• Electronics and Telecommunications Trends
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• v.33 no.2
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• pp.48-55
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• 2018

Immersive media, which maximizes the viewer's sense of presence and immersion, has been developed in the form of 3D stereoscopic media and UHD media. Going one step further, VR media, which can provide immersive experiences within an artificially created environment, have recently been considered a type of next-generation media. Within this trend, numerous IT and broadcasting companies around the world are actively investing their time and resources to boost the emerging VR industry. In this paper, we introduce the representative VR media acquisition and broadcasting service technologies that are leading the current VR industry.

• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.131-138
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• 2009

The similarity between two groups of displaying methods is demonstrated in two ways, analytically and experimentally. A variety of layouts of the integral photography and display devices based on the point light source model is classified and analyzed in terms of projections and common/separate image planes. In particularly, the transformation matrix is found. Simulation experiments based on the image processing were performed. The layouts, analytical formulas, and experimental results show the similarity of both groups for several layouts.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.927-928
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• 2015

무안경 3D 입체 디스플레이 장치는 패럴렉스 배리어(parallax barrier)와 렌티률러 렌즈(Lenticular lens)의 기반의 장치로 구분된다. 무안경 업체 디스플레이 장치를 통하여 입체영상을 디스플레이하기 위해서는 다중 시점(multi-view) 촬영 영상들의 서브픽셀 인터레이싱 방법을 통하여 하나의 영상으로 합성되어야 한다. 본 연구는 렌티큘러 렌즈 기반의 입체 디스플레이 장치에서 렌티큘러 렌즈의 속성에 따라 적응적으로 서브픽셀 인터레이싱 될 수 있는 기법을 제안하기 위한 사전 연구로서 기존에 발표된 서브픽셀 인터레이싱 기법의 종류를 분류하고 각 기법의 특성을 분석하고자 한다.

• Korean Journal of Remote Sensing
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• v.23 no.5
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• pp.439-445
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• 2007

Stereoscopic viewing is an efficient technique for not only computer vision but also remote sensing applications. Generally, stereo pair obtained at the same time is necessary for 3D viewing, but it is possible to synthesize a stereomate suitable for stereo view with a single image and disparity-map. There have been researches concerning the generation of the synthetic stereomate from remote sensing imagery. However it is hard to find researches concerning the restoration of occlusion in stereomate. In this paper, we generated synthetic stereomates from remote sensing images, focused on the occlusion restoration. In order to figure out proper restoration methods depending on the spatial resolution of remote sensing imagery, we tested several methods including general interpolation and inpainting technique, then evaluated the results.

• Smart Media Journal
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• v.1 no.3
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• pp.36-42
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• 2012

Recently, the smart applications, such as smart phone and smart TV, become a hot issue in IT consumer markets. In particular, the smart TV provides 3D video services, hence efficient coding methods for 3D video data are required. Three-dimensional (3D) video involves stereoscopic or multi-view images to provide depth experience through 3D display systems. Binocular cues are perceived by rendering proper viewpoint images obtained at slightly different view angles. Since the number of viewpoints of the multi-view video is limited, 3D display devices should generate arbitrary viewpoint images using available adjacent view images. In this paper, after we explain a view synthesis method briefly, we propose a new algorithm to compensate view synthesis errors around object boundaries. We describe a 3D warping technique exploiting the depth map for viewpoint shifting and a hole filling method using multi-view images. Then, we propose an algorithm to remove boundary noises that are generated due to mismatches of object edges in the color and depth images. The proposed method reduces annoying boundary noises near object edges by replacing erroneous textures with alternative textures from the other reference image. Using the proposed method, we can generate perceptually inproved images for 3D video systems.

• Journal of Sensor Science and Technology
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• v.7 no.6
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• pp.418-425
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• 1998

Stereo cameras are the most widely used sensing systems for automated machines including robots to interact with their three-dimensional(3D) working environments. The position of a target point in the 3D world coordinates can be measured by the use of stereo cameras and the camera calibration is an important preliminary step for the task. Existing camera calibration techniques can be classified into two large categories - linear and nonlinear techniques. While linear techniques are simple but somewhat inaccurate, the nonlinear ones require a modeling process to compensate for the lens distortion and a rather complicated procedure to solve the nonlinear equations. In this paper, a method employing a neural network for the calibration problem is described for tackling the problems arisen when existing techniques are applied and the results are reported. Particularly, it is shown experimentally that by utilizing the function approximation capability of multi-layer neural networks trained by the back-propagation(BP) algorithm to learn the error pattern of a linear technique, the measurement accuracy can be simply and efficiently increased.

• Journal of IKEEE
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• v.22 no.3
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• pp.866-869
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• 2018

This paper presents the analysis of the human driving behavior based on the expression as a GMDH technique focusing on the driver's collision avoidance maneuver. The driving data are collected by using the three dimensional driving simulator based on CAVE, which provides stereoscopic immersive vision. A GMDH is also introduced and applied to the measured data in order to build a mathematical model of driving behavior. From the obtained model, it is found that the longitudinal distance between cars($x_1$), the longitudinal relative velocity($x_2$) and the lateral displacement between cars($x_4$) play important roles in the collision avoidance maneuver under the 3D environments.

• Journal of Broadcast Engineering
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• v.18 no.4
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• pp.559-571
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• 2013

This paper has presented a few problems when the 2D video superimposed the overlay text was converted to the 3D stereoscopic video. To resolve the problems, it proposes the scenario which the original video is divided into two parts, one is the video only with overlay text graphic region and the other is the video with holes, and then processed respectively. And this paper focuses on research only to detect and extract the overlay text graphic region, which is a first step among the processes in the proposed scenario. To decide whether the overlay text is included or not within a frame, it is used the corner density map based on the Harris corner detector. Following that, the overlay text region is extracted using the hybrid method of color and motion information of the overlay text region. The experiment shows the results of the overlay text region detection and extraction process in a few genre video sequence.

• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.204-214
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• 2015

Depth map upsampling is an approach to increase the spatial resolution of depth maps obtained from a depth camera. Depth map quality is closely related to 3D perception of stereoscopic image, multi-view image and holography. In general, the performance of upsampled depth map is evaluated by PSNR (Peak Signal to Noise Ratio). On the other hand, time-consuming 3D subjective tests requiring human subjects are carried out for examining the 3D perception as well as visual fatigue for 3D contents. Therefore, if an objective metric is closely correlated with a subjective test, the latter can be replaced by the objective metric. For this, this paper proposes a best metric by investigating the relationship between diverse objective metrics and 3D subjective tests. Diverse reference and no-reference metrics are adopted to evaluate the performance of upsampled depth maps. The subjective test is performed based on DSCQS test. From the utilization and analysis of three kinds of correlations, we validated that SSIM and Edge-PSNR can replace the subjective test.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.232-243
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• 2021

Purpose: The purpose of this study was to evaluate the shear bond strength of various 3D printed denture base resins and the conventional denture base resin to various denture relining materials. Materials and Methods: For denture base materials, a heatcured (Vertex RS) and two types of 3D printed DENTCA Denture base II, NextDent^TM Base) were used. And 4 types denture relining materials (Tokuyama Rebase II fast, Kooliner, Denture Liner, Denture Liner, Lang Jet Denture Repair Kit) with different components were used. It was classified into 12 groups. Adhesion was performed between the resin base and the relining materials in accordance with ISO/TS 11405 standard. The shear bonding strength was measured, and then the adhesion interface was observed with a stereoscopic microscope and a scanning electron microscope. The fracture pattern was investigated through the analysis of the fragment. Results: In the 3D printed denture resin group, the shear bonding strength with relining materials was significantly lower than that of the heat-cured resin group (P < 0.05). The group of polymethyl methacrylate -based relining materials, high shear bonding strength was shown regardless of the type of denture. As for the fracture pattern, adhesive fracture appeared in most groups, and cohesive, mixed fracture appeared in some groups. Conclusion: The polymethyl methacrylate -based denture relining materials showed high shear bonding strength values compared to other denture relining materials. But, for direct methods, it is considered advantageous in terms of shear bonding strength to use a isobutyl methacrylate-based denture relining materials.