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This paper presents a new framework for an interactive segmentation of 3D images. The framework is based on a bimodal data structure defined by a region adjacency graph (RAG) that is associated with a hierarchical classification tree (HCT). The RAG provides information about the spatial and topological organisation of the extracted regions of the image. The HCT provides information about the similarities between the extracted regions of the image based on a predefined set of features. The first contribution of our work is the combination of a RAG and a HCT. An incremental system was obtained by defining operators that work with and on the RAG and the HCT. If a static predefined processing chain has been defined, these operators can be used in batch mode. If a scheduler is available, they can be used in an adaptive manner. Finally, if a user chooses the operator to be used after each step, the operators can be used interactively. The second contribution of this paper is the formal description of these operators. To give the user the ability to incrementally improve the segmentation, powerful visualisation of the segmentation state and interfaces have been proposed, an important advantage of the proposed framework. To validate the proposed framework, a user study has been conducted in a concrete case of texture segmentation. Our system obtains very satisfactory results even for complex volumetric textures, and helps real users by providing high quality segmentations. The system has been tested by specialists in sonography to segment 3D ultrasound images of the skin. Some examples of segmentation are presented to illustrate the benefit of the interactivity provided by our approach. [ABSTRACT FROM AUTHOR]

The importance of the image analysis with respect to industrial, medical, satellite image processing applications is gaining attention of many researchers in recent times. The recognition of faults present in the damaged images is vital for based applications. In this paper, we aim at developing a method for identifying faults that present in images. Our approach is based on the concept of Bit Plane Filter using convex hull methods. The bit plane filtering methods used to slice the given images to fix on the affected portion of the given images. The convex hull method is used to identify the control points that are needed for reconstruction of images. The performance of bit plane method is evaluated using simulation and it is proved that our approach produces better results when compared to current methods. [ABSTRACT FROM AUTHOR]

At present, a general belief is that viewing and 3-D images causes eye fatigue and discomfort because of the inconsistency between accommodation and convergence. However, our previous research found that both accommodation and convergence follow the position of virtual 3D objects synchronously. This was especially true in the case of young subjects aged in their 20s. In this study, we simultaneously measured variation of accommodation and convergence and their dependence on pupil diameter by changing the intensity of illumination as well as the brightness of the viewing screen. As a result, in the strongly lit environment, both accommodation and convergence nearly focused on the position of vertical objects. In a weakly lit environment, accommodation tends to focus on a position slightly father than that of convergence which is explained by the variation of pupil diameter. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To assess the value of multiplanar reformation (MPR) and three-dimensional multidetector computed tomography (MDCT) images in evaluating respiratory distress in neonates. Materials and methods: Sixteen neonates (⩽30days) who presented with respiratory distress (RD) and admitted in the neonatal intensive care unit of the Assuit university children hospital who were selected from a total of 1295 patients presented with RD in whom chest X-ray was inconclusive, so those 16 neonates underwent 64-rows MDCT in the period between November 2010 and November 2011. The recruited patients were sedated before examination and IV contrast medium administration was needed when there was suspected vascular anomaly. Scans were performed in supine position to cover the root of the neck down to the level of the adrenal glands. The images were sent to the workstation to be reviewed in the multiplanar and 3D images. Results: The final radiologic diagnoses included cystic adenomatoid malformation (n= 4, 25%), congenital lobar emphysema (n =1, 7%), pneumonia (n=5, 36%), hypoplastic lung (n =3, 22%), diaphragmatic hernia (n =2, 14%) and postoperative hydro-pneumothorax (n =1, 7%). Conclusion: The combination of fast speed, high spatial resolution, and enhanced quality of MPR and 3D images makes MDCT an ideal non-invasive method for evaluating surgical causes of neonatal respiratory distress. [Copyright &y& Elsevier]

Abstract: The features associated with modern synchrotron radiation machines (intense and coherent beams) result in a substantial extension of X-ray imaging capabilities in terms of spatial and temporal resolution, phase contrast and 3D images. This allows crystal growth-related information to be obtained which is not available otherwise. After briefly describing the main synchrotron radiation based imaging techniques of interest, we give original examples illustrating the new capabilities for crystal growth: characterisation of crystals grown for applications, such as ice tri-crystals produced for mechanical deformation studies; SiC; crystalline silicon for solar photovoltaic cells; in situ and in real time studies of quasicrystal growth (AlPdMn); and ultrafast tomography for the study of the growth of dendrites in metallic alloys. [Copyright &y& Elsevier]

With the progress of network transmission technology, the popularity of smart phones, the rise of social networking sites and micro-film, the birth of the fourth screen and the boom of 3D images and network industry, the media market has been shaped dramatically. As video sharing website is becoming more and more popular, it provides a great opportunity for creative young people to showcase their creativity and videos through these networks. This article is written for the young people who are interested in joining the imaging industry, summarizing the rapid development and transformation of the media industry. Hopefully it can provide some insights of the industry and inspire creative direction for young people. [ABSTRACT FROM AUTHOR]

The morphological tortuosity of a geodesic path in a medium can be defined as the ratio between its geodesic length and the Euclidean distance between its two extremities. Thus, the minimum tortuosity of all the geodesic paths into a medium in 2D or in 3D can be estimated by image processing methods using mathematical morphology. Considering a medium, the morphological tortuosities of its internal paths are estimated according to one direction, which is perpendicular to both starting and ending opposite extremities of the geodesic paths. The used algorithm estimates the morphological tortuosities from geodesic distance maps, which are obtained from geodesic propagations. The shape of the propagated structuring element used to estimate the geodesic distance maps on a discrete grid has a direct influence on the morphological tortuosity and has to be chosen very carefully. The results of our algorithm is an image with pixels p having a value equal to the length of the shortest path containing p and connected to two considered opposite boundaries A and B of the image. The analysis of the histogram of the morphological tortuosities gives access to their statistical distribution. Moreover, for each tortuosity the paths can be extracted from the original image, which highlights the location of them into the sample. However, these geodesic paths have to be reconstructed for further processing. The extraction, because applying a threshold on the tortuosities, results in disconnected components, especially for highly tortuous paths. This reconstruction consists in reconnecting these components to the geodesic path linking the two opposite faces, by means of a backtracking algorithm. [ABSTRACT FROM AUTHOR]

This paper describes the utility of three-dimensional (3D) images obtained with cone beam computed tomography (CBCT) for prediction of successful clinical outcome in two cases of intentional tooth replantation (IR). IR was performed for teeth affected by vertical root fracture and root perforation with local application of blood clot and oxy-tetracycline antibiotic. High-resolution 3D images demonstrated no evidence of ankylosis, but did reveal the presence of alveolar bone regeneration, suggesting a good long-term prognosis. Our observations in these cases suggested that local application of the above two materials might help to induce the regeneration of lost periodontal tissues in IR. [ABSTRACT FROM AUTHOR]

Open cell foams are a class of modern materials which is interesting for a wide variety of applications and which is not accessible to classical materialography based on 2d images. 3d imaging by micro computed tomography is a practicable alternative. Analysis of the resulting volume images is either based on a simple binarisation of the image or on so-called cell reconstruction by image processing. The first approach allows to estimate mean characteristics like the mean cell volume using the typical cell of a random spatial tessellation as model for the cell shape. The cell reconstruction allows estimation of empirical distributions of cell characteristics. This paper summarises the theoretical background for the first method, in particular estimation of the intrinsic volumes and their densities from discretized data and models for random spatial tessellations. The accuracy of the estimation method is assessed using the dilated edge systems of simulated random spatial tessellations. [ABSTRACT FROM AUTHOR]

Fractures of the proximal humerus are typical osteoporotic fractures of the elderly with an increasing incidence. Computed tomography (CT) with 3D reconstruction plays a more and more decisive role in the diagnostics because of an improved understanding of fractures in 3D images. The resulting correct fracture classification has significance for the decision of the best therapy procedure. Currently an extended version of the Codman classification with its four and more fragments is used to give additive information about varus or valgus dislocation, impression or distraction. The comparison of conservative and operative treatment showed no predominance of one of the procedures, therefore both strategies are justified. An operative treatment is recommended in complex fractures. Thus, early functional mobilization, early self-dependence and return to the activities of daily living are possible. Intramedullary nailing is advised in 2-part fractures, in dislocated multipart fractures locking plating or a primary reverse shoulder arthroplasty with refixation of the tuberosities in patients over 75 years. However, the improved plate and nail systems with polyaxiality, calcar screws, modern plate and nails designs as well as the possibility of arthroscopy-assisted nail implantation or plate removal combined with arthroscopic arthrolysis are innovative. [ABSTRACT FROM AUTHOR]

The article focuses on a study conducted to compare the reliability ofthree-dimensional (3D) images with dental casts and two-dimensional (2D) images and to investigate the differences among them. The study analyzed sample of pretreatment dental casts, 2D photographs, and 3D images of 70 patients with unilateral complete cleft lip and palate. The results revealed that 2D and 3D imaging of dental casts provides a valid alternative for actual study models for rating dental arch relationships.

Background: Further advances in modern microscopy are leading to teravoxel-sized tiled 3D images at high resolution, thus increasing the dimension of the stitching problem of at least two orders of magnitude. The existing software solutions do not seem adequate to address the additional requirements arising from these datasets, such as the minimization of memory usage and the need to process just a small portion of data. Results: We propose a free and fully automated 3D Stitching tool designed to match the special requirements coming out of teravoxel-sized tiled microscopy images that is able to stitch them in a reasonable time even on workstations with limited resources. The tool was tested on teravoxel-sized whole mouse brain images with micrometer resolution and it was also compared with the state-of-the-art stitching tools on megavoxel-sized publicy available datasets. This comparison confirmed that the solutions we adopted are suited for stitching very large images and also perform well on datasets with different characteristics. Indeed, some of the algorithms embedded in other stitching tools could be easily integrated in our framework if they turned out to be more effective on other classes of images. To this purpose, we designed a software architecture which separates the strategies that use efficiently memory resources from the algorithms which may depend on the characteristics of the acquired images. Conclusions: TeraStitcher is a free tool that enables the stitching of Teravoxel-sized tiled microscopy images even on workstations with relatively limited resources of memory (< 8 GB) and processing power. It exploits the knowledge of approximate tile positions and uses ad-hoc strategies and algorithms designed for such very large datasets. The produced images can be saved into a multiresolution representation to be efficiently retrieved and processed. We provide TeraStitcher both as standalone application and as plugin of the free software Vaa3D. [ABSTRACT FROM AUTHOR]

Abstract: Automated segmentation and analysis of tree-like structures from 3D medical images are important for many medical applications, such as those dealing with blood vasculature or lung airways. However, there is an absence of large databases of expert segmentations and analyses of such 3D medical images, which impedes the validation and training of proposed image analysis algorithms. In this work, we simulate volumetric images of vascular trees and generate the corresponding ground-truth segmentations, bifurcation locations, branch properties, and tree hierarchy. The tree generation is performed by iteratively growing a vascular structure based on a user-defined (possibly spatially varying) oxygen demand map. We describe the details of the algorithm and provide a variety of example results. [ABSTRACT FROM AUTHOR]

Abstract: The European Modular Cultivation System (EMCS) on the ISS allows long-term biological experiments, e.g. on plants. Video cameras provide near real-time 2D images from these experiments. A method to obtain 3D coordinates and stereoscopic images from these 2D images has been developed and is described in this paper. The procedure was developed to enhance the data output of the MULTIGEN-1 experiment in 2007. One of the main objectives of the experiment was to study growth movements of the Arabidopsis plants and the effect of gravity on these. 3D data were important during parts of the experiment and the paper presents the method developed to acquire 3D data, the accuracy of the data, limitations to the technique and ways to improve the accuracy. Sequences of 3D data obtained from the MULTIGEN-1 experiment are used to illustrate the potential of this newfound capability of the EMCS. In the experiment setup, a positional depth accuracy of about ±0.4mm for relative object distances and an absolute depth accuracy of about ±1.4mm for time dependent phenomena was reached. The ability to both view biological specimens in 3D as well as obtaining quantitative 3D data added greatly to the scientific output of the MULTIGEN-1 experiment. The uses of the technique to other researchers and their experiments are discussed. [Copyright &y& Elsevier]

Quantitative evaluation of axial vertebral rotation is essential for the determination of reference values in normal and pathological conditions and for understanding the mechanisms of the progression of spinal deformities. However, routine quantitative evaluation of axial vertebral rotation is difficult and error-prone due to the limitations of the observer, characteristics of the observed vertebral anatomy and specific imaging properties. The scope of this paper is to review the existing methods for quantitative evaluation of axial vertebral rotation from medical images along with all relevant publications, which may provide a valuable resource for studying the existing methods or developing new methods and evaluation strategies. The reviewed methods are divided into the methods for evaluation of axial vertebral rotation in 2D images and the methods for evaluation of axial vertebral rotation in 3D images. Key evaluation issues and future considerations, supported by the results of the overview, are also discussed. [ABSTRACT FROM AUTHOR]

In the framework of the Silent Wall ANR project, the CMM and the US2B are associated in order to characterize and to model fibrous media studying 3D images acquired with an X-Ray tomograph used by the US2B. The device can make 3D images of maximal 23043 voxels with resolutions in the range of 2 μm to 15 μm. Using mathematical morphology, measurements on file 3D X-Ray CT images are used to characterize materials. For example measuring the covariance on these images of an acoustic insulating material made of wooden fibres highlights the isotropy of the fibres orientations in the longitudinal planes which are perpendicular to the compression Oz axis. Moreover, it is possible to extract other morphological properties from these image processing methods such as the size distribution either of the fibres or of the pores by estimating the morphological opening granulometry of the considered medium. Using the theory of random sets introduced by Georges Matheron in the early 1970's, the aim of this work is to model such a fibrous material by parametric random media in 3D according to the prior knowledge of its morphological properties (covariance, porosity, size distributions, etc.). A Boolean model of random cylinders in 3D stacked in planes parallel to each other and perpendicular to the Oz compression axis is first considered. The granulometry results provide gamma distributions for the radii of the fibres. In addition, a uniform distribution of the orientations is chosen, according to the experimental isotropy measurements in the longitudinal planes. Finally the third statistical factor is the length distribution of the fibres which can be fitted by an exponential distribution. Thus it is possible to estimate the validity of this model first by trying to fit the experimental transverse and longitudinal covariances of the pores with the theoretical ones taking into account the statistical distributions of the dimensions of the random cylinders. The second method to validate the model consists in comparing morphological measurements (density profiles, covariance, opening granulometry, tortuosity, specific surface area) processed on real and on simulated media. [ABSTRACT FROM AUTHOR]

The aim of this paper is to provide a complete overview of the existing methods for quantitative evaluation of spinal curvature from medical images, and to summarize the relevant publications, which may not only assist in the introduction of other researchers to the field, but also be a valuable resource for studying the existing methods or developing new methods and evaluation strategies. Key evaluation issues and future considerations, supported by the results of the overview, are also discussed. [ABSTRACT FROM AUTHOR]

Little is known about how amyloid-β (Aβ) is deposited in relation to the complex ultrastructure of the brain. Here we combined serial section immunoelectron microscopy with 3D reconstruction to elucidate the spatial relationship between Aβ deposits and ultrastructurally identified cellular compartments. The analysis was performed in a transgenic mouse model with mutant presenilin-1, and mutant amyloid-β protein precursor (AβPP) and tau transgenes (3xTg-AD mice) and in aged dogs that develop Aβ plaques spontaneously. Reconstructions based on serial ultrathin sections of hippocampus (mice) or neocortex (dogs) that had been immunolabeled with Aβ (Aβ_{1-42}) antibodies showed that the organization of extracellular Aβ deposits is more complex than anticipated from light microscopic analyses. In both species, deposits were tightly associated with plasma membranes of pyramidal cell bodies and major dendrites. The deposits typically consisted of thin sheets as well as slender tendrils that climbed along the large caliber dendritic stems of pyramidal neurons. No preferential association was observed between Aβ deposits and thin dendritic branches or spines, nor was there any evidence of preferential accumulation of Aβ around synaptic contacts or glial processes. Our data suggest that plaque formation is a precisely orchestrated process that involves specialized domains of dendrosomatic plasma membranes. [ABSTRACT FROM AUTHOR]

• A mixture rule can predict the green density of Ti6Al4V/xAg powder mixes. • Pore filling by liquid phase drives the densification of Ti6Al4V/xAg composites. • Formation of Ti 2 Ag and TiAg is due to solid state diffusion into the Ti6Al4V matrix. • Isolated pores are obtained by adding 20 vol% of Ag into Ti6Al4V matrix. • Microhardness shows a linearly behavior with respect to the relative density. This work investigates the fabrication of Ti6Al4V/xAg composites processed by powder metallurgy. An atomized Ti6Al4V powder was blended with 0, 5, 10, 15 and 20 vol% of Ag particles, compacted in a die, and sintered above Ag melting point. The compressibility of the mixtures was analyzed, and the sintering kinetics was evaluated by dilatometry tests. The characterization of sintered samples by microtomography, SEM and diffraction analysis allowed determining the effect of Ag amount on the sintering process and on microstructural changes arising during sintering. The mechanical properties of sintered materials were investigated by microhardness. The compressibility of Ti6Al4V powder was found to be improved by adding soft Ag particles, which resulted in denser packing and larger plastic deformation. The densification during compaction can be predicted by Heckel model and the rule of mixture. It was next found that sintering was driven by volume diffusion in the solid state for Ag content lower than 10 vol% and involved a liquid phase for Ag content higher than 15 vol%. In the latter case, the liquid fills the interconnected pores under the action of capillary forces as the quantity of liquid increased. The microstructure was composed mainly of α-Ti, Ti 2 Ag, and Ag, which filled the pores between Ti6Al4V particles. Microhardness data showed a maximum value with 20 vol% of Ag. This value is similar to those reported for highly dense Ti6Al4V. It has thus proved that close to full-dense Ti6Al4V/20Ag composites can be processed by powder metallurgy. [ABSTRACT FROM AUTHOR]

During a Disaster Victims Identification (DVI) mission, international protocols rely on interdisciplinary work, especially between specialists from forensic imaging and anthropology. In case of air crashes or explosions, DVI units may face thousands of fragmented human remains (FHRs). The physical re-association of FHRs and the identification process is very complex and challenging, and relies upon expensive and destructive DNA analysis. A virtual re-association (VRA) of these fragments, using Multidetector Computed Tomography (MDCT), could be a helpful tool in forensic anthropology analysis, as it could assist in reducing the number of DNA samples. However, there is no standardized protocol for including such an approach into a DVI procedure. The aim of this study was to summarize and analyze existing techniques through a systematic review and to develop a protocol for virtual re-association of FHRs, adapted to the DVI context. A keyword-based literature search was conducted, focusing on the VRA methods using MDCT imaging and 3D surface scan methodology. Reviews and primary articles, published between 2005 and 2020 in the fields of forensic anthropology, paleoanthropology, archeology, and fracture reduction surgery were sorted out. A total of 45 publications were selected and analyzed based on their content and relevance. The results show that research on the re-association of FHRs increased significantly during the last five years. Seven steps regarding the MDCT-based method for the virtual re-association of FHRs could be identified: acquisition of 3D-images, segmentation of the MDCT-data, post-processing and surface generation, identification of intact and fracture surfaces, identification and registration of matching fragments, and validation of the re-association. The literature is surprisingly sparse regarding the FHRs re-association as a forensic tool, and mainly consists in case reports, whereas validated methods were presented in archeology and surgery publications. However, we were able to adapt the MDCT-based approach for the virtual re-association of the FHRs and propose an innovative protocol for DVI missions. This protocol includes the needed details, from the acquisition of MDCT imaging to the virtual re-association of 3D models and its validation. Each step has to be fully tested, adapted and validated in future studies. [ABSTRACT FROM AUTHOR]

A tomographic forward and inverse model is presented for deriving 3-D images of ionospheric electron density from ground-based dual-frequency Global Positioning System (GPS) measurements and ionosonde data. The GPS observation geometry is discretely modeled, and a linear algebraic relationship is derived between the integrated electron density measurements and the ionospheric electron density. Because the inverse problem is ill conditioned, regularization is used to stabilize the solution in the presence of noise. In this paper, we regularize the inverse problem by incorporating neighborhood smoothness and continuity constraints applicable to general ionospheric conditions. To avoid oversmoothing of edges, nonconvex regularizing functionals are used to capture potential localized ionospheric density structures. A deterministic relaxation technique is used to minimize the proposed cost function. The specific formulation of the reconstruction geometry is directly related to the sparseness and the nonuniform distribution of the GPS ray paths. The grid boundaries, the regularization parameters, the model order, and the grid placement are selected in conjunction with available remote sensing data and appropriate optimality criteria. The algorithm is tested using simulations of ionospheric structures with actual GPS observation geometry. These simulations demonstrate the effectiveness in detecting and reconstructing ionospheric height and density fluctuations, and illustrate the statistical performance and bounds of the inversion technique. [ABSTRACT FROM PUBLISHER]

Mining discriminative spatial patterns in image data is an emerging subject of interest in medical imaging, meteorology, engineering, biology, and other fields. In this paper, we propose a novel approach for detecting spatial regions that are highly discriminative among different classes of three dimensional (3D) image data. The main idea of our approach is to treat the initial 3D image as a hyper-rectangle and search for discriminative regions by adaptively partitioning the space into progressively smaller hyper-rectangles (sub-regions). We use statistical information about each hyper-rectangle to guide the selectivity of the partitioning. A hyper-rectangle is partitioned only if its attribute cannot adequately discriminate among the distinct labeled classes, and it is sufficiently large for further splitting. To evaluate the discriminative power of the attributes corresponding to the detected regions, we performed classification experiments on artificial and real datasets. Our results show that the proposed method outperforms major competitors, achieving 30% and 15% better classification accuracy on synthetic and real data respectively while reducing by two orders of magnitude the number of statistical tests required by voxel-based approaches. [ABSTRACT FROM AUTHOR]

In order to observe three-dimensional (3D) expression patterns of genes in whole animals, whole organs, or whole tissues, in situ hybridization (ISH) of many sections must be carried out and then used to construct a 3D image. For this purpose, we have developed an automatic microtome to prepare tissue sections with an adhesive film. We used commercially available film suitable for sectioning and ISH. We constructed a microtome and, after adherence of the film to a paraffin-embedded tissue block, cut the block with a blade to prepare sections on film. Then, the sections-on-film were automatically set in a plastic frame that was the same size as a conventional glass slide. With this automatic microtome, tissue sections can be made for ISH or immunohistochemistry in addition to conventional hematoxylin and eosin staining without specific training. We demonstrate that we can construct 3D images of gene expression patterns obtained by ISH on sections prepared with this automatic microtome. We have designated this method as ‘Film Tomography (FITO)’. [ABSTRACT FROM AUTHOR]

Validation studies of the new DentalPrint© software were carried out with experimental bite marks in pigskin. The bite marks were digitally photographed according to the ABFO guidelines for evidence collection. Dental casts used in the experiment were scanned in 3D and 2D, and comparison overlays were generated using DentalPrint© and Adobe® Photoshop® software, respectively. Digitized photographs of the experimental bite marks and the biting edges obtained in the overlays were compared by two different examiners to analyze the impact of training and experience with the two methods. Receiver operating characteristic (ROC) analysis, sensitivity, specificity, and 95% confidence intervals for each cutoff point were calculated. The expert examiner using DentalPrint© obtained the best results, with an area under the ROC curve of 0.76 (SE=0.057; CI at 95%=0.652–0.876). Fairly high specificity values were found for DentalPrint©, and the best results were obtained for the cutoff value that discriminated between the examiner's response “biter” and the rest of the possible (specificity 97.9%, CI at 95%=93.2%–99.6%). Therefore, the results presented here indicate that DentalPrint© is a useful, accurate tool for forensic purposes, although further research on the comparison process is needed to enhance the validity of bite mark analysis. [ABSTRACT FROM AUTHOR]

Volumetric three-dimensional (3-D) displays allow the user to explore a 3-D scene free of joysticks, keyboards, goggles, or trackers. For non-trivial scenes, computing and transferring a 3-D image to the display takes hundreds of seconds, which is a serious bottleneck for many applications. We propose to represent the 3-D scene with an occlusion camera reference image (OCRI). The OCRI is a compact scene representation that stores only and all scene samples that are visible from a viewing volume centered at a reference viewpoint. The OCRI enables computing and transferring the 3-D image an order of magnitude faster than when the entire scene is processed. The OCRI approach can be readily applied to several volumetric display technologies; we have tested the OCRI approach with good results on a volumetric display that creates a 3-D image by projecting 2-D scene slices onto a rotating screen [ABSTRACT FROM PUBLISHER]

Micro-optics have become the key technology in liquid crystal display systems due to its capabilities of miniaturization and design flexibility. Design consideration and experimental results of microoptical components for enhancing the image quality, providing better functions, increasing light efficiency, and generating 3D images in liquid crystal display (LCD) applications are presented. [ABSTRACT FROM PUBLISHER]

Presents a study which describes a new software package, DentalPrint, developed to generate comparison overlays from three-dimensional images of the suspect's dental casts. Importance of bite marks evidence found on the skin of a living person or a corpse and on objects in criminal investigations; Emphasis on the need for new three-dimensional (3D) imaging technologies in bite mark analysis; Presentation of the software package DentalPrint that generates different comparison overlays from 3D dental cast images depending on the pressure of the bite or the distortion caused by victim-biter interaction.

The curve skeleton of a 3D solid object provides a useful tool for shape analysis tasks. In this paper, we use a recent skeletonization algorithm based on voxel classification that originates a nearly thin, i.e., at most two-voxel thick, curve skeleton. We introduce a novel way to compress the nearly thin curve skeleton to one-voxel thickness, as well as an efficient pruning algorithm able to remove unnecessary skeleton branches without causing excessive loss of information. To this purpose, the pruning condition is based on the distribution of significant elements along skeleton branches. The definition of significance depends on the adopted skeletonization algorithm. In our case, it is derived from the voxel classification used during skeletonization. [Copyright &y& Elsevier]

Combining helical volumetric CT acquisition and thin-slice thickness during breath hold provides an accurate assessment of both focal and diffuse airway diseases. With multiple detector rows, compared with single-slice helical CT, multislice CT can cover a greater volume, during a simple breath hold, and with better longitudinal and in-plane spatial resolution and improved temporal resolution. The result in data set allows the generation of superior multiplanar and 3D images of the airways, including those obtained from techniques developed specifically for airway imaging, such as virtual bronchography and virtual bronchoscopy. Complementary CT evaluation at suspended or continuous full expiration is mandatory to detect air trapping that is a key finding for depicting an obstruction on the small airways. Indications for CT evaluation of the airways include: (a) detection of endobronchial lesions in patients with an unexplained hemoptysis; (b) evaluation of extent of tracheobronchial stenosis for planning treatment and follow-up; (c) detection of congenital airway anomalies revealed by hemoptysis or recurrent infection; (d) detection of postinfectious or postoperative airway fistula or dehiscence; and (e) diagnosis and assessment of extent of bronchiectasis and small airway disease. Improvement in image analysis technique and the use of spirometrically control of lung volume acquisition have made possible accurate and reproducible quantitative assessment of airway wall and lumen areas and lung density. This contributes to better insights in physiopathology of obstructive lung disease, particularly in chronic obstructive pulmonary disease and asthma. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study is to compare and analyze the similarities between three-dimensional images captured by a smartphone camera with depth sensors and a conventional 3dMD Face system., Materials and Methods: Twenty six individuals (16 female, 10 male) were involved in this study, agreed to take part and as such had no paralysis, tics, etc., which may prevent taking the image. Anthropometric points were marked, and plasters were placed on the forehead, upper nasal dorsum and zygoma to determine matching areas. 3D images were captured with a DOF (Depth of Field) camera of a smartphone (iPhone X, Apple Inc. CA, USA) and a 3D imaging system (3dMD, Atlanta, GA, USA). Linear and angular measurements were carried. Overlapping area amounts of matched images and X, Y and Z coordinates of landmarks were compared. For comparison of the data, student t-test and Mann-Whitney U test were used at P<0.05., Results: Statistically significant changes were found in distance between inner commissures of right and left eye fissure and nasolabial angle. RMS (Root Mean Square) values were found between 0.58 and 1., Conclusion: Images captured with a DOF camera of a smartphone, can be used to record and evaluate 3D soft tissue changes. However, due to the anatomical features of some regions, the deficiency of clear visualization needs improvements., (Copyright © 2021 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Advances in 3D imaging technology are transforming how radiologists search for cancer 1,2 and how security officers scrutinize baggage for dangerous objects. 3 These new 3D technologies often improve search over 2D images 4,5 but vastly increase the image data. Here, we investigate 3D search for targets of various sizes in filtered noise and digital breast phantoms. For a Bayesian ideal observer optimally processing the filtered noise and a convolutional neural network processing the digital breast phantoms, search with 3D image stacks increases target information and improves accuracy over search with 2D images. In contrast, 3D search by humans leads to high miss rates for small targets easily detected in 2D search, but not for larger targets more visible in the visual periphery. Analyses of human eye movements, perceptual judgments, and a computational model with a foveated visual system suggest that human errors can be explained by interaction among a target's peripheral visibility, eye movement under-exploration of the 3D images, and a perceived overestimation of the explored area. Instructing observers to extend the search reduces 75% of the small target misses without increasing false positives. Results with twelve radiologists confirm that even medical professionals reading realistic breast phantoms have high miss rates for small targets in 3D search. Thus, under-exploration represents a fundamental limitation to the efficacy with which humans search in 3D image stacks and miss targets with these prevalent image technologies. • Humans searching 3D image stacks miss small targets that are salient in 2D images • Optimal observers and deep neural networks do not show the deficits for 3D images • Human eye movement under-exploration in 3D search explains the misses • New 3D-imaging technologies should consider these human visuo-cognitive bottlenecks Will 3D imaging technologies always lead to improvements for the visual search of targets? Lago et al. show that, when humans search 3D image stacks, they under-explore with eye movements, overestimate the area they have searched, and often miss small targets that are salient in 2D images. [ABSTRACT FROM AUTHOR]

• We propose the CAN architecture to learn discriminative feature representations for saliency detection in RGB D images, by modeling multi modal and multi scale context dependencies within the context aware fusion and context dependent deconvolution. It is demonstrated that the proposed end to end CAN can a chieve favourable performance compared with state of the art methods. • A context aware fusion unit based on the LSTM architecture (MCFLSTM) is developed to learn complementary contexts from two modalities. The positive effect of this fusion approach is demonstrated experimentally. • A hierarchical LSTM structure called HSCLSTM is proposed to progressively refine saliency cues by modelling the context dependencies among different scales. Its effectiveness is also verified by experimental results. Convolutional neural networks (CNNs) have shown unprecedented success in object representation and detection. Nevertheless, CNNs lack the capability to model context dependencies among objects, which are crucial for salient object detection. As the long short-term memory (LSTM) is advantageous in propagating information, in this paper, we propose two variant LSTM units for the exploration of contextual dependencies. By incorporating these units, we present a context-aware network (CAN) to detect salient objects in RGB-D images. The proposed model consists of three components: feature extraction, context fusion of multiple modalities and context-dependent deconvolution. The first component is responsible for extracting hierarchical features in color and depth images using CNNs, respectively. The second component fuses high-level features by a variant LSTM to model multi-modal spatial dependencies in contexts. The third component, embedded with another variant LSTM, models local hierarchical context dependencies of the fused features at multi-scales. Experimental results on two public benchmark datasets show that the proposed CAN can achieve state-of-the-art performance for RGB-D stereoscopic salient object detection. [ABSTRACT FROM AUTHOR]

Human-Robot Interaction (HRI) provides assisted services in different real-time applications. The robotic systems identify objects through digital visualization wherein a three-dimensional (3D) image is converged to a plane-based projection. The projection is analyzed using the co-ordinates and identification points for recognizing the object. In such a converging process, the misidentification of projections in different planes results in recognition errors. This article proposes projection-dependent input processing (PDIP) method to reduce the misidentifications in object recognition. In this method, the input is the visualizing image projected in all the possible dimensions to identify the conjoining indices. The conjoined indices without intersection are segregated using labeled analysis. The non-correlating indices are identified in the possible dimension projections to prevent errors. The deviations in planes and indices matching are prevented by correlating the input with similar stored inputs with labels. The proposed method is verified using the metrics recognition ratio (96.4%), time (630.36 ms), complexity (5.93), and error (0.605). • Design & development of PDIP for reducing the misidentification in object recognition. • Analyzing the input based on visual image projection to define the conjoining indices. • It has been used to identify feature associated with input, reducing recognition time. [ABSTRACT FROM AUTHOR]

• Classical and advanced versions of a water flow dual-porosity model are presented. • Structure parameters from X-ray images are integrated in the advanced version. • Classical version gives best results but water exchange is not properly simulated. • Advanced version produces worse results but a new knowledge has been introduced. • Drainage dynamics at initial dried state is controlled by exchange among porosity domains. Modeling preferential flow in soils is still a challenge for the scientific community working on water resources. Indeed, it is an issue to determine the functional parameters of models dedicated to water flow, that are currently obtained by fitting processes, whereas their relationships with soil structure remain poorly known. Improved models are expected from a better understanding of the links between functional and structural parameters, which can be achieved thanks to recent developments in imaging methods such as X-ray Computed Tomography (CT). The paper seeks to improve a dual-porosity model, coupling matrix flow (by Richards equation) and preferential flow (by a Kinematic Dispersive Wave), by substituting some model parameters, usually obtained by inversion of experimental data, by those assessed from CT images of the soil structure. Thus, two versions of the model are compared, the "classical" and the "advanced" one including parameters determined using the 3D images of the sample structures. To compare model versions with real situations, infiltration experiments were conducted in lab on two different soils at two initial water contents. An X-ray medical scanner allowing acquisitions of large soil volumes (≈ 1700 cm3) with a voxel size of 400 µm was used to image the sample structures. Then, we derived two geometrical parameters from the macroporosity network: the percolating macroporosity and a characteristic dimension of this macropore network, the mean inter-macropore distance. The sensitivity analysis conducted on the classical version of the model showed that the kinematic coefficient and the dimensional parameter of the porous medium are the two main contributors to the cumulated drainage whatever the initial condition. Although experimental data are better simulated by the classical version of the model, drainage dynamics is also well simulated by the advanced version. However, differences between the model versions that are small for both soils at field capacity become significant for the dried state (mean initial matric potential of −3.5 m). This emphasizes the crucial effect of the sink-source term and in particular the complex effect of the dimensional parameter that it contains. Indeed, difficulties to simulate properly water exchange between porosity domains are encountered for both versions of the model. We conclude that empirical parameters that were up to now fitted from experiments could be deduced from geometrical indicators computed from CT images and that owning to these first results the applied methodology is promising to achieve a better understanding and modeling of preferential flow processes and to improve model predictability. [ABSTRACT FROM AUTHOR]

The conserved bilateral habenular nuclei (HA) in vertebrate diencephalon develop into compartmentalized structures containing neurons derived from different cell lineages. Despite extensive studies demonstrated that zebrafish larval HA display distinct left-right (L-R) asymmetry in gene expression and connectivity, the spatial gene expression domains were mainly obtained from two-dimensional (2D) snapshots of colorimetric RNA in situ hybridization staining which could not properly reflect different HA neuronal lineages constructed in three-dimension (3D). Combing the tyramide-based fluorescent mRNA in situ hybridization, confocal microscopy and customized imaging processing procedures, we have created spatial distribution maps of four genes for 4-day-old zebrafish and in sibling fish whose L-R asymmetry was spontaneously reversed. 3D volumetric analyses showed that ratios of cpd2, lov, ron, and nrp1a expression in L-R reversed HA were reversed according to the parapineal positions. However, the quantitative changes of gene expression in reversed larval brains do not mirror the gene expression level in the obverse larval brains. There were a total 87.78% increase in lov + nrp1a + and a total 12.45% decrease in lov + ron + double-positive neurons when the L-R asymmetry of HA was reversed. Thus, our volumetric analyses of the 3D maps indicate that changes of HA neuronal cell fates are associated with the reversal of HA laterality. These changes likely account for the behavior changes associated with HA laterality alterations., (© 2021 Wiley Periodicals LLC.)

The measurement of various body dimensions of horses plays a significant role in quality improvement, genetic breeding, health, and soundness. There has been significant advancement in the technology for acquiring stereoscopic images with a three-dimensional (3D) scanner. This study aimed to validate the accuracy of body measurements obtained from stereoscopic images taken with a 3D scanner. We manually took the following body measurements for 8 riding horses: height at the withers, height at the back, height at the croup, chest depth, width of the chest, width of the croup, width of the waist, girth circumference, cannon circumference, and body length. Using a versatile tablet-type 3D scanning device, we captured a 3D image of each horse. Relative errors varied from -1.37% to 6.25%. The correlation coefficient between manual and 3D measurements was significant for all body measurements (P<0.01) except for width of the waist and cannon circumference. The low accuracy of cannon circumference (r=0.248) was due to effect of hair. A simple regression analysis of all body measurements revealed a strong correlation (P<0.001, R 2 =0.9994, root-mean-square error [RMSE]=1.522). Notable advantages of this methodology include high accuracy, good operability, non-contact, high versatility, and low cost. Further studies are required for the establishment of an accurate measurement methodology that can scan the whole body in a shorter time., (©2021 The Japanese Society of Equine Science.)