Multi-view stereoscopic images were produced via the pick-up method with respect to the object set in the computer, and integral photography was generated from this multi-view stereoscopic image. When the multiview stereoscopic image was taken by pick-up, the optical axis of each camera of the array was aligned with one point in the front of the camera array. A calculation method was derived with respect to the depth position and width of the object displayed by integral photography generated using this method. Based on the derived calculation method, consideration was given to the distortion displayed and reproduced with respect to the depth position and width of the object in the prototyped integral photography.
The accommodation and convergence responses in a light field display which can provide up to 8 images to each eye of viewers are investigated. The DOF (Depth of Field) increase with the increasing number of projected images is verified for both monocular and binocular viewings. 7 subjects with eye sights greater than 1.0 reveal that their responses can match to their real object responses as the number of images increased to 7 and more, though there are distinctive differences between objects. The matching performance of the binocular is more stable than that of the monocular viewing for the number of images less than 6. But the response stability of the accommodation increases as the number becomes more than 7.
A method of displaying a multiview image set prepared by a computer on an electronic display device based on integral photography has been formulated. With the device, accommodation response was measured and the result that the accommodation response linearly changed within and outside the range of depth of focus was obtained. In contrast, in the measurement of the accommodation response using the stereoscopic image, the accommodation response showed a linear change within and outside the depth of focus at the spatial resolution of three cycle per degree (cpd) or less. Therefore, it can be considered that the measurement result of the accommodation response for integral photography with a spatial resolution of 3 cpd or less cannot be used to determine whether it is influenced by the integral photography display method or spatial resolution reduction. From these results, we found that spatial resolution is required to be 3 cpd or more when outside of the range of depth of focus in the measurement of the accommodation response for integral photography.
Color moirés induced at contact-type multiview three-dimensional and light-field imaging are reviewed, slanted color moirés are introduced, and the reason why they become invisible as the slanting angle increases is explained. The color moirés in the imaging are induced by the structural uniqueness of the imaging, i.e., viewing zone-forming optics (VZFO) on the display panel. The moirés behave differently from those by the beating effect. They are (1) basically chirped, (2) their fringe numbers and phases are also varying according to the changes in viewer’s viewing positions and viewing angles at a given viewing distance, (3) the pattern period of the VZFO is at least more than several times that of the pixel pattern, and (4) they are colored. The color moirés can hardly be eliminated because they are induced structurally, but they can be minimized by either reducing the regularity of the pixel pattern using a diffuser between the panel and the VZFO or aligning VZFO’s pattern to have a certain slanting angle with the pixel pattern in the panel.
We developed a measurement tool for binocular eye movement and examined the perception of depth distance in integral photography images, which is a type of three dimensional image, using the tool we developed. Furthermore, we evaluated the perception of the depth distance in integral photography images by the subjective test, and we considered the perception results of the depth distance, which were these two experimental results. Additionally, we examined the perception of the depth distance in the real objects, and compared with the results in the case of integral photography images and real objects.
A simulator which can test the visual perception response of light field displays is introduced. The simulator can provide up to 8 view images to each eye simultaneously to test the differences between different numbers of different view images in supermultiview condition. The images are going through a window with 4 mm width, which is located at the pupil plane of each eye. Since each view image has its own slot in the window, the image is separately entring the eye without overlapping with other images. The simulator shows that the vergence response of viewers' eyes for an image at a certain distance is closer to the real object of the same distance for 4 views than 2 views. This informs that the focusable depth range will increase more as the the number of different view images increases.
The Kinect sensor is a device that enables to capture a real scene with a camera and a depth sensor. A virtual model of the scene can then be obtained with a point cloud representation. A complex hologram can then be computed. However, complex data cannot be used directly because display devices cannot handle amplitude and phase modulation at the same time. Binary holograms are commonly used since they present several advantages. Among the methods that were proposed to convert holograms into a binary format, the direct-binary search (DBS) not only gives the best performance, it also offers the possibility to choose the display parameters of the binary hologram differently than the original complex hologram. Since wavelength and reconstruction distance can be modified, compensation of chromatic aberrations can be handled. In this study, we examine the potential of DBS for RGB holographic display.
In the first part of this paper, the principle and the development of IP display using computer software were described. Next, the measurement results of accommodation response for the developed IP display were described. As a result, the accommodation response was linearly changed as the depth position of the visual target moved in and out of the range of the depth of focus. On the other hand, the influences generated by the image blur for the accommodation response were investigated experimentally using stereoscopic images. The results showed that the accommodation response was coincident to the convergence point of stereoscopic images with less than 3 cpd spatial resolution. Based on these results, the considerations of the measurement results of the accommodation response for the development IP were examined. The requirements of the measurement condition of accommodation response for IP were also discussed.
A super-multiview condition simulator which can project up to four different view images to each eye is introduced. This simulator with the image having both disparity and perspective informs that the depth of field (DOF) will be extended to more than the default DOF values as the number of simultaneously but separately projected different view images to each eye increase. The DOF range can be extended to near 2 diopters with the four simultaneous view images. However, the DOF value increments are not prominent as the image with both disparity and perspective with the image with disparity only.
Despite an increased need for three-dimensional (3-D) functionality in curved displays, comparisons pertinent to human factors between curved and flat panel 3-D displays have rarely been tested. This study compared stereoscopic 3-D viewing experiences induced by a curved display with those of a flat panel display by evaluating subjective and objective measures. Twenty-four participants took part in the experiments and viewed 3-D content with two different displays (flat and curved 3-D display) within a counterbalanced and within-subject design. For the 30-min viewing condition, a paired t-test showed significantly reduced P300 amplitudes, which were caused by engagement rather than cognitive fatigue, in the curved 3-D viewing condition compared to the flat 3-D viewing condition at P3 and P4. No significant differences in P300 amplitudes were observed for 60-min viewing. Subjective ratings of realness and engagement were also significantly higher in the curved 3-D viewing condition than in the flat 3-D viewing condition for 30-min viewing. Our findings support that curved 3-D displays can be effective for enhancing engagement among viewers based on specific viewing times and environments.
In this paper the accommodation responses for integral photography still images were measured. The experimental results showed that the accommodation responses for integral photography images showed a linear change with images showing the depth position of integral photography, even if the integral photography images were located out of the depth of the field. Furthermore, the discrimination of depth perception, which relates to a blur effect in integral photography images, was subjectively evaluated for the examination of its influence on the accommodation response. As a result, the range of the discrimination of depth perception was narrow in comparison to the range of the rectilinear accommodation response. However, these results were consistent according to the propensity of statistical significance for the discrimination of depth perception in the out range of subjectively effective discriminations.
As advanced display technology has been developed, much attention has been given to flexible panels. On top of that, with the momentum of the 3D era, stereoscopic 3D technique has been combined with the curved displays. However, despite the increased needs for 3D function in the curved displays, comparisons between curved and flat panel displays with 3D views have rarely been tested. Most of the previous studies have investigated their basic ergonomic aspects such as viewing posture and distance with only 2D views. It has generally been known that curved displays are more effective in enhancing involvement in specific content stories because field of views and distance from the eyes of viewers to both edges of the screen are more natural in curved displays than in flat panel ones. For flat panel displays, ocular torsions may occur when viewers try to move their eyes from the center to the edges of the screen to continuously capture rapidly moving 3D objects. This is due in part to differences in viewing distances from the center of the screen to eyes of viewers and from the edges of the screen to the eyes. Thus, this study compared S3D viewing experiences induced by a curved display with those of a flat panel display by evaluating significant subjective and objective measures.
Depth perception caused from the motion parallax, which was derived from the horizontally moving pickup device, was examined. The image sequences were captured to the real scene using only horizontally moving pickup device or horizontally moving pickup device with setting the fixation point. As results, the depth perception was a relatively high performance in the case of horizontally moving pickup device with setting the fixation point. For the examination of this result, the displacement and the differential displacement on the pickup device and the motion perception for the visual stimuli, which means the captured image sequences, are investigated.
With an advent of autostereoscopic display technique and increased needs for smart phones, there has been a significant
growth in mobile TV markets. The rapid growth in technical, economical, and social aspects has encouraged 3D TV
manufacturers to apply 3D rendering technology to mobile devices so that people have more opportunities to come into
contact with many 3D content anytime and anywhere. Even if the mobile 3D technology leads to the current market
growth, there is an important thing to consider for consistent development and growth in the display market. To put it
briefly, human factors linked to mobile 3D viewing should be taken into consideration before developing mobile 3D
technology. Many studies have investigated whether mobile 3D viewing causes undesirable biomedical effects such as
motion sickness and visual fatigue, but few have examined main factors adversely affecting human health. Viewing
distance is considered one of the main factors to establish optimized viewing environments from a viewer's point of
view. Thus, in an effort to determine human-friendly viewing environments, this study aims to investigate the effect of
viewing distance on human visual system when exposing to mobile 3D environments. Recording and analyzing
brainwaves before and after watching mobile 3D content, we explore how viewing distance affects viewing experience
from physiological and psychological perspectives. Results obtained in this study are expected to provide viewing
guidelines for viewers, help ensure viewers against undesirable 3D effects, and lead to make gradual progress towards a
human-friendly mobile 3D viewing.