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Aim: Cleft lip and palate (CLP) patients have a greater predisposition to tooth malformation, which could affect pulp volume. The aim of this study is to evaluate the dental pulp volume of central incisors in 3D images between individuals with and without CLP. Materials and Methods: This retrospective case-control study is single-centered and was recruited between January 2016 and October 2022. Ninety-four patients who were followed in the Institute of Orthodontics were evaluated and divided into two groups: a control group of patients without CLP and a test group of patients with CLP. The 3D data were imported by 3D image semi-automatic segmenting software named ITK-SNAP to calculate tooth pulp volume. Results: The dental pulp volume for both groups, control and CLP, did not show statistically significant differences. In the cleft group, when comparing the pulp volume between the cleft side and the non-cleft side, the cleft side showed a smaller volume. Regarding age and sex, no statistically significant differences were observed. Conclusions: Although there are no differences in mean pulp volume between patients with and without CLP, there is a pulp volume reduction in the teeth on the cleft side when compared to the unaffected contralateral side.

International audience; The application of sampling methods with fine sieve meshes during archaeological excavations has considerably modified the image of the role of fishing in the economy of ancient societies. The use of these field techniques allows, by multiplying the data, a quantitative approach that restores the share of each species in consumption, from the smallest to the largest. The millimetre size of certain remains collected in the samples and the numerous similarities between skeletons of individuals of the same genus, or even of the same family, often make the precise identification of small species difficult. The Ichtyo3D2 project* is a continuation of a preliminary interdisciplinary project (2021) conducted by CCJ-UMR 7299 and CEREGE, which has experimented the use of 3D x-ray micro-CT (Computed Tomography) on vertebrae of three small teleost bones (Chelon saliens, Diplodus sargus, Boops boops). This technique gives us a high spatial resolution (up to submicron) and access to structural information (bone density, deformation, alteration, etc….). We have information such as bone density, age and season of capture which are difficult to detect in any other way and which are necessary for our studies on the exploitation of fisheries resources over the long term. The three-dimensional x-ray imaging analysis (CEREGE) of various skeleton elements made it possible to create an interactive database. This one will be used, ultimately, as an osteological atlas for various small Mediterranean and Black Sea species. The Centre Camille Jullian has an osteotheque that includes a number of small sparids (Diplodus sargus, Sarpa sarpa, Boops boops, Lithognatus mormyrus, Spicara Maena), small mugilids, labridae (Coris julis), serranidae (Seranus cabrilla) whose osteology is very poorly known, illustrated and disseminated. Nevertheless, these species appear on the list of species consumed by different communities over time. They characterise the diet of some social categories.Our objectives with this project are:1)to create a didactic tool for the identification of skeletal elements for any species dedicated to students and researchers interested in the exploitation of marine resources.2)to increase the data sets of interest in several fields of archaeo-ichthyology and more broadly in biology (anatomy, histology of skeletal tissues);3)to characterise the 3D structure (density, shape, porosity, etc.) on various parts of the skeletal elements for the species studied in order to have a better understanding of the conservation parameters of the archaeological remains.This project will also enable the validation of a high-performance technique for saving and replicating bones, whether they belong to a current repository or come from archaeological sites and if they have to be destroyed to carry out biochemical analyses.* The project has received funding from Excellence Initiative of Aix-Marseille University - A*MIDEX, a French "Investissements d’Avenir" programme - Institute for Mediterranean Archaeology ARKAIA (AMX-19-IET-003).

Most commercially successful face recognition systems combine information from multiple sensors (2D and 3D, visible light and infrared, etc.) to achieve reliable recognition in various environments. When only a single sensor is available, the robustness as well as efficacy of the recognition process suffer. In this paper, we focus on face recognition using images captured by a single 3D sensor and propose a method based on the use of region covariance matrixes and Gaussian mixture models (GMMs). All steps of the proposed framework are automated, and no metadata, such as pre-annotated eye, nose, or mouth positions is required, while only a very simple clustering-based face detection is performed. The framework computes a set of region covariance descriptors from local regions of different face image representations and then uses the unscented transform to derive low-dimensional feature vectors, which are finally modeled by GMMs. In the last step, a support vector machine classification scheme is used to make a decision about the identity of the input 3D facial image. The proposed framework has several desirable characteristics, such as an inherent mechanism for data fusion/integration (through the region covariance matrixes), the ability to explore facial images at different levels of locality, and the ability to integrate a domain-specific prior knowledge into the modeling procedure. Several normalization techniques are incorporated into the proposed framework to further improve performance. Extensive experiments are performed on three prominent databases (FRGC v2, CASIA, and UMB-DB) yielding competitive results.

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

Most commercially successful face recognition systems combine information from multiple sensors (2D and 3D, visible light and infrared, etc.) to achieve reliable recognition in various environments. When only a single sensor is available, the robustness as well as efficacy of the recognition process suffer. In this paper, we focus on face recognition using images captured by a single 3D sensor and propose a method based on the use of region covariance matrixes and Gaussian mixture models (GMMs). All steps of the proposed framework are automated, and no metadata, such as pre-annotated eye, nose, or mouth positions is required, while only a very simple clustering-based face detection is performed. The framework computes a set of region covariance descriptors from local regions of different face image representations and then uses the unscented transform to derive low-dimensional feature vectors, which are finally modeled by GMMs. In the last step, a support vector machine classification scheme is used to make a decision about the identity of the input 3D facial image. The proposed framework has several desirable characteristics, such as an inherent mechanism for data fusion/integration (through the region covariance matrixes), the ability to explore facial images at different levels of locality, and the ability to integrate a domain-specific prior knowledge into the modeling procedure. Several normalization techniques are incorporated into the proposed framework to further improve performance. Extensive experiments are performed on three prominent databases (FRGC v2, CASIA, and UMB-DB) yielding competitive results.

Background The volumetric ratio of the tongue to the oral cavity has been recognized to be one of the important factors for the maintenance of stable occlusion. Oral cavity capacity is changed after orthognathic surgery in patients with mandibular prognathism; however, the volumetric changes of the oral cavity including the tongue before and after surgery have not been analyzed. The purpose of this study was to evaluate the morphological and volumetric changes of the tongue and oral cavity following orthognathic surgery using a newly developed vinyl polysiloxane impression method. Materials and methods The study was performed in fifteen subjects who underwent surgical orthognathic treatment. Impressions of the tongue together with the oral cavity were obtained before orthognathic surgery and 1, 3, and 6 months after orthognathic surgery. These impression patterns were scanned using cone-beam computed tomography (CT), and three-dimensional (3D) images of the oral cavity including the tongue, and the upper and lower dental arches were reconstructed. The morphological and volumetric changes in the oral cavity capacity and the tongue volume were examined. Results The volume of the tongue with the volume of the oral cavity decreased after orthognathic surgery. There was a correlation between the decrease in the oral cavity capacity and tongue volume. The volumetric ratio of the tongue to the oral cavity seems to be maintained before and after orthognathic surgery. Conclusion VPS method, free from radiation exposure, may be useful for investigating the morphological and volumetric changes of the tongue and oral cavity, which may possibly influence the stability of the dental arch and occlusion during surgical orthodontic treatment.

In order to ensure the rationality of landscape design, it is of great practical significance to simulate the planning effect. Aiming at the problems of traditional garden landscape distribution simulation technology, this paper designs a new garden landscape distribution rationality simulation technology based on three-dimensional image and virtual reality technology. Firstly, a rational analysis method for landscape garden distribution based on three-dimensional images is proposed. Based on the correlation between different coordinate systems under a specific angle of view, a camera pose matrix is constructed, and SURF feature point detection is performed on the landscape garden image and the above feature points are clustered and matched. Secondly, the three-dimensional image reconstruction of the landscape garden image is realized based on the registered image feature points. Based on the three-dimensional image reconstruction results and virtual reality technology, the three-dimensional image analysis of the rationality of landscape distribution is completed. Finally, the case analysis and performance test results illustrate the superiority of the realized landscape garden distribution rationality technology. This method can provide scientific reference and basis for the modern landscape gardening industry to adopt three-dimensional images and other technologies.

International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies, 13, 8, 13A8S: 1-13

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.

Distance education has been offered for years, but the integration of technological developments and opportunities into education has recently increased its popularity and event it became an indispensable method during the Covid-19 pandemic period. In distance education, accessing all class materials such as lecture presentations, class notes, reading materials, videos, live chats or class hours, and archive records allow students (participants) to learn without being in the same environments with teachers or learners. Technology has made vast contributions to the field of education. For instance, 3D as a teaching tool for the class attracts students’ attention, makes the learning process more enjoyable, and increases participation. In particular, for the disciplines, such as forestry, earth, and environmental sciences, which require laboratory exercises, field observation, field trips, and in-situ measurements, 3D modeling has provided many benefits in distance education. It enables 3D demonstration of the individual tree species to develop a virtual field laboratory. This study focused on the data sources and techniques to generate a 3D model of the individual tree species that forestry students used for distance education. The capabilities of the method in the generation of 3D models were evaluated by using UAV-based SfM photogrammetry. The results indicated that implementing 3D images of individual tree species can be a promising method that may increase the interest, interaction and satisfaction of the students in distance education in forestry.

Online retailers are increasingly adopting 3D digital twins instead of 2D pictures on their e-commerce webpages. This research compares the effect of 3D vs. 2D pictures on consumers’ perceptions and future intentions toward an e-tailer. We advance that 3D pictures increase consumers’ intentions to patronize the e-tailer as mediated by telepresence, perceived control and attitude change. Furthermore, we address the role of two potential moderators: shopping values (functional vs. experiential) and level of preference articulation (preference matching vs. building). Results provide indications for marketing scholars and to practitioners to design more effective e-commerce webpages.

Leaching using deep eutectic solvent (DES) can be an alternative solution for environmentally friendly leaching. Two choline chloride (ChCl) based DESs are investigated using two different oxidants for each DES, which are ChCl-ethylene glycol and ChCl-lactic acid with iodine (I2) or hydrogen peroxide (H2O2) as the oxidants. This study attempts a new method of determining leaching dissolution rate by using 3D image analysis from single particle leaching experiment to optimize leaching process through time. X-ray computed tomography (CT) is used to scan the particle to get 3D images, volume and surface area of the particle before and after the leaching. Gold, silver and telluride minerals are used as the target minerals, whereas galena, chalcopyrite and pyrite are used as the gangue minerals. The dissolution rate of these minerals calculated from the 3D image processing are then combined with mineral liberation analysis (MLA) data of a sulphide concentrate. This MLA data provides mineralogical characteristic along with scanning electron microscopy (SEM)-based image to be used in leaching simulation to get mineral recoveries. This method shows that selectivity of each target and gangue mineral dissolution in different solution can be observed and compared. The dissolution rate can also be applied in predicting leaching using different characteristic of ores or concentrates. Batch leaching experiments using all the leaching solutions are also done to compare the leaching simulation result.

Diplomska naloga obravnava tematiko avtomatiziranega pobiranja izdelkov v razsutem stanju. Problem, katerega rešitve so predstavljene tekom naloge, je prepoznava lege in orientacije objektov, ki so naključno razporejeni v prostoru. V prvem delu naloge je opravljen pregled obstoječega stanja tehnike na področju pobiranja izdelkov in tridimenzionalnih merilnikov ter povzeto teoretično ozadje nekaterih uporabljenih funkcij za prepoznavo izdelkov. V drugem delu diplomske naloge smo uporabili 3D merilnik za zajem 3D slik objektov v razsutem stanju. Sledil je razvoj programske opreme v programskem jeziku Python, s katero smo nato obdelali 3D slike in jih pretvorili v intenzitetne globinske slike. V nadaljevanju smo te slike še dodatno obdelali z različnimi funkcijami, ki so dostopne znotraj odprtokodnih knjižnic ter jih nato uporabili kot vhodne podatke v treh različnih funkcijah za prepoznavo enostavnih objektov. V zaključku naloge smo preverili delovanje posamezne funkcije na različnih scenskih slikah, na katerih so bili objekti različnih oblik. Na podlagi rezultatov smo ovrednotili posamezno funkcijo ter ocenili, ali je primerna za prepoznavo izdelkov v razsutem stanju. The final thesis deals with the topic of automated collection of bulk products. The problem, whose solutions are presented during the task, is to recognize the position and orientation of objects randomly distributed in space. The first part of the thesis gives an overview of the current state of the art in the field of product picking and three-dimensional scanners and summarizes the theoretical background of some of the functions for the identification of products. In the second part of the thesis a 3D scanner was used to capture 3D images of bulk objects. This was followed by the development of a software in the programming language Python, with which we processed the 3D images and converted them into images with depth of field. Later, we have further processed these images with various functions available within open source libraries, which we then used as input in three different functions to identify simple objects. At the end of the assignment, we checked the results of each function on different sets of stage images showing objects with different shapes. Based on the results, we evaluated each function and estimated whether it was suitable for identifying bulk products.

Objective: The objective of this study is to use 3D digital lumbar models to investigate and simulate the optimal posterior operative approach for safe decompression and insertion of an interbody cage. Methods: Thirty lumbar spine (L3-S1) computed tomography data are collected for 3D reconstruction. We cut medial half part of the superior facet and define the distance between the margin of the operative side of the spinous process and the medial margin of the cut superior facet as “medial distance (MD)”. Then, we cut the total superior facet and define the distance between the margin of the operative side of the spinous process and the lateral side of the junction of the pedicle and the vertebral body as “extend distance (ED)”. The feasible insertion of the current standard width size (10 mm and 12 mm) interbody cages was assessed by the two aforementioned MD and ED approaches. Besides the ED, we also simulate four other extensive options of lateral upper, lateral lower, vertical upper and lower and transmedian contralateral decompression on 3D digital lumbar model. Results: The MD increased from 13.48 ± 1.28 mm at L3/4 to 18.05 ± 1.43 mm at L5/S1, and the ED increased from 16.64 ± 1.34 mm at L3/4 to 21.12 ± 1.62 mm at L5/S1. To insert a 10-mm-wide cage, 16.7% (left) and 13.3% (right) of MD for L3/4 is not enough, 60.0% (left) and 46.7% (right) of MD for L3/4 is subsafe, 13.3% (left) and 16.7% (right) of MD for L4/5 is subsafe and all others are safe. To insert a 12-mm-wide cage, 76.7% (left) and 60.0% (right) of MD for L3/4 is not enough, 20.0% (left) and 30.0% (right) of MD for L3/4 is subsafe, 13.3%% (left) and 16.7% (right) of MD for L4/5 is not enough, 63.3% (left) and 56.7% (right) of MD for L4/5 is subsafe and 6.7% (left) and 10.0% (right) of MD for L5/S1 is subsafe, whereas 33.3%% (left) and 30.0% (right) of ED for L3/4 is subsafe, 3.3% (left) and 3.3% (right) of ED for L4/5 is subsafe and all others are safe. Besides the ED, on 3D models, four other extensive options could be simulated too and may need to be performed for different special individuals. Conclusion: Our 3D digital image study provides a feasible optimal medial transforaminal lumbar interbody fusion approach with five extensive options on lower lumbar region. It can provide safe lumbar decompression and interbody fusion in most population. In addition, surgeons can choose the different extensive options for special individual conditions. The translational potential of this article: Transforminal lumbar interbody fusion is very common used for lumbar degenerative diseases. The optimal medial transforminal lumbar interbody fusion with five options provide a safe and precise approach for surgeons in treatment of lumbar degenerative diseases. Keywords: 3D images, Anatomic, Lumbar spine, Transforaminal lumbar interbody fusion

This paper focuses on challenging applications that can be expressed as an iterative pipeline of multiple 3d stencil stages and explores their optimization space on GPUs. For this study, we selected a representative example from the field of digital signal processing, the Anisotropic Nonlinear Diffusion algorithm. An open issue to these applications is to determine the optimal fission/fusion level of the involved stages and whether that combination benefits from data tiling. This implies exploring a large space of all the possible fission/fusion combinations with and without tiling, thus making the process non-trivial. This study provides insights to reduce the optimization tuning space and programming effort of iterative multiple 3d stencils. Our results demonstrate that all combinations that fuse the bottleneck stencil with high halos update cost ( $$>25\%$$ , this percentage can be measured or estimated experimentally for each single stencil) and high registers and shared memory accesses must not be considered in the exploration process. The optimal fission/fusion combination is up to 1.65 $$\times $$ faster than the case in which we fully decompose our stencil without tiling and 5.3 $$\times $$ faster with respect to the fully fused version on the NVIDIA GPUs.

Objective The aim of this study was to assess the role of multislice computed tomography (MSCT) using 2D and 3D images in evaluation of different types of Le Fort fractures. Subjects and methods 30 cases referred from the Emergency unit in Zagazig University Hospital were included in this study, based on clinical evidence of facial trauma, they underwent multislice computed tomography (MSCT) examination and were shown to be positive for pterygoid fractures. All patients subjected to non contrast MSCT in axial cuts. Multiplanar reformatted (MPR) images were acquired using the machine software in sagittal and coronal planes. Finally images were transferred to a workstation for reconstruction of 3D images. Results Sensitivity of multislice computed tomography (MSCT) in detecting compound Le Fort fractures for radiologists A, B and C was 94.4%, 66.7% and 100% respectively. Sensitivity of MSCT in detecting isolated Le Fort fractures for radiologists A, B and C was 100%. The difference between radiologists A, B and C in detecting Le Fort fractures types was insignificant. Good agreement between radiologists A, B, C and intraoperative findings. Conclusion Both 2D-CT and 3D-CT are the best methods in imaging of Le Fort fractures.

This manual has been developed within the “ARsim2care: Augmented reality application in clinical simulation” Project funded by the European Union Erasmus + Program, and it is one of the project’s intellectual outputs. The Project has been developed working with three European higher education institutions, Escola Superior de Enfermagem de Coimbra (ESEnfC), Erasmushogeschool Brussel (EhB) and the Public University of Navarre (UPNA), and the Industrial Augmented Reality (iAR) company. The main aim of this project is to develop an Augmented Reality (AR) software that, combined with clinical simulation anatomical models, lets students work on technical skills for performing invasive clinical procedures, helping them visualise internal anatomical structures (App ARsim2care). The procedures compiled in this manual are included in the ARSim2Care App: endotracheal intubation, arterial blood sampling, intramuscular injection, nasogastric tube insertion and suctioning via a tracheostomy tube. This manual includes the detailed description of each procedure, as well as illustrating the key internal anatomical structures to be visualised by the student during their work. This information is not only presented in English but also in the project partners’ languages: Spanish, Portuguese and Dutch. The manual comes in a PDF electronic version with 3D content in an attempt to include 3D images to look at the figures interactively from the different anatomical views that have been included. Co-funded by the Erasmus+ Program of the European Union

Melanoma is one of the most common types of cancer and is characterized by its aggressiveness and tendency to cause metastasis even after removal of the primary tumour, with a survival rate of only 24% after it takes place. The high level of angiogenesis showcased by all cancerous processes and particularly melanoma plays a significant role in this process; nevertheless, we lack a detailed model of the architecture of this cancer-induced new vasculature and the possible information it would provide for its palliation and prevention. Single Plane Illumination Microscopy (SPIM) can be used to generate high resolution 3D images of tissue samples while preserving their original structure intact and thus the relevance of said data for clinical applications. SPIM imaging is performed in combination with the CUBIC (Clear, Unobstructed Brain Imaging Cocktails) optical tissue clearing protocol and immunohistochemistry (IHC) vasculature labelling methods to study human melanoma samples and obtain a 3D reconstruction of its structure. This project focused on the optimization of the CUBIC protocol coupled with IHC for effective use on human melanoma samples for the generation of truthful 3D models of its vasculature. The clearing protocol details and lengths were adjusted for maximum efficiency with the best possible result, while the specifics of the required image acquisition and processing steps were assessed in their difficulty and feasibility. In the end, high-quality 3D images of human melanoma vasculature were successfully generated and visualized, paving the way for further future studies. Ingeniería Biomédica

International audience; Monitoring the growth and body condition of cows is essential for optimal management of modern dairy farms. However, monitoring is rarely performed on commercial farms. Modern technologies based on three-dimensional (3D) shape analysis could address this problem. The objective of the present study was to test and validate tools that can record and analyze 3D body shapes of animals. On 30 Holstein dairy cows, wither height (WH), heart girth (HG), chest depth (CD), hip width (HW), backside width (BaW) and ischial width (IW) were manually measured. These manual measurements were compared to those measured with a scanner (Morpho3D) that provided 3D images of the entire cow body. Correlations between manual and Morpho3D measurements were high: 0.89 for CD, 0.82 for HW, 0.78 for HG, 0.76 for BaW, 0.63 for IW and 0.62 for WH. The mean coefficient of variation of reproducibility for Morpho3D was 2.8%. Future development can provide new opportunities for dairy herd management based on determining animal body volume and surface area.

The paper presents a new method of more precise estimation of the depth map in 3D videos. The novelty of the proposed approach lies in sophisticated combination of partial results obtained by selected existing passive and active 3D scanning methods. The aim of the combination is to overcome drawbacks of individual methods and this way to improve the accessible precision of the final depth map. The active method used is incoherent profilometry scanning which fails on surface discontinuities. As a passive method, a stereo pair matching is used. This method is currently the most widely applied method of depth map estimation in the field of 3D capturing and is available in various implementations. Unfortunately, it fails if there is a lack of identifiable corresponding points in the scanned scene. The paper provides a specific way of combining these methods to improve the accuracy and usability. The proposed innovative technique exploits the advantages of both approaches. Specifically, the more accurate depth profiles of individual discontinuous objects obtained from the active method, and information about mean depths of the objects from the stereo pair are combined. Two implementations of the passive method have been tested for combination with active scanning: matching from stereo pair, and SIFT. The paper includes a brief description of the active and passive methods used and a thorough explanation of their combination. As an example, the proposed method is tested on a simple scene whose nature enables straight assessment of the achieved accuracy. The choice of a suitable implementation of the passive component is also shown and discussed. The obtained results of individual existing methods used and of the proposed combined method are given and compared. To demonstrate the contribution of the proposed combined method, also a comparison with the results obtained with a commercial solution is presented with significantly good results.

[Purpose] This study verified that the smoothness of reaching movements is able to quantitatively evaluate the effects of two- and three-dimensional images on movement in healthy people. In addition, clinical data of cerebrovascular accident patients were also analyzed by the same method. [Subjects] Ten healthy adult volunteers and two male patients with previous cerebrovascular accidents participated. [Methods] The subjects were tasked with reaching for objects shown on a display. The target and virtual limb, rendered with computer graphics, were shown on the display. Movements of the virtual limb were synchronized with those of the subject. Healthy subjects reached for targets with their dominant arm, and cerebrovascular accident patients used their paretic arm. A polarized display and polarized glasses were used when the subjects were shown three-dimensional images. In the present study, jerk cost was used to quantify the smoothness of movement. [Results] Six of the 10 healthy subjects had significantly smoother reaching movements when viewing the three-dimensional images. The two cerebrovascular accident patients tended to have smoother movements in response to the three-dimensional images. [Conclusion] Analysis of the smoothness of movement was able to detect the influence of the depth cue in vision on movement quantitatively for the healthy subjects and cerebrovascular accident patients.

Introducción: El sistema ventricular encefálico es muy complejo, y es especialmente difícil de comprender para los estudiantes de pregrado. Clásicamente, la anatomía ventricular puede enseñarse usando encéfalos cadavéricos, imágenes de tomografía o resonancia magnética. Presentamos nuestra experiencia con el uso de imágenes tridimensionales obtenidas mediante un sistema de neuronavegación. Material y métodos: Se obtuvieron imágenes de resonancia magnética de 3 pacientes. Las imágenes fueron introducidas en un sistema de neuronavegación y se reconstruyó específicamente el sistema ventricular encefálico y algunas estructuras gangliobasales. Posteriormente se solicitó la opinión de 38 estudiantes de pregrado que cursaban la materia neuroanatomía, sobre la utilidad de las imágenes en el estudio del sistema ventricular.Discusión: todas las imágenes obtenidas fueron de buena calidad, el 100% de los estudiantes manifestó que las imágenes eran muy útiles o esenciales para comprender cabalmente la anatomía ventricular. Conclusiones: el uso de imágenes obtenidas por un sistema de neuronavegación son útiles en la enseñanza de la anatomía del sistema ventricular encefálico.AIntroduction: Anatomy of cerebral ventricles is very complex. Classically, ventricular system anatomy has been taught employing cadaveric brains and CT or MRI images. We present 3D images of the ventricular system obtained by neuronavigation system and the results of its use in teaching anatomy of cerebral ventricles. Material and methods: Magnetic resonance images of three patients were obtained. These images were transferred to a neuronavigation system, and a 3D reconstruction of cerebral ventricles, were performed. Afterwards, 38 undergraduate students were required to give their opinion about how useful the images are in order to study the cerebral ventricles. Results: One hundred percent of the students agreed that the images were very useful or even essential to utterly comprehend the ventricular anatomy. Discussion: As other authors, we think that 3D images are very useful as a complement for teaching anatomy of cerebral ventricles. Conclusions: Employment of 3D images obtained in a computer system are useful for teaching the encephalic ventricular system anatomy, as a complementary tool.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Performing cell tracking is important for curing and preventing diseases. This is due to the fact that cellular motility is linked to several cellular processes. However, performing the analysis of the trajectory of a cell is not a simple job, because to store the information of the trajectory it is necessary a great amount of images, mainly in 3D images. Thus, it is necessary to create algorithms that can perform cell tracking in a practical and automatic way. In this work was given a continuation of the work of conclusion of course (TCC) of Sousa (2015) in order to improve the tracking algorithm already implemented and presented in Sousa (2015). To overcome the shortcomings of the algorithm implemented by Sousa (2015), modifications were made to the segmentation, labeling and tracking phases. In addition, methods have been added for the detection of cell division and the entry and exit of new cells of the video. The validation of the algorithm was done through an evaluation software that has routines for both the segmentation and the tracking part. 11 datasets were used for the validation, and the proposed algorithm was able to obtain results for 7 of them. Among the 7 datasets, 3 were 2D and the other 4, 3D. Although the results were not satisfactory for the 2D datasets, the 3Ds obtained satisfactory results during the tracking phase, with averages of accuracy ranging from 90.1% to 94.4%. From the validation, it was realized that, even having obtained satisfactory values, including some of them better than some found in the state of the art, the algorithm still needs improvements. Realizar o rastreamento de células é importante para a cura e prevenção de doenças. Isso se deve ao fato da motilidade celular estar ligada a vários processos celulares. Porém, realizar a análise da trajetória de uma célula não é um trabalho simples, pois para armazenar as informações da trajetória é necessário uma grande quantidade de imagens, principalmente em imagens 3D. Dessa forma, faz-se necessária a criação de algoritmos que possam realizar o rastreamento celular de forma prática e automática. Neste trabalho foi dada continuidade ao trabalho de conclusão de curso (TCC) de Sousa (2015) de forma a melhorar o algoritmo de rastreamento já implementado e apresentado em Sousa (2015). Para suprir as deficiências do algoritmo implementado por Sousa (2015), foram feitas modificações na fase de segmentação, de rotulação e de rastreamento. Além disso, foram adicionados métodos para a detecção de divisão celular e a entrada e saída de novas células do vídeo. A validação do algoritmo foi feita por meio de um software de avaliação que possui rotinas tanto para a parte de segmentação quanto para a de rastreamento. Foram utilizados 11 datasets para a validação, sendo que o algoritmo proposto conseguiu obter resultados para 7 deles. Dentre os 7 datasets, 3 eram 2D e os outros 4, 3D. Embora os resultados não tenham sido satisfatórios para os datasets 2D, os 3D obtiveram resultados satisfatórios durante a fase de rastreamento, com médias de acurácia variando de 90,1% a 94,4%. A partir da validação, percebeu-se que, mesmo tendo obtido valores satisfatórios, inclusive alguns deles melhores que alguns encontrados no estado da arte, o algoritmo ainda precisa de melhorias. São Cristóvão, SE

Objective: To determine if the Basic erosive tooth wear index (BEWE index) is able to assess and monitor ETW changes in two consecutive cast models, and detect methodological differences when using the corresponding 3D image replicas. Methods: A total of 480 pre-treatment and 2-year post-treatment orthodontic models (n = 240 cast models and n = 240 3D image replicas) from 120 adolescents treated between 2002 and 2013 at the Gent Dental Clinic, Belgium, were scored using the BEWE index. For data analysis only posterior sextants were considered, and inter-method differences were evaluated using Wilcoxon Signed Rank test, Kappa values and Mc Nemar tests (p < 0.05). Correlations between methods were determined using Kendall tau correlation test. Results: Significant changes of ETW were detected between two consecutive models when BEWE index was used to score cast models or their 3D image replicas (p < 0.001). A strong significant correlation (τb: 0.74; p < 0.001) was shown between both methods However, 3D image-BEWE index combination showed a higher probability for detecting initial surface changes, and scored significantly higher than casts (p < 0.001). Incidence and progression of ETW using 3D images was 13.3% (n = 16) and 60.9% (n = 56) respectively, with two subjects developing BEWE = 3 in at least one tooth surface. Conclusions: BEWE index is a suitable tool for the scoring of ETW lesions in 3D images and cast. The combination of both digital 3D records and index, can be used for the monitoring of ETW in a longitudinal approach. The higher sensibility of BEWE index when scoring 3D images might improve the early diagnosis of ETW lesions. Clinical significance: The BEWE index combined with digital 3D records of oral conditions might improve the practitioner performance with respect to early diagnosis, monitoring and managing ETW.

International audience; The granulometry operator is a mathematical operator largely employed in the 3D analysis of porous media to estimate the sizes of the pores detected in pervious materials and tissues. Quantifying the total porosity volume in a material with only closed pores is a relatively easy task. A simple numerical analysis of connected void or fluid phase components enables one to obtain such a volume. Unfortunately, for materials and/or tissues with (partly) open porosity granulometry calculations might become excessively time and memory consuming. In this work we suggest a method by means of which the open porosity map can be rapidly calculated on the basis of a pre-calculated distance map.

Samples with 40% vol. of pores and a pore size distribution between 100 and 500 µm were produced by powder metallurgy from Ti6Al4V alloy powders. Sintering was performed at 1300 °C during one hour in an inert Argon atmosphere in a vertical dilatometer. The compressive strength and the porosity of these samples was investigated before and after compression tests through X-ray microtomography. The values of the elastic modulus (8GPa) and yield strength (80MPa) are within the range of those used in bone implants. Porosity leads to greater deformation whereas fracture of compacts occurs perpendicularly to the applied load. It was determined that the origin of the failure is generated by rupture of interparticle necks and, large pores enhance the propagation of cracks.

Рассматривается метод компрессии, для трехмерных изображений, отличающийся от известных тем, что учитывает особенности получения цифровых трехмерных изображений с помощью анализа таблицы текстурных координат с использованием теоретико-множественного подхода. В работе стояла задача разработать метод компрессии для трехмерных изображений, отличающийся от известных тем, что учитывает особенности получения цифровых трехмерных изображений с помощью анализа таблицы текстурных координат Разработанные программные средства должны поддерживать поиск необходимых элементов в таблице текстурных координат. Для решения этой задачи был использован теоретико-множественный подход. Результаты оценки релевантности для соответствующих объектов и сами исследуемые объекты представляются в виде множества, элементы которого сортируются по убыванию уровня релевантности., The article considers a compression method for three-dimensional images, which differs from the known ones as it takes into account the main features of obtaining digital three-dimensional images by means of analysing the table of texture coordinates using the set-theoretic approach. The main task of the paper was to develop a compression method for three-dimensional images, which differs from the known ones as it takes into account the main features of obtaining digital three-dimensional images using the analysis of the texture coordinate table. Developed software should support the search for necessary elements in the table of texture coordinates. The set-theoretic approach was used to solve this problem. The results of relevance evaluation for the corresponding objects and the objects themselves are represented in the form of a set the elements of which are sorted in descending order of relevance level., №08(62) (2017)

V zaključnem delu predstavimo razvoj in delovanje programa za iskanje, prepoznavo in razvrščanje krožnih oblik v stereo sliki. Podan bo pregled uporabljenih algoritmov in metod za reševanje tega problema, na kratko pa opisanih še nekaj ostalih metod s tega področja. Podrobneje so opisani posamezni koraki v postopkih načrtovanja in realizacije projekta. Na kratko je predstavljena uporabljena strojna oprema, ter njene prednosti in pomanjkljivosti. Naloga se v nadaljevanju osredotoča na programski vidik reševanja problema. S stereo kamere zajemamo 3D slike, s pomočjo katerih lahko izračunamo globinsko sliko prostora. Na dobljeni globinski sliki iščemo kroge, ki predstavljajo okrogle predmete v prostoru. Z uporabo samo ene slike lahko enak prizor analiziramo v 2D pogledu. Z iskanjem, obdelavo, primerjanjem robov in podatkov iz obeh pristopov lahko dobimo precej zanesljiv način zaznave krožnih oblik v sliki. The final work presents development and functionality of a program, designed to search for, recognize and categorize circular forms in a stereo image. An overview will be given about the algorithms and methods used in solving this problem, as well as a short summary on some of the other available methods used in this field. Steps taken during research, development and production of this project will be described in further detail. The final work gives a short presentation of the hardware used in this project, briefly explaining its advantages and disadvantages. Next, it focuses on the programing aspect of the solution. A stereo camera is used to capture 3D images, which we can use to calculate the depth field of a given scene. The resulting depth map is used to search for circles, which represent round objects in space. By using only one of the images captured, we can analyze the same scene in a 2D view. By looking for, processing, and detecting edges, as well as comparing data from both procedures, we can achieve a rather reliable method of detecting circles in a given image.

OAPA We develop a fast algorithm for segmenting 3D images from linear measurements based on the Potts model (or piecewise constant Mumford-Shah model). To that end, we first derive suitable space discretizations of the 3D Potts model which are capable of dealing with 3D images defined on non-cubic grids. Our discretization allows us to utilize a specific splitting approach which results in decoupled subproblems of moderate size. The crucial point in the 3D setup is that the number of independent subproblems is so large that we can reasonably exploit the parallel processing capabilities of the graphics processing units (GPU). Our GPU implementation is up to 18 times faster than the sequential CPU version. This allows to process even large volumes in acceptable runtimes. As a further contribution, we extend the algorithm in order to deal with non-negativity constraints. We demonstrate the efficiency of our method for combined image deconvolution and segmentation on simulated data and on real 3D widefield fluorescence microscopy data.

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 (⩽30 days) 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.

There is a need to make cultural heritage sites accessible to all individuals, including those who are visually impaired. 3D printing technology provides the capability to print models of cultural heritage structure as teaching tools for the visually impaired. As well, Unmanned Aerial Vehicles (UAVs) have undergone significant advances in equipment capabilities and now have the ability to obtain high resolution images in a cost effective and efficient manner in order to create 3D models for 3D printing. This paper explores the use of UAVs to acquire high resolution images to generate 3D models that are printed using lowcost 3D printers intended to serve as a teaching aid for the visually impaired. A case study is presented for the Curium archaeological site.

Blood vessels inside the bone marrow (BM) play a vital role in the maintenance of hematopoietic stem cell (HSCs). Investigating the interaction of HSCs relative to vasculature has become the main headline for many recent studies. Advances in microscopy and image analysis using mouse models have allowed detection, identification and automated quantification of HSCs alongside their vascular niche. This resulted in new hypotheses concerning the activation state of HSCs adjacent to different blood vessel types (for example sinusoids vs. arterioles). Identifying the different types of BM vasculature has become critically important, however it still requires the use of complex immunostainings ex vivo or transgenic reporter mouse lines in vivo. To eliminate these requirements and increase the throughput of studies focusing on the HSC niche, we present a machine learning classification approach based on the Decision Tree Classifier to classify different regions of bone marrow vasculature into four distinct classes based on their discriminative features.

Building Information Modelling (BIM) technology is already part of the construction industry and is considered by professionals as a very useful tool for all phases of a construction project. BIM technology, with the particularly useful 3D illustrations which it provides, can be used to illustrate and monitor the progress of works effectively through the entire lifetime of the project. Unmanned Aerial Vehicles (UAVs) have undergone significant advances in equipment capabilities and now have the capacity to acquire high resolution imagery from different angles in a cost effective and efficient manner. By using photogrammetry, characteristics such as distances, areas, volumes, elevations, object sizes, and object shape can be determined within overlapping areas. This paper explores the combined use of BIM and UAV technologies in order to achieve efficient and accurate as-built data collection and 3D illustrations of the works progress during an infrastructure construction project.

Digital simulation is a wide-spreading tool for composite materials design and choice. Indeed it allows to generate and test digitally various structures more easily and quickly than with real manufacturing and tests processes. A feedback is needed following the choice and the fabrication of a virtual material in order to simultaneously validate the simulation and the fabrication process. With this aim, models similar to generated virtual structures are obtained by digitization of manufacturing materials. The same simulation algorithms can then be applied and allow to verify the forecasts. This thesis is also about the modelling of composite materials from 3D images, in order to rediscover in them the original virtual material. Image processing methods are applied to images to extract material structure data, i.e. each constituent localization, and orientation if applicable. These knowledge theoretically allow to simulate thermal and mechanical behavior of structures constituted of studied material. However to accurately represent composites requires practically a very small discretization step. Therefore behavior simulation of a macroscopic structure needs too much discretization points, and then time and memory. Hence a part of this thesis focuses also on determination of equivalent homogeneous material problem, which allows, when resolved, to lighten calculation time for simulation algorithms., La simulation numérique est un outil de plus en plus utilisé pour la conception et le choix de matériaux composites. Celle-ci permet en effet de générer et tester numériquement des structures très diverses plus facilement et plus rapidement qu’avec des procédés de fabrication et de tests réels. Suite au choix d’un matériau virtuel et sa fabrication tangible, un retour sur expérience est nécessaire afin de valider simultanément la simulation et le procédé de fabrication. Pour cela, la numérisation des matériaux fabriqués permet de renvoyer une modélisation comparable aux structures virtuelles générées. Il devient possible d’appliquer les mêmes algorithmes de simulation et de vérifier les prévisions.Le sujet de cette thèse consiste donc en la modélisation de matériaux composites réels à partir d’images 3D, afin d’y retrouver le matériau virtuel originel. Des méthodes de traitement d’images sont appliquées aux images afin d’en extraire les informations sur la structure du matériau, c’est-à-dire la localisation de chaque constituant et, s’il y a lieu, de leurs orientations. Ces connaissances permettent théoriquement de simuler le comportement thermique et mécanique de structures constituées du matériau étudié.Cependant, en pratique, représenter fidèlement les composites demande de prendre une discrétisation très fine. Par conséquent, une structure macroscopique demande beaucoup trop de points de discrétisation et donc de temps de calcul et de mémoire pour simuler son comportement. Un aspect de la thèse consiste donc aussi en la détermination d’un matériau homogène équivalent, permettant d’alléger la charge de calcul pour les algorithmes de simulation.

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 the 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.

Introduction: Nowadays virtual colonoscopy has become a reliable and efficient method of detecting primary stages of colon cancer such as polyp detection. One of the most important and crucial stages of virtual colonoscopy is colon segmentation because an incorrect segmentation may lead to a misdiagnosis. Materials and Methods: In this work, a hybrid method based on Geometric Deformable Models (GDM) in combination with an advanced region growing and thresholding methods is proposed. GDM are found to be an attractive tool for structural based image segmentation particularly for extracting the objects with complicated topology. There are two main parameters influencing the overall performance of GDM algorithm; the distance between the initial contour and the actual object’s contours and secondly the stopping term which controls the deformation. To overcome these limitations, a two stage hybrid based segmentation method is suggested to extract the rough but precise initial contours at the first stage of the segmentation. The extracted boundaries are smoothed and improved using a modified GDM algorithm by improving the stopping terms of the algorithm based on the gradient value of image voxels. Results: The proposed algorithm was implemented on forty data sets each containing 400-480 slices. The results show an improvement in the accuracy and smoothness of the extracted boundaries. The improvement obtained for the accuracy of segmentation is about 6% in comparison to the one achieved by the methods based on thresholding and region growing only. Discussion and Conclusion: The extracted contours using modified GDM are smoother and finer. The improvement achieved in this work on the performance of stopping function of GDM model together with applying two stage segmentation of boundaries have resulted in a great improvement on the computational efficiency of GDM algorithm while making smoother and finer colon borders.

Traditionally, seismic observations are carried out by the reflected wave method with multiple overlaps. Thus, the primary result of the processing of such data is the sum of CDP. For further imaging there is necessary to have the correct variant of migration without restrictions on the angle of reflectors, which is particularly important for the study of the geological structure of the mine fields. The paper presents a three-dimensional variant of the full-wave finite-difference migration in the time scale of the depths. That variant allows defining delicate structural features of the environment, the velocity model of which can be non-uniform across the board. The effectiveness of the proposed method to study the geological structure of the mine fields is demonstrated on a model example and practical materials observed in the Donbas region.

The increase the emerging technologies and the low cost related with 3D data acquisition have allowed researchers to open new doors of research in domains like building information modeling (BIM), in-process inspection, virtual simulation, reverse engineering, among others. However, these new doors carry out with them some challenges regarding data transmission, processing, storage, all of them currently being active research topics. This thesis aims to advance point cloud processing– specifically in segmentation– in three directions: First, we propose a hybrid technique for carrying out a semi-automatic segmentation using NARF and Min-Cut. Our technique can be modified to be used in different places or fields, for instance: in this thesis the technique was applied on urban and indoor environments, and dental models (medical field). Second, we conducted several tests to the hybrid technique and propose a method ology for the segmentation of dental models. In order to establish the methodology we used an exploratory study in segmentation of dental models, where it was tested by different algorithms (region growing, RANSAC, Min-Cut and the hybrid technique). Third, we developed another methodology based in the hybrid technique for segmenting objects in 3D scenes, aimed towards outdoor and indoor environments. A quantitative evaluation was carried out on a point cloud consisting of about 30 million points, with diverse objects of interest such as trees, cars, chairs, buildings Resumen: El aumento de las nuevas tecnologías emergentes y el bajo costo relacionado con los sistemas de adquisición 3D han permitido a los investigadores abrir nuevas puertas en la investigación en ámbitos como en la construcción de modelos de información (BIM), en el proceso de inspección, la simulación virtual, la ingeniería inversa, entre otros. Sin embargo, estas nuevas puertas traen consigo algunos desafíos en materias como: transmisión de datos, procesamiento, almacenamiento, permitiendo temas de investigación activos. Esta tesis tiene como objetivo avanzar en el procesamiento de nubes de puntos - específicamente en la segmentación - en tres direcciones: En primer lugar, se propone una técnica hibrida para llevar a cabo una segmentación semiautomática utilizando NARF y Min-Cut. Nuestra técnica puede ser modificado para ser utilizado en diferentes lugares o campos, por ejemplo: en esta tesis se aplicó la técnica en entornos urbanos e interiores, y los modelos dentales (campo de la medicina). En segundo lugar, hemos realizado varias pruebas con la técnica hibrida propuesta y se propone una metodología para la segmentación de los modelos dentales. La metodología se empleó en un estudio exploratorio para la segmentación de los modelos dentales, donde se probaron diferentes algoritmos (región de cultivo, RANSAC, MinCut y la técnica hibrida). Por último, se ha desarrollado una metodología basada para la segmentación de objetos en escenas 3D, dirigida hacia los ambientes interiores y exteriores. Una evaluación cuantitativa se llevó a cabo en la nube de puntos empleado el repositorio de Trimble que consta de nubes de cerca 30 millones de puntos, con diversos objetos de interés tales como árboles, coches, sillas, edificios Maestría

The main objective of the thesis is to improve our knowledge about dry snow metamorphismand its physical description, at the microscopic (ice grains and pores) andmacroscopic (snow layer) scales. First, the homogenization method of multiple scaleexpansions is applied for the first time to the physics involved in dry snow metamorphism.This way, we present the equivalent macroscopic descriptions of heat and vaportransfers derived from the physical description at micro-scale. We consider at the grainscale diffusion, conduction, and forced convection, coupled to phase changes (sublimationand deposition). Second, the effective properties of transport arising in the macroscopicdescriptions (effective thermal conductivity, effective coefficient of vapor diffusion, andintrinsic permeability) are estimated from 3D images of snow spanning the whole range ofdensity and snow types. Finally, the monitoring of metamorphism with time is considered.The relationship between the microstructure and the effective properties of a snow layerare investigated during temperature gradient metamorphism using 3D images. We presentthen a new cryogenic cell that we developed to monitor the grain to grain evolution of asnow sample by time-lapse tomography during the metamorphism, and which operates atroom temperature.; L’objectif général de la thèse est de contribuer à l’amélioration de nos connaissances sur les métamorphoses de la neige sèche et sur sa description physique, à l’échelle microscopique (grains de glace et pores) et macroscopique (couche de neige). Dans un premier temps,la méthode d’homogénéisation basée sur les développements asymptotiques à échelles multiples est appliquée à la physique des métamorphoses de la neige sèche. On présente ainsi les descriptions macroscopiques équivalentes du transport de vapeur et de chaleur dérivées à partir de la description de la physique à micro-échelle. On considère à l’échelle des grains la diffusion, la conduction, et la convection forcée, couplées aux changements de phase (sublimation et déposition). Dans un second temps, les propriétés effectives de transport impliquées dans les descriptions macroscopiques (conductivité thermique effective, coefficient effectif de diffusion de vapeur et perméabilité intrinsèque) sont estimées à l’aide d’images 3D de neige couvrant toute la gamme de masse volumique et de types de neige. Enfin, on s’intéresse au suivi temporel des métamorphoses. Les liens entre la microstructure et les propriétés effectives d’une couche de neige sont mis en évidence au cours d’une métamorphose de gradient de température en utilisant des images 3D.On présente ensuite une cellule cryogénique que nous avons mise au point pour le suivi grains à grains par tomographie des évolutions d’un échantillon de neige au cours des métamorphoses, et qui s’utilise à température ambiante.

Objective knowledge of tissue density distribution in CT/MRI brain datasets can be related to anatomical or neuro-functional regions for assessing pathologic conditions characterised by slight differences. The process of monitoring illness and its treatment could be then improved by a suitable detection of these variations. In this paper, we present an approach for three-dimensional (3D) classification of brain tissue densities based on a hierarchicalartificial neural network(ANN) able to classify the single voxels of the examined datasets. The method developed was tested on case studies selected by an expert neuro-radiologist and consisting of both normal andpathological conditions. The results obtained were submitted for validation to a group of physicians and they judged the system to be really effective in practical applications.

The "upper" airway, which is the most frequently analyzed portion in orthodontics and oral maxillofacial surgery, is divided anatomically into nasopharyix, oropharynx and the hypopharynx. This chapter summarizes several of the historical methods used to describe the airway, to discuss the limitations of these earlier methods, and to examine how new noninvasive low radiation dose and true 3D images enable the practitioner to better understand airway size, shape, and volume. Several initial investigations that have used this new technology to study the potential effects of clinical interventions on airway dimensional changes also are described. The airway parameters in healthy and apneic subjects are also discussed. Prior to adapting a new technology such as CBCT to examine the airway, its measurement accuracy and reliability must be validated. Both linear and angular measurements from CBCTs have been shown to be highly accurate with a measurement accuracy of up to 0.1 mm.

Optical microscopy has been used in biomedical studies for more than three centuries, but the limitations imposed by light scattering restricted it to superficial studies. However, novel systems have led to the acquisition of 3D images by means of novel laser techniques, thus making it possible to examine features at depths and resolutions that were impossible before. They are referred as optical tomography systems, and they are of special interest in developmental biology studies, where fluorescent proteins are to be identified in transgenic animals for determining cell and tissue behavior. The main problem resides in the fact that although it is a noninvasive technique the sample should be transparent. For this purpose different methods have been developed, all of them based on the idea that water inside the sample has to be replaced with a liquid that has the same refractive index that proteins and lipids for preventing light scattering effects. The resolution obtained with these techniques is such that a gap which was previously uncovered by other techniques is hence possible. This is due to the fact that techniques like confocal microscopy have a higher resolution, but consequently a smaller Field of View (FOV). On the other hand, there are tomographic techniques like Computed Tomography that cover a much larger FOV, but they have a smaller resolution, being in this way more appropriate for large animal or humans. Nevertheless, each imaging modality uses a different technique for obtaining the 3D image, and depending on the technique used, it will be more appropriate for an specific study. However, it is still not clear in the literature which advantages one technique has over another, and more importantly, under which conditions is it more convenient to use each technique. All in all, besides having created a theoretical model for characterizing an optical system, it was put into practice by means of a software that analyzes the 3D image for obtaining the desired results and quantifying the resolution of the system. Furthermore, after having tested it and concluding that the results were accurate, it was also proved to be useful when used for studying the effect of scattering on the PSF. The fact that this model is also incorporated in an easy to implement protocol that can be put into practice by a standard user gives account of the scope of the future applications in which it can be used. Ingeniería Biomédica

In this thesis, we improve a recent image segmentation algorithm based on a graph regularization process. The goal of this method is to compute an indicator function that satisfies a regularity and a fidelity criteria. Its particularity is to represent images with similarity graphs. This data structure allows relations to be established between similar pixels, leading to non-local processing of the data. In order to improve this approach, combine it with another non-local one: the texture features. Two solutions are developped, both based on Haralick features. In the first one, we propose a new fidelity term which is based on the work of Chan and Vese and is able to evaluate the homogeneity of texture features. In the second method, we propose to replace the fidelity criteria by the output of a supervised classifier. Trained to recognize several textures, the classifier is able to produce a better modelization of the problem by identifying the most relevant texture features. This method is also extended to multiclass segmentation problems. Both are applied to 2D and 3D textured images.; Dans cette thèse, nous nous intéressons à un récent algorithme de segmentation d’images basé sur un processus de régularisation de graphes. L’objectif d’un tel algorithme est de calculer une fonction indicatrice de la segmentation qui satisfait un critère de régularité ainsi qu’un critère d’attache aux données. La particularité de cette approche est de représenter les images à l’aide de graphes de similarité. Ceux-ci permettent d’établir des relations entre des pixels non-adjacents, et ainsi de procéder à un traitement non-local des images. Afin d’en améliorer la précision, nous combinons cet algorithme à une seconde approche non-locale : des caractéristiques de textures. Un nouveau terme d’attache aux données est dans un premier temps développé. Inspiré des travaux de Chan et Vese, celui-ci permet d’évaluer l’homogénéité d’un ensemble de caractéristiques de textures. Dans un second temps, nous déléguons le calcul de l’attache aux données à un classificateur supervisé. Entrainé à reconnaitre certaines classes de textures, ce classificateur permet d’identifier les caractéristiques les plus pertinentes, et ainsi de fournir une modélisation plus aboutie du problème. Cette seconde approche permet par ailleurs une segmentation multiclasse. Ces deux méthodes ont été appliquées à la segmentation d’images texturées 2D et 3D.

In a context of ever-growing interest in stereoscopic systems, but where no standardized algorithmic methods of stereoscopic quality assessment exist, our work stands as a step forward in the understanding of the human perception and judgment mechanisms related to the multidimensional concept of stereoscopic image quality. We used a series of tools in order to perform in-depth investigations in this direction: we proposed an adapted framework to structure the process of stereoscopic quality assessment, we implemented a stereoscopic system in our laboratory for performing various tests, we created three stereoscopic datasets with precise structures, and we performed several experimental studies using these datasets. The numerous experimental data obtained were used in order to propose a first mathematical framework for explaining the overall percept of stereoscopic quality in function of the physical parameters of the stereoscopic images under study.; Dans le contexte d'un intérêt grandissant pour les systèmes stéréoscopiques, mais sans méthodes reproductible pour estimer leur qualité, notre travail propose une contribution à la meilleure compréhension des mécanismes de perception et de jugement humains relatifs au concept multi-dimensionnel de qualité d'image stéréoscopique. Dans cette optique, notre démarche s'est basée sur un certain nombre d'outils : nous avons proposé un cadre adapté afin de structurer le processus d'analyse de la qualité des images stéréoscopiques, nous avons implémenté dans notre laboratoire un système expérimental afin de conduire plusieurs tests, nous avons crée trois bases de données d'images stéréoscopiques contenant des configurations précises et enfin nous avons conduit plusieurs expériences basées sur ces collections d'images. La grande quantité d'information obtenue par l'intermédiaire de ces expérimentations a été utilisée afin de construire un premier modèle mathématique permettant d'expliquer la perception globale de la qualité de la stéréoscopie en fonction des paramètres physiques des images étudiée.

Research and development on 3-D displays make great progress and even autostereoscopic 3-D displays are on the verge of being put onto the market. The main market within the near future will be, besides entertainment applications, the field of multimedia desktop displays. The use of autostereoscopic displays makes it possible to watch 3-D images without special glasses. Particularly in communication applications dark spectacles hamper natural face-to-face communication. This paper presents a concept for a realization of a 3-D desktop display which was developed at the Heinrich-Hertz-Institute. In this concept a collimation optic was combined with an autostereoscopic display unit. In the past, collimation optics were usually used in head mounted devices. Only a few realizations of autostereoscopic displays are known, which combine autostereoscopic technologies with collimation optics. Studies performed at NASA's Langley Research Center showed that the usable volume of depth can extend to large values when a collimation optic is integrated in a stereoscopic display. Results of our work showed that a "puppet theater effect" is not perceptible when a collimated display is used. Two autostereoscopic prototype setups suitable for communication applications were realized that avoid the disadvantages of most common stereoscopic displays.

For facilitating images under nonlinear transformations, the splitting-shooting method, the splitting-integrating method, and their combinations are presented in [1], which do not require nonlinear solutions, but have the low convergence rate O( 1 N ) of sequential pixel (or voxel) greyness, where N is the division number to split a 3D image voxel into N3 subvoxels. In this paper, new partition techniques of 3D subregions are proposed to evaluate carefully overlaps between a cube and the distorted subvoxel region and then applied to the splitting-shooting method, the splitting-integrating method, and their combinations. Error analysis is made to prove that the convergence rate O( 1 N 2 ) can be achieved, and numerical experiments are carried out to confirm the theoretical analysis mode. A remarkable advantage of the new discrete techniques is that no solutions of nonlinear equations are required either. The discrete techniques in this paper are well suited not only to solid objects but also to surfaces and curves in three dimensions, thus to benefit the study in many topics in computer science, such as computer vision, image processing, and pattern recognition.

The performances of several 3D imaging/video applications (going from 3DTV to video surveillance) benefit from the estimation or acquisition of accurate and high quality depth maps. However, the characteristics of depth information is strongly affected by the procedure employed in its acquisition or estimation (e.g., stereo evaluation, ToF cameras, structured light sensors, etc.), and the very definition of “quality” for a depth map is still under investigation. In this paper we proposed an unsupervised quality metric for depth information in Depth Image Based Rendering signals that predicts the accuracy in synthesizing 3D models and lateral views by using the considered depth information. The metric has been tested on depth maps generate with different algorithms and sensors. Moreover, experimental results show how it is possible to progressively improve the performance of 3D modelization by controlling the device/algorithm with this metric.

International audience; The detection of persons in an image has been the subject of several studies. Most of these works were done on images taken by cameras in visible light (RGB). In this paper, we are interested in people contours detection on the Kinect 3D images. We investigate the application of Gradient approach and optimal filters on depth images. We also use this detection to monitor the person via her gestures. Results show that edge detection of Canny is good for people in both light condition but, the performance of Sobel algorithm was better for the images taken in the dark depths.

We suggest a symmetric-polar pixellation scheme which makes possible a reduction of the computational cost for expectation maximization (EM) iterative algorithms. The proposed symmetric-polar pixellation allows us to deal with 3D images as a whole problem without dividing the 3D problem into 2D slices approach. Performance evaluation of each approach in terms of stability and image quality is presented. Exhaustive comparisons between all approaches were conducted in a 2D based image reconstruction model. From these 2D approaches, that showing the best performances were finally implemented and evaluated in a 3D based image reconstruction model. Comparison to 3D images reconstructed with FBP is also presented. Although the algorithm is presented in the context of computed tomography (CT) image reconstruction, it can be applied to any other tomographic technique as well, due to the fact that the only requirement is a scanning geometry involving measurements of an object under different projection angles. Real data have been acquired with a small animal (CT) scanner to verify the proposed mathematical description of the CT system., This work was supported by the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+I) under Grant, FIS2010-21216-CO2-01, Valencian Local Government under Grant Nos. PROMETEO 2008/114 and APOSTD/2010/012. The authors would like to thank Brennan Holt for checking and correcting the text.

In this thesis, we improve a recent image segmentation algorithm based on a graph regularization process. The goal of this method is to compute an indicator function that satisfies a regularity and a fidelity criteria. Its particularity is to represent images with similarity graphs. This data structure allows relations to be established between similar pixels, leading to non-local processing of the data. In order to improve this approach, combine it with another non-local one: the texture features. Two solutions are developped, both based on Haralick features. In the first one, we propose a new fidelity term which is based on the work of Chan and Vese and is able to evaluate the homogeneity of texture features. In the second method, we propose to replace the fidelity criteria by the output of a supervised classifier. Trained to recognize several textures, the classifier is able to produce a better modelization of the problem by identifying the most relevant texture features. This method is also extended to multiclass segmentation problems. Both are applied to 2D and 3D textured images., Dans cette thèse, nous nous intéressons à un récent algorithme de segmentation d’images basé sur un processus de régularisation de graphes. L’objectif d’un tel algorithme est de calculer une fonction indicatrice de la segmentation qui satisfait un critère de régularité ainsi qu’un critère d’attache aux données. La particularité de cette approche est de représenter les images à l’aide de graphes de similarité. Ceux-ci permettent d’établir des relations entre des pixels non-adjacents, et ainsi de procéder à un traitement non-local des images. Afin d’en améliorer la précision, nous combinons cet algorithme à une seconde approche non-locale : des caractéristiques de textures. Un nouveau terme d’attache aux données est dans un premier temps développé. Inspiré des travaux de Chan et Vese, celui-ci permet d’évaluer l’homogénéité d’un ensemble de caractéristiques de textures. Dans un second temps, nous déléguons le calcul de l’attache aux données à un classificateur supervisé. Entrainé à reconnaitre certaines classes de textures, ce classificateur permet d’identifier les caractéristiques les plus pertinentes, et ainsi de fournir une modélisation plus aboutie du problème. Cette seconde approche permet par ailleurs une segmentation multiclasse. Ces deux méthodes ont été appliquées à la segmentation d’images texturées 2D et 3D.