffmann, Andreas; Pongratz, Ludwig; Schriever, Sascha; Bläsius, Jana; Wehner, Martin; Gillner, Arnold

    2015-03-01

    The technology of 3D printing is conquering the world and awakens the interest of many users in the most varying of applications. New formulation approaches for photo-sensitive thiol-ene resins in combination with various printing technologies, like stereolithography (SLA), projection based printing/digital light processing (DLP) or two-photon polymerization (TPP) are presented. Thiol-ene polymerizations are known for its fast and quantitative reaction and to form highly homogeneous polymer networks. As the resins are locally and temporally photo-curable the polymerization type is very promising for 3D-printing. By using suitable wavelengths, photoinitiator-free fabrication is feasible for single- and two photon induced polymerization. In this paper divinyl ethers of polyethylene glycols in combination with star-shaped tetrathiols were used to design a simple test-system for photo-curable thiol-ene resins. In order to control and improve curing depth and lateral resolution in 3D-polymerization processes, either additives in chemical formulation or process parameters can be changed. The achieved curing depth and resolution limits depend on the applied fabrication method. While two-/multiphoton induced lithography offers the possibility of micron- to sub-micron resolution it lacks in built-up speed. Hence single-photon polymerization is a fast alternative with optimization potential in sub-10-micron resolution. Absorber- and initiator free compositions were developed in order to avoid aging, yellowing and toxicity of resulting products. They can be cured with UV-laser radiation below 300 nm. The development at Fraunhofer ILT is focusing on new applications in the field of medical products and implants, technical products with respect to mechanical properties or optical properties of 3D-printed objects. Recent process results with model system (polyethylene glycol divinylether/ Pentaerithrytol tetrakis (3-mercaptopropionat), Raman measurements of polymer conversion

  4. Geofencing-Based Localization for 3d Data Acquisition Navigation

    NASA Astrophysics Data System (ADS)

    Nakagawa, M.; Kamio, T.; Yasojima, H.; Kobayashi, T.

    2016-06-01

    Users require navigation for many location-based applications using moving sensors, such as autonomous robot control, mapping route navigation and mobile infrastructure inspection. In indoor environments, indoor positioning systems using GNSSs can provide seamless indoor-outdoor positioning and navigation services. However, instabilities in sensor position data acquisition remain, because the indoor environment is more complex than the outdoor environment. On the other hand, simultaneous localization and mapping processing is better than indoor positioning for measurement accuracy and sensor cost. However, it is not easy to estimate position data from a single viewpoint directly. Based on these technical issues, we focus on geofencing techniques to improve position data acquisition. In this research, we propose a methodology to estimate more stable position or location data using unstable position data based on geofencing in indoor environments. We verify our methodology through experiments in indoor environments.

  5. Incorporating polarization in stereo vision-based 3D perception of non-Lambertian scenes

    NASA Astrophysics Data System (ADS)

    Berger, Kai; Voorhies, Randolph; Matthies, Larry

    2016-05-01

    Surfaces with specular, non-Lambertian reflectance are common in urban areas. Robot perception systems for applications in urban environments need to function effectively in the presence of such materials; however, both passive and active 3-D perception systems have difficulties with them. In this paper, we develop an approach using a stereo pair of polarization cameras to improve passive 3-D perception of specular surfaces. We use a commercial stereo camera pair with rotatable polarization filters in front of each lens to capture images with multiple orientations of the polarization filter. From these images, we estimate the degree of linear polarization (DOLP) and the angle of polarization (AOP) at each pixel in at least one camera. The AOP constrains the corresponding surface normal in the scene to lie in the plane of the observed angle of polarization. We embody this constraint an energy functional for a regularization-based stereo vision algorithm. This paper describes the theory of polarization needed for this approach, describes the new stereo vision algorithm, and presents results on synthetic and real images to evaluate performance.

  6. A cross-platform solution for light field based 3D telemedicine.

    PubMed

    Wang, Gengkun; Xiang, Wei; Pickering, Mark

    2016-03-01

    Current telehealth services are dominated by conventional 2D video conferencing systems, which are limited in their capabilities in providing a satisfactory communication experience due to the lack of realism. The "immersiveness" provided by 3D technologies has the potential to promote telehealth services to a wider range of applications. However, conventional stereoscopic 3D technologies are deficient in many aspects, including low resolution and the requirement for complicated multi-camera setup and calibration, and special glasses. The advent of light field (LF) photography enables us to record light rays in a single shot and provide glasses-free 3D display with continuous motion parallax in a wide viewing zone, which is ideally suited for 3D telehealth applications. As far as our literature review suggests, there have been no reports of 3D telemedicine systems using LF technology. In this paper, we propose a cross-platform solution for a LF-based 3D telemedicine system. Firstly, a novel system architecture based on LF technology is established, which is able to capture the LF of a patient, and provide an immersive 3D display at the doctor site. For 3D modeling, we further propose an algorithm which is able to convert the captured LF to a 3D model with a high level of detail. For the software implementation on different platforms (i.e., desktop, web-based and mobile phone platforms), a cross-platform solution is proposed. Demo applications have been developed for 2D/3D video conferencing, 3D model display and edit, blood pressure and heart rate monitoring, and patient data viewing functions. The demo software can be extended to multi-discipline telehealth applications, such as tele-dentistry, tele-wound and tele-psychiatry. The proposed 3D telemedicine solution has the potential to revolutionize next-generation telemedicine technologies by providing a high quality immersive tele-consultation experience.

  7. Future of photorefractive based holographic 3D display

    NASA Astrophysics Data System (ADS)

    Blanche, P.-A.; Bablumian, A.; Voorakaranam, R.; Christenson, C.; Lemieux, D.; Thomas, J.; Norwood, R. A.; Yamamoto, M.; Peyghambarian, N.

    2010-02-01

    The very first demonstration of our refreshable holographic display based on photorefractive polymer was published in Nature early 20081. Based on the unique properties of a new organic photorefractive material and the holographic stereography technique, this display addressed a gap between large static holograms printed in permanent media (photopolymers) and small real time holographic systems like the MIT holovideo. Applications range from medical imaging to refreshable maps and advertisement. Here we are presenting several technical solutions for improving the performance parameters of the initial display from an optical point of view. Full color holograms can be generated thanks to angular multiplexing, the recording time can be reduced from minutes to seconds with a pulsed laser, and full parallax hologram can be recorded in a reasonable time thanks to parallel writing. We also discuss the future of such a display and the possibility of video rate.

  8. Building a 3D scanner system based on monocular vision.

    PubMed

    Zhang, Zhiyi; Yuan, Lin

    2012-04-10

    This paper proposes a three-dimensional scanner system, which is built by using an ingenious geometric construction method based on monocular vision. The system is simple, low cost, and easy to use, and the measurement results are very precise. To build it, one web camera, one handheld linear laser, and one background calibration board are required. The experimental results show that the system is robust and effective, and the scanning precision can be satisfied for normal users.

  9. ICER-3D: A Progressive Wavelet-Based Compressor for Hyperspectral Images

    NASA Technical Reports Server (NTRS)

    Kiely, A.; Klimesh, M.; Xie, H.; Aranki, N.

    2005-01-01

    ICER-3D is a progressive, wavelet-based compressor for hyperspectral images. ICER-3D is derived from the ICER image compressor. ICER-3D can provide lossless and lossy compression, and incorporates an error-containment scheme to limit the effects of data loss during transmission. The three-dimensional wavelet decomposition structure used by ICER-3D exploits correlations in all three dimensions of hyperspectral data sets, while facilitating elimination of spectral ringing artifacts. Correlation is further exploited by a context modeler that effectively exploits spectral dependencies in the wavelet-transformed hyperspectral data. Performance results illustrating the benefits of these features are presented.

  10. Anomalous surface segregation behaviour of some 3d elements in ferromagnetic iron.

    PubMed

    Gupta, Michèle; Gupta, Raju P

    2013-10-16

    The segregation of Cr in Fe is known to be anomalous since the barrier for surface segregation of Cr is not determined by the topmost surface layer, as one would expect, but rather by the subsurface layer where the energy of segregation is much larger and endothermic. This has been attributed to a complex interaction involving the antiferromagnetism of Cr and the ferromagnetism of Fe. We report in this paper the results of our ab initio electronic structure calculations on the segregation behaviour of all the 3d elements on the (1 0 0) surface of ferromagnetic iron in the hope of better understanding this phenomenon. We find a similar behaviour for the segregation of the next antiferromagnetic 3d element Mn in Fe, where the subsurface layer is also found to block the segregation of Mn to the surface. On the other hand, ferromagnetic Co exhibits a normal segregation behaviour. The elements Sc, Cu and Ni do not form solid solutions with ferromagnetic iron. The early elements Ti and V are non-magnetic in their metallic states, but are strongly polarized by Fe, and develop magnetic moments which are aligned antiferromagnetically to those of Fe atoms. While the subsurface layer blocks the segregation of Ti to the surface, no blocking behaviour is found for the segregation of V. The segregation behaviour of all these elements is strongly correlated with the displacement of the solute atoms on the surface of Fe. The elements showing anomalous segregation behaviour are all displaced upwards on the surface, while those showing normal segregation are pulled inwards. These results indicate that the antiferromagnetism of the segregating element plays the key role in the anomalous segregation behaviour in Fe.

  11. Additive manufactured polymeric 3D scaffolds with tailored surface topography influence mesenchymal stromal cells activity.

    PubMed

    Neves, Sara C; Mota, Carlos; Longoni, Alessia; Barrias, Cristina C; Granja, Pedro L; Moroni, Lorenzo

    2016-05-24

    Additive manufactured three-dimensional (3D) scaffolds with tailored surface topography constitute a clear advantage in tissue regeneration strategies to steer cell behavior. 3D fibrous scaffolds of poly(ethylene oxide terephthalate)/poly(butylene terephthalate) block copolymer presenting different fiber surface features were successfully fabricated by additive manufacturing combined with wet-spinning, in a single step, without any post-processing. The optimization of the processing parameters, mainly driven by different solvent/non-solvent combinations, led to four distinct scaffold types, with average surface roughness values ranging from 0.071 ± 0.012 μm to 1.950 ± 0.553 μm, average pore sizes in the x- and y-axis between 351.1 ± 33.6 μm and 396.1 ± 32.3 μm, in the z-axis between 36.5 ± 5.3 μm and 70.7 ± 8.8 μm, average fiber diameters between 69.4 ± 6.1 μm and 99.0 ± 9.4 μm, and porosity values ranging from 60.2 ± 0.8% to 71.7 ± 2.6%. Human mesenchymal stromal cells (hMSCs) cultured on these scaffolds adhered, proliferated, and produced endogenous extracellular matrix. The effect of surface roughness and topography on hMSCs differentiation was more evident for cells seeded at lower density, where the percentage of cells in direct contact with the surface was higher compared to more densely seeded scaffolds. Under osteogenic conditions, lower surface roughness values (0.227 ± 0.035 μm) had a synergistic effect on hMSCs behavior, while chondrogenesis was favored on rougher surfaces (1.950 ± 0.553 μm).

  12. 3D Mesh Segmentation Based on Markov Random Fields and Graph Cuts

    NASA Astrophysics Data System (ADS)

    Shi, Zhenfeng; Le, Dan; Yu, Liyang; Niu, Xiamu

    3D Mesh segmentation has become an important research field in computer graphics during the past few decades. Many geometry based and semantic oriented approaches for 3D mesh segmentation has been presented. However, only a few algorithms based on Markov Random Field (MRF) has been presented for 3D object segmentation. In this letter, we present a definition of mesh segmentation according to the labeling problem. Inspired by the capability of MRF combining the geometric information and the topology information of a 3D mesh, we propose a novel 3D mesh segmentation model based on MRF and Graph Cuts. Experimental results show that our MRF-based schema achieves an effective segmentation.

  13. 3D modeling to characterize lamina cribrosa surface and pore geometries using in vivo images from normal and glaucomatous eyes.

    PubMed

    Sredar, Nripun; Ivers, Kevin M; Queener, Hope M; Zouridakis, George; Porter, Jason

    2013-07-01

    En face adaptive optics scanning laser ophthalmoscope (AOSLO) images of the anterior lamina cribrosa surface (ALCS) represent a 2D projected view of a 3D laminar surface. Using spectral domain optical coherence tomography images acquired in living monkey eyes, a thin plate spline was used to model the ALCS in 3D. The 2D AOSLO images were registered and projected onto the 3D surface that was then tessellated into a triangular mesh to characterize differences in pore geometry between 2D and 3D images. Following 3D transformation of the anterior laminar surface in 11 normal eyes, mean pore area increased by 5.1 ± 2.0% with a minimal change in pore elongation (mean change = 0.0 ± 0.2%). These small changes were due to the relatively flat laminar surfaces inherent in normal eyes (mean radius of curvature = 3.0 ± 0.5 mm). The mean increase in pore area was larger following 3D transformation in 4 glaucomatous eyes (16.2 ± 6.0%) due to their more steeply curved laminar surfaces (mean radius of curvature = 1.3 ± 0.1 mm), while the change in pore elongation was comparable to that in normal eyes (-0.2 ± 2.0%). This 3D transformation and tessellation method can be used to better characterize and track 3D changes in laminar pore and surface geometries in glaucoma.

  14. Comprehensive evaluation of latest 2D/3D monitors and comparison to a custom-built 3D mirror-based display in laparoscopic surgery

    NASA Astrophysics Data System (ADS)

    Wilhelm, Dirk; Reiser, Silvano; Kohn, Nils; Witte, Michael; Leiner, Ulrich; Mühlbach, Lothar; Ruschin, Detlef; Reiner, Wolfgang; Feussner, Hubertus

    2014-03-01

    Though theoretically superior, 3D video systems did not yet achieve a breakthrough in laparoscopic surgery. Furthermore, visual alterations, such as eye strain, diplopia and blur have been associated with the use of stereoscopic systems. Advancements in display and endoscope technology motivated a re-evaluation of such findings. A randomized study on 48 test subjects was conducted to investigate whether surgeons can benefit from using most current 3D visualization systems. Three different 3D systems, a glasses-based 3D monitor, an autostereoscopic display and a mirror-based theoretically ideal 3D display were compared to a state-of-the-art 2D HD system. The test subjects split into a novice and an expert surgeon group, which high experience in laparoscopic procedures. Each of them had to conduct a well comparable laparoscopic suturing task. Multiple performance parameters like task completion time and the precision of stitching were measured and compared. Electromagnetic tracking provided information on the instruments path length, movement velocity and economy. The NASA task load index was used to assess the mental work load. Subjective ratings were added to assess usability, comfort and image quality of each display. Almost all performance parameters were superior for the 3D glasses-based display as compared to the 2D and the autostereoscopic one, but were often significantly exceeded by the mirror-based 3D display. Subjects performed the task at average 20% faster and with a higher precision. Work-load parameters did not show significant differences. Experienced and non-experienced laparoscopists profited equally from 3D. The 3D mirror system gave clear evidence for additional potential of 3D visualization systems with higher resolution and motion parallax presentation.

  15. 3D modelling of near-surface, environmental effects on AEM data

    NASA Astrophysics Data System (ADS)

    Beamish, David

    2004-11-01

    This study considers the three-dimensional (3D) modelling of compact, at-surface conductive bodies on frequency domain airborne electromagnetic (AEM) survey data. The context is the use of AEM data for environmental and land quality applications. The 3D structures encountered are typically conductive, of limited thickness (<20 m) and form 'point' source locations carrying potential environmental risk. The scale of such bodies may generate single-profile, 'bulls-eye' anomalies. In attempts to recover geological information, such anomalies may be considered to represent noise. In environmental AEM, the correct interpretation of such features is important. The study uses a combination of theoretical models and trial-fixed-wing survey data obtained in populated areas of the UK. Scale issues are discussed in terms of the volumetric footprints of the induced electric field generated by systems flown at both low and high elevation. One of the primary uses of AEM survey data lies in the assessment of conductivity maps. These are typically obtained using one-dimensional (1D) conductivity models at individual measurement points. In order to investigate the limitations of this approach, 3D modelling of conductive structures with dimensions less than 350×350 m and thicknesses extending to 20 m has been carried out. A 1D half space inversion of the data obtained at each frequency is then used to assess the behaviour of the spatial information. The results demonstrate that half space conductivity values obtained over compact 3D targets generally provide only apparent conductivity results. For thin, at-surface bodies, conductivity values are biased to lower values than the true conductivity except at high frequency. The spatial perturbation to both coupling ratios and 1D conductivity models can be laterally extensive. The results from 3D modelling indicate that the use of horizontal derivatives applied to the conductivity models offers enhanced edge detection. The practical

  16. The Martian Water Cycle Based on 3-D Modeling

    NASA Technical Reports Server (NTRS)

    Houben, H.; Haberle, R. M.; Joshi, M. M.

    1999-01-01

    Understanding the distribution of Martian water is a major goal of the Mars Surveyor program. However, until the bulk of the data from the nominal missions of TES, PMIRR, GRS, MVACS, and the DS2 probes are available, we are bound to be in a state where much of our knowledge of the seasonal behavior of water is based on theoretical modeling. We therefore summarize the results of this modeling at the present time. The most complete calculations come from a somewhat simplified treatment of the Martian climate system which is capable of simulating many decades of weather. More elaborate meteorological models are now being applied to study of the problem. The results show a high degree of consistency with observations of aspects of the Martian water cycle made by Viking MAWD, a large number of ground-based measurements of atmospheric column water vapor, studies of Martian frosts, and the widespread occurrence of water ice clouds. Additional information is contained in the original extended abstract.

  17. Robust statistical approaches for local planar surface fitting in 3D laser scanning data

    NASA Astrophysics Data System (ADS)

    Nurunnabi, Abdul; Belton, David; West, Geoff

    2014-10-01

    This paper proposes robust methods for local planar surface fitting in 3D laser scanning data. Searching through the literature revealed that many authors frequently used Least Squares (LS) and Principal Component Analysis (PCA) for point cloud processing without any treatment of outliers. It is known that LS and PCA are sensitive to outliers and can give inconsistent and misleading estimates. RANdom SAmple Consensus (RANSAC) is one of the most well-known robust methods used for model fitting when noise and/or outliers are present. We concentrate on the recently introduced Deterministic Minimum Covariance Determinant estimator and robust PCA, and propose two variants of statistically robust algorithms for fitting planar surfaces to 3D laser scanning point cloud data. The performance of the proposed robust methods is demonstrated by qualitative and quantitative analysis through several synthetic and mobile laser scanning 3D data sets for different applications. Using simulated data, and comparisons with LS, PCA, RANSAC, variants of RANSAC and other robust statistical methods, we demonstrate that the new algorithms are significantly more efficient, faster, and produce more accurate fits and robust local statistics (e.g. surface normals), necessary for many point cloud processing tasks. Consider one example data set used consisting of 100 points with 20% outliers representing a plane. The proposed methods called DetRD-PCA and DetRPCA, produce bias angles (angle between the fitted planes with and without outliers) of 0.20° and 0.24° respectively, whereas LS, PCA and RANSAC produce worse bias angles of 52.49°, 39.55° and 0.79° respectively. In terms of speed, DetRD-PCA takes 0.033 s on average for fitting a plane, which is approximately 6.5, 25.4 and 25.8 times faster than RANSAC, and two other robust statistical methods, respectively. The estimated robust surface normals and curvatures from the new methods have been used for plane fitting, sharp feature

  18. Performance analysis of different surface reconstruction algorithms for 3D reconstruction of outdoor objects from their digital images.

    PubMed

    Maiti, Abhik; Chakravarty, Debashish

    2016-01-01

    3D reconstruction of geo-objects from their digital images is a time-efficient and convenient way of studying the structural features of the object being modelled. This paper presents a 3D reconstruction methodology which can be used to generate photo-realistic 3D watertight surface of different irregular shaped objects, from digital image sequences of the objects. The 3D reconstruction approach described here is robust, simplistic and can be readily used in reconstructing watertight 3D surface of any object from its digital image sequence. Here, digital images of different objects are used to build sparse, followed by dense 3D point clouds of the objects. These image-obtained point clouds are then used for generation of photo-realistic 3D surfaces, using different surface reconstruction algorithms such as Poisson reconstruction and Ball-pivoting algorithm. Different control parameters of these algorithms are identified, which affect the quality and computation time of the reconstructed 3D surface. The effects of these control parameters in generation of 3D surface from point clouds of different density are studied. It is shown that the reconstructed surface quality of Poisson reconstruction depends on Samples per node (SN) significantly, greater SN values resulting in better quality surfaces. Also, the quality of the 3D surface generated using Ball-Pivoting algorithm is found to be highly depend upon Clustering radius and Angle threshold values. The results obtained from this study give the readers of the article a valuable insight into the effects of different control parameters on determining the reconstructed surface quality.

  19. Measuring surface topography with scanning electron microscopy. I. EZEImage: a program to obtain 3D surface data.

    PubMed

    Ponz, Ezequiel; Ladaga, Juan Luis; Bonetto, Rita Dominga

    2006-04-01

    Scanning electron microscopy (SEM) is widely used in the science of materials and different parameters were developed to characterize the surface roughness. In a previous work, we studied the surface topography with fractal dimension at low scale and two parameters at high scale by using the variogram, that is, variance vs. step log-log graph, of a SEM image. Those studies were carried out with the FERImage program, previously developed by us. To verify the previously accepted hypothesis by working with only an image, it is indispensable to have reliable three-dimensional (3D) surface data. In this work, a new program (EZEImage) to characterize 3D surface topography in SEM has been developed. It uses fast cross correlation and dynamic programming to obtain reliable dense height maps in a few seconds which can be displayed as an image where each gray level represents a height value. This image can be used for the FERImage program or any other software to obtain surface topography characteristics. EZEImage also generates anaglyph images as well as characterizes 3D surface topography by means of a parameter set to describe amplitude properties and three functional indices for characterizing bearing and fluid properties.

  20. A measurement method for micro 3D shape based on grids-processing and stereovision technology

    NASA Astrophysics Data System (ADS)

    Li, Chuanwei; Liu, Zhanwei; Xie, Huimin

    2013-04-01

    An integrated measurement method for micro 3D surface shape by a combination of stereovision technology in a scanning electron microscope (SEM) and grids-processing methodology is proposed. The principle of the proposed method is introduced in detail. By capturing two images of the tested specimen with grids on the surface at different tilt angles in an SEM, the 3D surface shape of the specimen can be obtained. Numerical simulation is applied to analyze the feasibility of the proposed method. A validation experiment is performed here. The surface shape of the metal-wire/polymer-membrane structures with thermal deformation is reconstructed. By processing the surface grids of the specimen, the out-of-plane displacement field of the specimen surface is also obtained. Compared with the measurement results obtained by a 3D digital microscope, the experimental error of the proposed method is discussed

  1. Quasi-3D modeling of surface potential and threshold voltage of Triple Metal Quadruple Gate MOSFETs

    NASA Astrophysics Data System (ADS)

    Gupta, Santosh Kumar; Shah, Mihir Kumar P.

    2017-01-01

    In this paper we present electrostatic model of 3D Triple Metal Quadruple Gate (TMQG) MOSFET of rectangular cross-section based on quasi-3D method. The analytical equations for channel potential and characteristic length have been derived by decomposing TMQG into two 2D perpendicular cross-sections (triple metal double gate, TMDG) and the effective characteristic length of TMQG is found using equivalent number of gates (ENG) method. For each of the TMDG, 2D Poisson's equation is solved by parabolic approximation and proper boundary conditions to calculate channel potential. The threshold voltage expression is developed using inversion carrier charge sheet density method. The developed models for channel potential and threshold voltage are validated using numerical simulations of TMQG. The developed model provides the design guidelines for TMQG with improved HCEs and SCEs.

  2. Active surface model improvement by energy function optimization for 3D segmentation.

    PubMed

    Azimifar, Zohreh; Mohaddesi, Mahsa

    2015-04-01

    This paper proposes an optimized and efficient active surface model by improving the energy functions, searching method, neighborhood definition and resampling criterion. Extracting an accurate surface of the desired object from a number of 3D images using active surface and deformable models plays an important role in computer vision especially medical image processing. Different powerful segmentation algorithms have been suggested to address the limitations associated with the model initialization, poor convergence to surface concavities and slow convergence rate. This paper proposes a method to improve one of the strongest and recent segmentation algorithms, namely the Decoupled Active Surface (DAS) method. We consider a gradient of wavelet edge extracted image and local phase coherence as external energy to extract more information from images and we use curvature integral as internal energy to focus on high curvature region extraction. Similarly, we use resampling of points and a line search for point selection to improve the accuracy of the algorithm. We further employ an estimation of the desired object as an initialization for the active surface model. A number of tests and experiments have been done and the results show the improvements with regards to the extracted surface accuracy and computational time of the presented algorithm compared with the best and recent active surface models.

  3. A strategy for GIS-based 3-D slope stability modelling over large areas

    NASA Astrophysics Data System (ADS)

    Mergili, M.; Marchesini, I.; Alvioli, M.; Metz, M.; Schneider-Muntau, B.; Rossi, M.; Guzzetti, F.

    2014-12-01

    GIS-based deterministic models may be used for landslide susceptibility mapping over large areas. However, such efforts require specific strategies to (i) keep computing time at an acceptable level, and (ii) parameterize the geotechnical data. We test and optimize the performance of the GIS-based, 3-D slope stability model r.slope.stability in terms of computing time and model results. The model was developed as a C- and Python-based raster module of the open source software GRASS GIS and considers the 3-D geometry of the sliding surface. It calculates the factor of safety (FoS) and the probability of slope failure (Pf) for a number of randomly selected potential slip surfaces, ellipsoidal or truncated in shape. Model input consists of a digital elevation model (DEM), ranges of geotechnical parameter values derived from laboratory tests, and a range of possible soil depths estimated in the field. Probability density functions are exploited to assign Pf to each ellipsoid. The model calculates for each pixel multiple values of FoS and Pf corresponding to different sliding surfaces. The minimum value of FoS and the maximum value of Pf for each pixel give an estimate of the landslide susceptibility in the study area. Optionally, r.slope.stability is able to split the study area into a defined number of tiles, allowing parallel processing of the model on the given area. Focusing on shallow landslides, we show how multi-core processing makes it possible to reduce computing times by a factor larger than 20 in the study area. We further demonstrate how the number of random slip surfaces and the sampling of parameters influence the average value of Pf and the capacity of r.slope.stability to predict the observed patterns of shallow landslides in the 89.5 km2 Collazzone area in Umbria, central Italy.

  4. 3D, wideband vibro-impacting-based piezoelectric energy harvester

    SciTech Connect

    Yu, Qiangmo; Yang, Jin Yue, Xihai; Yang, Aichao; Zhao, Jiangxin; Zhao, Nian; Wen, Yumei; Li, Ping

    2015-04-15

    An impacting-based piezoelectric energy harvester was developed to address the limitations of the existing approaches in single-dimensional operation as well as a narrow working bandwidth. In the harvester, a spiral cylindrical spring rather than the conventional thin cantilever beam was utilized to extract the external vibration with arbitrary directions, which has the capability to impact the surrounding piezoelectric beams to generate electricity. And the introduced vibro-impacting between the spiral cylindrical spring and multi-piezoelectric-beams resulted in not only a three-dimensional response to external vibration, but also a bandwidth-broadening behavior. The experimental results showed that each piezoelectric beam exhibited a maximum bandwidth of 8 Hz and power of 41 μW with acceleration of 1 g (with g=9.8 ms{sup −2}) along the z-axis, and corresponding average values of 5 Hz and 45 μW with acceleration of 0.6 g in the x-y plane. .

  5. Literary and Historical 3D Digital Game-Based Learning: Design Guidelines

    ERIC Educational Resources Information Center

    Neville, David O.; Shelton, Brett E.

    2010-01-01

    As 3D digital game-based learning (3D-DGBL) for the teaching of literature and history gradually gains acceptance, important questions will need to be asked regarding its method of design, development, and deployment. This article offers a synthesis of contemporary pedagogical, instructional design, new media, and literary-historical theories to…

  6. Highly Stretchable and UV Curable Elastomers for Digital Light Processing Based 3D Printing.

    PubMed

    Patel, Dinesh K; Sakhaei, Amir Hosein; Layani, Michael; Zhang, Biao; Ge, Qi; Magdassi, Shlomo

    2017-04-01

    Stretchable UV-curable (SUV) elastomers can be stretched by up to 1100% and are suitable for digital-light-processing (DLP)-based 3D-printing technology. DLP printing of these SUV elastomers enables the direct creation of highly deformable complex 3D hollow structures such as balloons, soft actuators, grippers, and buckyball electronical switches.

  7. 3D Printing Factors Important for the Fabrication of Polyvinylalcohol Filament-Based Tablets.

    PubMed

    Tagami, Tatsuaki; Fukushige, Kaori; Ogawa, Emi; Hayashi, Naomi; Ozeki, Tetsuya

    2017-01-01

    Three-dimensional (3D) printers have been applied in many fields, including engineering and the medical sciences. In the pharmaceutical field, approval of the first 3D-printed tablet by the U.S. Food and Drug Administration in 2015 has attracted interest in the manufacture of tablets and drugs by 3D printing techniques as a means of delivering tailor-made drugs in the future. In current study, polyvinylalcohol (PVA)-based tablets were prepared using a fused-deposition-modeling-type 3D printer and the effect of 3D printing conditions on tablet production was investigated. Curcumin, a model drug/fluorescent marker, was loaded into PVA-filament. We found that several printing parameters, such as the rate of extruding PVA (flow rate), can affect the formability of the resulting PVA-tablets. The 3D-printing temperature is controlled by heating the print nozzle and was shown to affect the color of the tablets and their curcumin content. PVA-based infilled tablets with different densities were prepared by changing the fill density as a printing parameter. Tablets with lower fill density floated in an aqueous solution and their curcumin content tended to dissolve faster. These findings will be useful in developing drug-loaded PVA-based 3D objects and other polymer-based articles prepared using fused-deposition-modeling-type 3D printers.

  8. Efficient near-real-time monitoring of 3D surface displacements in complex landslide scenarios

    NASA Astrophysics Data System (ADS)

    Allasia, Paolo; Manconi, Andrea; Giordan, Daniele; Baldo, Marco; Lollino, Giorgio

    2013-04-01

    Ground deformation measurements play a key role in monitoring activities of landslides. A wide spectrum of instruments and methods is nowadays available, going from in-situ to remote sensing approaches. In emergency scenarios, monitoring is often based on automated instruments capable to achieve accurate measurements, possibly with a very high temporal resolution, in order to achieve the best information about the evolution of the landslide in near-real-time, aiming at early warning purposes. However, the available tools for a rapid and efficient exploitation, understanding and interpretation of the retrieved measurements is still a challenge. This issue is particularly relevant in contexts where monitoring is fundamental to support early warning systems aimed at ensuring safety to people and/or infrastructures. Furthermore, in many cases the results obtained might be of difficult reading and divulgation, especially when people of different backgrounds are involved (e.g. scientists, authorities, civil protection operators, decision makers, etc.). In this work, we extend the concept of automatic and near real time from the acquisition of measurements to the data processing and divulgation, in order to achieve an efficient monitoring of surface displacements in landslide scenarios. We developed an algorithm that allows to go automatically and in near-real-time from the acquisition of 3D displacements on a landslide area to the efficient divulgation of the monitoring results via WEB. This set of straightforward procedures is called ADVICE (ADVanced dIsplaCement monitoring system for Early warning), and has been already successfully applied in several emergency scenarios. The algorithm includes: (i) data acquisition and transfer protocols; (ii) data collection, filtering, and validation; (iii) data analysis and restitution through a set of dedicated software, such as ©3DA [1]; (iv) recognition of displacement/velocity threshold and early warning (v) short term

  9. 3D modeling of geological anomalies based on segmentation of multiattribute fusion

    NASA Astrophysics Data System (ADS)

    Liu, Zhi-Ning; Song, Cheng-Yun; Li, Zhi-Yong; Cai, Han-Peng; Yao, Xing-Miao; Hu, Guang-Min

    2016-09-01

    3D modeling of geological bodies based on 3D seismic data is used to define the shape and volume of the bodies, which then can be directly applied to reservoir prediction, reserve estimation, and exploration. However, multiattributes are not effectively used in 3D modeling. To solve this problem, we propose a novel method for building of 3D model of geological anomalies based on the segmentation of multiattribute fusion. First, we divide the seismic attributes into edge- and region-based seismic attributes. Then, the segmentation model incorporating the edge- and region-based models is constructed within the levelset-based framework. Finally, the marching cubes algorithm is adopted to extract the zero level set based on the segmentation results and build the 3D model of the geological anomaly. Combining the edge-and region-based attributes to build the segmentation model, we satisfy the independence requirement and avoid the problem of insufficient data of single seismic attribute in capturing the boundaries of geological anomalies. We apply the proposed method to seismic data from the Sichuan Basin in southwestern China and obtain 3D models of caves and channels. Compared with 3D models obtained based on single seismic attributes, the results are better agreement with reality.

  10. A GIS-based 3D online information system for underground energy storage in northern Germany

    NASA Astrophysics Data System (ADS)

    Nolde, Michael; Malte, Schwanebeck; Ehsan, Biniyaz; Rainer, Duttmann

    2015-04-01

    We would like to present the concept and current state of development of a GIS-based 3D online information system for underground energy storage. Its aim is to support the local authorities through pre-selection of possible sites for thermal, electrical and substantial underground energy storages. Since the extension of renewable energies has become legal requirement in Germany, the underground storing of superfluously produced green energy (such as during a heavy wind event) in the form of compressed air, gas or heated water has become increasingly important. However, the selection of suitable sites is a complex task. The presented information system uses data of geological features such as rock layers, salt domes and faults enriched with attribute data such as rock porosity and permeability. This information is combined with surface data of the existing energy infrastructure, such as locations of wind and biogas stations, powerline arrangement and cable capacity, and energy distribution stations. Furthermore, legal obligations such as protected areas on the surface and current underground mining permissions are used for the process of pre-selecting sites suitable for energy storage. Not only the current situation but also prospective scenarios, such as expected growth in produced amount of energy are incorporated in the system. While the process of pre-selection itself is completely automated, the user has full control of the weighting of the different factors via the web interface. The system is implemented as an online 3D server GIS environment, so that it can easily be utilized in any web browser. The results are visualized online as interactive 3d graphics. The information system is implemented in the Python programming language in combination with current Web standards, and is build using only free and open source software. It is being developed at Kiel University as part of the ANGUS+ project (lead by Prof. Sebastian Bauer) for the federal state of

  11. Robust affine-invariant feature points matching for 3D surface reconstruction of complex landslide scenes

    NASA Astrophysics Data System (ADS)

    Stumpf, André; Malet, Jean-Philippe; Allemand, Pascal; Skupinski, Grzegorz; Deseilligny, Marc-Pierrot

    2013-04-01

    Multi-view stereo surface reconstruction from dense terrestrial photographs is being increasingly applied for geoscience applications such as quantitative geomorphology, and a number of different software solution and processing streamlines have been suggested. For image matching, camera self-calibration and bundle block adjustment, most approaches make use of scale-invariant feature transform (SIFT) to identify homologous points in multiple images. SIFT-like point matching is robust to apparent translation, rotation, and scaling of objects in multiple viewing geometries but the number of correctly identified matching points typically declines drastically with increasing angles between the viewpoints. For the application of multi-view stereo of complex landslide scenes, the viewing geometry is often constrained by the local topography and barriers such as rocks and vegetation occluding the target. Under such conditions it is not uncommon to encounter view angle differences of > 30% that hinder the image matching and eventually prohibit the joint estimation of the camera parameters from all views. Recently an affine invariant extension of the SIFT detector (ASIFT) has been demonstrated to provide more robust matches when large view-angle differences become an issue. In this study the ASIFT detector was adopted to detect homologous points in terrestrial photographs preceding 3D reconstruction of different parts (main scarp, toe) of the Super-Sauze landslide (Southern French Alps). 3D surface models for different time periods and different parts of the landslide were derived using the multi-view stereo framework implemented in MicMac (©IGN). The obtained 3D models were compared with reconstructions using the traditional SIFT detectors as well as alternative structure-from-motion implementations. An estimate of the absolute accuracy of the photogrammetric models was obtained through co-registration and comparison with high-resolution terrestrial LiDAR scans.

  12. Persistent and automatic intraoperative 3D digitization of surfaces under dynamic magnifications of an operating microscope.

    PubMed

    Kumar, Ankur N; Miga, Michael I; Pheiffer, Thomas S; Chambless, Lola B; Thompson, Reid C; Dawant, Benoit M

    2015-01-01

    One of the major challenges impeding advancement in image-guided surgical (IGS) systems is the soft-tissue deformation during surgical procedures. These deformations reduce the utility of the patient's preoperative images and may produce inaccuracies in the application of preoperative surgical plans. Solutions to compensate for the tissue deformations include the acquisition of intraoperative tomographic images of the whole organ for direct displacement measurement and techniques that combines intraoperative organ surface measurements with computational biomechanical models to predict subsurface displacements. The later solution has the advantage of being less expensive and amenable to surgical workflow. Several modalities such as textured laser scanners, conoscopic holography, and stereo-pair cameras have been proposed for the intraoperative 3D estimation of organ surfaces to drive patient-specific biomechanical models for the intraoperative update of preoperative images. Though each modality has its respective advantages and disadvantages, stereo-pair camera approaches used within a standard operating microscope is the focus of this article. A new method that permits the automatic and near real-time estimation of 3D surfaces (at 1 Hz) under varying magnifications of the operating microscope is proposed. This method has been evaluated on a CAD phantom object and on full-length neurosurgery video sequences (∼1 h) acquired intraoperatively by the proposed stereovision system. To the best of our knowledge, this type of validation study on full-length brain tumor surgery videos has not been done before. The method for estimating the unknown magnification factor of the operating microscope achieves accuracy within 0.02 of the theoretical value on a CAD phantom and within 0.06 on 4 clinical videos of the entire brain tumor surgery. When compared to a laser range scanner, the proposed method for reconstructing 3D surfaces intraoperatively achieves root mean square

  13. Electrochemical signal amplification for immunosensor based on 3D interdigitated array electrodes.

    PubMed

    Han, Donghoon; Kim, Yang-Rae; Kang, Chung Mu; Chung, Taek Dong

    2014-06-17

    We devised an electrochemical redox cycling based on three-dimensional interdigitated array (3D IDA) electrodes for signal amplification to enhance the sensitivity of chip-based immunosensors. The 3D IDA consists of two closely spaced parallel indium tin oxide (ITO) electrodes that are positioned not only on the bottom but also the ceiling, facing each other along a microfluidic channel. We investigated the signal intensities from various geometric configurations: Open-2D IDA, Closed-2D IDA, and 3D IDA through electrochemical experiments and finite-element simulations. The 3D IDA among the four different systems exhibited the greatest signal amplification resulting from efficient redox cycling of electroactive species confined in the microchannel so that the faradaic current was augmented by a factor of ∼100. We exploited the enhanced sensitivity of the 3D IDA to build up a chronocoulometric immunosensing platform based on the sandwich enzyme-linked immunosorbent assay (ELISA) protocol. The mouse IgGs on the 3D IDA showed much lower detection limits than on the Closed-2D IDA. The detection limit for mouse IgG measured using the 3D IDA was ∼10 fg/mL, while it was ∼100 fg/mL for the Closed-2D IDA. Moreover, the proposed immunosensor system with the 3D IDA successfully worked for clinical analysis as shown by the sensitive detection of cardiac troponin I in human serum down to 100 fg/mL.

  14. Digitized crime scene forensics: automated trace separation of toolmarks on high-resolution 2D/3D CLSM surface data

    NASA Astrophysics Data System (ADS)

    Clausing, Eric; Vielhauer, Claus

    2015-03-01

    Locksmith forensics is an important and very challenging part of classic crime scene forensics. In prior work, we propose a partial transfer to the digital domain, to effectively support forensic experts and present approaches for a full process chain consisting of five steps: Trace positioning, 2D/3D acquisition with a confocal 3D laser scanning microscope, detection by segmentation, trace type determination, and determination of the opening method. In particular the step of trace segmentation on high-resolution 3D surfaces thereby turned out to be the part most difficult to implement. The reason for that is the highly structured and complex surfaces to be analyzed. These surfaces are cluttered with a high number of toolmarks, which overlap and distort each other. In Clausing et al., we present an improved approach for a reliable segmentation of relevant trace regions but without the possibility of separating single traces out of segmented trace regions. However, in our past research, especially features based on shape and dimension turned out to be highly relevant for a fully automated analysis and interpretation. In this paper, we consequently propose an approach for this separation. To achieve this goal, we use our segmentation approach and expand it with a combination of the watershed algorithm with a graph-based analysis. Found sub-regions are compared based on their surface character and are connected or divided depending on their similarity. We evaluate our approach with a test set of about 1,300 single traces on the exemplary locking cylinder component 'key pin' and thereby are able of showing the high suitability of our approach.

  15. Shape representation for efficient landmark-based segmentation in 3-d.

    PubMed

    Ibragimov, Bulat; Likar, Boštjan; Pernuš, Franjo; Vrtovec, Tomaž

    2014-04-01

    In this paper, we propose a novel approach to landmark-based shape representation that is based on transportation theory, where landmarks are considered as sources and destinations, all possible landmark connections as roads, and established landmark connections as goods transported via these roads. Landmark connections, which are selectively established, are identified through their statistical properties describing the shape of the object of interest, and indicate the least costly roads for transporting goods from sources to destinations. From such a perspective, we introduce three novel shape representations that are combined with an existing landmark detection algorithm based on game theory. To reduce computational complexity, which results from the extension from 2-D to 3-D segmentation, landmark detection is augmented by a concept known in game theory as strategy dominance. The novel shape representations, game-theoretic landmark detection and strategy dominance are combined into a segmentation framework that was evaluated on 3-D computed tomography images of lumbar vertebrae and femoral heads. The best shape representation yielded symmetric surface distance of 0.75 mm and 1.11 mm, and Dice coefficient of 93.6% and 96.2% for lumbar vertebrae and femoral heads, respectively. By applying strategy dominance, the computational costs were further reduced for up to three times.

  16. Effects of scanning orientation on outlier formation in 3D laser scanning of reflective surfaces

    NASA Astrophysics Data System (ADS)

    Wang, Yutao; Feng, Hsi-Yung

    2016-06-01

    Inspecting objects with reflective surfaces using 3D laser scanning is a demanded but challenging part inspection task due to undesirable specular reflections, which produce extensive outliers in the scanned point cloud. These outliers need to be removed in order to alleviate subsequent data processing issues. Many existing automatic outlier removal methods do not detect outliers according to the outlier formation properties. As a result, these methods only offer limited capabilities in removing extensive and complex outliers from scanning objects with reflective surfaces. This paper reports an empirical study which experimentally investigates the outlier formation characteristics in relation to the scanning orientation of the laser probe. The objective is to characterize the scanning orientation effects on outlier formation in order to facilitate the development of an effective outlier detection and removal method. Such an experimental investigation was hardly done before. It has been found in this work that scanning orientation can directly affect outlier extensity and occurrence in 3D laser scanning. A general guidance on proper scan path planning can then be provided with an aim to reduce the occurrence of outliers. Further, the observed dependency of outlier formation on scanning orientation can be exploited to facilitate effective and automatic outlier detection and removal.

  17. Brownian nanoimaging of interface dynamics and ligand-receptor binding at cell surfaces in 3-D.

    PubMed

    Kuznetsov, Igor R; Evans, Evan A

    2013-04-01

    We describe a method for nanoimaging interfacial dynamics and ligand-receptor binding at surfaces of live cells in 3-D. The imaging probe is a 1-μm diameter glass bead confined by a soft laser trap to create a "cloud" of fluctuating states. Using a facile on-line method of video image analysis, the probe displacements are reported at ~10 ms intervals with bare precisions (±SD) of 4-6 nm along the optical axis (elevation) and 2 nm in the transverse directions. We demonstrate how the Brownian distributions are analyzed to characterize the free energy potential of each small probe in 3-D taking into account the blur effect of its motions during CCD image capture. Then, using the approach to image interactions of a labeled probe with lamellae of leukocytic cells spreading on cover-glass substrates, we show that deformations of the soft distribution in probe elevations provide both a sensitive long-range sensor for defining the steric topography of a cell lamella and a fast telemetry for reporting rare events of probe binding with its surface receptors. Invoking established principles of Brownian physics and statistical thermodynamics, we describe an off-line method of super resolution that improves precision of probe separations from a non-reactive steric boundary to ~1 nm.

  18. 3D Ag/ZnO hybrids for sensitive surface-enhanced Raman scattering detection

    NASA Astrophysics Data System (ADS)

    Huang, Chenyue; Xu, Chunxiang; Lu, Junfeng; Li, Zhaohui; Tian, Zhengshan

    2016-03-01

    To combine the surface plasma resonance of metal and local field enhancement in metal/semiconductor interface, Ag nanoparticles (NPs) were assembled on a ZnO nanorod array which was grown by hydrothermally on carbon fibers. The construction of dimensional (3D) Surface-Enhanced Raman Scattering (SERS) substrate is used for the sensitive detection of organic pollutants with the advantages such as facile synthesis, short detection time and low cost. The hybrid substrate was manifested a high sensitivity to phenol red at a lower concentration of 1 × 10-9 M and a higher enhancement factor of 3.18 × 109. Moreover, the ZnO nanostructures decorated with Ag NPs were demonstrated self-cleaning function under UV irradiation via photocatalytic degradation of the analytic molecules. The fabrication process of the materials and sensors, optimization of the SERS behaviors for different sized Ag NPs, the mechanism of SERS and recovery were presented with a detailed discussion.

  19. GlaRe, a GIS tool to reconstruct the 3D surface of palaeoglaciers

    NASA Astrophysics Data System (ADS)

    Pellitero, Ramón; Rea, Brice R.; Spagnolo, Matteo; Bakke, Jostein; Ivy-Ochs, Susan; Frew, Craig R.; Hughes, Philip; Ribolini, Adriano; Lukas, Sven; Renssen, Hans

    2016-09-01

    Glacier reconstructions are widely used in palaeoclimatic studies and this paper presents a new semi-automated method for generating glacier reconstructions: GlaRe, is a toolbox coded in Python and operating in ArcGIS. This toolbox provides tools to generate the ice thickness from the bed topography along a palaeoglacier flowline applying the standard flow law for ice, and generates the 3D surface of the palaeoglacier using multiple interpolation methods. The toolbox performance has been evaluated using two extant glaciers, an icefield and a cirque/valley glacier from which the subglacial topography is known, using the basic reconstruction routine in GlaRe. Results in terms of ice surface, ice extent and equilibrium line altitude show excellent agreement that confirms the robustness of this procedure in the reconstruction of palaeoglaciers from glacial landforms such as frontal moraines.

  20. 3D-confocal microscopy for surface analysis of microstructured materials

    NASA Astrophysics Data System (ADS)

    Kagerer, Bernd; Brodmann, Rainer; Valentin, Juergen; Filzek, Jan; Popp, Uwe

    2002-06-01

    The surface of technical materials is playing an ever more important part in modern production processes. However, standard roughness values, which are obtained from a profile, frequently no longer provide sufficient descriptions. What are desired are three-dimensional measurements of surfaces over a macroscopic range with a high degree of vertical and lateral resolution. This has become necessary to be able to describe both deterministic and non-deterministic structures in the same fashion. Due to increased requirements for data and the measuring speed demanded by industry, only optical systems are a possibility. Using the example of tribology, the capability of this technology is shown in this article on the basis of the commercial confocal 3D white light microscope, the NanoFocusTMμSurfTM. On the one hand, the technology and data preparation used are discussed, and on the other, a comparison is drawn with other standard optical measuring methods.

  1. Uncertainty studies of topographical measurements on steel surface corrosion by 3D scanning electron microscopy.

    PubMed

    Kang, K W; Pereda, M D; Canafoglia, M E; Bilmes, P; Llorente, C; Bonetto, R

    2012-02-01

    Pitting corrosion is a damage mechanism quite serious and dangerous in both carbon steel boiler tubes for power plants which are vital to most industries and stainless steels for orthopedic human implants whose demand, due to the increase of life expectation and rate of traffic accidents, has sharply increased. Reliable methods to characterize this kind of damage are becoming increasingly necessary, when trying to evaluate the advance of damage and to establish the best procedures for component inspection in order to determine remaining lives and failure mitigation. A study about the uncertainties on the topographies of corrosion pits from 3D SEM images, obtained at low magnifications (where errors are greater) and different stage tilt angles were carried out using an in-house software previously developed. Additionally, measurements of pit depths on biomaterial surfaces, subjected to two different surface treatments on stainless steels, were carried out. The different depth distributions observed were in agreement with electrochemical measurements.

  2. Contact Interface Verification for DYNA3D Scenario 2: Multi-Surface Contact

    SciTech Connect

    McMichael, L D

    2006-05-10

    A suite of test problems has been developed to examine contact behavior within the nonlinear, three-dimensional, explicit finite element analysis (FEA) code DYNA3D (Lin, 2005). The test problems use multiple interfaces and a combination of enforcement methods to assess the basic functionality of the contact algorithms. The results from the DYNA3D analyses are compared to closed form solutions to verify the contact behavior. This work was performed as part of the Verification and Validation efforts of LLNL W Program within the NNSA's Advanced Simulation and Computing (ASC) Program. DYNA3D models the transient dynamic response of solids and structures including the interactions between disjoint bodies (parts). A wide variety of contact surfaces are available to represent the diverse interactions possible during an analysis, including relative motion (sliding), separation and gap closure (voids), and fixed relative position (tied). The problem geometry may be defined using a combination of element formulations, including one-dimensional beam and truss elements, two-dimensional shell elements, and three-dimensional solid elements. Consequently, it is necessary to consider various element interactions during contact. This report and associated test problems examine the scenario where multiple bodies interact with each other via multiple interfaces. The test problems focus on whether any ordering issues exist in the contact logic by using a combination of interface types, contact enforcement options (i.e., penalty, Lagrange, and kinematic), and element interactions within each problem. The influence of rigid materials on interface behavior is also examined. The companion report (McMichael, 2006) and associated test problems address the basic contact scenario where one contact surface exists between two disjoint bodies. The test problems are analyzed using version 5.2 (compiled on 12/22/2005) of DYNA3D. The analytical results are used to form baseline solutions for

  3. Novel 3D imaging techniques for improved understanding of planetary surface geomorphology.

    NASA Astrophysics Data System (ADS)

    Muller, Jan-Peter

    2015-04-01

    Understanding the role of different planetary surface formation processes within our Solar System is one of the fundamental goals of planetary science research. There has been a revolution in planetary surface observations over the past decade for Mars and the Moon, especially in 3D imaging of surface shape (down to resolutions of 75cm) and subsequent correction for terrain relief of imagery from orbiting and co-registration of lander and rover robotic images. We present some of the recent highlights including 3D modelling of surface shape from the ESA Mars Express HRSC (High Resolution Stereo Camera), see [1], [2] at 30-100m grid-spacing; and then co-registered to HRSC using a resolution cascade of 20m DTMs from NASA MRO stereo-CTX and 0.75m DTMs from MRO stereo-HiRISE [3]. This has opened our eyes to the formation mechanisms of megaflooding events, such as the formation of Iani Vallis and the upstream blocky terrain, to crater lakes and receding valley cuts [4]. A comparable set of products is now available for the Moon from LROC-WA at 100m [5] and LROC-NA at 1m [6]. Recently, a very novel technique for the super-resolution restoration (SRR) of stacks of images has been developed at UCL [7]. First examples shown will be of the entire MER-A Spirit rover traverse taking a stack of 25cm HiRISE to generate a corridor of SRR images along the rover traverse of 5cm imagery of unresolved features such as rocks, created as a consequence of meteoritic bombardment, ridge and valley features. This SRR technique will allow us for ˜400 areas on Mars (where 5 or more HiRISE images have been captured) and similar numbers on the Moon to resolve sub-pixel features. Examples will be shown of how these SRR images can be employed to assist with the better understanding of surface geomorphology. Acknowledgements: The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under PRoViDE grant agreement n° 312377

  4. Research on gaze-based interaction to 3D display system

    NASA Astrophysics Data System (ADS)

    Kwon, Yong-Moo; Jeon, Kyeong-Won; Kim, Sung-Kyu

    2006-10-01

    There have been reported several researches on gaze tracking techniques using monocular camera or stereo camera. The most popular used gaze estimation techniques are based on PCCR (Pupil Center & Cornea Reflection). These techniques are for gaze tracking for 2D screen or images. In this paper, we address the gaze-based 3D interaction to stereo image for 3D virtual space. To the best of our knowledge, our paper first addresses the 3D gaze interaction techniques to 3D display system. Our research goal is the estimation of both of gaze direction and gaze depth. Until now, the most researches are focused on only gaze direction for the application to 2D display system. It should be noted that both of gaze direction and gaze depth should be estimated for the gaze-based interaction in 3D virtual space. In this paper, we address the gaze-based 3D interaction techniques with glassless stereo display. The estimation of gaze direction and gaze depth from both eyes is a new important research topic for gaze-based 3D interaction. We present our approach for the estimation of gaze direction and gaze depth and show experimentation results.

  5. Model-based measurement of food portion size for image-based dietary assessment using 3D/2D registration

    NASA Astrophysics Data System (ADS)

    Chen, Hsin-Chen; Jia, Wenyan; Yue, Yaofeng; Li, Zhaoxin; Sun, Yung-Nien; Fernstrom, John D.; Sun, Mingui

    2013-10-01

    Dietary assessment is important in health maintenance and intervention in many chronic conditions, such as obesity, diabetes and cardiovascular disease. However, there is currently a lack of convenient methods for measuring the volume of food (portion size) in real-life settings. We present a computational method to estimate food volume from a single photographic image of food contained on a typical dining plate. First, we calculate the food location with respect to a 3D camera coordinate system using the plate as a scale reference. Then, the food is segmented automatically from the background in the image. Adaptive thresholding and snake modeling are implemented based on several image features, such as color contrast, regional color homogeneity and curve bending degree. Next, a 3D model representing the general shape of the food (e.g., a cylinder, a sphere, etc) is selected from a pre-constructed shape model library. The position, orientation and scale of the selected shape model are determined by registering the projected 3D model and the food contour in the image, where the properties of the reference are used as constraints. Experimental results using various realistically shaped foods with known volumes demonstrated satisfactory performance of our image-based food volume measurement method even if the 3D geometric surface of the food is not completely represented in the input image.

  6. Model-based measurement of food portion size for image-based dietary assessment using 3D/2D registration

    PubMed Central

    Chen, Hsin-Chen; Jia, Wenyan; Yue, Yaofeng; Li, Zhaoxin; Sun, Yung-Nien; Fernstrom, John D.; Sun, Mingui

    2013-01-01

    Dietary assessment is important in health maintenance and intervention in many chronic conditions, such as obesity, diabetes, and cardiovascular disease. However, there is currently a lack of convenient methods for measuring the volume of food (portion size) in real-life settings. We present a computational method to estimate food volume from a single photographical image of food contained in a typical dining plate. First, we calculate the food location with respect to a 3D camera coordinate system using the plate as a scale reference. Then, the food is segmented automatically from the background in the image. Adaptive thresholding and snake modeling are implemented based on several image features, such as color contrast, regional color homogeneity and curve bending degree. Next, a 3D model representing the general shape of the food (e.g., a cylinder, a sphere, etc.) is selected from a pre-constructed shape model library. The position, orientation and scale of the selected shape model are determined by registering the projected 3D model and the food contour in the image, where the properties of the reference are used as constraints. Experimental results using various realistically shaped foods with known volumes demonstrated satisfactory performance of our image based food volume measurement method even if the 3D geometric surface of the food is not completely represented in the input image. PMID:24223474

  7. Model-based measurement of food portion size for image-based dietary assessment using 3D/2D registration.

    PubMed

    Chen, Hsin-Chen; Jia, Wenyan; Yue, Yaofeng; Li, Zhaoxin; Sun, Yung-Nien; Fernstrom, John D; Sun, Mingui

    2013-10-01

    Dietary assessment is important in health maintenance and intervention in many chronic conditions, such as obesity, diabetes, and cardiovascular disease. However, there is currently a lack of convenient methods for measuring the volume of food (portion size) in real-life settings. We present a computational method to estimate food volume from a single photographical image of food contained in a typical dining plate. First, we calculate the food location with respect to a 3D camera coordinate system using the plate as a scale reference. Then, the food is segmented automatically from the background in the image. Adaptive thresholding and snake modeling are implemented based on several image features, such as color contrast, regional color homogeneity and curve bending degree. Next, a 3D model representing the general shape of the food (e.g., a cylinder, a sphere, etc.) is selected from a pre-constructed shape model library. The position, orientation and scale of the selected shape model are determined by registering the projected 3D model and the food contour in the image, where the properties of the reference are used as constraints. Experimental results using various realistically shaped foods with known volumes demonstrated satisfactory performance of our image based food volume measurement method even if the 3D geometric surface of the food is not completely represented in the input image.

  8. Non-Newtonian Fluids Spreading with Surface Tension Effect: 3D Numerical Analysis Using FEM and Experimental Study

    NASA Astrophysics Data System (ADS)

    Hu, Bin; Kieweg, Sarah

    2010-11-01

    Gravity-driven thin film flow down an incline is studied for optimal design of polymeric drug delivery vehicles, such as anti-HIV topical microbicides. We develop a 3D FEM model using non-Newtonian mechanics to model the flow of gels in response to gravity, surface tension and shear-thinning. Constant volume setup is applied within the lubrication approximation scope. The lengthwise profiles of the 3D model agree with our previous 2D finite difference model, while the transverse contact line patterns of the 3D model are compared to the experiments. With incorporation of surface tension, capillary ridges are observed at the leading front in both 2D and 3D models. Previously published studies show that capillary ridge can amplify the fingering instabilities in transverse direction. Sensitivity studies (2D & 3D) and experiments are carried out to describe the influence of surface tension and shear-thinning on capillary ridge and fingering instabilities.

  9. ARGon{sup 3}: ''3D appearance robot-based gonioreflectometer'' at PTB

    SciTech Connect

    Hoepe, A.; Atamas, T.; Huenerhoff, D.; Teichert, S.; Hauer, K.-O.

    2012-04-15

    At the Physikalisch-Technische Bundesanstalt, the National Metrology Institute of Germany, a new facility for measuring visual appearance-related quantities has been built up. The acronym ARGon{sup 3} stands for ''3D appearance robot-based gonioreflectometer''. Compared to standard gonioreflectometers, there are two main new features within this setup. First, a photometric luminance camera with a spatial resolution of 28 {mu}m on the device under test (DUT) enables spatially high-resolved measurements of luminance and color coordinates. Second, a line-scan CCD-camera mounted to a spectrometer provides measurements of the radiance factor, respectively the bidirectional reflectance distribution function, in full V({lambda})-range (360 nm-830 nm) with arbitrary angles of irradiation and detection relative to the surface normal, on a time scale of about 2 min. First goniometric measurements of diffuse reflection within 3D-space above the DUT with subsequent colorimetric representation of the obtained data of special effect pigments based on the interference effect are presented.

  10. A miniature microbial fuel cell with conducting nanofibers-based 3D porous biofilm

    NASA Astrophysics Data System (ADS)

    Jiang, Huawei; Halverson, Larry J.; Dong, Liang

    2015-12-01

    Miniature microbial fuel cell (MFC) technology has received growing interest due to its potential applications in high-throughput screening of bacteria and mutants to elucidate mechanisms of electricity generation. This paper reports a novel miniature MFC with an improved output power density and short startup time, utilizing electrospun conducting poly(3,4-ethylenedioxythiophene) (PEDOT) nanofibers as a 3D porous anode within a 12 μl anolyte chamber. This device results in 423 μW cm-3 power density based on the volume of the anolyte chamber, using Shewanella oneidensis MR-1 as a model biocatalyst without any optimization of bacterial culture. The device also excels in a startup time of only 1hr. The high conductivity of the electrospun nanofibers makes them suitable for efficient electron transfer. The mean pore size of the conducting nanofibers is several micrometers, which is favorable for bacterial penetration and colonization of surfaces of the nanofibers. We demonstrate that S. oneidensis can fully colonize the interior region of this nanofibers-based porous anode. This work represents a new attempt to explore the use of electrospun PEDOT nanofibers as a 3D anode material for MFCs. The presented miniature MFC potentially will provide a high-sensitivity, high-throughput tool to screen suitable bacterial species and mutant strains for use in large-size MFCs.

  11. The National 3-D Geospatial Information Web-Based Service of Korea

    NASA Astrophysics Data System (ADS)

    Lee, D. T.; Kim, C. W.; Kang, I. G.

    2013-09-01

    3D geospatial information systems should provide efficient spatial analysis tools and able to use all capabilities of the third dimension, and a visualization. Currently, many human activities make steps toward the third dimension like land use, urban and landscape planning, cadastre, environmental monitoring, transportation monitoring, real estate market, military applications, etc. To reflect this trend, the Korean government has been started to construct the 3D geospatial data and service platform. Since the geospatial information was introduced in Korea, the construction of geospatial information (3D geospatial information, digital maps, aerial photographs, ortho photographs, etc.) has been led by the central government. The purpose of this study is to introduce the Korean government-lead 3D geospatial information web-based service for the people who interested in this industry and we would like to introduce not only the present conditions of constructed 3D geospatial data but methodologies and applications of 3D geospatial information. About 15% (about 3,278.74 km2) of the total urban area's 3D geospatial data have been constructed by the national geographic information institute (NGII) of Korea from 2005 to 2012. Especially in six metropolitan cities and Dokdo (island belongs to Korea) on level of detail (LOD) 4 which is photo-realistic textured 3D models including corresponding ortho photographs were constructed in 2012. In this paper, we represented web-based 3D map service system composition and infrastructure and comparison of V-world with Google Earth service will be presented. We also represented Open API based service cases and discussed about the protection of location privacy when we construct 3D indoor building models. In order to prevent an invasion of privacy, we processed image blurring, elimination and camouflage. The importance of public-private cooperation and advanced geospatial information policy is emphasized in Korea. Thus, the progress of

  12. Fourier-based reconstruction for fully 3-D PET: optimization of interpolation parameters.

    PubMed

    Matej, Samuel; Kazantsev, Ivan G

    2006-07-01

    Fourier-based approaches for three-dimensional (3-D) reconstruction are based on the relationship between the 3-D Fourier transform (FT) of the volume and the two-dimensional (2-D) FT of a parallel-ray projection of the volume. The critical step in the Fourier-based methods is the estimation of the samples of the 3-D transform of the image from the samples of the 2-D transforms of the projections on the planes through the origin of Fourier space, and vice versa for forward-projection (reprojection). The Fourier-based approaches have the potential for very fast reconstruction, but their straightforward implementation might lead to unsatisfactory results if careful attention is not paid to interpolation and weighting functions. In our previous work, we have investigated optimal interpolation parameters for the Fourier-based forward and back-projectors for iterative image reconstruction. The optimized interpolation kernels were shown to provide excellent quality comparable to the ideal sinc interpolator. This work presents an optimization of interpolation parameters of the 3-D direct Fourier method with Fourier reprojection (3D-FRP) for fully 3-D positron emission tomography (PET) data with incomplete oblique projections. The reprojection step is needed for the estimation (from an initial image) of the missing portions of the oblique data. In the 3D-FRP implementation, we use the gridding interpolation strategy, combined with proper weighting approaches in the transform and image domains. We have found that while the 3-D reprojection step requires similar optimal interpolation parameters as found in our previous studies on Fourier-based iterative approaches, the optimal interpolation parameters for the main 3D-FRP reconstruction stage are quite different. Our experimental results confirm that for the optimal interpolation parameters a very good image accuracy can be achieved even without any extra spectral oversampling, which is a common practice to decrease errors

  13. 3D imaging of telomeres and nuclear architecture: An emerging tool of 3D nano-morphology-based diagnosis.

    PubMed

    Knecht, Hans; Mai, Sabine

    2011-04-01

    Patient samples are evaluated by experienced pathologists whose diagnosis guides treating physicians. Pathological diagnoses are complex and often assisted by the application of specific tissue markers. However, cases still exist where pathologists cannot distinguish between closely related entities or determine the aggressiveness of the disease they identify under the microscope. This is due to the absence of reliable markers that define diagnostic subgroups in several cancers. Three-dimensional (3D) imaging of nuclear telomere signatures is emerging as a new tool that may change this situation offering new opportunities to the patients. This article will review current and future avenues in the assessment of diagnostic patient samples.

  14. Surface functionalization of 3D glass-ceramic porous scaffolds for enhanced mineralization in vitro

    NASA Astrophysics Data System (ADS)

    Ferraris, Sara; Vitale-Brovarone, Chiara; Bretcanu, Oana; Cassinelli, Clara; Vernè, Enrica

    2013-04-01

    Bone reconstruction after tissue loosening due to traumatic, pathological or surgical causes is in increasing demand. 3D scaffolds are a widely studied solution for supporting new bone growth. Bioactive glass-ceramic porous materials can offer a three-dimensional structure that is able to chemically bond to bone. The ability to surface modify these devices by grafting biologically active molecules represents a challenge, with the aim of stimulating physiological bone regeneration with both inorganic and organic signals. In this research work glass ceramic scaffolds with very high mechanical properties and moderate bioactivity have been functionalized with the enzyme alkaline phosphatase (ALP). The material surface was activated in order to expose hydroxyl groups. The activated surface was further grafted with ALP both via silanization and also via direct grafting to the surface active hydroxyl groups. Enzymatic activity of grafted samples were measured by means of UV-vis spectroscopy before and after ultrasonic washing in TRIS-HCl buffer solution. In vitro inorganic bioactivity was investigated by soaking the scaffolds after the different steps of functionalization in a simulated body fluid (SBF). SEM observations allowed the monitoring of the scaffold morphology and surface chemical composition after soaking in SBF. The presence of ALP enhanced the in vitro inorganic bioactivity of the tested material.

  15. 3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces

    PubMed Central

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2016-01-01

    Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity. PMID:27040483

  16. 3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces

    NASA Astrophysics Data System (ADS)

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2016-04-01

    Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity.

  17. 3D printing optical watermark algorithms based on the combination of DWT and Fresnel transformation

    NASA Astrophysics Data System (ADS)

    Hu, Qi; Duan, Jin; Zhai, Di; Wang, LiNing

    2016-10-01

    With the continuous development of industrialization, 3D printing technology steps into individuals' lives gradually, however, the consequential security issue has become the urgent problem which is imminent. This paper proposes the 3D printing optical watermark algorithms based on the combination of DWT and Fresnel transformation and utilizes authorized key to restrict 3D model printing's permissions. Firstly, algorithms put 3D model into affine transform, and take the distance from the center of gravity to the vertex of 3D object in order to generate a one-dimensional discrete signal; then make this signal into wavelet transform and put the transformed coefficient into Fresnel transformation. Use math model to embed watermark information into it and finally generate 3D digital model with watermarking. This paper adopts VC++.NET and DIRECTX 9.0 SDK for combined developing and testing, and the results show that in fixed affine space, achieve the robustness in translation, revolving and proportion transforms of 3D model and better watermark-invisibility. The security and authorization of 3D model have been protected effectively.

  18. 3D Surface Profile and Color Stability of Tooth Colored Filling Materials after Bleaching

    PubMed Central

    Irawan, Bryant Anthony; Irawan, Stacey Natalie; Masudi, Sam'an Malik; Sukminingrum, Ninin; Alam, Mohammad Khursheed

    2015-01-01

    This study aims to evaluate the effects of vital tooth bleaching with carbamide peroxide home bleaching and in-office bleaching on the color stability and 3D surface profile of dental restorative filling materials. Thirty discs (n = 30) measure 6 mm in diameter and 2 mm thick for each of three restorative materials. These are nanofilled composite Filtek Z350 XT, the submicron composite Estelite Σ Quick, and nanofilled glass ionomer Ketac N100 nanoionomer and were fabricated in shade A2. Each group was further divided into three subgroups (n = 10): subgroup A (Opalescence PF), subgroup B (Opalescence Boost in-office bleaching), and subgroup C (distilled water) serving as control. Samples were bleached according to the manufacturer's instructions for a period of two weeks. The Commission Internationale de L'Eclairage (CIE L*, a*, b*) system was chosen for image processing, while 3D surface profile was tested with atomic force microscopy (AFM). Statistical analyses were performed with the Mann-Whitney tests and Krusal-Wallis with a P value of ≤0.05. The three restorative materials showed significant color changes (ΔE); P ≤ 0.05. In diminishing order, the mean color changes recorded were Estelite Σ (3.82 ± 1.6) > Ketac Nano (2.97 ± 1.2) > Filtek Z350 XT (2.25 ± 1.0). However, none of the tested materials showed statistically significant changes in surface roughness; P > 0.05. PMID:26558267

  19. M3D (Media 3D): a new programming language for web-based virtual reality in E-Learning and Edutainment

    NASA Astrophysics Data System (ADS)

    Chakaveh, Sepideh; Skaley, Detlef; Laine, Patricia; Haeger, Ralf; Maad, Soha

    2003-01-01

    Today, interactive multimedia educational systems are well established, as they prove useful instruments to enhance one's learning capabilities. Hitherto, the main difficulty with almost all E-Learning systems was latent in the rich media implementation techniques. This meant that each and every system should be created individually as reapplying the media, be it only a part, or the whole content was not directly possible, as everything must be applied mechanically i.e. by hand. Consequently making E-learning systems exceedingly expensive to generate, both in time and money terms. Media-3D or M3D is a new platform independent programming language, developed at the Fraunhofer Institute Media Communication to enable visualisation and simulation of E-Learning multimedia content. M3D is an XML-based language, which is capable of distinguishing between the3D models from that of the 3D scenes, as well as handling provisions for animations, within the programme. Here we give a technical account of M3D programming language and briefly describe two specific application scenarios where M3D is applied to create virtual reality E-Learning content for training of technical personnel.

  20. Genome3D: a UK collaborative project to annotate genomic sequences with predicted 3D structures based on SCOP and CATH domains

    PubMed Central

    Lewis, Tony E.; Sillitoe, Ian; Andreeva, Antonina; Blundell, Tom L.; Buchan, Daniel W.A.; Chothia, Cyrus; Cuff, Alison; Dana, Jose M.; Filippis, Ioannis; Gough, Julian; Hunter, Sarah; Jones, David T.; Kelley, Lawrence A.; Kleywegt, Gerard J.; Minneci, Federico; Mitchell, Alex; Murzin, Alexey G.; Ochoa-Montaño, Bernardo; Rackham, Owen J. L.; Smith, James; Sternberg, Michael J. E.; Velankar, Sameer; Yeats, Corin; Orengo, Christine

    2013-01-01

    Genome3D, available at http://www.genome3d.eu, is a new collaborative project that integrates UK-based structural resources to provide a unique perspective on sequence–structure–function relationships. Leading structure prediction resources (DomSerf, FUGUE, Gene3D, pDomTHREADER, Phyre and SUPERFAMILY) provide annotations for UniProt sequences to indicate the locations of structural domains (structural annotations) and their 3D structures (structural models). Structural annotations and 3D model predictions are currently available for three model genomes (Homo sapiens, E. coli and baker’s yeast), and the project will extend to other genomes in the near future. As these resources exploit different strategies for predicting structures, the main aim of Genome3D is to enable comparisons between all the resources so that biologists can see where predictions agree and are therefore more trusted. Furthermore, as these methods differ in whether they build their predictions using CATH or SCOP, Genome3D also contains the first official mapping between these two databases. This has identified pairs of similar superfamilies from the two resources at various degrees of consensus (532 bronze pairs, 527 silver pairs and 370 gold pairs). PMID:23203986

  1. 3D nano surface profilometry by combining the photonic nanojet with interferometry

    NASA Astrophysics Data System (ADS)

    Montgomery, P. C.; Lecler, S.; Leong-Hoï, A.; Pfeiffer, P.

    2017-01-01

    Interference microscopy has become a standard technique for measuring microscopic surface roughness, being rapid, non-contact and having a high nanometric axial resolution. Nonetheless, a limitation is the lateral resolution of λ/2 due to diffraction. Amongst the many recently developed techniques for improving the lateral resolution in unlabelled far field imaging, the use of microspheres placed on the sample has recently been extended from 2D imaging to 3D measurement by combining it with interferometry. In the present work, results are shown of combining the high lateral resolution of the photonic nanojet produced by the microsphere with interference microscopy to achieve sub-diffraction limited lateral resolution with nanometric axial resolution. This is achieved by imaging through a microsphere placed on top of the sample in front of the interference objective in a Linnik setup. Results of the 3D measurements of narrow gratings through the microsphere are presented, that are not observable with the same objective in air since they are below the resolution limit. Simulations of the interaction between the photonic jet and the grating leads to a basic understanding of the image formation. This new technique opens new possibilities for high resolution characterization in nanomaterials and the biological sciences.

  2. 3D Simulation of Missing Pellet Surface Defects in Light Water Reactor Fuel Rods

    SciTech Connect

    B.W. Spencer; J.D. Hales; S.R. Novascone; R.L. Williamson

    2012-09-01

    The cladding on light water reactor (LWR) fuel rods provides a stable enclosure for fuel pellets and serves as a first barrier against fission product release. Consequently, it is important to design fuel to prevent cladding failure due to mechanical interactions with fuel pellets. Cladding stresses can be effectively limited by controlling power increase rates. However, it has been shown that local geometric irregularities caused by manufacturing defects known as missing pellet surfaces (MPS) in fuel pellets can lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. Nuclear fuel performance codes commonly use a 1.5D (axisymmetric, axially-stacked, one-dimensional radial) or 2D axisymmetric representation of the fuel rod. To study the effects of MPS defects, results from 1.5D or 2D fuel performance analyses are typically mapped to thermo-mechanical models that consist of a 2D plane-strain slice or a full 3D representation of the geometry of the pellet and clad in the region of the defect. The BISON fuel performance code developed at Idaho National Laboratory employs either a 2D axisymmetric or 3D representation of the full fuel rod. This allows for a computational model of the full fuel rod to include local defects. A 3D thermo-mechanical model is used to simulate the global fuel rod behavior, and includes effects on the thermal and mechanical behavior of the fuel due to accumulation of fission products, fission gas production and release, and the effects of fission gas accumulation on thermal conductivity across the fuel-clad gap. Local defects can be modeled simply by including them in the 3D fuel rod model, without the need for mapping between two separate models. This allows for the complete set of physics used in a fuel performance analysis to be included naturally in the computational representation of the local defect, and for the effects of the

  3. Evaluation of feature-based 3-d registration of probabilistic volumetric scenes

    NASA Astrophysics Data System (ADS)

    Restrepo, Maria I.; Ulusoy, Ali O.; Mundy, Joseph L.

    2014-12-01

    Automatic estimation of the world surfaces from aerial images has seen much attention and progress in recent years. Among current modeling technologies, probabilistic volumetric models (PVMs) have evolved as an alternative representation that can learn geometry and appearance in a dense and probabilistic manner. Recent progress, in terms of storage and speed, achieved in the area of volumetric modeling, opens the opportunity to develop new frameworks that make use of the PVM to pursue the ultimate goal of creating an entire map of the earth, where one can reason about the semantics and dynamics of the 3-d world. Aligning 3-d models collected at different time-instances constitutes an important step for successful fusion of large spatio-temporal information. This paper evaluates how effectively probabilistic volumetric models can be aligned using robust feature-matching techniques, while considering different scenarios that reflect the kind of variability observed across aerial video collections from different time instances. More precisely, this work investigates variability in terms of discretization, resolution and sampling density, errors in the camera orientation, and changes in illumination and geographic characteristics. All results are given for large-scale, outdoor sites. In order to facilitate the comparison of the registration performance of PVMs to that of other 3-d reconstruction techniques, the registration pipeline is also carried out using Patch-based Multi-View Stereo (PMVS) algorithm. Registration performance is similar for scenes that have favorable geometry and the appearance characteristics necessary for high quality reconstruction. In scenes containing trees, such as a park, or many buildings, such as a city center, registration performance is significantly more accurate when using the PVM.

  4. Holographic microscopy and microfluidics platform for measuring wall stress and 3D flow over surfaces textured by micro-pillars

    PubMed Central

    Bocanegra Evans, Humberto; Gorumlu, Serdar; Aksak, Burak; Castillo, Luciano; Sheng, Jian

    2016-01-01

    Understanding how fluid flow interacts with micro-textured surfaces is crucial for a broad range of key biological processes and engineering applications including particle dispersion, pathogenic infections, and drag manipulation by surface topology. We use high-speed digital holographic microscopy (DHM) in combination with a correlation based de-noising algorithm to overcome the optical interference generated by surface roughness and to capture a large number of 3D particle trajectories in a microfluidic channel with one surface patterned with micropillars. It allows us to obtain a 3D ensembled velocity field with an uncertainty of 0.06% and 2D wall shear stress distribution at the resolution of ~65 μPa. Contrary to laminar flow in most microfluidics, we find that the flow is three-dimensional and complex for the textured microchannel. While the micropillars affect the velocity flow field locally, their presence is felt globally in terms of wall shear stresses at the channel walls. These findings imply that micro-scale mixing and wall stress sensing/manipulation can be achieved through hydro-dynamically smooth but topologically rough micropillars. PMID:27353632

  5. SU-E-J-55: End-To-End Effectiveness Analysis of 3D Surface Image Guided Voluntary Breath-Holding Radiotherapy for Left Breast

    SciTech Connect

    Lin, M; Feigenberg, S

    2015-06-15

    Purpose To evaluate the effectiveness of using 3D-surface-image to guide breath-holding (BH) left-side breast treatment. Methods Two 3D surface image guided BH procedures were implemented and evaluated: normal-BH, taking BH at a comfortable level, and deep-inspiration-breath-holding (DIBH). A total of 20 patients (10 Normal-BH and 10 DIBH) were recruited. Patients received a BH evaluation using a commercialized 3D-surface- tracking-system (VisionRT, London, UK) to quantify the reproducibility of BH positions prior to CT scan. Tangential 3D/IMRT plans were conducted. Patients were initially setup under free-breathing (FB) condition using the FB surface obtained from the untaged CT to ensure a correct patient position. Patients were then guided to reach the planned BH position using the BH surface obtained from the BH CT. Action-levels were set at each phase of treatment process based on the information provided by the 3D-surface-tracking-system for proper interventions (eliminate/re-setup/ re-coaching). We reviewed the frequency of interventions to evaluate its effectiveness. The FB-CBCT and port-film were utilized to evaluate the accuracy of 3D-surface-guided setups. Results 25% of BH candidates with BH positioning uncertainty > 2mm are eliminated prior to CT scan. For >90% of fractions, based on the setup deltas from3D-surface-trackingsystem, adjustments of patient setup are needed after the initial-setup using laser. 3D-surface-guided-setup accuracy is comparable as CBCT. For the BH guidance, frequency of interventions (a re-coaching/re-setup) is 40%(Normal-BH)/91%(DIBH) of treatments for the first 5-fractions and then drops to 16%(Normal-BH)/46%(DIBH). The necessity of re-setup is highly patient-specific for Normal-BH but highly random among patients for DIBH. Overall, a −0.8±2.4 mm accuracy of the anterior pericardial shadow position was achieved. Conclusion 3D-surface-image technology provides effective intervention to the treatment process and ensures

  6. FGG-NUFFT-Based Method for Near-Field 3-D Imaging Using Millimeter Waves

    PubMed Central

    Kan, Yingzhi; Zhu, Yongfeng; Tang, Liang; Fu, Qiang; Pei, Hucheng

    2016-01-01

    In this paper, to deal with the concealed target detection problem, an accurate and efficient algorithm for near-field millimeter wave three-dimensional (3-D) imaging is proposed that uses a two-dimensional (2-D) plane antenna array. First, a two-dimensional fast Fourier transform (FFT) is performed on the scattered data along the antenna array plane. Then, a phase shift is performed to compensate for the spherical wave effect. Finally, fast Gaussian gridding based nonuniform FFT (FGG-NUFFT) combined with 2-D inverse FFT (IFFT) is performed on the nonuniform 3-D spatial spectrum in the frequency wavenumber domain to achieve 3-D imaging. The conventional method for near-field 3-D imaging uses Stolt interpolation to obtain uniform spatial spectrum samples and performs 3-D IFFT to reconstruct a 3-D image. Compared with the conventional method, our FGG-NUFFT based method is comparable in both efficiency and accuracy in the full sampled case and can obtain more accurate images with less clutter and fewer noisy artifacts in the down-sampled case, which are good properties for practical applications. Both simulation and experimental results demonstrate that the FGG-NUFFT-based near-field 3-D imaging algorithm can have better imaging performance than the conventional method for down-sampled measurements. PMID:27657066

  7. FGG-NUFFT-Based Method for Near-Field 3-D Imaging Using Millimeter Waves.

    PubMed

    Kan, Yingzhi; Zhu, Yongfeng; Tang, Liang; Fu, Qiang; Pei, Hucheng

    2016-09-19

    In this paper, to deal with the concealed target detection problem, an accurate and efficient algorithm for near-field millimeter wave three-dimensional (3-D) imaging is proposed that uses a two-dimensional (2-D) plane antenna array. First, a two-dimensional fast Fourier transform (FFT) is performed on the scattered data along the antenna array plane. Then, a phase shift is performed to compensate for the spherical wave effect. Finally, fast Gaussian gridding based nonuniform FFT (FGG-NUFFT) combined with 2-D inverse FFT (IFFT) is performed on the nonuniform 3-D spatial spectrum in the frequency wavenumber domain to achieve 3-D imaging. The conventional method for near-field 3-D imaging uses Stolt interpolation to obtain uniform spatial spectrum samples and performs 3-D IFFT to reconstruct a 3-D image. Compared with the conventional method, our FGG-NUFFT based method is comparable in both efficiency and accuracy in the full sampled case and can obtain more accurate images with less clutter and fewer noisy artifacts in the down-sampled case, which are good properties for practical applications. Both simulation and experimental results demonstrate that the FGG-NUFFT-based near-field 3-D imaging algorithm can have better imaging performance than the conventional method for down-sampled measurements.

  8. Porous Structures in Stacked, Crumpled and Pillared Graphene-Based 3D Materials

    PubMed Central

    Guo, Fei; Creighton, Megan; Chen, Yantao; Hurt, Robert; Külaots, Indrek

    2015-01-01

    Graphene, an atomically thin material with the theoretical surface area of 2600 m2g−1, has great potential in the fields of catalysis, separation, and gas storage if properly assembled into functional 3D materials at large scale. In ideal non-interacting ensembles of non-porous multilayer graphene plates, the surface area can be adequately estimated using the simple geometric law ~ 2600 m2g−1/N, where N is the number of graphene sheets per plate. Some processing operations, however, lead to secondary plate-plate stacking, folding, crumpling or pillaring, which give rise to more complex structures. Here we show that bulk samples of multilayer graphene plates stack in an irregular fashion that preserves the 2600/N surface area and creates regular slot-like pores with sizes that are multiples of the unit plate thickness. In contrast, graphene oxide deposits into films with massive area loss (2600 to 40 m2g−1) due to nearly perfect alignment and stacking during the drying process. Pillaring graphene oxide sheets by co-deposition of colloidal-phase particle-based spacers has the potential to partially restore the large monolayer surface. Surface areas as high as 1000 m2g−1 are demonstrated here through colloidal-phase deposition of graphene oxide with water-dispersible aryl-sulfonated ultrafine carbon black as a pillaring agent. PMID:26478597

  9. Experimental investigation and 3D-simulation of the ablated morphology of titanium surface using femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Liu, Dong; Chen, Chuansong; Man, Baoyuan; Meng, Xue; Sun, Yanna; Li, Feifei

    2015-12-01

    The femtosecond laser ablated morphology on titanium surface is investigated theoretically and experimentally. A three dimensional two temperature model (3D-TTM) is used to simulate the surface morphology of titanium sample which is irradiated by femtosecond laser pulses. The electron heat capacity and electron-phonon coupling coefficient of titanium (transition metal) are complex temperature dependent, so the two parameters are corrected based on the theory of electron density of states (DOS). The model is solved by the finite difference time domain (FDTD) method. The 3D temperature field near the target surface is achieved. The radius and depth of the ablated crater are obtained based on the temperature field. The evolutions of the crate's radius and depth with laser fluence are discussed and compared with the experimental results. It is found that the back-flow of the molten material and the deposition of the material vapor should be responsible for the little discrepancy between the simulated and experimental results. The present work makes a better understanding of the thermodynamic process of femtosecond laser ablating metal and meanwhile provides an effective method tool to predict the micro manufacturing process on metals with femtosecond laser.

  10. A novel graphene based nanocomposite for application in 3D flexible micro-supercapacitors

    NASA Astrophysics Data System (ADS)

    Marasso, S. L.; Rivolo, P.; Giardi, R.; Mombello, D.; Gigot, A.; Serrapede, M.; Benetto, S.; Enrico, A.; Cocuzza, M.; Tresso, E.; Pirri, C. F.

    2016-06-01

    In this work a hybrid graphene-based flexible micro-supercapacitor (MSC) exploiting a novel composite material was fabricated and extensively characterized. The MSC electrodes have been obtained from a synthesized composite aerogel of reduced graphene oxide and polycrystalline nanoparticles of molybdenum (IV) oxide (MoO2) and then dispersed in a solution containing poly(3,4-ethylenedioxythiophene) (PEDOT). Usually in MSCs the electrons have to percolate through the nanostructured Three-dimensional (3D) matrix in order to reach the collectors, made by metal thin films that provide electrical contacts only on the surface of active material. In the attempt to enable a more efficient charge transfer and to allow direct electrical contact without metal deposition, in this study a highly doped PEDOT acting both as current collector and as binder for the nanocomposite material has been employed. 3D MSCs were fabricated through a Lithographie, Galvanoformung, Abformung (LIGA)-like process to obtain high aspect ratio microstructures in polydimethylsiloxane replicas. Capacitance values of 94 F g-1 for the nanocomposite and of 14 mF cm-2 for the device were achieved. Moreover, bending test has demonstrated good performance preservation in a U shape conformation of the device.

  11. In Situ "Clickable" Zwitterionic Starch-Based Hydrogel for 3D Cell Encapsulation.

    PubMed

    Dong, Dianyu; Li, Junjie; Cui, Man; Wang, Jinmei; Zhou, Yuhang; Luo, Liu; Wei, Yufei; Ye, Lei; Sun, Hong; Yao, Fanglian

    2016-02-01

    Three-dimensional (3D) cell encapsulation in hydrogel provides superb methods to investigate the biochemical cues in directing cellular fate and behaviors outside the organism, the primary step of which is to establish suitable "blank platform" to mimic and simplify native ECM microenvironment. In this study, zwitterionic starch-based "clickable" hydrogels were fabricated via a "copper- and light- free" Michael-type "thiol-ene" addition reaction between acylated-modified sulfobetaine-derived starch (SB-ST-A) and dithiol-functionalized poly(ethylene glycol) (PEG-SH). By incorporating antifouling SB-ST and PEG, the hydrogel system would be excellently protected from nontarget protein adsorption to act as a "blank platform". The hydrogels could rapidly gel under physiological conditions in less than 7 min. Dynamic rheology experiments suggested the stiffness of the hydrogel was close to the native tissues, and the mechanical properties as well as the gelation times and swelling behaviors could be easily tuned by varying the precursor proportions. The protein and cell adhesion assays demonstrated that the hydrogel surface could effectively resist nonspecific protein and cell adhesion. The degradation study in vitro confirmed that the hydrogel was biodegradable. A549 cells encapsulated in the hydrogel maintained high viability (up to 93%) and started to proliferate in number and extend in morphology after 2 days' culture. These results indicated the hydrogel presented here could be a potential candidate as "blank platform" for 3D cell encapsulation and biochemical cues induced cellular behavior investigation in vitro.

  12. Key parameters in blood-surface interactions of 3D bioinspired ceramic materials.

    PubMed

    Díaz-Rodríguez, P; González, P; Serra, J; Landin, M

    2014-08-01

    Direct contact of materials with blood components may trigger numerous processes which ultimately lead to hemolysis, clot formation and recruitment of inflammatory cells. In this study, the blood-surface interactions for two inert bioinspired ceramic scaffolds obtained from natural resources; biomorphic carbon and silicon carbides (bioSiC) from different origins have been studied. The response of the blood in contact with carbon is well known, however little has been identified on the influence of their 3D porous structure. Moreover, to our knowledge, there is no reference in the literature about the hemocompatibility of biomorphic silicon carbide as a porous scaffold. The experimental results showed the surface energy to be crucial to evaluate the hemocompatibility of a material however the surface topography and material porosity are also parameters to be considered. Surface roughness modifies clot formation whereas for protein adsorption total sample porosity seems to be the key parameter to be considered for hydrophilic materials (biomorphic silicon carbides), while the size of the pores determines the hemolytic response.

  13. Modular optical topometric sensor for 3D acquisition of human body surfaces and long-term monitoring of variations.

    PubMed

    Bischoff, Guido; Böröcz, Zoltan; Proll, Christian; Kleinheinz, Johannes; von Bally, Gert; Dirksen, Dieter

    2007-08-01

    Optical topometric 3D sensors such as laser scanners and fringe projection systems allow detailed digital acquisition of human body surfaces. For many medical applications, however, not only the current shape is important, but also its changes, e.g., in the course of surgical treatment. In such cases, time delays of several months between subsequent measurements frequently occur. A modular 3D coordinate measuring system based on the fringe projection technique is presented that allows 3D coordinate acquisition including calibrated color information, as well as the detection and visualization of deviations between subsequent measurements. In addition, parameters describing the symmetry of body structures are determined. The quantitative results of the analysis may be used as a basis for objective documentation of surgical therapy. The system is designed in a modular way, and thus, depending on the object of investigation, two or three cameras with different capabilities in terms of resolution and color reproduction can be utilized to optimize the set-up.

  14. Investigation of 3D surface acoustic waves in granular media with 3-color digital holography

    NASA Astrophysics Data System (ADS)

    Leclercq, Mathieu; Picart, Pascal; Penelet, Guillaume; Tournat, Vincent

    2017-01-01

    This paper reports the implementation of digital color holography to investigate elastic waves propagating along a layer of a granular medium. The holographic set-up provides simultaneous recording and measurement of the 3D dynamic displacement at the surface. Full-field measurements of the acoustic amplitude and phase at different excitation frequencies are obtained. It is shown that the experimental data can be used to obtain the dispersion curve of the modes propagating in this granular medium layer. The experimental dispersion curve and that obtained from a finite element modeling of the problem are found to be in good agreement. In addition, full-field images of the interaction of an acoustic wave guided in the granular layer with a buried object are also shown.

  15. Automatic extraction of discontinuity orientation from rock mass surface 3D point cloud

    NASA Astrophysics Data System (ADS)

    Chen, Jianqin; Zhu, Hehua; Li, Xiaojun

    2016-10-01

    This paper presents a new method for extracting discontinuity orientation automatically from rock mass surface 3D point cloud. The proposed method consists of four steps: (1) automatic grouping of discontinuity sets using an improved K-means clustering method, (2) discontinuity segmentation and optimization, (3) discontinuity plane fitting using Random Sample Consensus (RANSAC) method, and (4) coordinate transformation of discontinuity plane. The method is first validated by the point cloud of a small piece of a rock slope acquired by photogrammetry. The extracted discontinuity orientations are compared with measured ones in the field. Then it is applied to a publicly available LiDAR data of a road cut rock slope at Rockbench repository. The extracted discontinuity orientations are compared with the method proposed by Riquelme et al. (2014). The results show that the presented method is reliable and of high accuracy, and can meet the engineering needs.

  16. Fruit bruise detection based on 3D meshes and machine learning technologies

    NASA Astrophysics Data System (ADS)

    Hu, Zilong; Tang, Jinshan; Zhang, Ping

    2016-05-01

    This paper studies bruise detection in apples using 3-D imaging. Bruise detection based on 3-D imaging overcomes many limitations of bruise detection based on 2-D imaging, such as low accuracy, sensitive to light condition, and so on. In this paper, apple bruise detection is divided into two parts: feature extraction and classification. For feature extraction, we use a framework that can directly extract local binary patterns from mesh data. For classification, we studies support vector machine. Bruise detection using 3-D imaging is compared with bruise detection using 2-D imaging. 10-fold cross validation is used to evaluate the performance of the two systems. Experimental results show that bruise detection using 3-D imaging can achieve better classification accuracy than bruise detection based on 2-D imaging.

  17. The fabrication of polymer-nanocone-based 3D Au nanoparticle array and its SERS performance

    NASA Astrophysics Data System (ADS)

    Zhao, Wenning; Wu, Yiyao; Liu, Xiaoguang; Xu, Yebin; Wang, Shuangbao; Xu, Zhimou

    2017-01-01

    By combining conical-pore-AAO template and NIL technology, we realized the transfer of three-dimensional nanoparticle array to polymer materials. Au nanoparticles were deposited on the surface of conical-pore-AAO template, then the nanostructure was duplicated onto the polymer wafer via NIL method and the nanoparticles were inlaid onto the nanocones. Polymer-nanocone-based 3D Au nanoparticle array was obtained. The product possesses excellent flexibility and transparency in visual and infrared range. As a new class of SERS substrate, the product exhibits excellent sensitivity and reproducibility. Compared with the traditional SERS substrates, it provides unique advantages, such as being flexible, transparent, lightweight, portable, easily handled and low cost.

  18. A Novel Multi-Purpose Matching Representation of Local 3D Surfaces: A Rotationally Invariant, Efficient, and Highly Discriminative Approach With an Adjustable Sensitivity.

    PubMed

    Al-Osaimi, Faisal R

    2016-02-01

    In this paper, a novel approach to local 3D surface matching representation suitable for a range of 3D vision applications is introduced. Local 3D surface patches around key points on the 3D surface are represented by 2D images such that the representing 2D images enjoy certain characteristics which positively impact the matching accuracy, robustness, and speed. First, the proposed representation is complete, in the sense, there is no information loss during their computation. Second, the 3DoF 2D representations are strictly invariant to all the 3DoF rotations. To optimally avail surface information, the sensitivity of the representations to surface information is adjustable. This also provides the proposed matching representation with the means to optimally adjust to a particular class of problems/applications or an acquisition technology. Each 2D matching representation is a sequence of adjustable integral kernels, where each kernel is efficiently computed from a triple of precise 3D curves (profiles) formed by intersecting three concentric spheres with the 3D surface. Robust techniques for sampling the profiles and establishing correspondences among them were devised. Based on the proposed matching representation, two techniques for the detection of key points were presented. The first is suitable for static images, while the second is suitable for 3D videos. The approach was tested on the face recognition grand challenge v2.0, the 3D twins expression challenge, and the Bosphorus data sets, and a superior face recognition performance was achieved. In addition, the proposed approach was used in object class recognition and tested on a Kinect data set.

  19. Optimized data processing for an optical 3D sensor based on flying triangulation

    NASA Astrophysics Data System (ADS)

    Ettl, Svenja; Arold, Oliver; Häusler, Gerd; Gurov, Igor; Volkov, Mikhail

    2013-05-01

    We present data processing methods for an optical 3D sensor based on the measurement principle "Flying Triangulation". The principle enables a motion-robust acquisition of the 3D shape of even complex objects: A hand-held sensor is freely guided around the object while real-time feedback of the measurement progress is delivered during the captioning. Although of high precision, the resulting 3D data usually may exhibit some weaknesses: e.g. outliers might be present and the data size might be too large. We describe the measurement principle and the data processing and conclude with measurement results.

  20. A novel 3D wavelet based filter for visualizing features in noisy biological data

    SciTech Connect

    Moss, W C; Haase, S; Lyle, J M; Agard, D A; Sedat, J W

    2005-01-05

    We have developed a 3D wavelet-based filter for visualizing structural features in volumetric data. The only variable parameter is a characteristic linear size of the feature of interest. The filtered output contains only those regions that are correlated with the characteristic size, thus denoising the image. We demonstrate the use of the filter by applying it to 3D data from a variety of electron microscopy samples including low contrast vitreous ice cryogenic preparations, as well as 3D optical microscopy specimens.

  1. A Little Knowledge of Ground Motion: Explaining 3-D Physics-Based Modeling to Engineers

    NASA Astrophysics Data System (ADS)

    Porter, K.

    2014-12-01

    Users of earthquake planning scenarios require the ground-motion map to be credible enough to justify costly planning efforts, but not all ground-motion maps are right for all uses. There are two common ways to create a map of ground motion for a hypothetical earthquake. One approach is to map the median shaking estimated by empirical attenuation relationships. The other uses 3-D physics-based modeling, in which one analyzes a mathematical model of the earth's crust near the fault rupture and calculates the generation and propagation of seismic waves from source to ground surface by first principles. The two approaches produce different-looking maps. The more-familiar median maps smooth out variability and correlation. Using them in a planning scenario can lead to a systematic underestimation of damage and loss, and could leave a community underprepared for realistic shaking. The 3-D maps show variability, including some very high values that can disconcert non-scientists. So when the USGS Science Application for Risk Reduction's (SAFRR) Haywired scenario project selected 3-D maps, it was necessary to explain to scenario users—especially engineers who often use median maps—the differences, advantages, and disadvantages of the two approaches. We used authority, empirical evidence, and theory to support our choice. We prefaced our explanation with SAFRR's policy of using the best available earth science, and cited the credentials of the maps' developers and the reputation of the journal in which they published the maps. We cited recorded examples from past earthquakes of extreme ground motions that are like those in the scenario map. We explained the maps on theoretical grounds as well, explaining well established causes of variability: directivity, basin effects, and source parameters. The largest mapped motions relate to potentially unfamiliar extreme-value theory, so we used analogies to human longevity and the average age of the oldest person in samples of

  2. Evaluating Dense 3d Reconstruction Software Packages for Oblique Monitoring of Crop Canopy Surface

    NASA Astrophysics Data System (ADS)

    Brocks, S.; Bareth, G.

    2016-06-01

    Crop Surface Models (CSMs) are 2.5D raster surfaces representing absolute plant canopy height. Using multiple CMSs generated from data acquired at multiple time steps, a crop surface monitoring is enabled. This makes it possible to monitor crop growth over time and can be used for monitoring in-field crop growth variability which is useful in the context of high-throughput phenotyping. This study aims to evaluate several software packages for dense 3D reconstruction from multiple overlapping RGB images on field and plot-scale. A summer barley field experiment located at the Campus Klein-Altendorf of University of Bonn was observed by acquiring stereo images from an oblique angle using consumer-grade smart cameras. Two such cameras were mounted at an elevation of 10 m and acquired images for a period of two months during the growing period of 2014. The field experiment consisted of nine barley cultivars that were cultivated in multiple repetitions and nitrogen treatments. Manual plant height measurements were carried out at four dates during the observation period. The software packages Agisoft PhotoScan, VisualSfM with CMVS/PMVS2 and SURE are investigated. The point clouds are georeferenced through a set of ground control points. Where adequate results are reached, a statistical analysis is performed.

  3. Tuning 3D topography on biomimetic surface for efficient self-cleaning and microfluidic manipulation

    NASA Astrophysics Data System (ADS)

    Guan, Wei-Sheng; Huang, Han-Xiong; Chen, An-Fu

    2015-03-01

    Currently, micro-/nanotopography on polymeric replica is generally limited to 2D when a mechanical demolding approach is applied. In this work, one-step replication of bio-inspired 3D topography is achieved using microinjection compression molding with novel dual-layer molds. Using a proposed flexible template, the replica topography and wettability are highly tunable during molding. Moreover, dual-scale topography on the mold is developed by coating the micropatterned insert with submicron silica particles. Contact angle and roll-off angle measurements indicate the lotus leaf, rose petal and rice leaf effects on biomimetic surfaces. Among the three kinds of surfaces, the petal-inspired surface possesses the superior performance in self-cleaning submicron contaminants and mechanical robustness, which is highly correlated to the low roughness-induced adhesive superhydrophobicity and the absence of fragile submicron-/nanostructure, respectively. Furthermore, a multi-layer mold structure is proposed for fabricating the open microfluidic devices. The embedment of the hydrophilic and hydrophobic silica particles in the microstructured open channel and the hydrophobic silica particles in the background area during replication renders the wettability contrast sharp, realizing the self-driven flow of microfluid confined within the open microchannel.

  4. Comparative validation of single-shot optical techniques for laparoscopic 3-D surface reconstruction.

    PubMed

    Maier-Hein, L; Groch, A; Bartoli, A; Bodenstedt, S; Boissonnat, G; Chang, P-L; Clancy, N T; Elson, D S; Haase, S; Heim, E; Hornegger, J; Jannin, P; Kenngott, H; Kilgus, T; Müller-Stich, B; Oladokun, D; Röhl, S; Dos Santos, T R; Schlemmer, H-P; Seitel, A; Speidel, S; Wagner, M; Stoyanov, D

    2014-10-01

    Intra-operative imaging techniques for obtaining the shape and morphology of soft-tissue surfaces in vivo are a key enabling technology for advanced surgical systems. Different optical techniques for 3-D surface reconstruction in laparoscopy have been proposed, however, so far no quantitative and comparative validation has been performed. Furthermore, robustness of the methods to clinically important factors like smoke or bleeding has not yet been assessed. To address these issues, we have formed a joint international initiative with the aim of validating different state-of-the-art passive and active reconstruction methods in a comparative manner. In this comprehensive in vitro study, we investigated reconstruction accuracy using different organs with various shape and texture and also tested reconstruction robustness with respect to a number of factors like the pose of the endoscope as well as the amount of blood or smoke present in the scene. The study suggests complementary advantages of the different techniques with respect to accuracy, robustness, point density, hardware complexity and computation time. While reconstruction accuracy under ideal conditions was generally high, robustness is a remaining issue to be addressed. Future work should include sensor fusion and in vivo validation studies in a specific clinical context. To trigger further research in surface reconstruction, stereoscopic data of the study will be made publically available at www.open-CAS.com upon publication of the paper.

  5. Fast and Precise 3D Fluorophore Localization based on Gradient Fitting

    PubMed Central

    Ma, Hongqiang; Xu, Jianquan; Jin, Jingyi; Gao, Ying; Lan, Li; Liu, Yang

    2015-01-01

    Astigmatism imaging approach has been widely used to encode the fluorophore’s 3D position in single-particle tracking and super-resolution localization microscopy. Here, we present a new high-speed localization algorithm based on gradient fitting to precisely decode the 3D subpixel position of the fluorophore. This algebraic algorithm determines the center of the fluorescent emitter by finding the position with the best-fit gradient direction distribution to the measured point spread function (PSF), and can retrieve the 3D subpixel position of the fluorophore in a single iteration. Through numerical simulation and experiments with mammalian cells, we demonstrate that our algorithm yields comparable localization precision to the traditional iterative Gaussian function fitting (GF) based method, while exhibits over two orders-of-magnitude faster execution speed. Our algorithm is a promising high-speed analyzing method for 3D particle tracking and super-resolution localization microscopy. PMID:26390959

  6. Simulation of the 3D viscoelastic free surface flow by a parallel corrected particle scheme

    NASA Astrophysics Data System (ADS)

    Jin-Lian, Ren; Tao, Jiang

    2016-02-01

    In this work, the behavior of the three-dimensional (3D) jet coiling based on the viscoelastic Oldroyd-B model is investigated by a corrected particle scheme, which is named the smoothed particle hydrodynamics with corrected symmetric kernel gradient and shifting particle technique (SPH_CS_SP) method. The accuracy and stability of SPH_CS_SP method is first tested by solving Poiseuille flow and Taylor-Green flow. Then the capacity for the SPH_CS_SP method to solve the viscoelastic fluid is verified by the polymer flow through a periodic array of cylinders. Moreover, the convergence of the SPH_CS_SP method is also investigated. Finally, the proposed method is further applied to the 3D viscoelastic jet coiling problem, and the influences of macroscopic parameters on the jet coiling are discussed. The numerical results show that the SPH_CS_SP method has higher accuracy and better stability than the traditional SPH method and other corrected SPH method, and can improve the tensile instability. Project supported by the Natural Science Foundation of Jiangsu Province, China (Grant Nos. BK20130436 and BK20150436) and the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province, China (Grant No. 15KJB110025).

  7. Event-Based 3D Motion Flow Estimation Using 4D Spatio Temporal Subspaces Properties.

    PubMed

    Ieng, Sio-Hoi; Carneiro, João; Benosman, Ryad B

    2016-01-01

    State of the art scene flow estimation techniques are based on projections of the 3D motion on image using luminance-sampled at the frame rate of the cameras-as the principal source of information. We introduce in this paper a pure time based approach to estimate the flow from 3D point clouds primarily output by neuromorphic event-based stereo camera rigs, or by any existing 3D depth sensor even if it does not provide nor use luminance. This method formulates the scene flow problem by applying a local piecewise regularization of the scene flow. The formulation provides a unifying framework to estimate scene flow from synchronous and asynchronous 3D point clouds. It relies on the properties of 4D space time using a decomposition into its subspaces. This method naturally exploits the properties of the neuromorphic asynchronous event based vision sensors that allows continuous time 3D point clouds reconstruction. The approach can also handle the motion of deformable object. Experiments using different 3D sensors are presented.

  8. Event-Based 3D Motion Flow Estimation Using 4D Spatio Temporal Subspaces Properties

    PubMed Central

    Ieng, Sio-Hoi; Carneiro, João; Benosman, Ryad B.

    2017-01-01

    State of the art scene flow estimation techniques are based on projections of the 3D motion on image using luminance—sampled at the frame rate of the cameras—as the principal source of information. We introduce in this paper a pure time based approach to estimate the flow from 3D point clouds primarily output by neuromorphic event-based stereo camera rigs, or by any existing 3D depth sensor even if it does not provide nor use luminance. This method formulates the scene flow problem by applying a local piecewise regularization of the scene flow. The formulation provides a unifying framework to estimate scene flow from synchronous and asynchronous 3D point clouds. It relies on the properties of 4D space time using a decomposition into its subspaces. This method naturally exploits the properties of the neuromorphic asynchronous event based vision sensors that allows continuous time 3D point clouds reconstruction. The approach can also handle the motion of deformable object. Experiments using different 3D sensors are presented. PMID:28220057

  9. Receptor-based 3D-QSAR in Drug Design: Methods and Applications in Kinase Studies.

    PubMed

    Fang, Cheng; Xiao, Zhiyan

    2016-01-01

    Receptor-based 3D-QSAR strategy represents a superior integration of structure-based drug design (SBDD) and three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis. It combines the accurate prediction of ligand poses by the SBDD approach with the good predictability and interpretability of statistical models derived from the 3D-QSAR approach. Extensive efforts have been devoted to the development of receptor-based 3D-QSAR methods and two alternative approaches have been exploited. One associates with computing the binding interactions between a receptor and a ligand to generate structure-based descriptors for QSAR analyses. The other concerns the application of various docking protocols to generate optimal ligand poses so as to provide reliable molecular alignments for the conventional 3D-QSAR operations. This review highlights new concepts and methodologies recently developed in the field of receptorbased 3D-QSAR, and in particular, covers its application in kinase studies.

  10. 3D Face Recognition Based on Multiple Keypoint Descriptors and Sparse Representation

    PubMed Central

    Zhang, Lin; Ding, Zhixuan; Li, Hongyu; Shen, Ying; Lu, Jianwei

    2014-01-01

    Recent years have witnessed a growing interest in developing methods for 3D face recognition. However, 3D scans often suffer from the problems of missing parts, large facial expressions, and occlusions. To be useful in real-world applications, a 3D face recognition approach should be able to handle these challenges. In this paper, we propose a novel general approach to deal with the 3D face recognition problem by making use of multiple keypoint descriptors (MKD) and the sparse representation-based classification (SRC). We call the proposed method 3DMKDSRC for short. Specifically, with 3DMKDSRC, each 3D face scan is represented as a set of descriptor vectors extracted from keypoints by meshSIFT. Descriptor vectors of gallery samples form the gallery dictionary. Given a probe 3D face scan, its descriptors are extracted at first and then its identity can be determined by using a multitask SRC. The proposed 3DMKDSRC approach does not require the pre-alignment between two face scans and is quite robust to the problems of missing data, occlusions and expressions. Its superiority over the other leading 3D face recognition schemes has been corroborated by extensive experiments conducted on three benchmark databases, Bosphorus, GavabDB, and FRGC2.0. The Matlab source code for 3DMKDSRC and the related evaluation results are publicly available at http://sse.tongji.edu.cn/linzhang/3dmkdsrcface/3dmkdsrc.htm. PMID:24940876

  11. Electro-holography display using computer generated hologram of 3D objects based on projection spectra

    NASA Astrophysics Data System (ADS)

    Huang, Sujuan; Wang, Duocheng; He, Chao

    2012-11-01

    A new method of synthesizing computer-generated hologram of three-dimensional (3D) objects is proposed from their projection images. A series of projection images of 3D objects are recorded with one-dimensional azimuth scanning. According to the principles of paraboloid of revolution in 3D Fourier space and 3D central slice theorem, spectra information of 3D objects can be gathered from their projection images. Considering quantization error of horizontal and vertical directions, the spectrum information from each projection image is efficiently extracted in double circle and four circles shape, to enhance the utilization of projection spectra. Then spectra information of 3D objects from all projection images is encoded into computer-generated hologram based on Fourier transform using conjugate-symmetric extension. The hologram includes 3D information of objects. Experimental results for numerical reconstruction of the CGH at different distance validate the proposed methods and show its good performance. Electro-holographic reconstruction can be realized by using an electronic addressing reflective liquid-crystal display (LCD) spatial light modulator. The CGH from the computer is loaded onto the LCD. By illuminating a reference light from a laser source to the LCD, the amplitude and phase information included in the CGH will be reconstructed due to the diffraction of the light modulated by the LCD.

  12. 3D face recognition based on multiple keypoint descriptors and sparse representation.

    PubMed

    Zhang, Lin; Ding, Zhixuan; Li, Hongyu; Shen, Ying; Lu, Jianwei

    2014-01-01

    Recent years have witnessed a growing interest in developing methods for 3D face recognition. However, 3D scans often suffer from the problems of missing parts, large facial expressions, and occlusions. To be useful in real-world applications, a 3D face recognition approach should be able to handle these challenges. In this paper, we propose a novel general approach to deal with the 3D face recognition problem by making use of multiple keypoint descriptors (MKD) and the sparse representation-based classification (SRC). We call the proposed method 3DMKDSRC for short. Specifically, with 3DMKDSRC, each 3D face scan is represented as a set of descriptor vectors extracted from keypoints by meshSIFT. Descriptor vectors of gallery samples form the gallery dictionary. Given a probe 3D face scan, its descriptors are extracted at first and then its identity can be determined by using a multitask SRC. The proposed 3DMKDSRC approach does not require the pre-alignment between two face scans and is quite robust to the problems of missing data, occlusions and expressions. Its superiority over the other leading 3D face recognition schemes has been corroborated by extensive experiments conducted on three benchmark databases, Bosphorus, GavabDB, and FRGC2.0. The Matlab source code for 3DMKDSRC and the related evaluation results are publicly available at http://sse.tongji.edu.cn/linzhang/3dmkdsrcface/3dmkdsrc.htm.

  13. Pep-3D-Search: a method for B-cell epitope prediction based on mimotope analysis

    PubMed Central

    Huang, Yan Xin; Bao, Yong Li; Guo, Shu Yan; Wang, Yan; Zhou, Chun Guang; Li, Yu Xin

    2008-01-01

    Background The prediction of conformational B-cell epitopes is one of the most important goals in immunoinformatics. The solution to this problem, even if approximate, would help in designing experiments to precisely map the residues of interaction between an antigen and an antibody. Consequently, this area of research has received considerable attention from immunologists, structural biologists and computational biologists. Phage-displayed random peptide libraries are powerful tools used to obtain mimotopes that are selected by binding to a given monoclonal antibody (mAb) in a similar way to the native epitope. These mimotopes can be considered as functional epitope mimics. Mimotope analysis based methods can predict not only linear but also conformational epitopes and this has been the focus of much research in recent years. Though some algorithms based on mimotope analysis have been proposed, the precise localization of the interaction site mimicked by the mimotopes is still a challenging task. Results In this study, we propose a method for B-cell epitope prediction based on mimotope analysis called Pep-3D-Search. Given the 3D structure of an antigen and a set of mimotopes (or a motif sequence derived from the set of mimotopes), Pep-3D-Search can be used in two modes: mimotope or motif. To evaluate the performance of Pep-3D-Search to predict epitopes from a set of mimotopes, 10 epitopes defined by crystallography were compared with the predicted results from a Pep-3D-Search: the average Matthews correlation oefficient (MCC), sensitivity and precision were 0.1758, 0.3642 and 0.6948. Compared with other available prediction algorithms, Pep-3D-Search showed comparable MCC, specificity and precision, and could provide novel, rational results. To verify the capability of Pep-3D-Search to align a motif sequence to a 3D structure for predicting epitopes, 6 test cases were used. The predictive performance of Pep-3D-Search was demonstrated to be superior to that of other

  14. A GIS Based 3D Online Decision Assistance System for Underground Energy Storage in Northern Germany

    NASA Astrophysics Data System (ADS)

    Nolde, M.; Schwanebeck, M.; Biniyaz, E.; Duttmann, R.

    2014-12-01

    We would like to present a GIS-based 3D online decision assistance system for underground energy storage. Its aim is to support the local land use planning authorities through pre-selection of possible sites for thermal, electrical and substantial underground energy storages. Since the extension of renewable energies has become legal requirement in Germany, the underground storing of superfluously produced green energy (such as during a heavy wind event) in the form of compressed air, gas or heated water has become increasingly important. However, the selection of suitable sites is a complex task. The assistance system uses data of geological features such as rock layers, salt caverns and faults enriched with attribute data such as rock porosity and permeability. This information is combined with surface data of the existing energy infrastructure, such as locations of wind and biogas stations, power line arrangement and cable capacity, and energy distribution stations. Furthermore, legal obligations such as protected areas on the surface and current underground mining permissions are used for the decision finding process. Not only the current situation but also prospective scenarios, such as expected growth in produced amount of energy are incorporated in the system. The decision process is carried out via the 'Analytic Hierarchy Process' (AHP) methodology of the 'Multi Object Decision Making' (MODM) approach. While the process itself is completely automated, the user has full control of the weighting of the different factors via the web interface. The system is implemented as an online 3D server GIS environment, with no software needed to be installed on the user side. The results are visualized as interactive 3d graphics. The implementation of the assistance system is based exclusively on free and open source software, and utilizes the 'Python' programming language in combination with current web technologies, such as 'HTML5', 'CSS3' and 'JavaScript'. It is

  15. 3-D Surface Depression Profiling Using High Frequency Focused Air-Coupled Ultrasonic Pulses

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Kautz, Harold E.; Abel, Phillip B.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

    1999-01-01

    Surface topography is an important variable in the performance of many industrial components and is normally measured with diamond-tip profilometry over a small area or using optical scattering methods for larger area measurement. This article shows quantitative surface topography profiles as obtained using only high-frequency focused air-coupled ultrasonic pulses. The profiles were obtained using a profiling system developed by NASA Glenn Research Center and Sonix, Inc (via a formal cooperative agreement). (The air transducers are available as off-the-shelf items from several companies.) The method is simple and reproducible because it relies mainly on knowledge and constancy of the sound velocity through the air. The air transducer is scanned across the surface and sends pulses to the sample surface where they are reflected back from the surface along the same path as the incident wave. Time-of-flight images of the sample surface are acquired and converted to depth/surface profile images using the simple relation (d = V*t/2) between distance (d), time-of-flight (t), and the velocity of sound in air (V). The system has the ability to resolve surface depression variations as small as 25 microns, is useable over a 1.4 mm vertical depth range, and can profile large areas only limited by the scan limits of the particular ultrasonic system. (Best-case depth resolution is 0.25 microns which may be achievable with improved isolation from vibration and air currents.) The method using an optimized configuration is reasonably rapid and has all quantitative analysis facilities on-line including 2-D and 3-D visualization capability, extreme value filtering (for faulty data), and leveling capability. Air-coupled surface profilometry is applicable to plate-like and curved samples. In this article, results are shown for several proof-of-concept samples, plastic samples burned in microgravity on the STS-54 space shuttle mission, and a partially-coated cylindrical ceramic

  16. 3D model-based catheter tracking for motion compensation in EP procedures

    NASA Astrophysics Data System (ADS)

    Brost, Alexander; Liao, Rui; Hornegger, Joachim; Strobel, Norbert

    2010-02-01

    Atrial fibrillation is the most common sustained heart arrhythmia and a leading cause of stroke. Its treatment by radio-frequency catheter ablation, performed using fluoroscopic image guidance, is gaining increasingly more importance. Two-dimensional fluoroscopic navigation can take advantage of overlay images derived from pre-operative 3-D data to add anatomical details otherwise not visible under X-ray. Unfortunately, respiratory motion may impair the utility of these static overlay images for catheter navigation. We developed an approach for image-based 3-D motion compensation as a solution to this problem. A bi-plane C-arm system is used to take X-ray images of a special circumferential mapping catheter from two directions. In the first step of the method, a 3-D model of the device is reconstructed. Three-dimensional respiratory motion at the site of ablation is then estimated by tracking the reconstructed catheter model in 3-D. This step involves bi-plane fluoroscopy and 2-D/3-D registration. Phantom data and clinical data were used to assess our model-based catheter tracking method. Experiments involving a moving heart phantom yielded an average 2-D tracking error of 1.4 mm and an average 3-D tracking error of 1.1 mm. Our evaluation of clinical data sets comprised 469 bi-plane fluoroscopy frames (938 monoplane fluoroscopy frames). We observed an average 2-D tracking error of 1.0 mm +/- 0.4 mm and an average 3-D tracking error of 0.8 mm +/- 0.5 mm. These results demonstrate that model-based motion-compensation based on 2-D/3-D registration is both feasible and accurate.

  17. Graphene Oxide-Based Electrode Inks for 3D-Printed Lithium-Ion Batteries.

    PubMed

    Fu, Kun; Wang, Yibo; Yan, Chaoyi; Yao, Yonggang; Chen, Yanan; Dai, Jiaqi; Lacey, Steven; Wang, Yanbin; Wan, Jiayu; Li, Tian; Wang, Zhengyang; Xu, Yue; Hu, Liangbing

    2016-04-06

    All-component 3D-printed lithium-ion batteries are fabricated by printing graphene-oxide-based composite inks and solid-state gel p