Abstract: Playing entertainment computer, video, and portable games, namely, digital games, is receiving more and more attention in academic research. Games are studied in different situations with numerous methods, but little is known about if and how the playing situation affects the user experience (UX) in games. In addition, it is hard to understand and study the psychology of UX in games. The objective of this study is to show how UX differs when the first-person shooter HALO is played in a laboratory and at home. To disclose this difference, a psychologically valid and multidimensional measurement framework is introduced. UX is profiled according to the level of the sense of presence, involvement, and flow in a between-subjects design. Statistically, the structure of the framework is grounded on a large and heterogeneous gamer data set (N = 2,182). The results showed that the profile of the sense of presence in the laboratory included higher levels of attention and arousal as compared with that of the natural environment. This finding was independent of any of the measured background variables. Other differences between the two situations were more related to the participantsâââ‰â¢ background. For example, gamers at hfome were more involved in the game and they felt a higher level of competence. No strong emotional differences between the two situations were found. The authors discuss the complex UX terminology and implications of the framework for implementation of learning games.
Abstract: We studied peopleâs experiences related to four different commercial near-to-eye displays (NEDs). A total of hundred and six participants viewed a 40-min film and completed several sickness-, visual strain- and workload-related questionnaires. The
severity of the symptoms varied among the devices used, but on average the sickness experienced and the eyestrain levels remained low. Headset fit affected not only the perceived workload, but also the pleasantness of tasks and NED-related opinion change. The participants were positively surprised at the NEDsâ high quality,and many were interested in using wearable displays in the future.
Abstract: The estimation of image quality is a demanding task â especially when estimating different high quality imaging products or their components. The challenge is the multivariate nature of image quality as well as the
need to use naïve observers as test subjects, since they are the actual end-users of the products. Here we use a subjective approach suitable for estimating the quality performance of different imaging device components
with naïve observers â the Interpretation Based Quality (IBQ) approach. From two studies with 61 naïve observers, 17 natural image contents and 13 different camera image signal processor pipelines, we determined the subjectively crucial image quality attributes and dimensions and the description of each pipeline perceived image quality performance. We found that the subjectively most important image quality dimensions were color shift/naturalness, darkness and sharpness. The first dimension, which was related to naturalness and colors, distinguished the good quality pipelines from the middle and low quality groups, and the dimensions of darkness and sharpness described why the quality failed in the low quality pipelines. The study suggests that the high-level concept naturalness is a requirement for high quality, whereas quality can fail for other reasons in low quality images, and this failure can be described by low-level concepts such as darkness and sharpness.
Abstract: Fifty-eight people used a mobile phone/near-to-eye display combination with three different applications: movie viewing, game playing, and reading. After a 40-min immersion period participants completed several questionnaires related to the usage experience, comfort, workload, and individual features. We found many differences in user experiences between tasks as well as a number of associations between individual factors and experiences reported. Participants' opinions on the near-to-eye display/mobile phone combination were generally positive, and several benefits were reported: namely, a more engrossing experience and longer use time in the future. We also compared experiences from mobile phone/near-to-eye display setups to mobile phone and TV usage.
Abstract: In this research project, the influence of different monocular near-to-eye display (NED) positions on user comfort has been investigated. In total, 43 subjects participated in tests; 22 used above and 21 below NED positions during dual-task performance for 40 minutes. SSQ and VSQ questionnaires were used to compare the eyestrain and other sickness symptoms before and after the task performance for both display positions. According to the subjective test results, the NED position above the eye causes more symptoms than the position below the eye.
Abstract: The aim of this study was to measure reading experiences on curved paper-like displays. The experimental materials were mockups that consisted of printed paper attached to a curved plastic surface. The experiment participants held the mockups in their hands and evaluated the reading experience with them. Twelve font sizes, two curvature magnitudes, and two curvature directions were used in the experiment. The results showed that reading text on a curved surface was easier when the curvature direction is perpendicular to the text direction. It was also found that concave surfaces were regarded as better in cases where the text direction was the same as the curvature direction.
Abstract: The benefits of stereoscopic viewing were explored in searching in words superimposed over a background. In the first experiment, eight participants searched for text in a normal 2-D display, a 3-D display using a parallax barrier, and a darkened 2-D display of equivalent brightness to the 3-D display. Word-search performance was significantly faster for the bright 2-D display vs. the 3-D display, but when brightness was controlled, performance on the 3-D display was better relative to the 2-D (dim) display. In a second experiment, the effect of floating text vs. sinking background disparity was assessed across four background conditions. Twenty participants saw only the floating-text (FT) condition and 20 participants saw only the sinking-background (SB) condition. Performance of the SB group was significantly better than that of FT group, and the advantage of SB disparity was greater with the more-complex backgrounds. Thus, when a parallax-barrier 3-D display is used to view text or other figural information overlaid on a background, it is proposed that the layer of primary interest (foreground) should be displayed with zero disparity (on the physical display surface) with the secondary layer (background) appearing to be sunk beneath that surface.
Abstract: We studied whether visual completion can be produced within three-dimensional (3-D), moving, chromatic objects. Rotating thin and thick discs with red sectors, forming the corners of Kanizsa triangle, were presented on a display. Observers also rotated a hand-held real thin Kanizsa triangle. An illusory, moving contour encompassing an illusory colourful triangle was generally observed. This indicates that the visual system is capable of filling in complex (3-D, moving, chromatic) percepts.
Abstract: A phantom surface is a stereoscopic illusory area that can be seen in depth although there is no conventional stereoscopic cues [Liu, L., Stevenson, S.B., & Schor, C.M. (1994). Quantitative stereoscopic depth without binocular correspondence. Nature, 367, 66-69; Gillam, B. & Nakayama, K. (1999). Quantitative depth for a phantom surface can be based on cyclopean occlusion cues alone. Vision Research, 39, 109-112]. The phenomenon has been explained as an example of half-occlusion processing in which the visual system uses information about cyclopean occlusion structure of the visual world. We created stereo capture stereograms in which phantom surfaces changed the perceived depth of conventionally defined binocular textures. Because conventional stereoscopic matching is strongly affected by half-occlusion processing, we suggest that half-occlusion processing is an integral part of the early stereoscopic processing and solving of the correspondence problem.
Abstract: We studied whether neon spreading can be induced within three-dimensional illusory triangles. Kanizsa triangles were induced by black pacman disks consisting of red sectors with curved sides. Viewing our stimuli monocularly produced two-dimensional illusory contours and surfaces as well as neon spreading in each figure. Triangles appeared concave or convex under stereoscopical viewing. Neon colour spreading was induced within illusory figures bending in three-dimensional space, suggesting that neural contour completion and surface filling-in interact across depth. Surprisingly, neon spreading was induced above the intervening surface even when the inducers were below the surface. Neon colour and illusory configuration were preserved behind the intervening surface only when it appeared transparent.
Abstract: In stereo capture a stereogram of a crossed illusory figure pulls a texture bounded by the illusory contours to the same depth plane with the illusory figure. We investigated whether three-dimensionally curved and slanted illusory figures could capture a repeating background texture. According to results, stereoscopic capture was perceived when a disparate illusory contour was slanted provided that the period of the background texture was consistent with the three-dimensional geometry of the illusory surface. We suggest that stereo capture is actually induced by disparate rows of points defined by vertical cut-out sectors and the induced disparity spread is constrained by illusory contours and possible discrete matches of the background texture.
Abstract: In binocular vision horizontal magnification of one retinal image leads to a percept of three-dimensional slant around a vertical axis. It is demonstrated that the perception of slant is diminished when an occlusion interpretation is possible. A frontoparallel plane located in the immediate vicinity of a slanted surface in a location which allows a perception of occlusion reduces the magnitude of perceived slant significantly. When the same plane is placed on the other side, the slant perception is normal because there is no alternative occlusion interpretation. The results indicate that a common border between the occluder and a slanted surface is not a necessary condition for the reduction effect. If the edges are displaced and the edge of the slanted surface is placed in a location in which it could be occluded, the effect still appears.
Abstract: We investigated processes that determine the depth localization of monocular points which have no unambiguous depth. It is known that horizontally adjacent binocular objects are used in depth localization and for a distance of 25-40 min arc monocular points localize to the leading edge of a depth constraint zone, which is an area defined by the visibility lines between which the points in the real world must be. We demonstrate that this rule is not valid in complex depth scenes. Adding other disparate objects to the scene changes the localization of the monocular point in a way that cannot be explained by the da Vinci explanation of monocular-binocular integration. The effect of additional disparate objects is asymmetric in depth: a crossed object does not affect the da Vinci effect but an uncrossed object biases the depth localization of monocular objects to uncrossed direction. We conclude that a horizontally adjacent binocular plane does not completely determine the depth localization of a monocular point and that depth spreading from other binocular elements biases the localization process.
Abstract: It has been shown in several studies that the selection of letters or numerals from an array can occur efficiently if criteria such as location, colour, shape, or size are used. It is also known that there are at least two components of spatial attention, the transient exogenous and the sustained endogenous. An interesting question is whether it is possible to elicit similar components when colour or shape information is used as a selection criterion. Experiments are reported the aim of which was to try to produce colour or shape precue effects on location and colour/shape discrimination accuracy, and to determine the minimum latency of these effects by sampling numerous cue lead times from 0 ms to 1000 ms. The results showed that, although accuracy did not increase monotonically with increased cue lead time, there were two transient peaks of performance at cue lead times of 0-200 ms, culminating at 30-50 ms and at 160-200 ms. It is suggested that the first component reflects nonspecific exogenous activation, triggered by the onset of a cue; the second component, in turn, may reflect feature-specific endogenous activation related to selection by colour or shape.
Abstract: The military environment is changing, e.g., the operating environment is becoming more varied and demanding. Due to these challenges, new user interfaces (UIs) are required providing improved soldier protection and performance both in daytime and nighttime conditions. The new UIs should, e.g., improve the soldierâs situation awareness, i.e., perception of information, integration of pieces of information, determination of their relevance to oneâs goals, and projection of their status in the future. The aim of the Finnish project called âSupporting situation awareness in demanding operating environments through wearable interfacesâ is to develop UIs for wearable computers that help the special force soldier carry out his/her main
critical tasks, e.g., detection and identification of enemies and features of the surrounding environment, navigation and selflocalization,
development of tactics and communication between and within military units. The main portions of the work are task and work analysis, and conceptual design and evaluation of prototype systems. The present paperâs aim is to present the project and the methods that are used in the functional analysis of military tasks.
Abstract: In mixed-resolution (MR) stereoscopic video, one view is presented with a lower resolution compared with the other one; therefore, a lower bitrate, a reduced computational complexity, and a decrease in memory access bandwidth can be expected in coding. The human visual system is known to fuse left and right views in such a way that the perceptual visual quality is closer to that of the higher-resolution view. In this paper, a subjective assessment of mixed resolution (MR) stereoscopic videos is presented and the results are analyzed and compared with previous subjective tests presented in the literature. Three downsampling ratios 1/2, 3/8, and 1/4 were used to create lower-resolution views. Hence, the lower-resolution view had different spatial resolutions in terms of pixels per degree (PPD) for each downsam-pling ratio. It was discovered that the subjective viewing experience tended to follow a logarithmic func-tion of the spatial resolution of the lower-resolution view measured in PPD. A similar behavior was also found from the results of an earlier experiment. Thus, the results suggest that the presented logarithmic function characterizes the expected viewing experience of MR stereoscopic video.
Abstract: In this study, two experiments were conducted to evaluate the psycho-physiological effects by practical use of monocular head-mounted display (HMD) in a real-world environment, based on the assumption of consumer-level applications as viewing video content and receiving navigation information while walking. In the experiment 1, the workload was examined for different types of presenting stimuli using an HMD (monocular or binocular, see-through or non-see-through). The experiment 2 focused on the relationship between the real-world environment and the visual information presented using a monocular HMD. The workload was compared between a case where participants walked while viewing video content without relation to the real-world environment, and a case where participants walked while viewing visual information to augment the real-world environment as navigations.
Abstract: A novel asymmetric stereoscopic video coding method is presented in this paper. The proposed coding method is based on uneven sample domain quantization for different views and is typically applied to-gether with a reduction of spatial resolution for one of the views. Any transform-based video compres-sion, such as the Advanced Video Coding (H.264/AVC) standard, can be used with the proposed method. We investigate whether the binocular vision masks the coded views of different types of degradations caused by the proposed method. The paper presents a subjective viewing study, where the proposed compression method is compared with two other coding techniques: full-resolution symmetric and mixed-resolution stereoscopic video coding. We show that the average subjective viewing experience ratings of the proposed method are higher than those of the other tested methods in six out of eight test cases.
Abstract: We measured the eye movements of participants who watched 6-minute movie in stereoscopic and non-stereoscopic form. We analyzed four shots of the movie. The results indicate that in a 2D movie viewers tend to look at the actors, as most of the eye movements are clustered there. The significance of the actors start at the beginning of a shot, as the eyes of the viewer focus almost immediately to them. In S3D movie the eye movement patterns were more widely distributed to other targets. For example, complex stereoscopic structures and structures nearer than the actor captured the interest and eye movements of the participants. Also, the tendency to first look at the actors was diminished in the S3D shots. The results suggests that in a S3D movie there are more eye movements which are directed to wider array of objects than in a 2D movie.
Abstract: High-quality stereoscopic image content must be viewable in a variety of visual environments, from 3-D theaters to 3-D mobile devices. Stereoscopic effects, however, are affected by screen size, viewing distance, and other parameters. In this study, the authors focus on the stereoscopic image quality experience of viewing 3-D content on a mobile device in order to compare it with that of viewing 3-D content on a large screen. The stereoscopic image quality experience was evaluated using Interpretation Based Quality (IBQ) methodology, which combines existing approaches to image quality evaluation, such as the paired comparison and interview, and assesses the viewer experience using both quantitative and qualitative data. Five stereoscopic images were used in the experiment. The results of the experiment suggest that the discomfort felt while viewing stereoscopic images on a 3-D mobile device arise from not only visual fatigue but also the effects of the smaller screen size. The study also revealed the types of stereoscopic images that are suitable for viewing on 3-D mobile devices.
Abstract: Digital 3D cinema has recently become popular and a number of high-quality 3D films have been produced. However, in contrast with advances in 3D display technology, it has been pointed out that there is a lack of suitable 3D content and content creators. Since 3D display methods and viewing environments vary widely, there is expectation that high-quality content will be multi-purposed. On the other hand, there is increasing interest in the bio-medical effects of image content of various types and there are moves toward international standardization, so 3D content production needs to take into consideration safety and conformity with international guidelines. The aim of the authors' research is to contribute to the production and application of 3D content that is safe and comfortable to watch by developing a scalable 3D conversion technology. In this paper, the authors focus on the process of changing the screen size, examining a conversion algorithm and its effectiveness. The authors evaluated the visual load imposed during the viewing of various 3D content converted by the prototype algorithm as compared with ideal conditions and with content expanded without conversion. Sheffe's paired comparison method was used for evaluation. To examine the effects of screen size reduction on viewers, changes in user impression and experience were elucidated using the IBQ methodology. The results of the evaluation are presented along with a discussion of the effectiveness and potential of the developed scalable 3D conversion algorithm and future research tasks.
Abstract: In this paper we compare simulator sickness symptoms produced by racing game in three different conditions. In the first experiment the participants played the Need for Speed car racing game with an ordinary 17" display and in the second and third experiments they used a head-worn virtual display for the game playing. The difference between experiments 2 and 3 was in the use of stereoscopy, as in the third experiment the car racing game was seen in stereoscopic three-dimensions. Our results indicated that there were no significant differences in sickness symptoms when we compared the ordinary display and the virtual display in non-stereoscopic mode. In stereoscopic condition the eye strain and disorientation symptoms were significantly elevated compared to the ordinary display. We conclude that using a virtual display as an accessory in a mobile device is a viable alternative, because the non-stereoscopic virtual display did not produce significantly more sickness symptoms compared to ordinary game playing.
Abstract: The purpose of the study was to compare pseudo-text and letter-search tasks in studying character sizes in different contrast conditions. Four character sizes (0.14, 0.16, 0.22, and 0.24 deg) and two contrast levels (CMichelsonequals;0.06 and CMichelsonequals;0.99) were used. According to the results, search performance improved with increasing character size and contrast in both tasks. Contrast had more effect on performance in the letter-search task than in the pseudo-text task. Consequently, the letter-search method may be better for investigating small displays in bright lighting conditions, which usually cause low contrast in displays. However, the use of the pseudo-text method is less time-consuming because the results were less variable.
