A Perceptual Color-Matching Method for Examining Color Blending in Augmented Reality Head-Up Display Graphics

Augmented reality (AR) offers new ways to visualize information on-the-go. As noted in related work, AR graphics presented via optical see-through AR displays are particularly prone to color blending, whereby intended graphic colors may be perceptually altered by real-world backgrounds, ultimately degrading usability. This work adds to this body of knowledge by presenting a methodology for assessing AR interface color robustness, as quantitatively measured via shifts in the CIE color space, and qualitatively assessed in terms of users’ perceived color name. We conducted a human factors study where twelve participants examined eight AR colors atop three real-world backgrounds as viewed through an in-vehicle AR head-up display (HUD); a type of optical see-through display used to project driving-related information atop the forward-looking road scene. Participants completed visual search tasks, matched the perceived AR HUD color against the WCS color palette, and verbally named the perceived color. We present analysis that suggests blue, green, and yellow AR colors are relatively robust, while red and brown are not, and discuss the impact of chromaticity shift and dispersion on outdoor AR interface design. While this work presents a case study in transportation, the methodology is applicable to a wide range of AR displays in many application domains and settings

Determination of Secondary Students’ Preferences Regarding Design Features Used in Digital Textbooks

The aim of this study was to determine secondary school students’ choice of design features for digital textbooks. As a part of the research—which was conducted using a mixed technique—a literature review was carried out to source points to consider in the designing of digital textbooks and experts’ opinions were obtained. Based on the results, an 88-question survey was then developed to elicit the preferences of secondary school students with regard to design features for digital textbooks. Also, in this study, three digital textbooks with different design features—but with the same content—were developed to be used by the students. The students were then informed about digital textbook technology by researchers and the digital textbooks were made available to them. Finally, the survey was administered in four separate sessions, and the results were revealed by analysis of the data collected. The findings showed that students wanted digital books with a front, back and bookplate. They took the view that elements for transitions between pages were necessary along with the table of contents, index, glossary and search tools. Students also expressed a desire for images in digital textbooks, especially three-dimensional lifelike drawings, videos and animations

Lightness, Brightness, and Transparency in Optical See-Through Augmented Reality

Augmented reality (AR), as a key component of the future metaverse, has leaped from the research labs to the consumer and enterprise markets. AR optical see-through (OST) devices utilize transparent optical combiners to provide visibility of the real environment as well as superimpose virtual content on top of it. OST displays distinct from existing media because of their optical additivity, meaning the light reaching the eyes is composed of both virtual content and real background. The composition results in the intended virtual colors being distorted and perceived transparent. When the luminance of the virtual content decreases, the perceived lightness and brightness decrease, and the perceived transparency increases. Lightness, brightness, and transparency are modulated by one physical dimension (luminance), and all interact with the background and each other. In this research, we aim to identify and quantify the three perceptual dimensions, as well as build mathematical models to predict them. In the first part of the study, we focused on the perceived brightness and lightness with two experiments: a brightness partition scaling experiment to build brightness scales, and a diffuse white adjustment experiment to determine the absolute luminance level required for diffuse white appearances on 2D and 3D AR stimuli. The second part of the research targeted at the perceived transparency in the AR environment with three experiments. The transparency was modulated by the background Michelson contrast reduction in either average luminance or peak-to-peak luminance difference to investigate, and later illustrated, the fundamental mechanism evoking transparency perception. The first experiment measured the transparency detection thresholds and confirmed that contrast sensitivity functions with contrast adaptation could model the thresholds. Subsequently, the transparency perception was investigated through direct anchored scaling experiment by building perceived transparency scales from the virtual content contrast ratio to the background. A contrast-ratio-based model was proposed predicting the perceived transparency scales. Finally, the transparency equivalency experiment between the two types of contrast modulation confirmed the mechanism difference and validated the proposed model

Representing and Indexing Archaeological Information

The need to preserve and remember the past is a particular human trait. The richness of our cultural history is approached by a vast array of disciplines, that investigate and manage it. However, their effectiveness can be hindered by several technical issues. One of the concerns of experts in this area is the way the importance of cultural heritage is communicated in order to cultivate interest, curiosity and respect. Another concern is the lack of suitable tools that can handle the dimension and complexity of the collections with which they interact. With the emergence of digital tools and the creation of online repositories for the collections of cultural institutions, it is possible to suggest different solutions to tackle these problems. The proposed solution aims to facilitate access and interaction with cultural information, through the implementation of an application capable of integrating multiple forms of representation of historical artifacts. The application tackles two problems that arise from distinct goals. One is the need to represent, in a single view, collections of related items from different repositories. The other is how to, effectively, communicate the information associated with an artifact and its context. This MSc dissertation is part of a collaborative effort between NOVA LINCS researchers and several archaeological institutions of the Iberian Extremadura, aiming to develop tools that will support research and help sharing the cultural wealth of archaeological sites and artifacts from the region. In this dissertation, the developed application covers a general view of the aforementioned problems, while being flexible to the customization of the representation of cultural data. The solution was evaluated on usability and effectiveness on reaching the proposed goals, during a process that involved target audience users and experts in the area of culture and history, as well as human-computer interaction. The results provided positive conclusions

Ambient Intelligence for Next-Generation AR

Next-generation augmented reality (AR) promises a high degree of context-awareness - a detailed knowledge of the environmental, user, social and system conditions in which an AR experience takes place. This will facilitate both the closer integration of the real and virtual worlds, and the provision of context-specific content or adaptations. However, environmental awareness in particular is challenging to achieve using AR devices alone; not only are these mobile devices' view of an environment spatially and temporally limited, but the data obtained by onboard sensors is frequently inaccurate and incomplete. This, combined with the fact that many aspects of core AR functionality and user experiences are impacted by properties of the real environment, motivates the use of ambient IoT devices, wireless sensors and actuators placed in the surrounding environment, for the measurement and optimization of environment properties. In this book chapter we categorize and examine the wide variety of ways in which these IoT sensors and actuators can support or enhance AR experiences, including quantitative insights and proof-of-concept systems that will inform the development of future solutions. We outline the challenges and opportunities associated with several important research directions which must be addressed to realize the full potential of next-generation AR.Comment: This is a preprint of a book chapter which will appear in the Springer Handbook of the Metavers

The state of the art in empirical user evaluation of graph visualizations

While graph drawing focuses more on the aesthetic representation of node-link diagrams, graph visualization takes into account other visual metaphors making them useful for graph exploration tasks in information visualization and visual analytics. Although there are aesthetic graph drawing criteria that describe how a graph should be presented to make it faster and more reliably explorable, many controlled and uncontrolled empirical user studies flourished over the past years. The goal of them is to uncover how well the human user performs graph-specific tasks, in many cases compared to previously designed graph visualizations. Due to the fact that many parameters in a graph dataset as well as the visual representation of them might be varied and many user studies have been conducted in this space, a state-of-the-art survey is needed to understand evaluation results and findings to inform the future design, research, and application of graph visualizations. In this paper, we classify the present literature on the topmost level into graph interpretation, graph memorability, and graph creation where the users with their tasks stand in focus of the evaluation not the computational aspects. As another outcome of this work, we identify the white spots in this field and sketch ideas for future research directions