(JBE Vol. 23, No. 1, January 2018) (Regular Paper) 23 1, 2018 1 (JBE Vol. 23, No. 1, January 2018) https://doi.org/10.5909/jbe.2018.23.1.74 ISSN 2287-9137 (Online) ISSN 1226-7953 (Print) HMD a), b) Effects of Image Resolution and HMD Luminance on Virtual Reality Viewing Experience Hyejin Lee a) and Donghun Chung b),,., HD, 2K, 4K 3, 20, 60, 100 3. 2 3, 6,.,.,,,,. Abstract The research investigated the interaction effect of video resolution and device luminance on the perceived characteristics, presence, and fatigue viewing virtual reality. Experiments were composed of mixed design, and the resolution and luminance were classified into three types, HD, 2K, and 4K, and 20, 60, and 100, respectively. Participants watched video of 6-minutes randomly, and responded to the questionnaire after watching each video. The results showed that no interaction effect existed. Meanwhile, there are statistically significant differences on the luminance of depth perception, the resolution of visual intervention, and the resolution of adjustment fatigue. Also, higher resolution and luminance showed higher cognitive function, presence and fatigue. Keyword : virtual reality, resolution, luminance, presence, fatigue a) (Dept. of Journalism and Communication, Kwang-woon University) b) (School of Communications, Kwang-woon University) Corresponding Author : (Donghun Chung) E-mail: donghunc@gmail.com Tel: +82-2-940-5584 ORCID: https://orcid.org/0000-0001-8563-4392 2016 (NRF-2016S1A5A2A01024089). Manuscript received September 8, 2017; Revised November 14, 2017; Accepted December 14, 2017. Copyright 2017 Korean Institute of Broadcast and Media Engineers. All rights reserved. This is an Open-Access article distributed under the terms of the Creative Commons BY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited and not altered.
1 : HMD (Hyejin Lee et al.: Effects of Image Resolution and HMD Luminance on Virtual Reality Viewing Experience) I. (Virtual Reality : VR).,.,., HMD(Head Mounted Display) [1]. HMD 360,. [2].,.,.,,. (user interface) [3].. HMD.,,,, (Presence). II. 1.,. (ubiquitous),. [4]. [5],,..,.,., [6]. 100, 1989 Jaron Lanier
(JBE Vol. 23, No. 1, January 2018). 1960, Ivan Sutherland 1965. 80 VPL Research, 90 [6]. Milgram & Kishino [8],,. [7],.,,. 360, 3D., HMD. HMD,. 2.,..., [9]. 24mm,, 1/60 [10]., 1 60, 450ppi [11]. [12, 13]..,,..., [14]..,., [15].,, [16].., [17].,. HMD. Zhang [18] HMD
1 : HMD (Hyejin Lee et al.: Effects of Image Resolution and HMD Luminance on Virtual Reality Viewing Experience), HMD 17cd/m2.. 3..,. (perceptual illusion) [19],,, [20]. [21],,. [22],. 3D 4D,, [21]. [23]..,. (cybersickness) [24,25]. 3D,,,,,,, [25]. (motion sickness), MS [26].,. [27].,,,, [24,28]. [25,28,29]. Kennedy [30],..,..,. 1. (HD, 2K, 4K) HMD (20, 60, 100)? 2. (HD, 2K, 4K) HMD (20, 60, 100)? 3. (HD, 2K, 4K) HMD (20, 60, 100)?
(JBE Vol. 23, No. 1, January 2018) III. 1. 4. 81, 6 75. 40 (53.3%) 35 (46.7%), 22 (SD = 2.16).. 3( : HD, 2K, 4K) X 3( : 20, 60, 100) (within-between subject mixed-factorial design). (between-subject factor), (within-subject factors). 25, 4K, 60.. (simple random sample),, (counterbalancing). Galaxy S6 HMD Gear VR. (metaverse) 1) (UNREAL) 3D VR 360 (Gustav Klimt) (Kiss), (Leonardo da Vinci) (Vincent van Gogh).,. HD 2K 4K 3. HD HD, 4K 4K. HD 4K HD, 2K 4K 3. 10, 30, 50, 70, 90,, 4,,. 20, 60, 100. 1. Fig. 1. Experimental Instruments 1) 2002 Commercial, dram, movie computer graphic extreme contents, 2015 Virtual reality contents (http://metaverse360.co.kr/).
이혜진 외 1인: 영상의 해상도와 HMD의 휘도가 가상현실 시청 경험에 미치는 영향 (Hyejin Lee et al.: Effects of Image Resolution and HMD Luminance on Virtual Reality Viewing Experience) 누 명 시간을 3분, 6분, 9분으로 나 어 10 의 대상자에게 시청 파일럿 테스트 결과, 연구참여자 10명 중 7명이 6분 이상의 영상 시청을 힘들어 했으며, 어지러움과 을 하도록 했다. 불편함을 호소하며 시청하는 것을 중단하기를 요청하였다. 이러한 결과를 토대로 영상 시청 시간은 6분 정도가 적당하 판단하였고, 3편의 영상을 시청하여야 하기 때문에 각 각의 영상 시청은 2분으로 편집했다. 다고 2. 실험 과정 격리되어 밀폐된 실험실에서 진행되었으 삼성 Gear VR 2대와 갤럭시 S6의 스마트 실험은 외부와 며, 실험을 위해 준비했다. 실험조건에 따라 각각 HD, 2K, 4K로 조작된 세 개 유형의 영상이 사용되었다. 실험실은 빛과 음 향을 모두 차단함으로써 외부와 독립된 상태를 유지하였다. 실험 진행 시간은 실험 내용 안내부터 영상물의 시청, 설문 작성까지 30분 정도 소요되었고, 피험자 한 명씩 개별적으 로 실험이 진행되었다. 실험 진행자는 실험에 대한 설명을 간단하게 한 후 진행하였으며, 실험 참여자가 알 수 없도록 처치물의 변화를 주었다. 실험 참여자는 2분 영상을 총 세 번 시청하였고, 각 영상 시청이 끝난 후에는 설문을 작성하 폰 4대를 였다. 그림 2. 실험 과정 Fig. 2. Experiment Procedure 3. 7 9 측정 측정은 3D 영상 평가를 위해 개발한 양호 철과 정동훈(2012) 의 연구를 참고하여 설문 문항을 작성 본 실험연구의 [31] 하였다. 이들은 3D 영상평가를 위한 요인으로 인지된 특성 안 뢰 당 과 프레즌스를 제 하고 각 요인들의 신 도와 타 도를 검증한 바 있다. 인지된 특성은 깊이지각감(depth perception) 6문항, 입체감(tangibility) 5문항, 화면 선명도(clarity) 3문항, 실물감(materiality) 6문항, 휘도(Luminance) 6문항, 그리고 메시지 전달력(transmit)의 3문항의 6개 요인으로 구성되며, 본 연구에 맞게 재구성하여 총 29문항으로 측정 하였다. 프레즌스는 공간관여(spatial involvement) 5문항, 시간관여(temporal involvement) 4문항, 몰입 역동감(dynamic immersion) 3문항, 몰입 실재감(realistic immersion) 3 문항의 4개 요인으로 구성되었으며, 본 연구에 맞게 재구성 하여 총 15문항으로 측정하였다. 피로도는 양호철과 정동 훈(2012)[31]의 연구결과와 이혜진 외(2014)[32]의 연구결과 련 항 탕 28문항, 에서 피로와 관 된 문 을 바 으로 본 연구에 맞게 재구 움 ness) 3문항의 2개 요인으로 구성되며, 총 31문항으로 측정 하였다. 피로도 문항이 다른 항목에 비해 문항수가 많은 것 성하여 피로도(fatigue) 부자연스러 (unnatural- 은 다양한 형태의 시각적 피로를 보고자하였기 때문이다.
(JBE Vol. 23, No. 1, January 2018) 5.,.,,., (Chronbach's α)., 7, 6, 3, 3. 6, 4, 4, 5, 5, 4, 4, 3..,,,,. 1. Table 1. Variable's Reliability, mean and standard deviation of the dependent variables Perceived characteristics Presence Fatigue Factor The number of questions M SD Chronbach s alpha depth perception 7 3.65.45.912 materiality 6 2.97.64.877 message transmission 3 3.64.08.950 screen clarity 3 2.50.09.924 Involvement 6 2.82.38.950 Temporal involvement 4 3.09.77.926 Dynamic immersion 4 2.74.38.901 Visual fatigue 5 1.73.39.942 Painful fatigue 5 2.01.87.906 accommodation fatigue Fatigue of viewing environment 4 2.04.68.864 4 3.47.56.837 Unnaturalness 3 2.95.22.967 2, 3, 2. <Table 1>. IV. HMD,. (Mixed repeated measures ANOVA). (interaction) F(4, 144) =.94, p >.05, η² =.03 (main effects)., F(2, 144) = 2.22, p >.05, η² =.03 F(2, 72) =.92, p >.05, η² =.02. F(4, 144) =.98, p >.05, η² =.0 3, F(2, 144) = 3.21, p >.05, η² =.04, F(2, 72) = 2.51, p >.05, η² =.07. F(4, 144) = 1.07, p >.05, η² =.03, F(2, 144) = 1.98, p >.05, η² =.03 F(2, 72) =.92, p >.05, η² =.03., F(4, 144) =.35, p >.05, η² =.01, F(2, 144) =.16, p >.05, η² =.00 F(2, 72) =.22, p >.05,
1 : HMD (Hyejin Lee et al.: Effects of Image Resolution and HMD Luminance on Virtual Reality Viewing Experience) η² =.01., F(4, 144) = 1.76, p >.05, η² =.0 5, F(2, 144) =.42, p >.05, η² =.01 F(2, 72) =.13, p >.001, η² =.00. <Table 2>. 2. Table 2. Main and interaction effects of perceived characteristic Factor Brightness F-value and effect size Main effect Resolution Interaction effect Brightness* Resolution F p η² F p η² F p η² Perceived characteristics 2.22 0.11 0.03 0.92 0.40 0.02 0.94 0.44 0.03 Depth perception 3.21 0.04 0.04 2.51 0.09 0.07 0.98 0.42 0.03 Materiality 1.98 0.14 0.03 0.92 0.40 0.03 1.07 0.37 0.03 Message transmission 0.16 0.86 0.00 0.22 0.80 0.01 0.35 0.84 0.01 Screen clarity 0.42 0.66 0.01 0.13 0.88 0.00 1.76 0.14 0.05., F(4, 142) = 1.04, p >.05, η² =.03., F(2, 142) =.10, p >.05, η² =.00 F(2, 71) =.61, p >.05, η² =.02., F(4, 142) =.76, p >.05, η² =.02, F(2, 142) =.19, p >.05, η² =.00 F(2, 71) =.31, p >.05, η² =.01. F(4, 142) = 1.12, p >.05, η² =.03. F(2, 142) =.20, p >.05, η² =.00, F(2, 71) = 4.09, p =.02, η² =.10. F(4, 142) =.77, p >.05, η² =.02, F(2, 142) = 2.54, p >.05, η² =.03 F(2, 71) =.56, p >.05, η² =.02. <Table 3>. 3. Table 3. Main and interaction effects of Presence Factor Brightness F-value and effect size Main effect Resolution Interaction effect Brightness* Resolution F p η² F p η² F p η² Presence 0.10 0.91 0.00 0.61 0.55 0.02 1.04 0.39 0.03 Involvement 0.19 0.82 0.00 0.31 0.73 0.01 0.76 0.55 0.02 Temporal involvement 0.20 0.82 0.00 4.09 0.02 0.10 1.12 0.35 0.03 Dynamic immersion 2.54 0.08 0.03 0.56 0.58 0.02 0.77 0.55 0.02 3. F(4, 144) = 1.46, p >.05, η² =.04, F(2, 144) = 1.23, p >.05, η² =.02 F(2, 72) = 1.61, p >.05, η² =.04., F(4, 144) = 1.03, p >.05, η² =.03, F(2, 144) =.35, p >.05, η² =.00 F(2, 72) = 1.38, p >.05, η² =.04. F(3.46, 124.47) = 2.46, p >.05, η² =.06 F(1.73, 124.47) =.26, p >.05, η² =.00, F(2, 72) =.20, p >.05, η² =.0 1. F(3.86, 138.85) =.28, p >.05, η² =.01 F(1.93, 138.85) = 1.96, p >.05, η² =.03
(JBE Vol. 23, No. 1, January 2018), F(2, 72) = 5.30, p =.01, η² =.13. F(4, 144) = 2.35, p >.05, η² =.06, F(2, 144) = 1.94, p >.05, η² =.03, F(2, 72) =.69, p =.05, η² =.02. F(4, 144) =.76, p >.05, η² =.02 F(2, 144) =.13, p >.05, η² =.00, F(2, 72) = 1.12, p >.05, η² =.03. <Table 4>. 4. Table 4. Main and interaction effects of Fatigue Factor Brightness F-value and effect size Main effect Resolution Interaction effect Brightness* Resolution F p η² F p η² F p η² Fatigue 1.23 0.30 0.02 1.61 0.21 0.04 1.46 0.22 0.04 Visual fatigue 0.35 0.71 0.00 1.38 0.26 0.04 1.03 0.39 0.03 Painful fatigue 0.26 0.74 0.00 0.20 0.82 0.01 2.46 0.06 0.06 Accommodation fatigue 1.96 0.15 0.03 5.30 0.01 0.13 0.28 0.88 0.01 Fatigue of viewing 1.94 0.15 0.03 0.69 0.50 0.02 2.35 0.06 0.06 environment Unnaturalness 0.13 0.88 0.00 1.12 0.33 0.03 0.76 0.55 0.02 V.,,,..,..,., HD, 2K 4K, Gear VR 20, 60, 100,,.,. HMD,,,.,.,.,., 100,.
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이혜진 외 1인: 영상의 해상도와 HMD의 휘도가 가상현실 시청 경험에 미치는 영향 (Hyejin Lee et al.: Effects of Image Resolution and HMD Luminance on Virtual Reality Viewing Experience) 저자소개 이혜진 - 년 2월 : 을지대학교 안경광학과 (보건학석사) 년 3월 ~ 2015년 8월 : 광운대학교 신문방송학과 박사과정 수료 년 9월 ~ 현재 : Comm. & Tech. Lab 선임연구원 : http://orcid.org/ 0000-0002-5000-921X 주관심분야 : 시각피로도, UX평가, HCI(Usability) 2013 2013 2015 ORCID 정동훈 - 년 8월 : 미시간주립대학교 커뮤니케이션학과 (박사) 년 9월 ~ 2005년 5월 : 오하이오대학교 커뮤니케이션학부 연구원 년 6월 ~ 2007년 8월 : 아칸사대학교 커뮤니케이션학과 교수 년 2월 ~ 2014년 2월 : 컬럼비아대학교 컴퓨터사이언스학과 방문연구원 년 9월 ~ 현재 : 광운대학교 미디어영상학부 교수 : https://orcid.org/0000-0001-8563-4392 주관심분야 : HCI(Usability), 디지털 혁신, 디지털캠페인 2004 2004 2005 2013 2007 ORCID 85