HVEI 2025 Program
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TUESDAY 4 FEBRUARY 2025
Lightness and Color Perception I
Session Chair: Damon Chandler, Ritsumeikan University
09:20 - 10:30
Grand Peninsula B
09:30HVEI-206
Explaining top-down influences on lightness judgments with a computational neural model, Michael Rudd, University of Nevada, Reno (US) [view abstract]
Rudd and Zemach (2007) analyzed brightness matches made with disk/annulus stimuli under four conditions in which the disk was either a luminance increment or decrement with respect to the annulus, and the annulus was either an increment or decrement with respect to the background. In all cases, the disk brightness measured by the luminance of a matching disk exhibited a parabolic dependence on the annulus luminance when plotted on a log-log scale. Rudd (2010) further showed that the shape of this parabolic relationship can be influenced by instructions to match the disk's brightness (perceived luminance) or lightness (perceived reflectance) under different assumptions about the illumination. Here, I compare these previous results to those of recent experiments in which the match disk used to measure the target disk appearance was either surrounded by an annulus or not (Rudd, Kavcar, & Crognale, 2023). I model the entire body of data with a modified version of a neural model involving edge integration and contrast gain control (Rudd, 2010, 2017), in which top-down influences control the weights given to edges in the edge integration process act either before or after the contrast gain control stage of the model, depending on experimental conditions.
09:50HVEI-207
Some further developments on a neurobiologically-based model for color sensations in humans, Charles Wu, Perception and Cognition Research (US) [view abstract]
At HVEI-2012, I presented a neurobiologically-based model for trichromatic color sensations in humans psychophysically, my model is based on a color-sensation model proposed by the British psychologist William McDougall in 1901. In this model, the central stage directly corresponding to color sensations is trichromatic, uncorrelated with Hering's opponent colors at all; furthermore, based on the presently known organization of the primate (including the humankind) visual system, I have mapped this central stage to V1-L4 namely, layer 4 in primary visual cortex. Here I apply my model to three aspects of color vision: 3D color solid, dichromatism, and ocular agnosticism. (1) 3D color solid: V1-L4 is known to have a gradient of cell densities from the layer's top (i.e., its pia or outer side) to its bottom (i.e., its white-matter or inner side). Considering together with the proposition that the population size of a cell assembly directly corresponds to the magnitude of a color sensation, it can be inferred that the neurobiologically-based color solid is a tilted cuboid, very close to the tilted double-pyramid color solid proposed by the German psychologist Ebbinghaus. (2) Color blindness: Take deuteranopia as example, at the retinal level, M-cones are lost and replaced by L-cones; but at the cortical level, deuteranopia shows as a fusion (or non-differentiation) between the two bottom layers of V1-L4. (3) Ocular agnosticism: Even though color sensation is monocular, we are normally not aware of which eye we are seeing with this phenomenon is known as ocular agnosticism (or informally, blindness to eye-of-origin ) and has been described by many investigators (e.g., by Helmholtz in his classic on physiological optics). The nature of ocular integration within V1-L4 can fully explain this ocular agnosticism. A realistic and neurobiologically-based model for color sensations would certainly turn out to be significant and useful for future technologies to enhance human color experiences.
10:10HVEI-208
JIST-first Accepted: The effect of simultaneous contrast on color deficient observers, Luca Armellin, Universita degli Studi di Milano (Italy); Alice Plutino, Universiteit van Amsterdam (Netherlands); Andrea Mazzoni, Aerospace Medical Institute (Italy); Alessandro Rizzi, Universita degli Studi di Milano (Italy) [view abstract]
Today, different models and instruments exist to study and model color vision and color vision deficiency. These systems are often modeled at a spectral and retinal level. In this paper, we aim at proposing a new approach to set up models and aids for color vision deficiencies, considering the role of spatial color processing in the humanvisual system. In particular, we will present the results of a perceptual test aiming at identifying the role of the spatial arrangement in color discrimination in Color Deficient Observers (CDOs) and Color Normal Observers (CNOs), usingthe simultaneous contrast effect.
Perceptually Based Quality I
Session Chair: Susan Farnand, Rochester Institute of Technology
11:00 - 12:20
Grand Peninsula B
11:20HVEI-209
How does the perceived quality of compressed images depend on image content?, Claire Mantel, DTU Electro, Department of Electrical and Photonics Engineering (Denmark); Hui Wang, DTU Electro, Department of Electrical and Photonics Engineering (Denmark); Thierry Sorreze, DTU Electro, Department of Electrical and Photonics Engineering (Denmark); S ren Forchhammer, DTU Electro, Department of Electrical and Photonics Engineering (Denmark) [view abstract]
The impact of image compression algorithms varies significantly across image contents in a way that is challenging to predict. The general trend towards richer visual content, e.g. High Dynamic Range and Wide Color Gamut, increases both the relevance and complexity of this issue. Focusing on the perceived quality of compressed images, this study analyzes first in which proportion their variance is due to compression levels, image content and compression type respectively. ANOVA analysis on 3 HDR datasets indicates that the variance of the subjective evaluations is due for 45-62% to the compression level and for 7-10% to the image content. Secondly, we present a framework for identifying which image features are efficient to predict the role of content in quality perception that builds on traditional regression analysis by adding an adaptation of the recent Model Class Reliance approach. In an experiment on 6 published datasets of subjective quality grades of compressed images, OLS-R and KNN models predicting the grades using the compression levels and one feature characterizing the original content are built. Then the Empirical Model Reliance and Model Class Reliance are calculated to measure the importance of the content feature in the regression model. Results show that traditional regression analysis alone is not robust for identifying the most relevant features and confirms that when the most useful features for SDR are SI/block contrast measures, other characterize best HDR content such as DR and color feature.
11:40HVEI-210
On the effects of video game texture resolution on navigation performance, Nicko Caluya, Ritsumeikan University (Japan); Carlos Rhenell Koga, Ritsumeikan University (Japan); Damon Chandler, Ritsumeikan University (Japan) [view abstract]
2D textures presented side by side or in succession have served as a fundamental stimulus for visual discrimination, masking, appearance, and quality assessment studies. However, when viewed in context, textures rarely lie on a 2D plane; rather, they form part of a 3D scene. Furthermore, when the user can navigate within the 3D space, scales and perspectives can constantly change. Here, we explore how the perceived quality changes from 2D to 3D, and to what extent this quality relates to usability. Specifically, we adopted an interactive and 3D-based approach, motivated by observations in playability of video games. Although higher quality textures may convey higher realism, conflicts like additional latency in rendering and induction of potential visual distractions may lead to worse game performance. Thus, we conducted a preliminary study in which participants navigated a virtual room with floors consisting of textured tiles similar in appearance, with the objective of correctly walking a path by stepping on tiles of only the designated texture. Our results showed that participants significantly underperformed in the condition full of lower resolution tiles (64x64) versus the higher-resolution counterparts, in terms of incorrect tiles selected. The results and insights of this study inform our ongoing experiments that extend the idea towards other modalities (e.g., various game controls and mechanics) and display devices (e.g., VR headsets).
12:00HVEI-211
Cloud gaming quality based on a passive video quality experiment and bootstrapped analysis, Kjell Brunnstr m, RISE Research Institutes of Sweden AB (Sweden); Linnea Runsten-Fredriksson, RISE Research Institutes of Sweden (Sweden); Shirin Rafiei, RISE Research Institutes of Sweden AB (Sweden) [view abstract]
The International Telecommunication Union has a project for developing objective quality models called Parametric Bitstream-Based Quality assessment of Cloud Gaming services (P.BBQCG). The model will be divided into an interaction quality module and a video coding impairment module. To evaluate these two modules an experimental campaign was done where labs from different parts of the world have performed user studies to collect data to base the evaluation on. This paper will describe an experiment for collecting data for evaluating the video coding impairment module. The analysis will be based on bootstrapping approach.
12:20HVEI-212
User preference towards HDR10 playback strategies by video player applications, Pooshpanjan Roy Biswas, DXOMARK (France); Adrien Carmone, DXOMARK (France); Thibault Cabana; Eloi Zalczer; Paul Bernardi; Frederic Guichard [view abstract]
Modern HDR video playback strategies often involve adjustments by industry stakeholders, such as applying different Electro-Optical Transfer Functions (EOTFs), modifying peak luminance, or altering color characteristics, to enhance visual appeal. These modifications, however, can deviate from the original artistic intent. Understanding observer preferences for such alterations is crucial, especially for smartphone playback under diverse ambient lighting.This study aims to pilot an assessment of user preferences for different HDR playback strategies on smartphones, focusing on EOTF, luminance, and color reproduction. The challenge lies in balancingthese factors to enhance visual comfort and overall experience without compromising visual quality.A psychophysical experiment employed three HDR10-capable Android video players on identical smartphones within controlled ambient settings (dark, indoor, outdoor). Observers evaluated video playback based on seven criteria, such as overall quality, brightness, skin-tones, contrast etc.,, To ensure unbiased results, three-level randomization of video, application, and question order was implemented. Additionally, objective colorimetric data were acquired using an imaging colorimeter.Preliminary findings from eight observers revealed no significant differences in player ratings in reference conditions. However, differences emerged under low and bright lighting for brightness and contrast preferences, with one player outperforming others in overall quality and color rendering. Further data from 15 observers and deeper colorimetric analysis are forthcoming.
Perceptually Based Quality II
Session Chair: Edward Fry, Apple, Inc.
15:30 - 17:30
Grand Peninsula B
15:30HVEI-213
HVEI Keynote: Predicting visible differences in virtual and augmented reality, Alexandre Chapiro, Meta [view abstract]
Abstract TBD
16:30HVEI-214
Time-domain analysis for variable-refresh-rate display flicker, Hyosun Kim; Hyungsuk Hwang; Dongyeol Yeom; Yongjo Kim [view abstract]
The cutting-edge displays are emerging with a technology called VRR (Variable Refresh Rate), which supports a wider range of refresh rates. Although VRR can reduce power consumption, users may experience flickering issues as the display refresh rate varies depending on the image characteristics (e.g. speed). Therefore, more accurate method for predicting flicker prediction in VRR displays is necessary. This research purposes a flicker prediction model for VRR displays. We introduce time-domain analysis using Impulse Response Function (IRF) to capture aperiodic luminance fluctuations and extract data in VRR situations. Additionally, to an appropriate weighting function applied to account for the effects of brightness and size on periodic luminace fluctuations. The result demostrate that time-domian analysis with an appropriate weighting function offer a more accurate prediction of flicker perception in VRR displays.
WEDNESDAY 5 FEBRUARY 2025
Computer Vision and Image Analysis of Art
Session Chair: David Stork
09:20 - 10:30
Grand Peninsula B
09:30HVEI-215
Art history, computer vision and the face of Abraham Lincoln, Betsy Mathisen (US) [view abstract]
All the pieces of the puzzle have been gathered: A miniature portrait painting on ivory approximately 2 in diameter dated circa 1840-1842, found next to a letter detailing the owner's family relationship to Mary Todd Lincoln. The distinctive features of President Lincoln's face and substantial asymmetry. A 19th century fine art historian's extraordinary investigation, but no historical document to prove her hypothesis. The pathway is open for the great minds of art and science to determine if this miniature painting is the earliest image of Abraham Lincoln and to solve this puzzle. The challenge is to provide the art world enough ammunition to definitively give a potentialAmerican national treasure a rightful home in history. And to open the doors for future collaboration in identifying historical faces of the past. One of these great minds is that of David Stork. Dr. Stork is an Adjunct Professor at Stanford University and an expert in computer-based image analysis. Dr. Stork holds 64 U.S. patents and has published over 220 peer-reviewed scholarly works in machine learning, pattern recognition, computational optics, and image understanding of art. His recent publication Pixels and Paintings Foundations of Computer-Assisted Connoisseurship1 invites a dialog between art scholars and the computer vision community.
09:50HVEI-216
Computational tools for analyses of color of costumes in large corpora of fine art paintings, Christine Li, Columbia University (US); David Stork, Stanford University (US) [view abstract]
Clothing is a lens through which a society expresses its culture and history. Its stylized portrayal in painting adds an immensely rich layer of cultural self introspection---how artists see themselves and their contemporaries, expressed through art. Particularly of interest in this study is color: how has color in costumes in portraiture painting changed over time, across art styles, and for different genders? In this study, we apply computational methods drawn from computer vision, machine learning, economics, and statistics to a large corpora of over 12k portrait paintings to analyze trends in color over the past 600 years. For each painting, we obtained clothing segmentation masks using a fine-tuned SegFormer model, performed gender classification using CLIP, extracted dominant colors via clustering analysis, and computed Color Contrast Index (CI) and Diversity Index (DI). We highlight particularly noteworthy observations. For example, Pop Art and Fauvist paintings rank highest in CI and DI values, respectively, while Symbolist and Mannerist paintings rank the lowest. With the exception of the latter half of the 20th century, the DI of female portraits is always higher than that of male portraits, and this DI gender gap largely increases from the 15th to 18th centuries but shrinks in the past 300 years. This study is, to our knowledge, the most comprehensive, large-scale analysis of colors of clothing in paintings. Lastly, we release the code used in our analysis, to make more widely available the tools for applying state-of-the-art deep learning methods to fine-art analysis for other scholars in the art and computer science communities.
10:10HVEI-217
Symmetry and asymmetry in historical "Lotto carpets" and their relevance to claims the artist used projection optics, Evan Laksono, Stanford University (US) [view abstract]
In 2000, the celebrated British-American artist David Hockney claimed that some Western artists, as early as 1430, secretly used optical devices during the execution of their works (a quarter millennium earlier than scholars have secure evidence of such praxis). The central evidence or " Rosetta Stone" put forth by Hockney and his collaborator Charles Falco concerns geometric anomalies in the carpet design in Lorenzo Lotto's Husband and wife, which these proponents claim are "optical"effects arising when the artist refocused a secret optical projector. The theory's proponents uncritically assume that the intrinsic shape of the design in the carpet in Lotto\rq s studio was highly symmetric, and ascribe the asymmetries in the painting to the artist tracing two "exposures" with different centers of projection, altered to overcome the purported projector's depth of field. We test the proponents'implicit assumption that the inherent design in the carpet was highly symmetric by quantifying the symmetry and asymmetry in forty-one hand-made "Lotto carpets." We find that the distribution of asymmetry is several times greater than that implicitly assumed by Hockney and Falco. We conclude, in the parlance of statistics, that Hockney and Falco are "fitting noise"and thus that their claims that Lotto used optics are invalid. These technical results comport with contextual and historical evidence rejecting the optical claim for this painting, such as the lack of documentary evidence in Lotto's personal notebook or Libro di spese, among other facts.
Special Session on Holistic and Multisensory Aesthetic Experience, Part I
Session Chair: Marella Campagna, University of Bamberg
11:00 - 12:20
Grand Peninsula B
11:00HVEI-218
KEYNOTE: Experiencing art changing the world to the better, [view abstract]
The capacity of art to effect transformation at the individual and societal levels is grounded in its capacity to foster empathy, awareness, and critical thinking. Art experience provides individuals with exposure to a multiplicity of perspectives, emotions, and ideas that can challenge preconceived notions and inspire novel modes of thinking. Art functions as a reflective device, reflecting societal issues while providing a forum for dialogue and introspection. Art encourages individuals to engage with the world around them on a deeper level, fostering understanding and compassion. By promoting creativity and collaboration, art can also drive positive social change, encouraging activism and inspiring communities to take action on issues such as social justice, environmental protection, and human rights. Ultimately, the experience of art can lead to a more connected, empathetic, and proactive society.
12:00HVEI-219
Multisensory aesthetic perception: A quantitative-qualitative study on visuo-tactile interactions with material textures, Marella Campagna, Bamberg University (Germany); Alexander Pastukhov, Bamberg University (Germany); Claus-Christian Carbon, Bamberg University (Germany) [view abstract]
In real-world interactions, material textures elicit a complex interplay of sensory modalities, primarily vision and touch. Recent research advances have sought to unravel material perception, focusing on how visual and haptic systems interact. Despite these efforts, a clear understanding of bottom-up and top-down processes in visuo-tactile aesthetics remains limited. This study aimed to explore visuo-tactile sensory perception and material texture interactions using a multimethodological approach.Thirty right-handed participants with normal or corrected-to-normal vision, engaged with various textures through a Touch Perception Task (TPT). A think-out-loud protocol captured participants' qualitative feedback during visuo-tactile exploration, while self-reports detailed their sensory and affective experiences, personality traits, and need for touch. Eye-tracking technology measured fixation and pupillary responses, complemented by video analysis of hand movements during material engagement. We classified diverse sensory and affective responses toward the material textures by analyzing both pupillometry data and prototypical hand movements. The findings demonstrated that materials such as sandpapers (K40, K1200) and silks showed contrasting sensory/affective profiles. Sandpaper K40 was unexpectedly pleasant, despite perceived roughness, due to its larger, smoother particles and possible low-frequency vibrations. In contrast, K1200, although visually softer, was experienced as irritating due to its fine grain and unengaging visual properties. Faux fur emerged as the most favored material, evoking comfort and safety. Hand movement analysis revealed deviations from traditional lateral motion used in texture assessments, possibly driven by cognitive, affective, and aesthetic factors. Our integrated approach, combining physiological and behavioral data, provides deeper insights into the cognitive-affective interplay of visuo-tactile experiences. These findings suggest that visual complexity (in)congruence between visual anticipation and actual haptic experience, and material properties like texture and vibration influence aesthetic judgments, expanding our understanding of sensory integration processes beyond singular assessments of independent dimensions.
12:20HVEI-220
Aesthetic experiences: Mostly pleasurable, often meaningful, potentially translational, transcendent, and transformative, Claus-Christian Carbon, University of Bamberg (Germany) [view abstract]
Psychological aesthetics explores how humans experience and respond to art, beauty, and design, revealing that these encounters are often multi-faceted, offering pleasure, deeper meaning, and even personal transformation. This presentation will delve into the diverse dimensions of aesthetic experience. It begins with the pleasure derived from art and beauty, showing how it enhances emotional well-being. Beyond pleasure, aesthetic experiences often serve as a platform for meaning-making, enabling reflection and the search for purpose. These insights have translational potential, informing people about highly complex narratives via a very compact piece of art, which functions relatively culture-independently and can strongly impact the beholder s affective and cognitive processing. Additionally, we explore how certain aesthetic encounters can evoke transcendence, fostering a connection to something greater than the self. Finally, we examine the transformative power of aesthetics, showing how profound experiences with beauty can reshape identity, values, and emotional life. This talk highlights the integral role of aesthetics in human flourishing, personal growth, societal well-being, and cultural development.
Special Session on Holistic and Multisensory Aesthetic Experience, Part II
Session Chair: Marella Campagna, University of Bamberg
15:30 - 17:30
Grand Peninsula B
15:30HVEI-221
Aesthetic Experiences: Is there an art-specific processing mode? comparing the experience of art appreciation in a gallery and a shop context using VR, Itay Goetz (Germany); Jennifer Tesch ; Dragan Jankovic; Claus-Christian Carbon [view abstract]
When people engage with art, they accept and even embrace feelings they often tend to avoid. These include, among others, the experience of negative emotions, peak emotions, cognitive challenges, semantic instability, uncertainty and more. For about 300 years, philosophers and psychologists of art have argued that when people engage with objects identified as art, they adopt a cognitive mode distinct from everyday processing that affects subsequent interaction with these objects. We addressed this experimentally through a VR (Virtual Reality) study. Thirty-two participants were randomly assigned into one of two experimental conditions, where they freely interacted with the same nine unfamiliar artistic pictures from a variety of styles presented either in an art (gallery) or everyday (shop) context. Participants expressed their experiences via a think-aloud protocol and the Art Reception Survey (ARS). Additionally, the dynamics of viewing distances were recorded, and participants also completed open-ended questions and questionnaires immediately after the VR experience and two weeks later. While the quantitative evaluative data did not yield significant differences between both contexts, the qualitative data revealed fundamental experiential differences. These findings strongly suggest that an art specific mode may indeed exist. What is more, the findings point at numerous similarities between the processing of art in our study and our concept of MAX (Mode of Art eXperience), which unifies the numerous previous approaches describing this phenomenon. Namely, we found that the processing of art de-automatise everyday goal-directed practical processing and calls for deeper engagement with artifacts, search for meaning through associative thinking and weighing of interpretive, competing interpretations, imagination, openness to peak affective experiences, and more. Importantly, the existence of such mode points at the power of art to drive societal change: Art encourages and even pushes people to engage in critical thinking, consider ideas from perspectives different from their own, feel sympathy towards otherwise neglected topics and people and more.
15:50HVEI-222
Transcending the everyday: The holistic and multisensory essence of aesthetic experiences, Sadia Sadia, RMIT Royal Melbourne Institute of Technology University (Australia) [view abstract]
[Aesthetic Experiences] Sadia Sadia is an artist practitioner, basing her investigations in practice-based and practice-led research into encompassing environments. She proposes that there is the potential to configure technology to heighten profound experiences with art, which may be cathartic, epiphanic, transcendental or conversion, but which are innate and universal. Her research draws on cognitive and perceptual psychology and neuroaesthetics and goes to the heart of how the encompassing environment in art may be modelled to initiate such experiences. Sadia will discuss how she employs these methodologies and strategies in her own work, which frequently includes the distortion or manipulation of time and the use of surrounded audio and sound in a multiplicity of configurations including Atmos.
16:10HVEI-223
On the aesthetic experience, Christopher Tyler, Smith-Kettlewell Institute (US) [view abstract]
Aesthetics is currently on the ascendant as a key factor in the design of consumable products across the globe.They have value not just in the optimal capability to perform their intended function, but in the aesthetic quality that they express in doing so. There is a particular experience that may be identified as "the aesthetic experience", distinguishable from the merely pleasurable:the deliciousness of food, the beauty of a sunset, the flush of sex, etc.The aesthetic experience takes things out of their everyday context to imbue them with the extra significance of the aesthetic context. Before going to an art museum, for example, everything around signifies its affordances through the everyday functionality of its immediate use - streets, trees, cellphone, etc. Within the museum, I encounter many things that challenge this viewpoint, and push my interpretative system to probe non-quotidian functionality and the nature of things in themselves at many fundamental and societal levels. Math equations do something similar for mathematical initiates, but the meaningfulness is in the domain of conceptual/geometrical abstraction into is in the immense range of possibilities of expression of its simple laws, as illustrated by the proliferations of outcomes of fractal equations.
16:30HVEI-224
Pictorial detail and levels of meaning in the art of Rene Magritte, Russell Hamer, Smith-Kettlewell Eye Research Institute (US) [view abstract]
Rene Magritte, the Belgian Surrealist (1898-1967), was a master at evoking multiple levels of meaning in our perceptuo-cognitive responses to his works. Moreover, many of his works draw us into rich philosophical territory, where the nature of reality and meaning are evoked and challenged. Magritte understood perception as representation in the brain and paintings as representations of ideas: the function of painting is to make poetry visible, to render thought visible . I will analyze several works that evoke striking perceptual and emotional experiences and raise philosophical questions. Subtle pictorial details in these works are strategically designed to have profound perceptual impact on us: perceptual amplifiers . These often escape notice with casual viewing, and yet can nevertheless work their magic on us by imbuing the painting with percepts that shock (surprise) or impose an emotional tone that disturbs.
THURSDAY 6 FEBRUARY 2025
Perception in Augmented/Virtual/360 Environments
Session Chair: Alex Chapiro, Meta
08:30 - 10:30
Regency A
08:30HVEI-193
KEYNOTE: Transparency and scission in augmented reality, Michael Murdoch [view abstract]
Optical see-through Augmented Reality (OST-AR) is a developing technology with exciting applications including medicine, industry, education, and entertainment. OST-AR creates a mix of virtual and real, using an optical combiner that blends images and graphics with the real-world environment. Such an overlay of visual information is simultaneously futuristic and familiar: like the sci-fi navigation and communication interfaces in movies, but also much like banal reflections in glass windows. OST-AR's transparent displays cause background bleed-through, distorting color and contrast, yet virtual content is usually easily understandable. Perceptual scission, or the cognitive separation of layers, is an important mechanism, influenced by transparency, depth, parallax, and more, that helps us see what is real and what is virtual. In examples from Pepper's Ghost, veiling luminance, mixed material modes, window shopping, and today's OST-AR systems, transparency and scission provide surprising and ordinary results. Ongoing psychophysical research is addressing perceived characteristics of color, material, and images in OST-AR, testing and harnessing the perceptual effects of transparency and scission. Results help both understand the visual mechanisms and improve tomorrow's AR systems.
09:30HVEI-194
Investigation of whether perspective guide vergence when gazing at moving object in 360-degree images, Hisaki Nate, Tokyo Polytechnic University (Japan); Tamaki Takamura, Tokyo Polytechnic University (Japan) [view abstract]
The vergence of subjects was measured while they observed 360-degree images of a virtual reality (VR) goggle. In our previous experiment, we observed a shift in vergence in response to the perspective information presented in 360-degree images when static targets were displayed within them. The aim of this study was to investigate whether a moving target that an observer was gazing at could also guide his vergence. We measured vergence when subjects viewed moving targets in 360-degree images. In the experiment, the subjects were instructed to gaze at the ball displayed in the 360-degree images while wearing the VR goggle. Two different paths were generated for the ball. One of the paths was the moving path that approached the subjects from a distance (Near path). The second path was the moving path at a distance from the subjects (Distant path).Two conditions were set regarding the moving distance (Short and Long). The moving distance of the left ball in the long-distance condition was a factor of two greater than that in the short-distance condition. These factors were combined to created four conditions (Near-Short, Near-Long, Distant-Short and Distant-Long). And two different time intervals (5s and 10s) were designated for the movement of the ball only in the short-distance conditions. The moving time of the long-distance condition was always 10s. In total, six types of conditions were created. The results of the experiment demonstrated that the vergence was larger when the ball was in close proximity to the subjects than when it was at a distance. That was that the perspective information of 360-degree images shifted the subjects' vergence. This suggests that the perspective information of the images provided observers with high-quality depth information that guided their vergence toward the target position. Furthermore, this effect was observed not only for static targets, but also for moving targets.
10:10HVEI-195
From Polaroid to augmented reality: The enduring avantages of whiteborders, Michael Murdoch, Rochester Institute of Technology (US) [view abstract]
Ubiquitous throughout the history of photography, white borders on photo prints and vintage Polaroids remain useful as new technologies including augmented reality emerge for general use. In novel optical see-through augmented reality (OST-AR) displays, physical transparency limits the visibility of dark stimuli. However, image manipulations as simple as white borders have a strong visual effect, making the dark objects appear darker and more opaque. In this work, the practical value of known, inter-related effects including lightness induction, glare illusion, Bartleson-Breneman effect, and simultaneous contrast are explored. The results show promising improvements to visibility and visual quality in future OST-AR interfaces.
Fundamental and Extended Visual Perception
Session Chair: Bjorn Sommer, Royal College of Art
11:00 - 13:00
Regency A
11:00HVEI-196
Computational trichromacy reconstruction: empowering the color-vision deficient to recognize colors using augmented reality, Yuhao Zhu, University of Rochester (US); Ethan Chen, University of Rochester (US); Colin Hascup, University of Rochester (US); Yukang Yan, University of Rochester (US); Gaurav Sharma, University of Rochester (US) [view abstract]
We propose an assistive technology that helps individuals with Color Vision Deficiencies (CVD) to recognize/name colors. A dichromat's color perception is a reduced two-dimensional (2D) subset of a normal trichromat's three dimensional color (3D) perception, leading to confusion when visual stimuli that appear identical to the dichromat are referred to by different color names. Using our proposed system, CVD individuals can interactively induce distinct perceptual changes to originally confusing colors via a computational color space transformation. By combining their original 2D precepts for colors with the discriminative changes, a three dimensional color space is reconstructed, where the dichromat can learn to resolve color name confusions and accurately recognize colors. Our system is implemented as an Augmented Reality (AR) interface on smartphones, where users interactively control the rotation through swipe gestures and observe the induced color shifts in the camera view or in a displayed image. Through psychophysical experiments and a longitudinal user study, we demonstrate that such rotational color shifts have discriminative power (initially confusing colors become distinct under rotation) and exhibit structured perceptual shifts dichromats can learn with modest training. The AR App is also evaluated in two real-world scenarios (building with lego blocks and interpreting artistic works); users all report positive experience in using the App to recognize object colors that they otherwise could not.
11:20HVEI-197
JPI-first Pending (JPI-0197): Effectiveness of visual, auditory, and haptic guidance cues for visual targets in virtual environments, Hila Sabouni, Iowa State University (US) [view abstract]
Virtual reality is increasingly being utilized in domains like training, education, and entertainment, as it can provide a more immersive and interactive experience. Maintaining this immersion necessitates a well-integrated guidance system to prevent any inconsistencies that could conflict with the environment and break the sense of immersion. However, the design of such guidance cues can be a challenge. This research explored the effectiveness of three different attention guidance cues, an extended field of view through a rear-view mirror (passive guidance), and audio alerts and haptic alerts (active guidance), in a scavenger hunt-style visual search task. A control condition with no guidance was included. Participants were tasked with visually searching and locating seven specified paintings in a virtual environment of the remodeled Louvre Museum. Performance was primarily evaluated through qualitative surveys as well as two quantitative metrics: the frequency with which users checked the task list of seven paintings and the total time to complete the task. Results indicated that haptic feedback was significantly more effective at reducing the frequency to check the task list when compared to the control condition. Audio feedback was also effective. The rear-view mirror was the least effective. Unexpectedly, the guidance cues did not reduce task completion time. The insights from this research offer virtual reality designers a valuable approach to constructing more responsive virtual environments through the use of effective attentional guidance cues.
11:40HVEI-198
JPI-first (JPI-0196): Experimental investigation of depth cues for small-field light sources in darkness, Yuko Harada, Chiba University ; Midori Tanaka, Chiba University (Japan); Takahiko Horiuchi, Chiba University (Japan) [view abstract]
In recent years, the effects of light pollution have become significant, and the need for image reproduction of a faithful and preferred starry sky has increased. Previous studies have analyzed the relationship between the luminance, size, and color temperature of stars and the fidelity and preference of their appearance, as well as color perception. This study examines the depth perception of stars. We consider star images as a set of "small-field light sources" that can be viewed as point light sources with minimal viewing angles. Our goal was to experimentally elucidate the cues for depth perception. In the experiment, we asked observers to watch two points of different size, luminance, and color temperature and to select the one perceived in front to confirm the relationship between the three depth cues of retinal image size, light attenuation, and color, and their association with depth perception. The experimental results confirmed that retinal image size and light attenuation were effective for a small-field light source. These results suggest that the interaction between the retinal image size and light attenuation may be explained by retinal illuminance. However, the effect of color was small, and the point with higher saturation was slightly more likely to be perceived in front of it when the hue was close to that of the point.
12:00HVEI-199
Impact of camera height and field-of-view on distance judgement and gap selection in digital rear-view mirrors in vehicles, Felix Thulinsson, RISE Research Institutes of Sweden AB (Sweden); Niclas S derlund, RISE Research Institutes of Sweden AB (Sweden); Shirin Rafiei, RISE Research Institutes of Sweden AB (Sweden); Bo Schenkman, RISE Research Institutes of Sweden AB (Sweden); Anders Djupsj backaa, RISE Research Institutes of Sweden AB (Sweden); B rje Andr n, RISE Research Institutes of Sweden AB (Sweden); Kjell Brunnstr m , RISE Research Institutes of Sweden AB (Sweden) [view abstract]
This study investigates how different camera perspectives presented in digital rear-view mirrors in vehicles, a.k.a. Camera Monitor Systems (CMS), impact on drivers' distance judgement and decision-making in dynamic driving scenarios. The study examines (1) the effects of field of view and (2) camera height on drivers' ability to judge distances to rearward vehicles and to select safe gaps in potentially hazardous situations. A controlled video experiment was conducted, involving 27 participants who performed distance estimations and last safe gap selection tasks using a simulated side-view mirror display. Participants viewed pre-recorded driving scenarios with varying combinations of field of view (40 , 76 , 112 ) and camera heights (1meter, 2.3meter). The results indicate that no significant effects were found for camera height, but wider field of views led to more accurate distance estimations. However, the use of a wider field of view also increased the risk of potentially dangerous overestimations of distance, as evidenced by the last safe gap results. They suggest that a wider field of view leads to the selection of smaller and potentially risky gaps. Conversely, narrow field of views resulted in underestimations of distance, potentially leading to overly cautious and less efficient driving decisions. These findings inform CMS design guidelines how to improve driver perception and road safety, in order to reduce accidents from vehicle distance misjudgments.
12:20HVEI-200
JIST-first Accepted (JIST1933): Influence of display sub-pixel arrays on roughness appearance, Kosei Aketagawa, Chiba University (Japan); Midori Tanaka, Chiba University (Japan); Takahiko Horiuchi, Chiba University (Japan) [view abstract]
With recent advancements in display technology, the perception of objects based on their images has become a crucial aspect of the human visual experience. "Shitsukan" refers to a comprehensive perception of an object's appearance, encompassing various attributes such as roughness, glossiness, and transparency. The accurate reproduction of these characteristics is increasingly necessary in various applications. However, how pixel structures in different displays affect shitsukan perception remains unclear. To achieve consistent reproduction and effective shitsukan management across displays, it is essential to clarify the impact of pixel structure on shitsukan perception. This study aimed to investigate the effect of display pixel arrangements on roughness perception. In an evaluation experiment, the effects of three sub-pixel arrays (red, green and blue [RGB], red, green, blue, and white [RGBW], and PenTile) on roughness perception using natural images were analyzed. The experimental results showed that variations in sub-pixel arrays significantly influence roughness perception under the given conditions. The mean responses of all observers indicated that the PenTile array exhibited the highest perceived roughness, followed by the RGB and RGBW arrays. These findings suggest that variations in sub-pixel arrays can influence roughness perception. Moreover, a comprehensive analysis of observer responses via cluster analysis indicated that the relative influence of sub-pixel arrays on roughness perception varied among observers. It was also confirmed that differences in perceived roughness arise from image content and texture complexity. Specifically, the effect of sub-pixel arrays was more pronounced for images with complex textures and high-frequency components, while differences between arrays were less noticeable in images with simpler textures.
12:40HVEI-201
Cross-modal brain plasticity in haptic perception, kinesthetics & spatial navigation: Profound interhemispheric asymmetry, Lora Likova, Smith-Kettlewell Eye Research Institute (US); Kristyo Mineff, Smith-Kettlewell Eye Research Institute (US); Zhangziyi Zhang, Smith-Kettlewell Eye Research Institute (US); Michael Liang, Smith-Kettlewell Eye Research Institute (US); Christopher Tyler, Smith-Kettlewell Eye Research Institute (US) [view abstract]
Introduction: The occipito-temporal cortex incorporates a pivotal brain area traditionally associated with visual motion processing, area hMT+. Previously considered exclusively visual, its role has been expanded by recent findings to include sensitivity to visual tasks beyond motion, such as static body parts, handedness, and tool usage. This leads to the question of how this extended visual functionality is reorganized in the absence of vision, particularly for non-visual self-produced motion like haptic perception or kinesthetically-guided body-motion during navigation?Methods: A group of totally blind subjects underwent the Cognitive-Kinesthetic Memory-Drawing Training (Likova, 2012), tailored for spatial navigation, using raised-line tactile maps. The whole brain was scanned before and after the training in a Siemens 3T Prisma scanner while the navigational maps were (i) haptically explored with left hand to be memorized (30 s); after a 20 s rest period, the maps were (ii) drawn-from-haptic-memory based on kinesthetic feedback only using a stylus with the opposite hand (30 s). Before and after training, a custom Virtual Reality (VR) system was used to assess the transfer of training effect to the participants' navigational abilities.Results: Both non-visual tasks strongly activated hMT+ despite the lack of any vision or visual motion. Moreover, our paradigm revealed an unsuspected interhemispheric functional asymmetry in the occipitotemporal cortex. The left-hand haptic memory encoding task activated the right-hemisphere hMT+ only but failed to do so in its ipsilateral hemisphere. In contrast, the right-hand kinesthetic drawing-from-haptic-memory task strongly activated hMT+ bilaterally. Further post-training analyses revealed for the first time a large-scale massive brain reorganization in the blind forming previously unknown clusters of occipitotemporal areas neighboring hMT+, which, expressed the same left/right asymmetry as hMT+ per se. The profoundly asymmetric pattern of hMT+ thus spread across neighboring visual areas despite their well-known distinct functionality in the sighted, turning them instead into large homogeneous clusters with asymmetric responses in the blind.Granger Causal connectivity analysis was run pre & post training to investigate the brain reorganization at network level including all of the areas of each cluster, as well as the classic motor, somatosensory and memory areas. Remarkably, inputs to hMT+ derived entirely from the frontal and prefrontal cortex, while outputs from hMT+ went entirely to posterior cortex, including key areas of the navigational network. The VR assessments demonstrated highly significant improvement in both speed and precision of the navigational performance post-training, confirming transfer of learning effects.Conclusions: This study provides multifaceted insights into non-visual functionality of the visual-motion complex, its novel interhemispheric asymmetries, and their implications for functional brain architecture and learning-induced plasticity. Furthermore, the results revealed for the first time the emergence of training-driven functional-homogenization of occipitotemporal clusters surrounding hMT+, highlighting a remarkable form of cross-modal reorganization in the blind. The VR assessments confirmed the behavioral relevance of these learning effects and their transfer from the hand-scale to full body-scale of navigation. These findings advance our understanding of neuroplasticity and sensory compensation, demonstrating how the brain adapts to the absence of vision to optimize spatial navigation, haptic perception and kinesthetics.
Lightness and Color Perception II
Session Chair: Nicko Reginio Caluya, Ritsumeikan University
14:00 - 16:00
Regency A
14:00HVEI-202
Colour vision deficiencies and colour emotion, Miriam Kagerer, Norwegian University of Science and Technology (Norway) [view abstract]
The topic of how colour emotion and colour vision deficiencies interact with each other is barely researched, and existing studies have contradicting results. This study will investigate how these two topics interact with each other and try to prove that colour emotion is affected by colour vision deficiencies.\\ This was done through an online colour-emotion associations questionnaire in two phases. The first phase had 60 participants, of which 15 reported having colour vision deficiencies and the second had 18 participants, of which 8 were identified to have colour vision deficiencies. Within the questionnaires, the participants selected emotions from the Geneva Emotion Wheel which they associated with 12 colour patches or 4 colour terms and then rated how strong this association is from 1 to 5.\\Results show indications that colour vision deficiencies lead to reduced strength of colour-emotion associations and a higher number of people who do not associate emotions with certain or all colours. Additionally, it was found that the colour vision deficiency group associates fewer emotions with each colour than the normal vision group and differences in specific colour-emotion associations were found between the two groups.
14:20HVEI-203
Effect of varying background lightness on performance on a pseudo-isochromatic colour vision test, Phil Green, NTNU (Norway); Reiner Eschbach, NTNU (Norway); Peter Nussbaum, NTNU (Norway) [view abstract]
14:40HVEI-204
Preservation of color metadata across transformations of pixel data, Coleman Earlywine, University of Kentucky (US); Henry Dietz, University of Kentucky (US) [view abstract]
Image data is now commonly represented in any of a myriad of file formats, from proprietary raw formats through standards like JPEG or PNG. In addition to recording pixel values, most of these formats contain metadata that defines how pixel values translate into particular colors and brightnesses. Unfortunately, when non-trivial computations are used to transform pixel values, it is often necessary that both the metadata and file format used be changed. For example, when the parsek tool aligns images and produces a raw super resolution result, problematic shifts in color and tonality have been observed. The goal of the current work has been to understand what is causing these shifts and how can they be avoided.Toward that goal, the color and tonal metadata information representations in a variety of file formats is reviewed. The effectiveness of preserving appearance when file format is changed is then reviewed. A reference color and tonal rendering is obtained by examining the thumbnail renderings embedded in raw formats.
15:00HVEI-205
Defining the gamut of extended colour gamut printing, Phil Green, NTNU (Norway) [view abstract]
A gamut boundary test chart can be used to define the gamut of a colour reproduction system as a set of vertices and triangular faces. This makes it possible to analyse characteristics of a reproduction system gamut, such as its volume. A standard chart is currently defined only for RGB and CMYK colour spaces, but the increased adoption of extended colour gamut printing requires a different approach. Here a new test chart is proposed that extends the colour spaces to include extended-gamut printing, with up to seven colorants.