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Item Automating Visualization Quality Assessment: a Case Study in Higher Education(The Eurographics Association, 2021) Holliman, Nicolas S.; Xu, Kai and Turner, MartinWe present a case study in the use of machine+human mixed intelligence for visualization quality assessment, applying automated visualization quality metrics to support the human assessment of data visualizations produced as coursework by students taking higher education courses. A set of image informatics algorithms including edge congestion, visual saliency and colour analysis generate machine analysis of student visualizations. The insight from the image informatics outputs has proved helpful for the marker in assessing the work and is also provided to the students as part of a written report on their work. Student and external reviewer comments suggest that the addition of the image informatics outputs to the standard feedback document was a positive step. We review the ethical challenges of working with assessment data and of automating assessment processes.Item Visualizing Usage Data from a Diabetes Management System(The Eurographics Association, 2020) Duce, David A.; Martin, Clare; Russell, Alex; Brown, Dan; Aldea, Arantza; Alshaigy, Bedour; Harrison, Rachel; Waite, Marion; Leal, Yenny; Wos, Marzena; Fernandez-Balsells, Mercè; Real, José Manuel Fernández; Nita, Lucian; López, Beatriz; Massana, Joaquim; Avari, Parizad; Herrero, Pau; Jugnee, Narvada; Oliver, Nick; Reddy, Monika; Ritsos, Panagiotis D. and Xu, KaiThis article explores the role for visualization in interpreting data collected by a customised analytics framework within a healthcare technology project. It draws on the work of the EU-funded PEPPER project, which has created a personalised decision-support system for people with type 1 diabetes. Our approach was an exercise in exploratory visualization, as described by Bergeron's three category taxonomy. The charts revealed different patterns of interaction, including variability in insulin dosing schedule, and potential causes of rejected advice. These insights into user behaviour are of especial value to this field, as they may help clinicians and developers understand some of the obstacles that hinder the uptake of diabetes technology.Item A Gesture Recognition Model for Virtual Reality Motion Controllers(The Eurographics Association, 2020) Headleand, Chris; Williams, Benjamin; Holopainen, Jussi; Gilliam, Marlon; Ritsos, Panagiotis D. and Xu, KaiIn this paper we discuss gesture recognition in the domain of Virtual Reality (VR) video games. We begin by presenting a detailed review of the literature. Furthermore, we discuss some of the specific opportunities and challenges that are specific to the VR domain. Most commercial VR devices come with tracked motion controllers as a default interface which facilitates the possibility of gesture control. However, video games specifically require a high degree of accuracy to prevent non-gesture actions being evaluated. To tackle this challenge we present a novel modification to the Hidden Markov Model gesture recognition approach. We expand on previous work with gestures in with the implementation of an adaptive database system allowing users to quickly engage with an application without significant training. Our results on a benchmark problem shows that the approach can produce impressive accuracy rates. The results from our benchmarking shows promise for the usability of gesture based interaction systems for VR devices in the future. Our system achieves high levels of recognition accuracy competitive with the best performing existing system whilst requiring minimal user independent training.Item Visual Analysis of Popping in Progressive Visualization(The Eurographics Association, 2021) Waterink, Ethan; Kosinka, Jiri; Frey, Steffen; Frosini, Patrizio and Giorgi, Daniela and Melzi, Simone and Rodolà , EmanueleProgressive visualization allows users to examine intermediate results while they are further refined in the background. This makes them increasingly popular when dealing with large data and computationally expensive tasks. The characteristics of how preliminary visualizations evolve over time are crucial for efficient analysis; in particular unexpected disruptive changes between iterations can significantly hamper the user experience. This paper proposes a visualization framework to analyze the refinement behavior of progressive visualization. We particularly focus on sudden significant changes between the iterations, which we denote as popping artifacts, in reference to undesirable visual effects in the context of level of detail representations in computer graphics. Our visualization approach conveys where in image space and when during the refinement popping artifacts occur. It allows to compare across different runs of stochastic processes, and supports parameter studies for gaining further insights and tuning the algorithms under consideration. We demonstrate the application of our framework and its effectiveness via two diverse use cases with underlying stochastic processes: adaptive image space sampling, and the generation of grid layouts.Item A Study on Natural 3D Shape Manipulation in VR(The Eurographics Association, 2018) Cordeiro, E.; Giannini, F.; Monti, M.; Mendes, D.; Ferreira, A.; Livesu, Marco and Pintore, Gianni and Signoroni, AlbertoCurrent immersive modeling environments use non-natural tools and interfaces to support traditional shape manipulation operations. In the future, we expect the availability of natural methods of interaction with 3D models in immersive environments to become increasingly important in several industrial applications. In this paper, we present a study conducted on a group of potential users with the aim of verifying if there is a common strategy in gestural and vocal interaction in immersive environments when the objective is modifying a 3D shape model. The results indicate that users adopt different strategies to perform the different tasks but in the execution of a specific activity it is possible to identify a set of similar and recurrent gestures. In general, the gestures made are physically plausible. During the experiment, the vocal interaction was used quite rarely and never to express a command to the system but rather to better specify what the user was doing with gestures.Item 3D Visualisations Should Not be Displayed Alone - Encouraging a Need for Multivocality in Visualisation(The Eurographics Association, 2021) Roberts, Jonathan C.; Mearman, Joseph W.; Butcher, Peter W. S.; Al-Maneea, Hayder M.; Ritsos, Panagiotis D.; Xu, Kai and Turner, MartinWe believe that 3D visualisations should not be used alone; by coincidentally displaying alternative views the user can gain the best understanding of all situations. The different presentations signify manifold meanings and afford different tasks. Natural 3D worlds implicitly tell many stories. For instance, walking into a living room, seeing the TV, types of magazines, pictures on the wall, tells us much about the occupiers: their occupation, standards of living, taste in design, whether they have kids, and so on. How can we similarly create rich and diverse 3D visualisation presentations? How can we create visualisations that allow people to understand different stories from the data? In a multivariate 2D visualisation a developer may coordinate and link many views together to provide exploratory visualisation functionality. But how can this be achieved in 3D and in immersive visualisations? Different visualisation types, each have specific uses, and each has the potential to tell or evoke a different story. Through several use-cases, we discuss challenges of 3D visualisation, and present our argument for concurrent and coordinated visualisations of alternative styles, and encourage developers to consider using alternative representations with any 3D view, even if that view is displayed in a virtual, augmented or mixed reality setup.Item Interaction Framework within Collaborative Virtual Environments for Multiple Users each interacting with Multiple Degrees-Of-Freedom Controllers(The Eurographics Association, 2020) Sandoval, Mario; Morris, Tim; Turner, Martin; Ritsos, Panagiotis D. and Xu, KaiCollaboration is a process in which two or more agents work together to achieve shared goals. However, many existing platforms cannot generate a collaborative environment to engage multiple users with multiple controllers in a seamless manner. To address this need, this poster and work in progress article will describe LISU (Library for Interactive Settings and User-modes) an input management computing framework that enables collaboration across multiple input controllers as its default. Within the system team members cohabit any real-time simulation environments simultaneously and are then able to jointly control visualisation software across multiple controllers while being continually monitored and evaluated at a low level, allowing research questions to be answered.Item Learning Activities in Colours and Rainbows for Programming Skill Development(The Eurographics Association, 2021) Roberts, Jonathan C.; Xu, Kai and Turner, MartinWe present how we have created a series of bilingual (English and Welsh) STEM activities focusing on rainbows, colours, light and optical effects. The activities were motivated by the many rainbows that appeared in windows in the UK, in support of the National Health Service at the start of the coronavirus pandemic. Rainbows are hopeful and are very fitting to be used as a positive iconic image at a time of much uncertainty. In this paper we explain how we have developed and organised the activities, focusing on colours, computer graphics and computer programming. Each lesson contains one or more activities, which enable people to take an active role in their learning.We have carefully prepared and organised several processes to guide academic colleagues to create and publish different activities in the theme. Which means that the activities appear similarly structured, can be categorised and searched in a consistent way. This structure can act as a blueprint for others to follow and apply to develop their own online course. The activities incrementally take people through learning about colour, rainbows, planning what to program, design and strategies to create colourful pictures using simple computer graphics principles based in processing.org.Item SlowDeepFood: a Food Computing Framework for Regional Gastronomy(The Eurographics Association, 2021) Gilal, Nauman Ullah; Al-Thelaya, Khaled; Schneider, Jens; She, James; Agus, Marco; Frosini, Patrizio and Giorgi, Daniela and Melzi, Simone and Rodolà , EmanueleFood computing recently emerged as a stand-alone research field, in which artificial intelligence, deep learning, and data science methodologies are applied to the various stages of food production pipelines. Food computing may help end-users in maintaining healthy and nutritious diets by alerting of high caloric dishes and/or dishes containing allergens. A backbone for such applications, and a major challenge, is the automated recognition of food by means of computer vision. It is therefore no surprise that researchers have compiled various food data sets and paired them with well-performing deep learning architecture to perform said automatic classification. However, local cuisines are tied to specific geographic origins and are woefully underrepresented in most existing data sets. This leads to a clear gap when it comes to food computing on regional and traditional dishes. While one might argue that standardized data sets of world cuisine cover the majority of applications, such a stance would neglect systematic biases in data collection. It would also be at odds with recent initiatives such as SlowFood, seeking to support local food traditions and to preserve local contributions to the global variation of food items. To help preserve such local influences, we thus present a full end-to-end food computing network that is able to: (i) create custom image data sets semi-automatically that represent traditional dishes; (ii) train custom classification models based on the EfficientNet family using transfer learning; (iii) deploy the resulting models in mobile applications for real-time inference of food images acquired through smart phone cameras. We not only assess the performance of the proposed deep learning architecture on standard food data sets (e.g., our model achieves 91:91% accuracy on ETH’'s Food-101), but also demonstrate the performance of our models on our own, custom data sets comprising local cuisine, such as the Pizza-Styles data set and GCC-30. The former comprises 14 categories of pizza styles, whereas the latter contains 30 Middle Eastern dishes from the Gulf Cooperation Council members.Item RECCS: Real-Time Camera Control for Particle Systems(The Eurographics Association, 2021) Köster, Marcel; Groß, Julian; Krüger, Antonio; Xu, Kai and Turner, MartinInteractive exploration and analysis of large 3D particle systems, consisting of hundreds of thousands of particles, are common tasks in the field of scientific and information visualization. These steps typically involve selection and camera-update operations in order to reveal patterns or to focus on subsets. Moreover, if a certain region is known to be potentially interesting or a selection has been made, the user will have to choose a proper camera setup to investigate further. However, such a setup is typically chosen in a way that the interesting region is in the center of the screen. Unfortunately, it still needs to show important characteristics of the selected subset and has the least amount of occlusions with respect to other particles but shows enough context information in terms of non-selected particles. In this paper, we propose a novel method for real-time camera control in 3D particle systems that fulfills these requirements. It is based on a user and/or domain-specific evaluation heuristic and parallel optimization algorithm that is designed for Graphics-Processing Units (GPUs). In addition, our approach takes only several milliseconds to complete, even on the aforementioned large datasets while consuming only a few megabytes in global GPU memory in general. This is due the fact that we are able to reduce the processing complexity significantly using screenspace information and the excessive use of fast on-chip shared memory. This allows it to be seamlessly integrated into modern visualization systems that need real-time feedback while processing large particle-based datasets.