Asymmetric circular projection for dynamic virtual reality video stream switching

Author(s):  
Yueming Wang ◽  
Ronggang Wang ◽  
Zhenyu Wang ◽  
Wen Gao
Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1121 ◽  
Author(s):  
Nassr Alsaeedi ◽  
Dieter Wloka

The aim of the study is to develop a real-time eyeblink detection algorithm that can detect eyeblinks during the closing phase for a virtual reality headset (VR headset) and accordingly classify the eye’s current state (open or closed). The proposed method utilises analysis of a motion vector for detecting eyelid closure, and a Haar cascade classifier (HCC) for localising the eye in the captured frame. When the downward motion vector (DMV) is detected, a cross-correlation between the current region of interest (eye in the current frame) and a template image for an open eye is used for verifying eyelid closure. A finite state machine is used for decision making regarding eyeblink occurrence and tracking the eye state in a real-time video stream. The main contributions of this study are, first, the ability of the proposed algorithm to detect eyeblinks during the closing or the pause phases before the occurrence of the reopening phase of the eyeblink. Second, realising the proposed approach by implementing a valid real-time eyeblink detection sensor for a VR headset based on a real case scenario. The sensor is used in the ongoing study that we are conducting. The performance of the proposed method was 83.9% for accuracy, 91.8% for precision and 90.40% for the recall. The processing time for each frame took approximately 11 milliseconds. Additionally, we present a new dataset for non-frontal eye monitoring configuration for eyeblink tracking inside a VR headset. The data annotations are also included, such that the dataset can be used for method validation and performance evaluation in future studies.


2018 ◽  
Vol 48 (1) ◽  
pp. 107-118 ◽  
Author(s):  
Jarosław Sulkowski ◽  
Janusz Błaszczyk ◽  
Adam Grzybowski ◽  
Kacper Karcz ◽  
Paweł Kowaleczko

Abstract Commercially available drone type unmanned aerial vehicles (UAV), as well as parts and subsystems enabling the assemble of UAVs, are becoming more and more widely available, and their performance is constantly improving. The current possibilities of a drone assembled by a hobbyist predispose are not only to be used as a reconnaissance tool but also as a guided missile. The use of a camera with a video stream transmitter simultaneously with virtual reality goggles and video stream receiver gives the pilot an impression of being on the drone, which makes it possible to control it with extreme precision, even at high speeds. The article presents research aimed at determining the extent and type of damage made on exemplary racer drone caused by intense microwave field radiations.


2004 ◽  
Vol 63 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Fred W. Mast ◽  
Charles M. Oman

The role of top-down processing on the horizontal-vertical line length illusion was examined by means of an ambiguous room with dual visual verticals. In one of the test conditions, the subjects were cued to one of the two verticals and were instructed to cognitively reassign the apparent vertical to the cued orientation. When they have mentally adjusted their perception, two lines in a plus sign configuration appeared and the subjects had to evaluate which line was longer. The results showed that the line length appeared longer when it was aligned with the direction of the vertical currently perceived by the subject. This study provides a demonstration that top-down processing influences lower level visual processing mechanisms. In another test condition, the subjects had all perceptual cues available and the influence was even stronger.


Swiss Surgery ◽  
2002 ◽  
Vol 8 (6) ◽  
pp. 250-254
Author(s):  
Vogelbach ◽  
Bogdan ◽  
Rosenthal ◽  
Pfefferkorn ◽  
Triponez

Fragestellung: Die dieser Untersuchung zugrunde liegende Frage war, ob das angewandte Ausbildungskonzept geeignet war, um am Beispiel der Einführung der laparoskopischen Cholezystektomie eine neue Operationsmethode in einer universitären Ausbildungsklinik mit einer grossen Anzahl Chirurgen zu etablieren. Patienten und Methodik: Seit Einführung der ersten laparoskopischen Cholezystektomie wurden alle Cholezystektomien während zwei Jahren (Mai 1990 bis Mai 1992) prospektiv erfasst. Ein Ausbildungskonzept wurde gewählt, bei dem jeweils ein Operateur durch einen Tutor geschult wurde und so 15 konsekutive Eingriffe durchführte, um dann die Technik einem weiteren auszubildenden Chirurgen zu instruieren. Resultate: In zwei Jahren wurden 355 Patienten cholezystektomiert. 60% der Operationen wurden laparoskopisch durchgeführt oder begonnen. 40% der Operationen wurden offen durchgeführt. In den ersten zwei Jahren konnten 13 Operateure (durchschnittlich 16 Operationen / Operateur , range 1 - 60) in die neue Technik eingeführt werden. Es traten keine schweren Komplikationen, insbesondere keine Gallenwegsverletzungen in dieser Einführungsphase auf. Diskussion: In der Literatur wird dieses Vorgehen bei der Einführungsphase seit 1992 wiederholt vorgestellt, diskutiert und empfohlen. Zwischenzeitlich gibt es Richtlinien von Fachgesellschaften und nationalen Institutionen, welche die Ausbildung zur Ausführung neuer chirurgischer Techniken reglementieren. In den letzten Jahren verlagern sich die ersten Ausbildungsschritte in Richtung Trainingskurse an skill-stations und virtual reality Trainer. Schlussfolgerung: Das beschriebene Ausbildungskonzept bewährte sich in der Einführungsphase der laparoskopischen Cholezystektomie zu Beginn der 90er-Jahre.


Dreaming ◽  
2018 ◽  
Vol 28 (3) ◽  
pp. 205-224 ◽  
Author(s):  
Patrick McNamara ◽  
Kendra Holt Moore ◽  
Yiannis Papelis ◽  
Saikou Diallo ◽  
Wesley J. Wildman
Keyword(s):  

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