@article{wu-2021-vi, title = "Visualization working group at TU Wien: Visibile Facimus Quod Ceteri Non Possunt", author = "Hsiang-Yun Wu and Aleksandr Amirkhanov and Nicolas Grossmann and Tobias Klein and David Kou\v{r}il and Haichao Miao and Laura R. Luidolt and Peter Mindek and Renata Raidou and Ivan Viola and Manuela Waldner and Eduard Gr\"{o}ller", year = "2021", abstract = "Building-up and running a university-based research group is a multi-faceted undertaking. The visualization working group at TU Wien (vis-group) has been internationally active over more than 25 years. The group has been acting in a competitive scientific setting where sometimes contradicting multiple objectives require trade-offs and optimizations. Research-wise the group has been performing basic and applied research in visualization and visual computing. Teaching-wise the group has been involved in undergraduate and graduate lecturing in (medical) visualization and computer graphics. To be scientifically competitive requires to constantly expose the group and its members to a strong international competition at the highest level. This necessitates to shield the members against the ensuing pressures and demands and provide (emotional) support and encouragement. Internally, the vis-group has developed a unique professional and social interaction culture: work and celebrate, hard and together. This has crystallized into a nested, recursive, and triangular organization model, which concretizes what it takes to make a research group successful. The key elements are the creative and competent vis-group members who collaboratively strive for (scientific) excellence in a socially enjoyable environment.", month = mar, doi = "https://doi.org/10.1016/j.visinf.2021.02.003", journal = "Visual Informatics", volume = "5", pages = "76--84", URL = "https://www.cg.tuwien.ac.at/research/publications/2021/wu-2021-vi/", } @xmascard{AA2020, title = "X-Mas Card 2020", author = "Aleksandr Amirkhanov", year = "2020", month = dec, URL = "https://www.cg.tuwien.ac.at/research/publications/2020/AA2020/", } @article{amirkhanov2020visual, title = "Visual Analytics in Dental Aesthetics", author = "Aleksandr Amirkhanov and Matthias Bernhard and Alexey Karimov and Sabine Stiller and Andreas Geier and Eduard Gr\"{o}ller and Gabriel Mistelbauer", year = "2020", abstract = "Dental healthcare increasingly employs computer-aided design software, to provide patients with high-quality dental prosthetic devices. In modern dental reconstruction, dental technicians address the unique anatomy of each patient individually, by capturing the dental impression and measuring the mandibular movements. Subsequently, dental technicians design a custom denture that fits the patient from a functional point of view. The current workflow does not include a systematic analysis of aesthetics, and dental technicians rely only on an aesthetically pleasing mock-up that they discuss with the patient, and on their experience. Therefore, the final denture aesthetics remain unknown until the dental technicians incorporate the denture into the patient. In this work, we present a solution that integrates aesthetics analysis into the functional workflow of dental technicians. Our solution uses a video recording of the patient, to preview the denture design at any stage of the denture design process. We present a teeth pose estimation technique that enables denture preview and a set of linked visualizations that support dental technicians in the aesthetic design of dentures. These visualizations assist dental technicians in choosing the most aesthetically fitting preset from a library of dentures, in identifying the suitable denture size, and in adjusting the denture position. We demonstrate the utility of our system with four use cases, explored by a dental technician. Also, we performed a quantitative evaluation for teeth pose estimation, and an informal usability evaluation, with positive outcomes concerning the integration of aesthetics analysis into the functional workflow.", journal = "Computer Graphics Forum", volume = "39", number = "7", doi = "https://doi.org/10.1111/cgf.14174", pages = "635–646", pages = "635--646", keywords = "Applied computing -> Life and medical sciences, Human-centered computing -> Visualization application domains", URL = "https://www.cg.tuwien.ac.at/research/publications/2020/amirkhanov2020visual/", } @article{amirkhanov-2019-manylands, title = "ManyLands: A Journey Across 4D Phase Space of Trajectories", author = "Aleksandr Amirkhanov and Ilona Kosiuk and Peter Szmolyan and Artem Amirkhanov and Gabriel Mistelbauer and Eduard Gr\"{o}ller and Renata Raidou", year = "2019", abstract = "Mathematical models of ordinary differential equations are used to describe and understand biological phenomena. These models are dynamical systems that often describe the time evolution of more than three variables, i.e., their dynamics take place in a multi-dimensional space, called the phase space. Currently, mathematical domain scientists use plots of typical trajectories in the phase space to analyze the qualitative behavior of dynamical systems. These plots are called phase portraits and they perform well for 2D and 3D dynamical systems. However, for 4D, the visual exploration of trajectories becomes challenging, as simple subspace juxtaposition is not sufficient. We propose ManyLands to support mathematical domain scientists in analyzing 4D models of biological systems. By describing the subspaces as Lands, we accompany domain scientists along a continuous journey through 4D HyperLand, 3D SpaceLand, and 2D FlatLand, using seamless transitions. The Lands are also linked to 1D TimeLines. We offer an additional dissected view of trajectories that relies on small-multiple compass-alike pictograms for easy navigation across subspaces and trajectory segments of interest. We show three use cases of 4D dynamical systems from cell biology and biochemistry. An informal evaluation with mathematical experts confirmed that ManyLands helps them to visualize and analyze complex 4D dynamics, while facilitating mathematical experiments and simulations.", month = oct, journal = "Computer Graphics Forum", volume = "38", number = "7", doi = "10.1111/cgf.13828", pages = "191--202", keywords = "Visual analytics, Web-based interaction", URL = "https://www.cg.tuwien.ac.at/research/publications/2019/amirkhanov-2019-manylands/", } @unknown{manylands_award, title = "EG VCBM 2019 Image Contest Award, people's choice—ManyLands: A Journey Across 4D Phase Space of Biological Systems", author = "Aleksandr Amirkhanov and Ilona Kosiuk and Peter Szmolyan and Artem Amirkhanov and Gabriel Mistelbauer and Eduard Gr\"{o}ller and Renata Raidou", year = "2019", URL = "https://www.cg.tuwien.ac.at/research/publications/2019/manylands_award/", } @inproceedings{amirkhanov-2018-withteeth, title = "WithTeeth: Denture Preview in Augmented Reality", author = "Aleksandr Amirkhanov and Artem Amirkhanov and Matthias Bernhard and Zsolt Toth and Sabine Stiller and Andreas Geier and Eduard Gr\"{o}ller", year = "2018", abstract = "Dentures are prosthetic devices replacing missing or damaged teeth, often used for dental reconstruction. Dental reconstruction improves the functional state and aesthetic appearance of teeth. State-of-the-art methods used by dental technicians typically do not include the aesthetic analysis, which often leads to unsatisfactory results for patients. In this paper, we present a virtual mirror approach for a dental treatment preview in augmented reality. Different denture presets are visually evaluated and compared by switching them on the fly. Our main goals are to provide a virtual dental treatment preview to facilitate early feedback, and hence to build the confidence and trust of patients in the outcome. The workflow of our algorithm is as follows. First, the face is detected and 2D facial landmarks are extracted. Then, 3D pose estimation of upper and lower jaws is performed and high-quality 3D models of the upper and lower dentures are fitted. The fitting uses the occlusal plane angle as determined manually by dental technicians. To provide a realistic impression of the virtual teeth, the dentures are rendered with motion blur. We demonstrate the robustness and visual quality of our approach by comparing the results of a webcam to a DSLR camera under natural, as well as controlled lighting conditions.", month = oct, isbn = "978-3-03868-072-7", address = "https://diglib.eg.org/handle/10.2312/vmv20181250", event = "VMV18", editor = "Beck, Fabian and Dachsbacher, Carsten and Sadlo, Filip", booktitle = "Vision, Modeling and Visualization", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/amirkhanov-2018-withteeth/", } @incollection{heinzl-2018-ct-book, title = "Processing, Analysis and Visualization of CT Data in Industrial X-Ray Computed Tomography", author = "Christoph Heinzl and Aleksandr Amirkhanov and Johannes Kastner", year = "2018", abstract = "In an almost inexhaustible multitude of possibilities, CT allows to inspect highly complex systems and materials. Compared to other testing techniques CT provides results in a quick way: It is nondestructive and does not interfere with the specimen, it allows non-touching characterizations and what is most important CT allows to characterize hidden or internal features. However, CT would not have reached its current status in engineering without the achievements and possibilities in data processing. Only through processing, analysis and visualization of CT data, detailed insights into previously unachievable analyses are facilitated. Novel means of data analysis and visualization illustrate highly complex problems by means of clear and easy to understand renderings. In this chapter, we explore various aspects starting from the generalized data analysis pipeline, aspects of processing, analysis and visualization for metrology, nondestructive testing as well as specialized analyses.", booktitle = "Processing, Analysis and Visualization of CT Data", publisher = "Springer", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/heinzl-2018-ct-book/", } @article{raidou_2018_bladderrunner, title = "Bladder Runner: Visual Analytics for the Exploration of RT-Induced Bladder Toxicity in a Cohort Study", author = "Renata Raidou and Oscar Casares-Magaz and Aleksandr Amirkhanov and Vitali Moiseenko and Ludvig Paul Muren and John P. Einck and Anna Vilanova i Bartroli and Eduard Gr\"{o}ller", year = "2018", abstract = "We present the Bladder Runner, a novel tool to enable detailed visual exploration and analysis of the impact of bladder shape variation on the accuracy of dose delivery, during the course of prostate cancer radiotherapy (RT). Our tool enables the investigation of individual patients and cohorts through the entire treatment process, and it can give indications of RT-induced complications for the patient. In prostate cancer RT treatment, despite the design of an initial plan prior to dose administration, bladder toxicity remains very common. The main reason is that the dose is delivered in multiple fractions over a period of weeks, during which, the anatomical variation of the bladder - due to differences in urinary filling - causes deviations between planned and delivered doses. Clinical researchers want to correlate bladder shape variations to dose deviations and toxicity risk through cohort studies, to understand which specific bladder shape characteristics are more prone to side effects. This is currently done with Dose-Volume Histograms (DVHs), which provide limited, qualitative insight. The effect of bladder variation on dose delivery and the resulting toxicity cannot be currently examined with the DVHs. To address this need, we designed and implemented the Bladder Runner, which incorporates visualization strategies in a highly interactive environment with multiple linked views. Individual patients can be explored and analyzed through the entire treatment period, while inter-patient and temporal exploration, analysis and comparison are also supported. We demonstrate the applicability of our presented tool with a usage scenario, employing a dataset of 29 patients followed through the course of the treatment, across 13 time points. We conducted an evaluation with three clinical researchers working on the investigation of RT-induced bladder toxicity. All participants agreed that Bladder Runner provides better understanding and new opportunities for the exploration and analysis of the involved cohort data.", journal = "Computer Graphics Forum", volume = "37", number = "3", issn = "1467-8659", doi = "10.1111/cgf.13413", pages = "205-216", pages = "205--216", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/raidou_2018_bladderrunner/", } @inproceedings{amirkhanov-2017-cffet, title = "Comparison of Final Fracture Extraction Techniques for Interrupted In situ Tensile Tests of Glass Fiber Reinforced Polymers", author = "Aleksandr Amirkhanov and Dietmar Salaberger and Johannes Kastner and Christoph Heinzl and Eduard Gr\"{o}ller", year = "2017", abstract = "To develop and optimize of advanced composite materials such as glass fiber reinforced polymers (GFRPs) for a specific application area is an important topic. To inspect mechanical properties of GFRPs, material engineers use interrupted in situ tensile tests. During these tests, a test specimen is scanned multiple times in an industrial computed tomography (CT) scanner under various loads, starting from no load until the final fracture of the specimen. In this work we focus on the final step of the interrupted in situ tensile test, which is scanned when the specimen is completely losing its structural integrity in the final fracture zone. The defects occurring in the subsequent loading stages merge and ultimately form the final fracture. For this reason, conventional techniques tend to generate error prone final fracture regions or surfaces and thus require more advanced algorithms for extraction. The main contribution of this paper is found in the comparison of different techniques for extracting the final fracture. In the comparison we outline advantages and drawbacks of the presented techniques relative to each other.", month = feb, booktitle = "Proceedings of 7th Conference on Industrial Computed Tomography , Leuven , Belgium (iCT 2017) ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/amirkhanov-2017-cffet/", } @inproceedings{rao-2017-dc, title = "Damage characterization in SFRP using X-ray computed tomography after application of incremental and interrupted in situ quasi static tensile loading", author = "Guruprasad Rao and Aleksandr Amirkhanov and Dietmar Salaberger and Johannes Kastner and Christoph Heinzl", year = "2017", abstract = "The use of short fibre reinforced polymers (SFRP) is increasing steadily in automotive and aerospace industries due to its mechanical properties and light weight. The mechanical and physical properties of SFRP depend on the geometrical characterestics of the reinforcing material. Under tensile stress many defects are induced in SFRP composites. X-ray computed tomography (XCT) is a non-destructive method for damage characterization of SFRP. It helps us to understand the material behaviour under different intermediate stress conditions and gauge the strength of the material. This paper aims to study the evolution of various damages in SFRP composite material. The composite consists of a polyamide matrix and 30 wt. % of short glass fibres. Sheets with two types of fibre orientation (0° and 90°) were chosen relative to the flow direction. The damages were induced after application of pre-determined tensile loads in a quasi-static method using an in situ tensile testing device.The tensile force was applied using controlled displacement inside the in situ device. Damages were analysed after every step of force application using XCT at the resolution of 4.5 µm3 voxel size. The workflow based on automatic fibre extraction followed by automated defect detection and classification was used to retrieve quantitative results of the damage evolution. The detected defects were analysed and classified into four types: 1) fibre pull-outs, 2) fibre fractures, 3) matrix fractures and 4) fibre/matrix debonding. The increase in tensile force shows changes in the number and volume of the defects. The classification of defects at every step after applying force helps to understand evolution of damage mechanisms in the stressed region.", month = feb, booktitle = "Proceedings of 7th Conference on Industrial Computed Tomography , Leuven , Belgium (iCT 2017)", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/rao-2017-dc/", } @article{Groeller_2016_P1, title = " Visual Analysis of Defects in Glass Fiber Reinforced Polymers for 4DCT Interrupted In situ Tests", author = "Aleksandr Amirkhanov and Artem Amirkhanov and Dietmar Salaberger and Johannes Kastner and Eduard Gr\"{o}ller and Christoph Heinzl", year = "2016", abstract = "Material engineers use interrupted in situ tensile testing to investigate the damage mechanisms in composite materials. For each subsequent scan, the load is incrementally increased until the specimen is completely fractured. During the interrupted in situ testing of glass fiber reinforced polymers (GFRPs) defects of four types are expected to appear: matrix fracture, fiber/matrix debonding, fiber pull-out, and fiber fracture. There is a growing demand for the detection and analysis of these defects among the material engineers. In this paper, we present a novel workflow for the detection, classification, and visual analysis of defects in GFRPs using interrupted in situ tensile tests in combination with X-ray Computed Tomography. The workflow is based on the automatic extraction of defects and fibers. We introduce the automatic Defect Classifier assigning the most suitable type to each defect based on its geometrical features. We present a visual analysis system that integrates four visualization methods: 1) the Defect Viewer highlights defects with visually encoded type in the context of the original CT image, 2) the Defect Density Maps provide an overview of the defect distributions according to type in 2D and 3D, 3) the Final Fracture Surface estimates the material fracture’s location and displays it as a 3D surface, 4) the 3D Magic Lens enables interactive exploration by combining detailed visualizations in the region of interest with overview visualizations as context. In collaboration with material engineers, we evaluate our solution and demonstrate its practical applicability.", journal = "Computer Graphics Forum (2016)", volume = " 35", number = "3", issn = "doi: 10.1111/cgf.12896", pages = "201--210", URL = "https://www.cg.tuwien.ac.at/research/publications/2016/Groeller_2016_P1/", } @article{Red_Andreas_2015_FFT, title = "Fuzzy feature tracking", author = "Andreas Reh and Aleksandr Amirkhanov and Johann Kastner and Eduard Gr\"{o}ller and Christoph Heinzl", year = "2015", abstract = "In situ analysis is becoming increasingly important in the evaluation of existing as well as novel materials and components. In this domain, specialists require answers on questions such as: How does a process change internal and external structures of a component? or How do the internal features evolve?In this work, we present a novel integrated visual analysis tool to evaluate series of X-ray Computed Tomography (XCT) data. We therefore process volume datasets of a series of XCT scans, which non-destructively cover the evolution of a process by in situ scans. After the extraction of individual features, a feature tracking algorithm is applied to detect changes of features throughout the series as events. We distinguish between creation, continuation, split, merge and dissipation events. As an explicit tracking is not always possible, we introduce the computation of a Tracking Uncertainty. We visualize the data together with the determined events in multiple linked-views, each emphasizing individual aspects of the 4D-XCT dataset series: A Volume Player and a 3D Data View show the spatial feature information, whereas the global overview of the feature evolution is visualized in the Event Explorer. The Event Explorer allows for interactive exploration and selection of the events of interest. The selection is further used as basis to calculate a Fuzzy Tracking Graph visualizing the global evolution of the features over the whole series.We finally demonstrate the results and advantages of the proposed tool using various real world applications, such as a wood shrinkage analysis and an AlSiC alloy under thermal load. Graphical abstractDisplay Omitted HighlightsWe calculate a Tracking Uncertainty in order to find correlated features.The Event Explorer shows a global overview of events and feature properties.The Fuzzy Tracking Graph is used to track features through all time-steps.The Volume Player shows control elements to traverse the steps of a dataset series.", month = dec, journal = "Computers and Graphics", number = "PB", volume = "53", pages = "177--184", URL = "https://www.cg.tuwien.ac.at/research/publications/2015/Red_Andreas_2015_FFT/", } @inproceedings{weissenboeck-2014, title = "FiberScout: An Interactive Tool for Exploring and Analyzing Fiber Reinforced Polymers", author = "Johannes Weissenb\"{o}ck and Artem Amirkhanov and Weimin Li and Andreas Reh and Aleksandr Amirkhanov and Eduard Gr\"{o}ller and Johann Kastner and Christoph Heinzl", year = "2014", abstract = "Advanced composites such as fiber reinforced polymers are promising candidate materials for future components as they allow integrating the continuously rising demands of industry regarding costeffectiveness, function-orientation, integration and weight. The most important structures of fiber reinforced polymers are the individual fibers, as their characteristics (stiffness, strength, ductility, durability, etc.) to a large extent determine the properties of the final component. The main contribution of this paper is the introduction of a new system for interactive exploration and visual analysis of fiber properties in X-ray computed tomography data of fiber reinforced polymers. The presented tool uses parallel coordinates to define and configure initial fiber classes. Using a scatter plot matrix linked to the parallel coordinates the initial classification may be refined. This allows to analyze hidden relationships between individual fiber properties. 2D and 3D views depict the resulting fiber classifications. By using polar plots an intuitive rendering of the fiber orientation distribution is provided. In addition, two modules of higher abstraction are proposed: The Blob visualization creates a hull around fibers with similar characteristics. The fiber metadata visualization allows to calculate overlays for 2D and 3D views containing regional information of particular material characteristics. The proposed system has been evaluated by two groups of domain experts. Applying the presented concepts the user feedback shows that the domain experts are now able to efficiently perform tasks as classification of fibers, visualization of fiber lengths and orientations, and visualization of fiber regions. The insights gained can be forwarded to the design office as well as to material development and simulation, in order to speed up the development of novel composite components.", month = mar, isbn = "978-1-4799-2874-3 ", publisher = "IEEE Computer Society", location = "Yokohama", booktitle = "Proceedings of 2014 IEEE Pacific Visualization Symposium (PacificVis) (2014)", pages = "153--160", URL = "https://www.cg.tuwien.ac.at/research/publications/2014/weissenboeck-2014/", } @article{wu-2021, title = "Visualization working group at TU Wien: Visible Facimus Quod Ceteri Non Possunt", author = "Hsiang-Yun Wu and Aleksandr Amirkhanov and Nicolas Grossmann and Tobias Klein and David Kou\v{r}il and Haichao Miao and Laura R. Luidolt and Peter Mindek and Renata Raidou and Ivan Viola and Manuela Waldner and Eduard Gr\"{o}ller", abstract = "Building-up and running a university-based research group is a multi-faceted undertaking. The visualization working group at TU Wien (vis-group) has been internationally active over more than 25 years. The group has been acting in a competitive scientific setting where sometimes contradicting multiple objectives require trade-offs and optimizations. Research-wise the group has been performing basic and applied research in visualization and visual computing. Teaching-wise the group has been involved in undergraduate and graduate lecturing in (medical) visualization and computer graphics. To be scientifically competitive requires to constantly expose the group and its members to a strong international competition at the highest level. This necessitates to shield the members against the ensuing pressures and demands and provide (emotional) support and encouragement. Internally, the vis-group has developed a unique professional and social interaction culture: work and celebrate, hard and together. This has crystallized into a nested, recursive, and triangular organization model, which concretizes what it takes to make a research group successful. The key elements are the creative and competent vis-group members who collaboratively strive for (scientific) excellence in a socially enjoyable environment.", doi = "https://doi.org/10.1016/j.visinf.2021.02.003", journal = "Visual Informatics", volume = "5", pages = "76--84", URL = "https://www.cg.tuwien.ac.at/research/publications/ongoing/wu-2021/", }