Towards Better Methods of Stereoscopic 3D Media Adjustment and Stylization

Stereoscopic 3D (S3D) media is pervasive in film, photography and art. However, working with S3D media poses a number of interesting challenges arising from capture and editing. In this thesis we address several of these challenges. In particular, we address disparity adjustment and present a layer-based method that can reduce disparity without distorting the scene. Our method was successfully used to repair several images for the 2014 documentary “Soldiers’ Stories” directed by Jonathan Kitzen. We then explore consistent and comfortable methods for stylizing stereo images. Our approach uses a modified version of the layer-based technique used for disparity adjustment and can be used with a variety of stylization filters, including those in Adobe Photoshop. We also present a disparity-aware painterly rendering algorithm. A user study concluded that our layer-based stylization method produced S3D images that were more comfortable than previous methods. Finally, we address S3D line drawing from S3D photographs. Line drawing is a common art style that our layer-based method is not able to reproduce. To improve the depth perception of our line drawings we optionally add stylized shading. An expert survey concluded that our results were comfortable and reproduced a sense of depth

The Dento-Gingival Junction as Seen with Light Microscopy and Scanning Electron Microscopy

The purpose of this paper is to review the anatomical relationship of the Dento-Gingival Junction as seen in the human dentition. The junction is described under light microscopy and then reviewed as seen in the SEM with the authors\u27 unpublished findings. The authors\u27 material was derived from extracted human teeth with remaining marginal gingival tissue. The specimens were fixed with 2% glutaraldehyde in O.15M sodium cacodylate buffer (pH 7.2) for 24 h. The specimens were then washed and freeze-fractured in Freon 113 using liquid nitrogen. Afterwards they were processed by freeze-drying or CPD methods, coated with gold, and placed in the scanning electron microscope (SEM) for viewing. These specimens demonstrated the presence of numerous Sharpey\u27s fibers at the cemental surface. A large number of fibrils intermingled with the fibers to produce a dense mass of tissue. Junctional epithelium, with the adjacent homogeneous dental cuticle was demonstrated. Plaque deposits on the tooth surface extended to a cell-free zone. Morphological detail viewed with SEM and light microscopy are compared

Stylized 3D Scene Synthesis in Virtual Reality

Many forms of life in the natural world have the extraordinary capacity to sense their environments, to learn, and to remember, just as humans do, even though they are vastly different from us. In this dissertation, I presented novel techniques developed to exhibit an interactive abstract virtual reality experience that invites viewers to see the natural world from a different perspective. I developed the vertex displacement and color turbulence approaches to showcase organisms. The organisms can also modulate their shapes according to the volumes and frequencies of sound. Furthermore, the experience displays turbulent flow on the organisms’ surface to demonstrate the concept of energy flow, or vitality, among all organisms in the natural world. Another novel feature is that viewers can interact with the surface colors through ray casting from a handheld controller

A new species of Rhabdotalebra Young (Hemiptera: Cicadellidae: Typhlocybinae) associated with the guaran-guaran (Bignoniaceae: Tecoma stans L.) in Argentina

The genus Rhabdotalebra Young is reviewed, including description of a new species, R. albinoi n. sp., from Buenos Aires province, Argentina. A detailed morphological description and illustrations of the new species are provided. A key of all known Rhabdotalebra species is provided to facilitate the comparison of the new species with those previously known, based on pattern coloration and male and female genitalia, is given. Some field observations on its biology are also provided.Facultad de Ciencias Naturales y Muse

Dynamic data structures and saliency-influenced rendering

With increasing heterogeneity of modern hardware, different requirements for 3d applications arise. Despite the fact that real-time rendering of photo-realistic images is possible using today’s graphics cards, still large computational effort is required. Furthermore, smart-phones or computers with older, less powerful graphics cards may not be able to reproduce these results. To retain interactive rendering, usually the detail of a scene is reduced, and so less data needs to be processed. This removal of data, however, may introduce errors, so called artifacts. These artifacts may be distracting for a human spectator when gazing at the display. Thus, the visual quality of the presented scene is reduced. This is counteracted by identifying features of an object that can be removed without introducing artifacts. Most methods utilize geometrical properties, such as distance or shape, to rate the quality of the performed reduction. This information used to generate so called Levels Of Detail (LODs), which are made available to the rendering system. This reduces the detail of an object using the precalculated LODs, e.g. when it is moved into the back of the scene. The appropriate LOD is selected using a metric, and it is replaced with the current displayed version. This exchange must be made smoothly, requiring both LOD-versions to be drawn simultaneously during a transition. Otherwise, this exchange will introduce discontinuities, which are easily discovered by a human spectator. After completion of the transition, only the newly introduced LOD-version is drawn and the previous overhead removed. These LOD-methods usually operate with discrete levels and exploit limitations of both the display and the spectator: the human. Humans are limited in their vision. This ranges from being unable to distinct colors at varying illumination scenarios to the limitation to focus only at one location at a time. Researchers have developed many applications to exploit these limitations to increase the quality of an applied compression. Some popular methods of vision-based compression are MPEG or JPEG. For example, a JPEG compression exploits the reduced sensitivity of humans regarding color and so encodes colors with a lower resolution. Also, other fields, such as auditive perception, allow the exploitation of human limitations. The MP3 compression, for example, reduces the quality of stored frequencies if other frequencies are masking it. For representation of perception various computer models exist. In our rendering scenario, a model is advantageous that cannot be influenced by a human spectator, such as the visual salience or saliency. Saliency is a notion from psycho-physics that determines how an object “pops out” of its surrounding. These outstanding objects (or features) are important for the human vision and are directly evaluated by our Human Visual System (HVS). Saliency combines multiple parts of the HVS and allows an identification of regions where humans are likely to look at. In applications, saliency-based methods have been used to control recursive or progressive rendering methods. Especially expensive display methods, such as pathtracing or global illumination calculations, benefit from a perceptual representation as recursions or calculations can be aborted if only small or unperceivable errors are expected to occur. Yet, saliency is commonly applied to 2d images, and an extension towards 3d objects has only partially been presented. Some issues need to be addressed to accomplish a complete transfer. In this work, we present a smart rendering system that not only utilizes a 3d visual salience model but also applies the reduction in detail directly during rendering. As opposed to normal LOD-methods, this detail reduction is not limited to a predefined set of levels, but rather a dynamic and continuous LOD is created. Furthermore, to apply this reduction in a human-oriented way, a universal function to compute saliency of a 3d object is presented. The definition of this function allows to precalculate and store object-related visual salience information. This stored data is then applicable in any illumination scenario and allows to identify regions of interest on the surface of a 3d object. Unlike preprocessed methods, which generate a view-independent LOD, this identification includes information of the scene as well. Thus, we are able to define a perception-based, view-specific LOD. Performance measures of a prototypical implementation on computers with modern graphic cards achieved interactive frame rates, and several tests have proven the validity of the reduction. The adaptation of an object is performed with a dynamic data structure, the TreeCut. It is designed to operate on hierarchical representations, which define a multi-resolution object. In such a hierarchy, the leaf nodes contain the highest detail while inner nodes are approximations of their respective subtree. As opposed to classical hierarchical rendering methods, a cut is stored and re-traversal of a tree during rendering is avoided. Due to the explicit cut representation, the TreeCut can be altered using only two core operations: refine and coarse. The refine-operation increases detail by replacing a node of the tree with its children while the coarse-operation removes the node along with its siblings and replaces them with their parent node. These operations do not rely on external information and can be performed in a local manner. These only require direct successor or predecessor information. Different strategies to evolve the TreeCut are presented, which adapt the representation using only information given by the current cut. These evaluate the cut by assigning either a priority or a target-level (or bucket) to each cut-node. The former is modelled as an optimization problem that increases the average priority of a cut while being restricted in some way, e.g. in size. The latter evolves the cut to match a certain distribution. This is applied in cases where a prioritization of nodes is not applicable. Both evaluation strategies operate with linear time complexity with respect to the size of the current TreeCut. The data layout is chosen to separate rendering data and hierarchy to enable multi-threaded evaluation and display. The object is adapted over multiple frames while the rendering is not interrupted by the used evaluation strategy. Therefore, we separate the representation of the hierarchy from the rendering data. Due to its design, this overhead imposed to the TreeCut data structure does not influence rendering performance, and a linear time complexity for rendering is retained. The TreeCut is not only limited to alter geometrical detail of an object. The TreeCut has successfully been applied to create a non-photo-realistic stippling display, which draws the object with equal sized points in varying density. In this case the bucket-based evaluation strategy is utilized, which determines the distribution of the cut based on local illumination information. As an alternative, an attention drawing mechanism is proposed, which applies the TreeCut evaluation strategies to define the display style of a notification icon. A combination of external priorities is used to derive the appropriate icon version. An application for this mechanism is a messaging system that accounts for the current user situation. When optimizing an object or scene, perceptual methods allow to account for or exploit human limitations. Therefore, visual salience approaches derive a saliency map, which encodes regions of interest in a 2d map. Rendering algorithms extract importance from such a map and adapt the rendering accordingly, e.g. abort a recursion when the current location is unsalient. The visual salience depends on multiple factors including the view and the illumination of the scene. We extend the existing definition of the 2d saliency and propose a universal function for 3d visual salience: the Bidirectional Saliency Weight Distribution Function (BSWDF). Instead of extracting the saliency from 2d image and approximate 3d information, we directly compute this information using the 3d data. We derive a list of equivalent features for the 3d scenario and add them to the BSWDF. As the BSWDF is universal, also 2d images are covered with the BSWDF, and the calculation of the important regions within images is possible. To extract the individual features that contribute to visual salience, capabilities of modern graphics card in combination with an accumulation method for rendering is utilized. Inspired from point-based rendering methods local features are summed up in a single surface element (surfel) and are compared with their surround to determine whether they “pop out”. These operations are performed with a shader-program that is executed on the Graphics Processing Unit (GPU) and has direct access to the 3d data. This increases processing speed because no transfer of the data is required. After computation, each of these object-specific features can be combined to derive a saliency map for this object. Surface specific information, e.g. color or curvature, can be preprocessed and stored onto disk. We define a sampling scheme to determine the views that need to be evaluated for each object. With these schemes, the features can be interpolated for any view that occurs during rendering, and the according surface data is reconstructed. These sampling schemes compose a set of images in form of a lookup table. This is similar to existing rendering techniques, which extract illumination information from a lookup. The size of the lookup table increases only with the number of samples or the image size used for creation as the images are of equal size. Thus, the quality of the saliency data is independent of the object’s geometrical complexity. The computation of a BSWDF can be performed either on a Central Processing Unit (CPU) or a GPU, and an implementation requires only a few instructions when using a shader program. If the surface features have been stored during a preprocess, a reprojection of the data is performed and combined with the current information of the object. Once the data is available, the computation of the saliency values is done using a specialized illumination model, and a priority for each primitive is extracted. If the GPU is used, the calculated data has to be transferred from the graphics card. We therefore use the “transform feedback” capabilities, which allow high transfer rates and preserve the order of processed primitives. So, an identification of regions of interest based on the currently used primitives is achieved. The TreeCut evaluation strategies are then able to optimize the representation in an perception-based manner. As the adaptation utilizes information of the current scene, each change to an object can result in new visual salience information. So, a self-optimizing system is defined: the Feedback System. The output generated by this system converges towards a perception-optimized solution. To proof the saliency information to be useful, user tests have been performed with the results generated by the proposed Feedback System. We compared a saliency-enhanced object compression to a pure geometrical approach, common for LOD-generation. One result of the tests is that saliency information allows to increase compression even further as possible with the pure geometrical methods. The participants were not able to distinguish between objects even if the saliency-based compression had only 60% of the size of the geometrical reduced object. If the size ratio is greater, saliency-based compression is rated, on average, with higher score and these results have a high significance using statistical tests. The Feedback System extends an 3d object with the capability of self-optimization. Not only geometrical detail but also other properties can be limited and optimized using the TreeCut in combination with a BSWDF. We present a dynamic animation, which utilizes a Software Development Kit (SDK) for physical simulations. This was chosen, on the one hand, to show the universal applicability of the proposed system, and on the other hand, to focus on the connection between the TreeCut and the SDK. We adapt the existing framework, and include the SDK within our design. In this case, the TreeCut-operations not only alter geometrical but also simulation detail. This increases calculation performance because both the rendering and the SDK operate on less data after the reduction has been completed. The selected simulation type is a soft-body simulation. Soft-bodies are deformable in a certain degree but retain their internal connection. An example is a piece of cloth that smoothly fits the underlying surface without tearing apart. Other types are rigid bodies, i.e. idealistic objects that cannot be deformed, and fluids or gaseous materials, which are well suited for point-based simulations. Any of these simulations scales with the number of simulation nodes used, and a reduction of detail increases performance significantly. We define a specialized BSWDF to evaluate simulation specific features, such as motion. The Feedback System then increases detail in highly salient regions, e.g. those with large motion, and saves computation time by reducing detail in static parts of the simulation. So, detail of the simulation is preserved while less nodes are simulated. The incorporation of perception in real-time rendering is an important part of recent research. Today, the HVS is well understood, and valid computer models have been derived. These models are frequently used in commercial and free software, e.g. JPEG compression. Within this thesis, the Tree-Cut is presented to change the LOD of an object in a dynamic and continuous manner. No definition of the individual levels in advance is required, and the transitions are performed locally. Furthermore, in combination with an identification of important regions by the BSWDF, a perceptual evaluation of a 3d object is achieved. As opposed to existing methods, which approximate data from 2d images, the perceptual information is directly acquired from 3d data. Some of this data can be preprocessed if necessary, to defer additional computations during rendering. The Feedback System, created by the TreeCut and the BSWDF, optimizes the representation and is not limited to visual data alone. We have shown with our prototype that interactive frame rates can be achieved with modern hardware, and we have proven the validity of the reductions by performing several user tests. However, the presented system only focuses on specific aspects, and more research is required to capture even more capabilities that a perception-based rendering system can provide

Evolution of reptilian visual systems: Retinal projections in a nocturnal lizard, Gekko gecko (linnaeus)

On the basis of the development of the dorsal ventricular ridge of the telencephalon, lizards can be divided into a type I group, to which Gekko and the majority of lizard families belong, and a type II group with more derived features, of which Iguana is representative. Most studies of retinal projections have utilized lizards of the type II group, which are adapted to a diurnal niche. Gekko gecko is differently adapted in that it is nocturnal. Study of the retinal projections was undertaken in Gekko gecko in order to insure that conclusions regarding the pattern of retinal pathways in saurians would be based on a sample which was more representative of the total range of variation. Unilateral removal of the retina by suction cannula was carried out on 12 adult specimens of Gekko gecko . After survival times of 10 to 74 days, brains were processed with various silver methods. The retina projects contralaterally to the pars dorsalis and pars ventralis of the lateral geniculate nucleus and the pars ventralis of the ventrolateral nucleus in the thalamus, nuclei geniculatus pretectalis, lentiformis mesencephali, and posterodorsalis in the pretectum, layers 8–14 of the optic tectum and nucleus opticus tegmenti. Additionally, the retina projects ipsilaterally to the dorsal and ventral lateral geniculate nuclei and to the pretectal nuclei, as well as to the optic tectum, particularly layers 8 and 9. The finding of ipsilateral retinothalamic projections in Gekko supports the idea that this pathway is generalized among saurians. However, presence of ipsilateral retinothalamic projections and the degree of binocular overlap cannot be correlated when lizards, snakes, crocodiles, and turtles are compared. The functional significance of this pathway therefore remains obscure. Ipsilateral retinotectal projections have not been previously described in land vertebrates other than mammals. Whether their presence is correlated with nocturnal visual habits or is generalized among type I lizards remains to be determined. The pattern of retinal projections has been studied in too few representatives of non-mammalian land vertebrates to presently permit conclusions regarding the origin of non-decussating pathways.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49995/1/901570407_ftp.pd

An anthropological examination of classic Maya burials from Moho Cay, Belize: skeletal and dental evidence of demography, diet and health

In the Maya area, archaeological excavations have yielded an abundance of skeletal material from a multitude of sites throughout Belize, Guatemala, Mexico, El Salvador and Honduras. In 1979, a series of excavations led by Heather McKillop at Moho Cay, Belize, revealed a number of human interments. This thesis analyzes the Moho Cay skeletal collection composed of remains from eight discrete Late Classic (A.D. 600-800) burials and nine other archaeological units. Skeletal and dental analysis of the remains included assessing minimum number of individuals per burial and establishing age and sex for each individual. The bones were also examined for signs of skeletal and dental pathology, as well as cultural modifications. Additionally, this thesis includes chi-square analysis of the occurrence of dental pathology and level of attrition as related to tooth class. As pathologies of the skeleton are direct reflections of the individual’s diet and health, the findings of this analysis present a picture of the health and diet of the Moho Cay community. Overall, this study has found that the Moho Cay Maya had moderate dental health and good overall health since few cases of skeletal pathology were observed. The results of this research do not corroborate the hypotheses of Late Classic decline in public health

A new species of australian frog (Myobatrachidae:Uperoleia) from the New South Wales mid-north coast sandplains

The discovery of new vertebrate species in developed countries is still occurring at surprising rates for some taxonomic groups, especially the amphibians and reptiles. While this most often occurs in under-explored areas, it occasionally still happens in well-inhabited regions. We report such a case with the discovery and description of <i>U. mahonyi</i> <b>sp. nov.</b>, a new species of frog from a highly populated region of New South Wales, Australia. We provide details of its morphology, calls, embryos and tadpoles, and phylogenetic relationships to other species of eastern <i>Uperoleia</i>. We also provide the results of targeted surveys to establish its distribution and provide observations of its habitat associations. As a consequence of these surveys, we comment on the likely restricted nature of the species' distribution and habitat, and place this in the context of a preliminary assessment of its putative conservation status, which should be assessed for listing under the IUCN's red list. We note this species, which is morphologically distinct, has gone unnoticed for many decades despite numerous eco-logical surveys for local development applications

Spatial Interaction for Immersive Mixed-Reality Visualizations

Growing amounts of data, both in personal and professional settings, have caused an increased interest in data visualization and visual analytics. Especially for inherently three-dimensional data, immersive technologies such as virtual and augmented reality and advanced, natural interaction techniques have been shown to facilitate data analysis. Furthermore, in such use cases, the physical environment often plays an important role, both by directly influencing the data and by serving as context for the analysis. Therefore, there has been a trend to bring data visualization into new, immersive environments and to make use of the physical surroundings, leading to a surge in mixed-reality visualization research. One of the resulting challenges, however, is the design of user interaction for these often complex systems. In my thesis, I address this challenge by investigating interaction for immersive mixed-reality visualizations regarding three core research questions: 1) What are promising types of immersive mixed-reality visualizations, and how can advanced interaction concepts be applied to them? 2) How does spatial interaction benefit these visualizations and how should such interactions be designed? 3) How can spatial interaction in these immersive environments be analyzed and evaluated? To address the first question, I examine how various visualizations such as 3D node-link diagrams and volume visualizations can be adapted for immersive mixed-reality settings and how they stand to benefit from advanced interaction concepts. For the second question, I study how spatial interaction in particular can help to explore data in mixed reality. There, I look into spatial device interaction in comparison to touch input, the use of additional mobile devices as input controllers, and the potential of transparent interaction panels. Finally, to address the third question, I present my research on how user interaction in immersive mixed-reality environments can be analyzed directly in the original, real-world locations, and how this can provide new insights. Overall, with my research, I contribute interaction and visualization concepts, software prototypes, and findings from several user studies on how spatial interaction techniques can support the exploration of immersive mixed-reality visualizations.Zunehmende Datenmengen, sowohl im privaten als auch im beruflichen Umfeld, führen zu einem zunehmenden Interesse an Datenvisualisierung und visueller Analyse. Insbesondere bei inhärent dreidimensionalen Daten haben sich immersive Technologien wie Virtual und Augmented Reality sowie moderne, natürliche Interaktionstechniken als hilfreich für die Datenanalyse erwiesen. Darüber hinaus spielt in solchen Anwendungsfällen die physische Umgebung oft eine wichtige Rolle, da sie sowohl die Daten direkt beeinflusst als auch als Kontext für die Analyse dient. Daher gibt es einen Trend, die Datenvisualisierung in neue, immersive Umgebungen zu bringen und die physische Umgebung zu nutzen, was zu einem Anstieg der Forschung im Bereich Mixed-Reality-Visualisierung geführt hat. Eine der daraus resultierenden Herausforderungen ist jedoch die Gestaltung der Benutzerinteraktion für diese oft komplexen Systeme. In meiner Dissertation beschäftige ich mich mit dieser Herausforderung, indem ich die Interaktion für immersive Mixed-Reality-Visualisierungen im Hinblick auf drei zentrale Forschungsfragen untersuche: 1) Was sind vielversprechende Arten von immersiven Mixed-Reality-Visualisierungen, und wie können fortschrittliche Interaktionskonzepte auf sie angewendet werden? 2) Wie profitieren diese Visualisierungen von räumlicher Interaktion und wie sollten solche Interaktionen gestaltet werden? 3) Wie kann räumliche Interaktion in diesen immersiven Umgebungen analysiert und ausgewertet werden? Um die erste Frage zu beantworten, untersuche ich, wie verschiedene Visualisierungen wie 3D-Node-Link-Diagramme oder Volumenvisualisierungen für immersive Mixed-Reality-Umgebungen angepasst werden können und wie sie von fortgeschrittenen Interaktionskonzepten profitieren. Für die zweite Frage untersuche ich, wie insbesondere die räumliche Interaktion bei der Exploration von Daten in Mixed Reality helfen kann. Dabei betrachte ich die Interaktion mit räumlichen Geräten im Vergleich zur Touch-Eingabe, die Verwendung zusätzlicher mobiler Geräte als Controller und das Potenzial transparenter Interaktionspanels. Um die dritte Frage zu beantworten, stelle ich schließlich meine Forschung darüber vor, wie Benutzerinteraktion in immersiver Mixed-Reality direkt in der realen Umgebung analysiert werden kann und wie dies neue Erkenntnisse liefern kann. Insgesamt trage ich mit meiner Forschung durch Interaktions- und Visualisierungskonzepte, Software-Prototypen und Ergebnisse aus mehreren Nutzerstudien zu der Frage bei, wie räumliche Interaktionstechniken die Erkundung von immersiven Mixed-Reality-Visualisierungen unterstützen können