scholarly journals Design of monocular head-mounted displays, with a case study on fire-fighting

2007 ◽  
Vol 221 (12) ◽  
pp. 1729-1743 ◽  
Author(s):  
J Wilson ◽  
P Wright
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Optical Design ◽  
Physical World ◽  
Design Guidelines ◽  
Fire Fighting ◽  
Joint Torque ◽  
Head Mounted Displays ◽  
Context Specific

The paper presents a design methodology and a case study for monocular head-mounted displays (HMDs), wherein a user can simultaneously and easily see the physical world by looking through and/or around the display. The design approach is user-focused because of the complexity of the human visual system, and because HMDs are very task, user, and context specific. A literature review of factors related to HMD design is given. This includes considerations for basic optical design, the human visual system, and head and neck biomechanics. General HMD design guidelines are given based on these considerations. For the specific case study on fire-fighting, it is recommended that the HMD be mounted at 15° to 45° below the Frankfurt plane, with a 15° to 40° field of view. A resolution of 20–60 px/deg should be focused at 1 m or farther. The neck joint torque due to the HMD should not exceed about 1 Nm. This equates to a typical maximum weight of 0.5 to 1 kg depending on the mounting location.

scholarly journals The Impact of Dynamic Convergence on the Human Visual System in Head Mounted Displays

2021 ◽  
Author(s):  
◽  
Ryan Sumner
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Statistical Significance ◽  
Depth Range ◽  
Binocular Fusion ◽  
Virtual Objects ◽  
Beneficial Effects ◽  
Mixed Response ◽  
Head Mounted Displays ◽  
The Impact

<p>The Accommodation-Vergence Conflict (AVC) is a phenomenon in the area of Head-Mounted Displays (HMDs) and one of the key issues hindering the popularity of HMDs largely due to it causing a large number of users to suffer from simulator sickness. There have been several proposed solutions developed by previous researchers, including the introduction of 'Dynamic Convergence' (DC) which, addresses the AVC problem in terms of the vergence depth cue. DC also helps in the performance of binocular fusion when viewing at a close vergence depth. As of yet however, DC has not undergone detailed testing for a number of important cases, which limits the amount of data that has been collected on DC's interaction with the human visual system. In addition, no DC research as of yet has dealt with the effect of a change in vergence depth, and how that change in the vergence angle of the focal plane would effect a user.  Thus, this thesis adds to the growing body of research and knowledge in this field by implementing DC with the addition of some transitions between a change in vergence depth. This is done within the Unity3D game engine in order to further investigate the impact of DC with regard to viewing close virtual objects on HMDs through a number of cases. The added transitions are also tested to see if they have any beneficial effects for users when the vergence angle changes. The investigation is centered around a perception based performance/appreciation-oriented visual study whereby participants were asked about their ability to perform binocular fusion on close virtual objects that were either stationary or moving and varying distances and speeds. Participants were also asked to report any symptoms of discomfort.  The research has adopted a mixed methodology experimental approach by conducting user experiments and surveys, before analysing the results through both in-depth quantitative statistical analysis and a variety of qualitative statistical techniques in order to measure and investigate the scale of the problem associated with the impact of DC on the human visual system in HMDs when viewing close virtual objects.  From the investigation it was confirmed that the approximate effective vergence depth range for DC was 0.3m or less, with statistical significance confirmed at the 0.15m distance. Participants reported having an easier time performing binocular fusion at these closer distances while DC was enabled. As a result of this, the majority of cases and scenarios did not report any significant negative responses in terms of discomfort symptoms. However attempts at improving DC with a transition between vergence depths were met with a mixed response from participants. While the need of a transition way be dependent on the user, there still exists some demand for one, thus it should still be available as an option.</p>

scholarly journals The Impact of Dynamic Convergence on the Human Visual System in Head Mounted Displays

2021 ◽  
Author(s):  
◽  
Ryan Sumner
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Statistical Significance ◽  
Depth Range ◽  
Binocular Fusion ◽  
Virtual Objects ◽  
Beneficial Effects ◽  
Mixed Response ◽  
Head Mounted Displays ◽  
The Impact

<p>The Accommodation-Vergence Conflict (AVC) is a phenomenon in the area of Head-Mounted Displays (HMDs) and one of the key issues hindering the popularity of HMDs largely due to it causing a large number of users to suffer from simulator sickness. There have been several proposed solutions developed by previous researchers, including the introduction of 'Dynamic Convergence' (DC) which, addresses the AVC problem in terms of the vergence depth cue. DC also helps in the performance of binocular fusion when viewing at a close vergence depth. As of yet however, DC has not undergone detailed testing for a number of important cases, which limits the amount of data that has been collected on DC's interaction with the human visual system. In addition, no DC research as of yet has dealt with the effect of a change in vergence depth, and how that change in the vergence angle of the focal plane would effect a user.  Thus, this thesis adds to the growing body of research and knowledge in this field by implementing DC with the addition of some transitions between a change in vergence depth. This is done within the Unity3D game engine in order to further investigate the impact of DC with regard to viewing close virtual objects on HMDs through a number of cases. The added transitions are also tested to see if they have any beneficial effects for users when the vergence angle changes. The investigation is centered around a perception based performance/appreciation-oriented visual study whereby participants were asked about their ability to perform binocular fusion on close virtual objects that were either stationary or moving and varying distances and speeds. Participants were also asked to report any symptoms of discomfort.  The research has adopted a mixed methodology experimental approach by conducting user experiments and surveys, before analysing the results through both in-depth quantitative statistical analysis and a variety of qualitative statistical techniques in order to measure and investigate the scale of the problem associated with the impact of DC on the human visual system in HMDs when viewing close virtual objects.  From the investigation it was confirmed that the approximate effective vergence depth range for DC was 0.3m or less, with statistical significance confirmed at the 0.15m distance. Participants reported having an easier time performing binocular fusion at these closer distances while DC was enabled. As a result of this, the majority of cases and scenarios did not report any significant negative responses in terms of discomfort symptoms. However attempts at improving DC with a transition between vergence depths were met with a mixed response from participants. While the need of a transition way be dependent on the user, there still exists some demand for one, thus it should still be available as an option.</p>

Evaluation of the Human Visual System in Cosmetics Foundation Colour Selection

2020 ◽  
Vol 2020 (1) ◽  
pp. 60-64
Author(s):  
Altynay Kadyrova ◽  
Majid Ansari-Asl ◽  
Eva Maria Valero Benito
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Skin Tone ◽  
Skin Colour ◽  
Psychophysical Experiment ◽  
Spectral Measurements ◽  
Practical Applications ◽  
Subjective Evaluations ◽  
Colour Measurements ◽  
Colour Quantification

Colour is one of the most important appearance attributes in a variety of fields including both science and industry. The focus of this work is on cosmetics field and specifically on the performance of the human visual system on the selection of foundation makeup colour that best matches with the human skin colour. In many cases, colour evaluations tend to be subjective and vary from person to person thereby producing challenging problems to quantify colour for objective evaluations and measurements. Although many researches have been done on colour quantification in last few decades, to the best of our knowledge, this is the first study to evaluate objectively a consumer's visual system in skin colour matching through a psychophysical experiment under different illuminations exploiting spectral measurements. In this paper, the experiment setup is discussed and the results from the experiment are presented. The correlation between observers' skin colour evaluations by using PANTONE Skin Tone Guide samples and spectroradiometer is assessed. Moreover, inter and intra observer variability are considered and commented. The results reveal differences between nine ethnic groups, between two genders, and between the measurements under two illuminants (i.e.D65 and F (fluorescent)). The results further show that skin colour assessment was done better under D65 than under F illuminant. The human visual system was three times worse than instrument in colour matching in terms of colour difference between skin and PANTONE Skin Tone Guide samples. The observers tend to choose lighter, less reddish, and consequently paler colours as the best match to their skin colour. These results have practical applications. They can be used to design, for example, an application for foundation colour selection based on correlation between colour measurements and human visual system based subjective evaluations.

Objective Video Quality Method Based on Mutual Information and Human Visual System

2012 ◽  
Vol 58 (2) ◽  
pp. 147-152
Author(s):  
Michal Mardiak ◽  
Jaroslav Polec
Keyword(s):  
Mutual Information ◽  
Visual System ◽  
Human Visual System ◽  
Quality Evaluation ◽  
Video Quality ◽  
Evaluation Criteria ◽  
Test Sequence ◽  
Quality Metric ◽  
Two Stages ◽  
Video Quality Metric

Objective Video Quality Method Based on Mutual Information and Human Visual SystemIn this paper we present the objective video quality metric based on mutual information and Human Visual System. The calculation of proposed metric consists of two stages. In the first stage of quality evaluation whole original and test sequence are pre-processed by the Human Visual System. In the second stage we calculate mutual information which has been utilized as the quality evaluation criteria. The mutual information was calculated between the frame from original sequence and the corresponding frame from test sequence. For this testing purpose we choose Foreman video at CIF resolution. To prove reliability of our metric were compared it with some commonly used objective methods for measuring the video quality. The results show that presented objective video quality metric based on mutual information and Human Visual System provides relevant results in comparison with results of other objective methods so it is suitable candidate for measuring the video quality.

scholarly journals Structured Computational Modeling of Human Visual System for No-reference Image Quality Assessment

2021 ◽  
Author(s):  
Wen-Han Zhu ◽  
Wei Sun ◽  
Xiong-Kuo Min ◽  
Guang-Tao Zhai ◽  
Xiao-Kang Yang
Keyword(s):  
Information Processing ◽  
Image Quality ◽  
Visual System ◽  
Computational Modeling ◽  
Quality Assessment ◽  
Human Visual System ◽  
Visual Communication ◽  
Visual Experience ◽  
Image Quality Assessment ◽  
Model Based

AbstractObjective image quality assessment (IQA) plays an important role in various visual communication systems, which can automatically and efficiently predict the perceived quality of images. The human eye is the ultimate evaluator for visual experience, thus the modeling of human visual system (HVS) is a core issue for objective IQA and visual experience optimization. The traditional model based on black box fitting has low interpretability and it is difficult to guide the experience optimization effectively, while the model based on physiological simulation is hard to integrate into practical visual communication services due to its high computational complexity. For bridging the gap between signal distortion and visual experience, in this paper, we propose a novel perceptual no-reference (NR) IQA algorithm based on structural computational modeling of HVS. According to the mechanism of the human brain, we divide the visual signal processing into a low-level visual layer, a middle-level visual layer and a high-level visual layer, which conduct pixel information processing, primitive information processing and global image information processing, respectively. The natural scene statistics (NSS) based features, deep features and free-energy based features are extracted from these three layers. The support vector regression (SVR) is employed to aggregate features to the final quality prediction. Extensive experimental comparisons on three widely used benchmark IQA databases (LIVE, CSIQ and TID2013) demonstrate that our proposed metric is highly competitive with or outperforms the state-of-the-art NR IQA measures.

scholarly journals Bioclimatic and Regenerative Design Guidelines for a Circular University Campus in India

2021 ◽  
Vol 13 (15) ◽  
pp. 8238
Author(s):  
Noemi Bakos ◽  
Rosa Schiano-Phan
Keyword(s):  
Construction Industry ◽  
Assessment Tool ◽  
Economic Benefits ◽  
Design Guidelines ◽  
University Campus ◽  
Design Strategies ◽  
Regenerative Design ◽  
Governmental Institutions ◽  
Social Environmental

To transform the negative impacts of buildings on the environment into a positive footprint, a radical shift from the current, linear ‘make-use-dispose’ practice to a closed-loop ‘make-use-return’ system, associated with a circular economy, is necessary. This research aims to demonstrate the possible shift to a circular construction industry by developing the first practical framework with tangible benchmarks for a ‘Circular University Campus’ based on an exemplary case study project, which is a real project development in India. As a first step, a thorough literature review was undertaken to demonstrate the social, environmental and economic benefits of a circular construction industry. As next step, the guideline for a ‘Circular University Campus’ was developed, and its applicability tested on the case study. As final step, the evolved principles were used to establish ‘Project Specific Circular Building Indicators’ for a student residential block and enhance the proposed design through bioclimatic and regenerative design strategies. The building’s performance was evaluated through computational simulations, whole-life carbon analysis and a circular building assessment tool. The results demonstrated the benefits and feasibility of bioclimatic, regenerative building and neighbourhood design and provided practical prototypical case study and guidelines which can be adapted by architects, planners and governmental institutions to other projects, thereby enabling the shift to a restorative, circular construction industry.

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