3D facial merging for virtual human reconstruction

There is an increasing need of easy and affordable technologies to automatically generate virtual 3D models from their real counterparts. In particular, 3D human reconstruction has driven the creation of many clever techniques, most of them based on the visual hull (VH) concept. Such techniques do not require expensive hardware; however, they tend to yield 3D humanoids with realistic bodies but mediocre faces, since VH cannot handle concavities. On the other hand, structured light projectors allow to capture very accurate depth data, and thus to reconstruct realistic faces, but they are too expensive to use several of them. We have developed a technique to merge a VH-based 3D mesh of a reconstructed humanoid and the depth data of its face, captured by a single structured light projector. By combining the advantages of both systems in a simple setting, we are able to reconstruct realistic 3D human models with believable faces.

Application of two segmentation protocols during the processing of virtual images in rapid prototyping: ex vivo study with human dry mandibles

The aim of this study was to evaluate the accuracy of virtual three-dimensional (3D) reconstructions of human dry mandibles, produced from two segmentation protocols (outline only and all-boundary lines).Twenty virtual three-dimensional (3D) images were built from computed tomography exam (CT) of 10 dry mandibles, in which linear measurements between anatomical landmarks were obtained and compared to an error probability of 5 %.The results showed no statistically significant difference among the dry mandibles and the virtual 3D reconstructions produced from segmentation protocols tested (p = 0,24).During the designing of a virtual 3D reconstruction, both outline only and all-boundary lines segmentation protocols can be used.Virtual processing of CT images is the most complex stage during the manufacture of the biomodel. Establishing a better protocol during this phase allows the construction of a biomodel with characteristics that are closer to the original anatomical structures. This is essential to ensure a correct preoperative planning and a suitable treatment.

Range of motion in anterior femoroacetabular impingement

The range of motion of normal hips and hips with femoroacetabular impingement relative to some specific anatomic reference landmarks is unknown. We therefore described: (1) the range of motion pattern relative to landmarks; (2) the location of the impingement zones in normal and impinging hips; and (3) the influence of surgical débridement on the range of motion. We used a previously developed and validated noninvasive 3-D CT-based method for kinematic hip analysis to compare the range of motion pattern, the location of impingement, and the effect of virtual surgical reconstruction in 28 hips with anterior femoroacetabular impingement and a control group of 33 normal hips. Hips with femoroacetabular impingement had decreased flexion, internal rotation, and abduction. Internal rotation decreased with increasing flexion and adduction. The calculated impingement zones were localized in the anterosuperior quadrant of the acetabulum and were similar in the two groups and in impingement subgroups. The average improvement of internal rotation was 5.4 degrees for pincer hips, 8.5 degrees for cam hips, and 15.7 degrees for mixed impingement. This method helps the surgeon quantify the severity of impingement and choose the appropriate treatment option; it provides a basis for future image-guided surgical reconstruction in femoroacetabular impingement with less invasive techniques.

Sviluppo di un sistema di Realta Aumentata applicato a un modello 3D della prostata, sviluppato a partire da immagini RM, al fine di facilitare la dissezione del tumore e la conservazione dei fasci neuro vascolari durante l'intervento chirurgico di prostatectomia radicale robot-assistita

La realtà aumentata (AR) è una nuova tecnologia adottata in chirurgia prostatica con l'obiettivo di migliorare la conservazione dei fasci neurovascolari (NVB) ed evitare i margini chirurgici positivi (PSM). Abbiamo arruolato prospetticamente pazienti con diagnosi di cancro alla prostata (PCa) sul base di biopsia di fusione mirata con mpMRI positiva. Prima dell'intervento, i pazienti arruolati sono stati indirizzati a sottoporsi a ricostruzione del modello virtuale 3D basato su mpMRI preoperatoria immagini. Infine, il chirurgo ha eseguito la RARP con l'ausilio del modello 3D proiettato in AR all'interno della console robotica (RARP guidata AR-3D). I pazienti sottoposti a AR RARP sono stati confrontati con quelli sottoposti a "RARP standard" nello stesso periodo. Nel complesso, i tassi di PSM erano comparabili tra i due gruppi; I PSM a livello della lesione indice erano significativamente più bassi nei pazienti riferiti al gruppo AR-3D (5%) rispetto a quelli nel gruppo di controllo (20%; p = 0,01). La nuova tecnica di guida AR-3D per l'analisi IFS può consentono di ridurre i PSM a livello della lesione dell'indice

Are virtual planning and guided surgery for head and neck reconstruction economically viable?

PURPOSE: Virtual planning and guided surgery with or without prebent or milled plates are becoming more and more common for mandibular reconstruction with fibular free flaps (FFFs). Although this excellent surgical option is being used more widely, the question of the additional cost of planning and cutting-guide production has to be discussed. In capped payment systems such additional costs have to be offset by other savings if there are no special provisions for extra funding. Our study was designed to determine whether using virtual planning and guided surgery resulted in time saved during surgery and whether this time gain resulted in self-funding of such planning through the time saved. MATERIALS AND METHODS: All consecutive cases of FFF surgery were evaluated during a 2-year period. Institutional data were used to determine the price of 1 minute of operative time. The time for fibula molding, plate adaptation, and insetting was recorded. RESULTS: During the defined period, we performed 20 mandibular reconstructions using FFFs, 9 with virtual planning and guided surgery and 11 freehand cases. One minute of operative time was calculated to cost US $47.50. Multiplying this number by the time saved, we found that the additional cost of virtual planning was reduced from US $5,098 to US $1,231.50 with a prebent plate and from US $6,980 to US $3,113.50 for a milled plate. CONCLUSIONS: Even in capped health care systems, virtual planning and guided surgery including prebent or milled plates are financially viable.

Multi-view 3D reconstruction using virtual cameras

Ce mémoire s'intéresse à la reconstruction d'un modèle 3D à partir de plusieurs images. Le modèle 3D est élaboré avec une représentation hiérarchique de voxels sous la forme d'un octree. Un cube englobant le modèle 3D est calculé à partir de la position des caméras. Ce cube contient les voxels et il définit la position de caméras virtuelles. Le modèle 3D est initialisé par une enveloppe convexe basée sur la couleur uniforme du fond des images. Cette enveloppe permet de creuser la périphérie du modèle 3D. Ensuite un coût pondéré est calculé pour évaluer la qualité de chaque voxel à faire partie de la surface de l'objet. Ce coût tient compte de la similarité des pixels provenant de chaque image associée à la caméra virtuelle. Finalement et pour chacune des caméras virtuelles, une surface est calculée basée sur le coût en utilisant la méthode de SGM. La méthode SGM tient compte du voisinage lors du calcul de profondeur et ce mémoire présente une variation de la méthode pour tenir compte des voxels précédemment exclus du modèle par l'étape d'initialisation ou de creusage par une autre surface. Par la suite, les surfaces calculées sont utilisées pour creuser et finaliser le modèle 3D. Ce mémoire présente une combinaison innovante d'étapes permettant de créer un modèle 3D basé sur un ensemble d'images existant ou encore sur une suite d'images capturées en série pouvant mener à la création d'un modèle 3D en temps réel.

Three-dimensional Reconstruction of Ovaries of Leaf-cutting Ant (Atta sexdens rubropilosa) Queens (Hymenoptera: Formicidae)

In this study, the ovary morphology of newly emerged ant queens of Atta sexdens rubropilosa was studied in whole mount preparations by confocal microscopy. The ovaries are composed of approximately 40 ovarioles, showing non-synchronic oocyte maturation. The terminal filament with clusters of undifferentiated cells was found at the distal end of the ovarioles. Next to this region is the germarium, composed of several elongated cystocytes interconnected by cytoplasmic bridges. The nurse cells (23-28 cells) result from asymmetric mitosis. Cytoskeleton analysis showed F-actin concentrated at the muscle cells of the external tunica and in fusomes inside the ovarioles. Microtubules were concentrated around the nuclei of the nurse and follicular cells. In contrast, the oocytes and the external tunica showed faint staining for tubulin.

Accident or homicide - virtual crime scene reconstruction using 3D methods

The analysis and reconstruction of forensically relevant events, such as traffic accidents, criminal assaults and homicides are based on external and internal morphological findings of the injured or deceased person. For this approach high-tech methods are gaining increasing importance in forensic investigations. The non-contact optical 3D digitising system GOM ATOS is applied as a suitable tool for whole body surface and wound documentation and analysis in order to identify injury-causing instruments and to reconstruct the course of event. In addition to the surface documentation, cross-sectional imaging methods deliver medical internal findings of the body. These 3D data are fused into a whole body model of the deceased. Additional to the findings of the bodies, the injury inflicting instruments and incident scene is documented in 3D. The 3D data of the incident scene, generated by 3D laser scanning and photogrammetry, is also included into the reconstruction. Two cases illustrate the methods. In the fist case a man was shot in his bedroom and the main question was, if the offender shot the man intentionally or accidentally, as he declared. In the second case a woman was hit by a car, driving backwards into a garage. It was unclear if the driver drove backwards once or twice, which would indicate that he willingly injured and killed the woman. With this work, we demonstrate how 3D documentation, data merging and animation enable to answer reconstructive questions regarding the dynamic development of patterned injuries, and how this leads to a real data based reconstruction of the course of event.

Virtual reconstruction of the 400 toneladas nao from Diego García de Palacio’s Instrucción náutica (1587)

The period between 1570-1620 has left a remarkable amount of documents related to shipbuilding in the Iberian Peninsula. Among them, the Instrucción nautica written by Diego García de Palacio in 1587 is widely recognized as the first published book that includes an extensive discussion of ship design and construction. García de Palacio centres his discussion on a 400 toneladas nao, a series of woodcuts that illustrate the shape and dimensions of the ship accompany the explanation. In the late XVI century ship hulls were designed following procedures based upon an old shipwrightry tradition born in the Mediterranean. By simple rules the master shipwright plots the central frame and tail frames and complete the hull body using wooden ribbands. Computer software for 3D modelling using NURBs surfaces helps to recreate ships hulls. In this work the 400 toneladas nao is reconstructed and her hydrostatic parameters are compared with other ships.

Rice morphogenesis and plant architecture: Measurement, specification and the reconstruction of structural development by 3D architectural modelling

Background and Aims The morphogenesis and architecture of a rice plant, Oryza sativa, are critical factors in the yield equation, but they are not well studied because of the lack of appropriate tools for 3D measurement. The architecture of rice plants is characterized by a large number of tillers and leaves. The aims of this study were to specify rice plant architecture and to find appropriate functions to represent the 3D growth across all growth stages. Methods A japonica type rice, 'Namaga', was grown in pots under outdoor conditions. A 3D digitizer was used to measure the rice plant structure at intervals from the young seedling stage to maturity. The L-system formalism was applied to create '3D virtual rice' plants, incorporating models of phenological development and leaf emergence period as a function of temperature and photoperiod, which were used to determine the timing of tiller emergence. Key Results The relationships between the nodal positions and leaf lengths, leaf angles and tiller angles were analysed and used to determine growth functions for the models. The '3D virtual rice' reproduces the structural development of isolated plants and provides a good estimation of the fillering process, and of the accumulation of leaves. Conclusions The results indicated that the '3D virtual rice' has a possibility to demonstrate the differences in the structure and development between cultivars and under different environmental conditions. Future work, necessary to reflect both cultivar and environmental effects on the model performance, and to link with physiological models, is proposed in the discussion.

Knowledge-based Virtual Reconstruction of Museum Artifacts

Within the framework of heritage preservation, 3D scanning and modeling for heritage documentation has increased significantly in recent years, mainly due to the evolution of laser and image-based techniques, modeling software, powerful computers and virtual reality. 3D laser acquisition constitutes a real development opportunity for 3D modeling based previously on theoretical data. The representation of the object information rely on the knowledge of its historic and theoretical frame to reconstitute a posteriori its previous states. This project proposes an approach dealing with data extraction based on architectural knowledge and Laser statement informing measurements, the whole leading to 3D reconstruction. The experimented Khmer objects are exposed at Guimet museum in Paris. The purpose of this digital modeling meets the need of exploitable models for simulation projects, prototyping, exhibitions, promoting cultural tourism and particularly for archiving against any likely disaster and as an aided tool for the formulation of virtual museum concept.

Virtual Reconstruction of the Ancient Russian Fortress Koporye

One of the major strategic tasks in Russia’s northwest of the past centuries was the defense of the country’s territories from enemy incursions coming from the West. In order to solve this task, a robust shield in the form of a system of fortresses was created between the 13th and 15th centuries. The system included such fortresses as Koporye, Yam, Korela, Oreshek, and others. In our age, these monuments have become an essential part of Russia’s historic and cultural heritage and an important element of the tourism cluster “The Silver Ring of Russia.” The Centre of Design and Multimedia at St. Petersburg National Research University of Information Technologies, Mechanics and Optics, jointly with the Department of History and the Faculty of Arts at St. Petersburg State University, working under a three-year grant from the Russian Foundation for Humanities Research (#12-01-12041), is implementing a multimedia information system “Ancient Fortresses of Russia’s Northwest”. Historically accurate virtual reconstruction of several fortresses as they existed during certain historic periods, done in such a way as to allow the future creation of virtual tours of these sites, has become the focus of this project’s research. In the present paper, we describe the main phases and results of virtual reconstruction of the best-preserved fortress, Koporye.

Graled (Grapevine leaf digitalization) Software for the Detection and Graphic Reconstruction of Ampelometric Differences Between Vitis Leaves

Raster graphic ampelometric software was not exclusively developed for the estimation of leaf area, but also for the characterization of grapevine (Viti vinifera L.) leaves. The software was written in C-Hprogramming language, using the C-1-1- Builder 2007 for Windows 95-XP and Linux operation systems. It handles desktop-scanned images. On the image analysed with the GRA.LE.D., the user has to determine 11 points. These points are then connected and the distances between them calculated. The GRA.LE.D. software supports standard ampelometric measurements such as leaf area, angles between the veins and lengths of the veins. These measurements are recorded by the software and exported into plain ASCII text files for single or multiple samples. Twenty-two biometric data points of each leaf are identified by the GRA.LE.D. It presents the opportunity to statistically analyse experimental data, allows comparison of cultivars and enables graphic reconstruction of leaves using the Microsoft Excel Chart Wizard. The GRA. LE.D. was thoroughly calibrated and compared to other widely used instruments and methods such as photo-gravimetry, LiCor L0100, WinDIAS2.0 and ImageTool. By comparison, the GRA.LE.D. presented the most accurate measurements of leaf area, but the LiCor L0100 and the WinDIAS2.0 were faster, while the photo-gravimetric method proved to be the most time-consuming. The WinDIAS2.0 instrument was the least reliable. The GRA.LE.D. is uncomplicated, user-friendly, accurate, consistent, reliable and has wide practical application.