• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.1-16
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• 2012

In order to improve the workflow of 3D video production, this paper analyzes the visual fatigue caused from distortions in 3D video production stage through a set of subjective visual assessment tests. To establish a set of objective indicators for subjective visual tests, various distortions in production stage are investigated to be categorized into 7 representative visual-fatigue-producing factors, and to conduct visual assessment tests for each selected category, 4 test video clips are produced by combining the extent of camera movement as well as the object(s) movement in the scene. Each produced test video is distorted to reflect each of the selected 7 visual-fatigue-producing factors, and we set 7 levels of distortion for each factor, resulting in 196 5-second-long video clips for testing. Based on these test materials and the recommendation of ITU-R BT.1438, subjective visual assessment tests are conducted by 101 applicants. The test results provide a relative importance and the tolerance limit of each visual-fatigue-producing factor, which corresponds to various distortions in 3D video production field.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.11a
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• pp.14-17
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• 2010

Following the proliferation of three-dimensional video contents and displays, many terrestrial broadcasting companies prepare for starting stereoscopic 3DTV service. In terrestrial stereoscopic broadcast, it is a difficult task to code and transmit two video sequences while sustaining as high quality as 2DTV broadcast attains due to the limited bandwidth defined by the existing digital TV standards such as ATSC. Thus, a terrestrial 3DTV broadcasting system with heterogeneous video coding systems is considered for terrestrial 3DTV broadcast where the left image and right images are based on MPEG-2 and H.264/AVC, respectively, in order to achieve both high quality broadcasting service and compatibility for the existing 2DTV viewers. Without significant change in the current terrestrial broadcasting systems, we propose a joint rate control scheme for stereoscopic 3DTV service. The proposed joint rate control scheme applies to the MPEG-2 encoder a quadratic rate-quantization model which is adopted in the H.264/AVC. Then the controller is designed for the sum of two bit streams to meet the bandwidth requirement of broadcasting standards while the sum of image distortions is minimized by adjusting quantization parameter computed from the proposed optimization scheme. Besides, we also consider a condition on quality difference between the left and right images in the optimization. Experimental results demonstrate that the proposed bit rate control scheme outperforms the rate control method where each video coding standard uses its own bit rate control algorithm in terms of minimizing the mean image distortion as well as the mean value and the variation of absolute image quality differences.

• Journal of Korea Multimedia Society
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• v.19 no.4
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• pp.706-716
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• 2016

Each year, significant amounts of Stereoscopic 3D(S3D) contents have been introduced. However, viewers who enjoy the contents readily experience a sense of fatigue on account of various factors. Consequently, many improvement studies have been conducted with the domain of disparity by, for example, simply controlling the disparity or optimizing the reaction speed of viewers' eyes to vergence. However, such studies are limited to the disparity domain and therefore are restricted to a limited number of applications. In this study, we attempted to transcend this limitation and analyzed how a reconstruction in color and brightness, as well as disparity and other important features, affects eyes in terms of vergence adaptation. As a result, we found that, the higher the color similarity is, the better it positively affects vergence adaptation during viewing. Based on this analysis, we propose in this paper a similar color extraction method between takes that are applicable to real-life situations. In an evaluation, the algorithm was applied to publicly available S3D contents and produced a converted color optimized image. The vergence adaptation time of this applied contents was significantly decreased. Also it was minimized through color reconstruction, thereby, being resulted in enhancing viewer concentration.

• Journal of Broadcast Engineering
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• v.13 no.4
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• pp.427-439
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• 2008

This paper proposes a novel method to convert monoscopic soccer videos to stereoscopic videos. Through the soccer video analysis process, we detect shot boundaries and classify soccer frames into long shot or non-long shot. In the long shot case, the depth mapis generated relying on the size of the extracted ground region. For the non-long shot case, the shot is further partitioned into three types by considering the number of ground blocks and skin blocks which is obtained by a simple skin-color detection method. Then three different depth assignment methods are applied to each non-long shot types: 1) Depth estimation by object region extraction, 2) Foreground estimation by using the skin block and depth value computation by Gaussian function, and 3)the depth map generation for shots not containing the skin blocks. This depth assignment is followed by stereoscopic image generation. Subjective evaluation comparing generated depth maps and corresponding stereoscopic images indicate that the proposed algorithm can yield the sense of depth from a single view images.

• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.515-520
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• 2016

Volumetric image system has many applications recently in education, 3D movie, medical images but these applications have several problems that need to be overcome. Volumetric display may process a amount of visual data and design the high efficient vision system for realtime display. In case of stereo system for volumetric display motion vectors, disparity vectors from the stereoscopic sequences and residual images with the reference images has been transmitted, and the stereoscopic sequences have been reconstructed at the receiver for volumetric display. So central issue for the design of efficient volumetric image system lies in selecting an appropriate stereo matching and robust vision system. In this paper, we proposed high efficient vision system, which design vision stage with rotating and moving horizontally, and match the successive stereo image efficiently. In experimental results with volumetric image system, the proposed method represents high efficiency with minimizing error and low computational load for volumetric display.

• Journal of Korea Game Society
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• v.13 no.3
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• pp.5-18
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• 2013

This study analyzed the effect by comparing it with 2D game using playtest experimental treatment methodology to verify the video effect, materiality and fatigue effect of 3D video game. First, for the hypothesis to verify the difference of video experience of users for 3D and 2D games, visual clarity was rejected, but materiality, tangibility and presence hypotheses were all accepted. Second, it was shown that there was no difference in eye fatigue and physical fatigue in 3D and 2D games. It was different from results of existing research which claimed that fatigue occurred due to video distortion occurring in 3D video and fatigue inducing factors. Third, the results of measurement of changes in brain wave occurring in the course of playing 3D and 2D games showed that there was no difference in average amplitude of EEG alpha wave, but EEG beta wave occurred in higher amplitude. This study proved the cerebral physiological change and difference in the process of experience to use 3D video game by complementing the methodology in measurement in EEG brain wave in the traditional experimental method.

• Journal of Broadcast Engineering
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• v.19 no.5
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• pp.616-626
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• 2014

In this paper, we introduce a real-time stereo-to-multiview conversion system using FPGA and GPU. The system is based on two different devices so that it consists of two major blocks. The first block is a disparity estimation block that is implemented on FPGA. In this block, each disparity map of stereoscopic video is estimated by DP(dynamic programming)-based stereo matching. And then the estimated disparity maps are refined by post-processing. The refined disparity map is transferred to the GPU device through USB 3.0 and PCI-express interfaces. Stereoscopic video is also transferred to the GPU device. These data are used to render arbitrary number of virtual views in next block. In the second block, disparity-based view interpolation is performed to generate virtual multi-view video. As a final step, all generated views have to be re-arranged into a single image at full resolution for presenting on the target autostereoscopic 3D display. All these steps of the second block are performed in parallel on the GPU device.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.919-921
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• 2013

영상시장의 개척과 디지털 기술의 발전과 더불어 차세대 3D 입체영상기술에 대한 관심과 수요가 증가하고 있다. 입체 정보는 크게 '단안 입체 정보(monoscopic depth cue)'와 '양안 입체 정보(stereoscopic depth cue)'로 분류 할 수 있다. 단안 입체 정보는 은폐, 상대적 크기, 상대적 밀도, 시야 안의 높이, 공기투시, 운동투시, 초점조절인 7가지로 경험에 의한 입체감을 지각하는 것을 말하며 양안 입체 정보는 두 눈으로 볼 때 처음으로 깊이를 지각 할 수 있는 것으로 크게 '동시시(simultaneous perception)', '융합(sensory fusion)', '입체시(stereoscopic vision)'의 세종류의 기능으로 분류한다. 3D 촬영은 이 양안시의 원리를 이용하여 두 대의 카메라의 좌우 영상을 합성하여 깊이감 있는 영상을 만들어 내게 된다. 본 논문에서는 3D 촬영방법은 촬영방식에 따라 크게 평행방식, 직교방식, 교차방식이 있는데 이중 중 원거리 촬영에 유리한 교차방식을 활용하여 사이드 바이 사이드 리그(Rig; 카메라를 수평으로 설치할 수 있도록 만들어진 장치)를 원거리 촬영에 맞게 축간거리를 기존의 리그 사이즈보다 2배 이상 긴 리그를 제작하여 보다 먼 거리에서의 상이한 좌우 영상획득이 가능하도록 설계하였다. 또한, 일정한 간격에 따라 피사체를 촬영하면서 거리에 따른 양 카메라의 가장 이상적인 IOD(Interocular Distance)와 CONV(Convergence)를 찾고, 교차방식촬영에 따른 특징적인 아티팩트인 키스톤 왜곡(Keystone distance)의 보정을 통한 원거리 입체영상을 효과적으로 획득하는데 본 연구방법을 제안하고자 한다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.6
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• pp.35-47
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• 2011

A present experimental broadcasting is service compatible to delivery left view and right view of a dual stream for backward compatible with 2D device. It has a limitation of quality for a transmission of dual stream in terrestrial bandwidth 19 Mbps. This paper proposes adjunct terrestrial-3D broadcasting system which can provide a stable quality beyond a limitation of quality from fixed bandwidth. It proposes the system that composes a high quality stereoscopic video through synchronizing Real time broadcasting and Non Real Time broadcasting Regardless of the terrestrial bandwidth. So this paper tries to analyze each technique of Real-Time broadcasting and NRT broadcasting, and verify this proposal through the technique of an algorithm that we can implement NRT adjunct high quality 3DTV system and the experiments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12C
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• pp.1208-1215
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• 2006

In this paper, we propose an algorithm that creates three-dimensional (3D) stereoscopic video from two-dimensional (2D) video encoded by H.264 instead of using the conventional stereo-camera process. Motion information of each frame can be obtained by the given motion vectors in most of videos encoded by MPEG standards. Especially, we have accurate motion vectors for H.264 streams because of the availability of a variety of block sizes. 2D/3D video conversion algorithm proposed in this paper can create the left and right images that correspond to the original image by using cut detection method, delay factors, motion types, and image types. We usually have consistent motion type na direction in a given cut because each frame in the same cut has high correlation. We show the improved performance of the proposed algorithm through experimental results.