The Ups and Downs of Camera-Monitor Systems: The Effect of Camera Position on Rearward Distance Perception

2020 ◽  
pp. 001872081989586
Author(s):  
Christoph Bernhard ◽  
Heiko Hecht
Keyword(s):  
Depth Perception ◽  
Applied Research ◽  
Distance Perception ◽  
Distance Estimation ◽  
Environmental Information ◽  
Field Of View ◽  
Car Following ◽  
Main Effect ◽  
Camera Position ◽  
Metric Distances

Objective This study investigates the effects of different positions of side-mounted rear-view cameras on distance estimation of drivers. Background Camera-monitor systems bring advantages as compared to conventional rear-view mirrors, such as improved aerodynamics and enlarged field-of-view. Applied research has mainly focused on the comparison between cameras and mirrors or on positioning of in-vehicle monitors. However, the positioning of the exterior camera awaits investigation given that the perspective of the observer at does affect depth perception at large. Method In two experiments, a total of 50 students estimated metric distances to static vehicles presented in realistic or 3D-rendered pictures. The pictures depicted the rearward scene of a car following the driver as viewed through a camera at varying vertical and horizontal positions. The following vehicle’s size and environmental information varied among conditions and experiments. Results Lower camera positions led to distance overestimation and higher positions to underestimation. The effect increased as the distance to the following vehicle decreased. Moreover, larger vehicles led to stronger distance underestimation, especially in low camera positions. Interestingly, the main effect of camera position disappeared when the ego-vehicles’ back was visible. Conclusion Different rearward viewpoints affect distance estimation of drivers, especially in close distances. However, a visible reference of one’s own vehicle seems to mostly compensate this effect. Application In general, the rear-view camera should be mounted rather higher and to the front of the vehicle. Also, the vehicle’s back should always be visible. Low camera positions are not recommended.

scholarly journals DL-based segmentation of endoscopic scenes for mitral valve repair

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Matthias Ivantsits ◽  
Lennart Tautz ◽  
Simon Sündermann ◽  
Isaac Wamala ◽  
Jörg Kempfert ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Minimally Invasive ◽  
Mitral Valve Repair ◽  
Video Stream ◽  
Field Of View ◽  
Valve Repair ◽  
Distance Measurements ◽  
Anatomical Structures ◽  
Endoscopic Video ◽  
Camera Position

AbstractMinimally invasive surgery is increasingly utilized for mitral valve repair and replacement. The intervention is performed with an endoscopic field of view on the arrested heart. Extracting the necessary information from the live endoscopic video stream is challenging due to the moving camera position, the high variability of defects, and occlusion of structures by instruments. During such minimally invasive interventions there is no time to segment regions of interest manually. We propose a real-time-capable deep-learning-based approach to detect and segment the relevant anatomical structures and instruments. For the universal deployment of the proposed solution, we evaluate them on pixel accuracy as well as distance measurements of the detected contours. The U-Net, Google’s DeepLab v3, and the Obelisk-Net models are cross-validated, with DeepLab showing superior results in pixel accuracy and distance measurements.

Geometry and Visual Space from Antiquity to the Early Moderns

Space ◽  
2020 ◽  
pp. 184-222
Author(s):  
Gary Hatfield
Keyword(s):  
Visual Perception ◽  
Distance Perception ◽  
Visual Space ◽  
Field Of View ◽  
Size Perception ◽  
Mental Calculation ◽  
Straight Lines ◽  
Comparative Examination

This chapter examines the development of a geometrical framework for understanding and explaining spatial aspects of visual perception, including perception of the sizes, shapes, and positions of things in the field of view. The structure of this framework is built on the fact that vision typically occurs in straight lines (rectilinearly). Within this framework, the chapter selectively focuses on size perception. This focus allows for a comparative examination of how a single problem was treated geometrically by various theorists, ancient, medieval, and modern. The theorists examined are Euclid and Ptolemy, who were extramissionists, and Ibn al-Haytham, Kepler, Descartes, and Berkeley, each of whom adopted, in one way or another, an intromissionist scheme. In comparing Descartes and Berkeley, notice is taken of Berkeley’s interpretive bent in treating Descartes’s account of distance perception in a way that requires mental calculation, where Descartes sometimes offered psychophysiological mechanisms (avoiding mental calculation).

Environmental Information Required by Individuals with Visual Impairments Who Use Orientation and Mobility Aids to Navigate Campuses

2020 ◽  
Vol 114 (4) ◽  
pp. 263-276
Author(s):  
Konstantinos Papadopoulos ◽  
Konstantinos Charitakis ◽  
Eleni Koustriava ◽  
Georgios Kouroupetroglou ◽  
Rainer Stiefelhagen ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Visual Impairments ◽  
Environmental Information ◽  
Repeated Measures Analysis ◽  
Main Effect ◽  
Mobility Aids ◽  
Orientation And Mobility ◽  
Information Safety ◽  
Convenience Sampling ◽  
Tactile Maps

Introduction: This study investigated the user requirements of individuals with visual impairments regarding the information to be included in orientation and mobility (O&M) aids in order for optimally useful audio-tactile maps of campuses to be developed. In addition, this study aimed at investigating the importance (usefulness) that individuals with visual impairments attribute to environmental information of campuses. Methods: The researchers listed 213 pieces of environmental information concerning campuses and address them in survey by conducting a respective questionnaire. Participants were asked to evaluate the information, regarding the importance or usefulness of the information in regard to safety, location of services, and orientation and wayfinding during movement. Through convenience sampling 115 adults (aged from 18 to 64 years) with visual impairments from four countries (Greece, Cyprus, Turkey, and Germany) took part in the research. Results: Pieces of environmental information, sorted in descending order starting with the most useful ones, have been listed. A repeated measures analysis of variance yielded a significant main effect for the type of information (safety, location of services, and wayfinding and orientation): F(2, 228) = 70.868, p < .001. Discussion: This study resulted in the specification of the most significant or useful information that should be included in O&M aids of campuses for individuals with visual impairments. Implications for practitioners: The results of this study will hold the interest of developers of O&M aids, O&M practitioners, rehabilitation teachers, and instructors who design and construct O&M aids. Moreover, the context for appropriately designed tactile or audio-tactile maps for campuses is provided, and campuses around the world could rely on this study for the creation of a valuable accessibility aid.

Effect of Relative Positions of Segments on Strength of the Mueller-Lyer Illusion

1971 ◽  
Vol 33 (3_suppl) ◽  
pp. 1051-1058 ◽  
Author(s):  
Clive M. Davis ◽  
Marshall H. Segall
Keyword(s):  
Visual Field ◽  
Depth Perception ◽  
Interaction Effects ◽  
The Other ◽  
Relative Height ◽  
Lyer Illusion ◽  
Main Effect ◽  
Depth Cue

Segall, Campbell, and Herskovits (1966) postulated that the Mueller-Lyer illusion results from the misapplication of normally valid visual inference habits related to depth perception. To test the hypothesis that the depth cue of the relative height of the Mueller-Lyer segments in the visual field affects susceptibility, 100 Ss were presented two identical sets of 15 slides of Mueller-Lyer stimuli, one set with the >—–< above the <——> and the other set in the reverse orientation. Placement of the >—–< above the <—–> produced significantly greater illusion susceptibility, as predicted by the depth cue hypothesis. Females were more susceptible than males, but there were no interaction effects of sex with figure orientation or trials nor a main effect for trials. The results were interpreted as supporting an empiricistic explanation of the Mueller-Lyer illusion.

Age Differences in the Useful Field of View during Real-World Driving

2005 ◽  
Vol 49 (2) ◽  
pp. 182-185 ◽  
Author(s):  
Frank Schieber ◽  
Jess Gilland
Keyword(s):  
Target Detection ◽  
Age Differences ◽  
Real World ◽  
Field Of View ◽  
Peripheral Target ◽  
Car Following ◽  
Useful Field Of View ◽  
Target Eccentricity ◽  
Age Related ◽  
Age Related Changes

Age differences in the useful field of view (UFOV) were assessed during real-world driving using a newly developed car-following protocol. Nineteen young (mean age = 23) and 19 older (mean age = 73) drivers were examined. Peripheral target detection performance declined significantly with age and target eccentricity. However, consistent with several recent studies, no age by target eccentricity interaction was observed. These findings contribute to the validation of the UFOV construct and provide a foundation for better understanding age-related changes in visual attention in the real-world driving domain.

Visual aspects of advanced sensors and helmet-mounted displays

2014 ◽  
Vol 118 (1200) ◽  
pp. 155-168 ◽  
Author(s):  
P. J. Morgan-Warren ◽  
M. Woodcock
Keyword(s):  
Situational Awareness ◽  
Ocular Dominance ◽  
Distance Estimation ◽  
Coupled Systems ◽  
Field Of View ◽  
Remote Sensors ◽  
Common Causes ◽  
Other Information ◽  
Estimation Problems ◽  
Visual Problems

Abstract Visually coupled systems such as helmet mounted displays are designed to improve aircrew situational awareness by providing timely flight, targeting and other information overlaid on real or sensor-derived views of the external environment. Data can be presented in monocular, biocular or binocular fashion and are associated with visual conflicts and potential ophthalmic problems. Restricted sensor spectrum, limits of resolution, inherent system latency, the displaced visual input from remote sensors and restricted field of view may contribute to ophthalmic symptoms in aircrew. Disruption to binocularity and reliance on monocular cues for depth perception and hyperstereopsis from sensor-induced convergence disparity may cause distance estimation problems, whereas inappropriate accommodative stimuli and ocular dominance factors are common causes of eyestrain. Binocular rivalry from discordant imagery to each eye may compromise visual performance via several mechanisms. This article discusses the potential visual problems associated with visually coupled systems and the challenges of integrating complex systems with the aircrew interface.

Motion Parallax and Distance Estimation Underwater

1974 ◽  
Vol 38 (3) ◽  
pp. 747-750
Author(s):  
Steven H. Ferris
Keyword(s):  
Head Movement ◽  
Distance Perception ◽  
Motion Parallax ◽  
Distance Estimation ◽  
Vertical Axis ◽  
Improve Performance ◽  
Water Turbidity ◽  
Position Constancy ◽  
Before And After ◽  
Positive Results

The possible value of monocular motion parallax for improving distance perception underwater was investigated. Submerged Ss either kept their heads stationary or rotated their heads about a vertical axis while judging the distance of objects placed 4 to 15 ft. away. Both before and after training with feedback to increase accuracy of judgment, head movement did not significantly improve performance. Water turbidity and loss of position constancy are two probable reasons for the failure to replicate the positive results previously obtained in air.

scholarly journals The utilization of landscape pictures extracted from open picture collections for the determination of interest in spatial features

2018 ◽  
Author(s):  
Jens Ingensand ◽  
Jean Christophe Foltête ◽  
Stéphane Cretegny ◽  
Nicolas Blanc ◽  
Sarah Composto
Keyword(s):  
Focal Length ◽  
Digital Terrain Model ◽  
Field Of View ◽  
Terrain Model ◽  
Digital Terrain ◽  
Spatial Features ◽  
Automated Method ◽  
Camera Position

This paper describes a method that uses georeferenced landscape pictures extracted from open picture collections for the determination of the population's interest in spatial features. The automated method takes into account the coordinates of the camera position as well as the azimuth angle, the focal length and the crop factor in order to calculate a field of view using a digital terrain model (DTM). This field of view can thereafter be used for the determination of interest in spatial features. In a case study involving more than 3'000 georeferenced pictures we investigate the potential of the method.

scholarly journals An Adaptive Prediction Target Search Algorithm for Multi-AUVs in an Unknown 3D Environment

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3853 ◽  
Author(s):  
Juan Li ◽  
Jianxin Zhang ◽  
Gengshi Zhang ◽  
Bingjian Zhang
Keyword(s):  
High Efficiency ◽  
Search Algorithm ◽  
Autonomous Underwater Vehicles ◽  
Environmental Information ◽  
Field Of View ◽  
Current Layer ◽  
Evaluation Function ◽  
Target Search ◽  
Search Tasks ◽  
Adaptive Prediction

For a target search of autonomous underwater vehicles (AUVs) in a completely unknown three-dimensional (3D) underwater environment, a multi-AUV collaborative target search algorithm based on adaptive prediction is proposed in this paper. The environmental information sensed by the forward-looking sonar is used to judge the current state of view, and the AUV system uses this environmental information to perform the target search task. If there is no target in the field of view, the AUV system will judge whether all sub-regions of the current layer have been searched or not. The next sub-region for searching is determined by the evaluation function and the task assignment strategy. If there are targets in the field of view, the evaluation function and the estimation function of the adaptive predictive optimization algorithm is used to estimate the location of the unknown target. At the same time, the algorithm also can reduce the positioning error caused by the noise of the sonar sensor. In this paper, the simulation results show that the proposed algorithm can not only deal with static targets and random dynamic interference target search tasks, but it can also perform target search tasks under some random AUV failure conditions. In this process, the underwater communication limits are also considered. Finally, simulation experiments indicate the high efficiency and great adaptability of the proposed algorithm.

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