• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.60-72
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• 2012

After the movie "AVATAR" became a good model of cash-cow in 3D movie, the profit of 3D-movie significantly reduced. One of the reasons why it happens comes from rare understanding of human factors for instance how viewers get immersed, but sometimes tired. Although 3D images should be more considered human visual system including eye, unfortunately most communication research ignored human factors. For those reasons this study observed the effect of 3D video on viewers' psychological response, especially for perceived eye movement, perceived characteristics, visual fatigue, and presence. With 90 participants, the results show that viewers' perceived feature effects on their presence. In detail, first, materiality and tangibility are more important factors than clarity in 3D video, and it means that when making 3D content or devices, materiality and tangibility should be considers that any other factor. Second, this study examined whether we perceive our eyes as media, and the result shows that as viewers' presence level became higher we perceive eye movements more, and as viewers' presence level became higher perceived visual fatigue became lower. This result means that when we move eyes, we interact with surrounded environment, so 3D content needs to provide vivid features to be more interactive. On the other hand, since level of presence increase visual fatigue, it must be balanced when producing and playing.

• Journal of Broadcast Engineering
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• v.18 no.1
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• pp.31-42
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• 2013

This paper proposes a photogrammetric rectification method based on Bayesian approach as a method that eliminates vertical parallax between stereo images to minimize visual fatigue of 3D contents. The image rectification consists of two phases; geometry estimation and epipolar transformation. For geometry estimation, coplanarity-based relative orientation algorithm was used in this paper. To ensure robustness for mismatch and localization error occurred by automation of tie point extraction, Bayesian approach was applied by introducing several prior constraints. As epipolar transformation perspective transformation was used based on condition of collinearity to minimize distortion of result images and modification for input images. Other algorithms were compared to evaluate performance. For geometry estimation, traditional relative orientation algorithm, 8-points algorithm and stereo calibration algorithm were employed. For epipolar transformation, Hartley algorithm and Bouguet algorithm were employed. The evaluation results showed that the proposed algorithm produced results with high accuracy, robustness about error sources and minimum image modification.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.12
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• pp.99-107
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• 1998

A stereo vision system such as the structure of human's eyes has two cameras at separated positions from which we can obtain two input images and then put them together to create 3-D image. It can show more virtual effect than the conventional 2-D image system. But, the stereo image system has to control the convergence angle so that the stereo disparity could always be zero because observers can be fatigued and unconscious of stereo image in conditions that the stereo disparity is not zero for a long work. Therefore, in the paper, optical JTC system which can process adaptive tracking of a specific moving object is proposed as a new approach to keep the stereo disparity to be zero. In this method, optical JTC system obtains the values of the relative locations of a moving objects in left and right images and then these values are used for maintaining the stereo disparity to be zero. Through some optical experiments the proposed stereo vision system is proved to be insensitive to background noises and operate in real-time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.41-49
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• 2015

The common way to obtain a stereoscopic image of a subject at a distance is to place two cameras on the parallel axis rather than crossing axis. To find the IAD and maximum focal length, left and right images are obtained by varying the IAD of cameras and the focal length of the camera lens and the depth budget for the obtained images is analyzed through post production. Then, the database for IAD and focal length of the camera lens with the depth range that does not cause visual fatigue and visual discomfort are developed. These data are used to design fuzzy control and deduce the IAD and focal length of the camera lens to shoot a subject at a distance, and the function of the fuzzy control is confirmed through the actual shooting within the range of deduced IAD and focal length of the camera lens.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.353-359
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• 2006

Image frame analysis is a conventional way of evaluating loop detector's performance. In image frame analysis, the time to evaluate performance is linearly proportional to the number of evaluated subjects, and the results can be subjective, depending on operator's personal evaluation standards and physical condition. Also, this method is often inferior in accuracy to that provided by the evaluated devices. Therefore, it is critical to develop a portable standard system which has better accuracy and more objectivity in evaluating vehicle detectors. This paper discusses function and reliability of tape-switch detector, which can be a replacement for image frame analysis, for effectively measuring traffic volume, speed, and occupancy.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.2 s.302
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• pp.101-112
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• 2005

As we perceive the world as 3-dimensional through our two eyes, we can extract 3-dimensional information from stereo images obtained from two or more cameras. Since stereo images have a large amount of data, with recent advances in digital video coding technology, efficient compression algorithms have been developed for stereo images. In order to compress stereo images and to obtain 3-D information such as depth, we find disparity vectors by using disparity estimation algorithm generally utilizing pixel differences between stereo pairs. However, it is not unusual to have stereo images having different intensity values for several reasons, such as incorrect control of the iris of each camera, disagreement of the foci of two cameras, orientation, position, and different characteristics of CCD (charge-coupled device) cameras, and so on. The intensity differences of stereo pairs often cause undesirable problems such as incorrect disparity vectors and consequent low coding efficiency. By compensating intensity differences between left and right images, we can obtain higher coding efficiency and hopefully reduce the perceptual burden of brain to combine different information incoming from two eyes. We propose several methods of intensity compensation such as local intensity compensation, global intensity compensation, and hierarchical intensity compensation as very simple and efficient preprocessing tool. Experimental results show that the proposed algerian provides significant improvement in coding efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.2
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• pp.130-138
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• 2014

In this paper, the SMV 3D display method using liquid crystal shutter glass(LCSG) and SPB has been proposed. The proposed SMV display can solve the resolution degradation problem of conventional multiview displays that using based time-multiplexing method. Also, observers fatigue due to the mismatch between accommodation and vergence problem of glass-type 3D displays and conventional multiview displays, can be improved using SMV 3D display method.

• Journal of Broadcast Engineering
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• v.13 no.3
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• pp.339-349
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• 2008

We present a novel method to estimate the light source direction and relight a face texture image of a single 3D model under arbitrary unknown illumination conditions. We create a virtual irradiance sphere to detect the light source direction from a given illuminated texture image using both normal vector mapping and weighted bilinear interpolation. We then induce a relighting equation with estimated ambient and diffuse coefficients. We provide the result of a series of experiments on light source estimation, relighting and face recognition to show the efficiency and accuracy of the proposed method in restoring the shading and shadows areas of a face texture image. Our approach for face relighting can be used for not only illuminant invariant face recognition applications but also reducing visual load and Improving visual performance in tasks using 3D displays.

• Journal of Korea Multimedia Society
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• v.16 no.1
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• pp.42-49
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• 2013

The camera motion is accompanied with the translation and/or the rotation of objects in frames of a video sequence. An unnecessary rotation of objects declines the quality of the moving pictures and in addition is a primary cause of the viewers' fatigue. In this paper, a novel method for correcting rotated frames in video sequences is presented, where the modified Mojette transform is applied to the motion-compensated area in each frame. The Mojette transform is one of discrete Radon transforms, and is modified for correcting the rotated frames as follows. First, the bin values in the Mojette transform are determined by using pixels on the projection line and the interpolation of pixels adjacent to the line. Second, the bin values are calculated only at some area determined by the motion estimation between current and reference frames. Finally, only one bin at each projection is computed for reducing the amount of the calculation in the Mojette transform. Through the simulation carried out on various test video sequences, it is shown that the proposed scheme has good performance for correcting the rotation of frames in moving pictures.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.7
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• pp.1653-1660
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• 2010

In this study, change of body surface temperature was measured using Digital Infrared Thermographic Imaging(DITI) to check muscle fatigue recovery & muscle pain control by magnetic stimulations. For clinical trials, subjects were divided into 3 groups : non stimulation group(NSG), electrical stimulation group(ESG) and micro magnetic stimulation group(MSG). In result, temperature differences between left and right arm surfaces were measured as much as $0.86{\pm}0.43^{\circ}C$(n=96) after the exercise, $0.78{\pm}0.12^{\circ}C$ after the electrical stimulation and $0.1{\pm}0.39^{\circ}C$ after the micro magnetic stimulation. Also after 3days, temperature differences between left and right arm surfaces were measured as much as $0.3{\pm}0.14^{\circ}C$ in the NSG, $0.05{\pm}0.21^{\circ}C$ in the ESG and $0.03{\pm}0.21^{\circ}C$ in the MSG. These data showed that the lowest temperature difference between left/right body surface was measured in MSG.