• ETRI Journal
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• 제38권5호
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• pp.996-1007
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• 2016

This paper presents new hole-filling methods for generating multiview images by using depth image based rendering (DIBR). Holes appear in a depth image captured from 3D sensors and in the multiview images rendered by DIBR. The holes are often found around the background regions of the images because the background is prone to occlusions by the foreground objects. Background-oriented priority and gradient-oriented priority are also introduced to find the order of hole-filling after the DIBR process. In addition, to obtain a sample to fill the hole region, we propose the fusing of depth and color information to obtain a weighted sum of two patches for the depth (or rendered depth) images and a new distance measure to find the best-matched patch for the rendered color images. The conventional method produces jagged edges and a blurry phenomenon in the final results, whereas the proposed method can minimize them, which is quite important for high fidelity in stereo imaging. The experimental results show that, by reducing these errors, the proposed methods can significantly improve the hole-filling quality in the multiview images generated.

• Restorative Dentistry and Endodontics
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• 제16권2호
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• pp.118-125
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• 1991

Eighty - eight recently extracted teeth were used to evaluate the leakage characteristics of the following retrofilling materials; amalgam, zinc oxide eugenol cement, glass - ionomer cement, and cermet glass - ionomer cement. Root canals were prepared with step - back method and obturated with gutta percha and zinc oxide eugenol sealer. Root apex were resected 2 mm from apex and class I cavities were prepared with 2 mm or 4 mm depth. The cavities were filled with above materials. After application of varnish on all surface except resected surface, the roots were placed in 1 % methylene blue solution for 6 days. After longitudinal polishing to expose cental parts of filled materials, penetrated depths of dye were measured. The results were as follws. 1. As retrofilling material, glass ionomer cement filling groups showed less leakage than the other groups except zinc oxide eugenol cement filling group(p<0.01). 2. Amalgam filling groups had greater leakage than zinc oxide eugenol cement filling group(p<0.01). 3. 4 mm depth of retrofilled cavity had no effect on leakage characteristics compared with 2 mm depth cavity(p>0.05). 4. Glass ionomer cement and cermet glass ionomer cement filling groups showed less apical leakage than amalgam filling groups. But there was no statistical significance(p>0.05). 5. There was no difference in apical leakage between glass ionomer cement filling groups and cermet glass ionomer cement filling groups(p>0.05).

• Proceedings of the Korean Society of Computer Information Conference
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• 한국컴퓨터정보학회 2012년도 제46차 하계학술발표논문집 20권2호
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• pp.79-82
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• 2012

3차원 멀티미디어 서비스에 대한 관심이 높아짐에 따라 관련 연구들이 현재 다양하게 논의되고 있다. Stereoscopy영상을 생성하기 위한 기존의 방법으로는 두 대의 촬영용 카메라를 일정한 간격으로 띄워놓고 피사체를 촬영한 후 해당 좌시점과 우시점을 생성하는 방법을 이용하였다. 하지만 이는 영상 대역폭의 부담을 가져오게 된다. 이를 해결하기 위하여 Depth정보와 한 장의 영상을 이용한 DIBR(Depth Image Based Rendering) Algorithm에 대한 연구가 많이 이루어지고 있다. 그중 Gaussian Depth Map을 이용한 Hole-Filling 방법은 DIBR에서 가장 자연스러운 결과를 보여주지만 다른 DIBR Algorithm들에 비해 속도가 현저히 느리다는 단점이 있다. 본 논문에서는 영상 생성의 고속화를 위해 GPU를 이용한 Gaussian Hole-Filling Algorithm의 병렬처리 구조를 제안하고 이를 이용한 DIBR Algorithm 생성과정을 제시한다.

• Journal of the Korea Society of Computer and Information
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• 제17권7호
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• pp.53-65
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• 2012

Existing method of creating Stereoscopy image, creates viewpoint image from the left and right by shooting one object with 2 lens in certain distance. However, in case of 3-D TV using Stereoscopy camera, the necessity to transmit 2 viewpoint images from the left and right simultaneously, increases the amount of bandwidth. Various and more effective alternatives are under discussion. Among the alternatives, DIBR(Depth Image Based Rendering) creates viewpoint images from the left and right using one image and its Depth information, thus decreasing the amount of transmitted bandwidth. For this reason, there have been various studies on Algorithm to create DIBR Image in existing Static Scene. In this paper, I would like to suggest Gaussian Hole-filling solution, which utilizes reverse-depth image to fill the hole naturally, while minimizing distortion of background. In addition, we have analyzed the effectiveness of each Algorithm by comparing and calculating its functions.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1998년도 제17회 KOSCI SYMPOSIUM 논문집
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• pp.37-46
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• 1998

In this experiments, smoke filling behaviors in a large space were investigated. Also, it found that the smoke filling time can be predicted with a simplified zone model. Thermocouples were used to measure the temperature of the hot gases layer and also later to determine the smoke layer depth. Height markers were also hung from the roof so that observers could visibly assess the smoke layer depth.

• Journal of the Korea Organic Resources Recycling Association
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• 제8권3호
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• pp.124-130
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• 2000

This study was conducted to evaluate effects of gas retention time and filling depth of a compost-based biofilter on removal of vapor phase gasoline and to suggest operational improving method. Gas empty bed retention times(EBRTs) were 4, 10, and 20 minutes, respectively. EBRT of over 10 minutes was required in both cases of TPH(total petroleum hydrocarbons) and BTEK (bezene, toluene, ethylbenzene, and xylene). Filling depths were 25, 50, 75, and 100cm, respectively. To treat gasoline TPH effectively, controlling other operational parameters including EBRT and gas loading rate was more important than increasing filling depth simply. 1m filling depth was sufficient in treating BTEX without controlling other operational parameters greatly.

• Journal of KIISE
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• 제44권2호
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• pp.186-194
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• 2017

Depth-image-based rendering is a technique that can be applied in a variety of 3D-display systems. It generates the images that have been captured from virtual viewpoints by using a depth map. However, disoccluded hole-filling problems remain a challenging issue, as a newly exposed area appears in the virtual view. Image inpainting is a popular approach for the filling of the hole region. This paper presents a robust hole-filling method that reduces the error and generates a high quality-virtual view. First, the adaptive-patch size is decided using the color and depth information. Also, a partial filling method for which the patch similarity is used is proposed. These efforts reduce the error occurrence and the propagation. The experiment results show that the proposed method synthesizes the virtual view with a higher visual comfort compared with the existing methods.

• Current Optics and Photonics
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• 제4권6호
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• pp.545-550
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• 2020

We propose a hole-filling method to solve discontinuous depth representation and to reduce the visible seams and cracks that cause the limitation of the viewing angle of the three-dimensional (3D) image in the multilayer type 3D display system. The occlusion and the disocclusion regions between layers, such as the visible seams and cracks, are a major bottleneck of the multilayer type 3D display system to represent a volumetric 3D image by stacking multiple images. As a result, in the reconstructed 3D image, the visible seams and cracks appear as brighter overlapping and undesirable cut-off. In order to resolve the problems above, we applied the depth-fused effect to the sub-depth map generating algorithm and improve the viewing characteristics of the multilayer type 3D display. The experimental demonstrations are also provided to verify the proposed scheme.

• Restorative Dentistry and Endodontics
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• 제12권2호
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• pp.17-23
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• 1987

The purpose of this study was to evaluate the sealing properties of endodontic cavity filling materials according to the time intervals after filling. Access cavities were prepared in extracted human premolar or molar teeth and filled with caviton, zinc oxide eugenol cement, zinc oxide eugenol cement with a base of gutta percha stopping and gutta percha stopping. After filling at the intervals of immediate, 2 days and 2 weeks the teeth were immersed for 2 weeks in 1% methylene blue solutions. Longitudinal sections were obtained from approximately center of teeth and the depth of dye penetration into the access cavities were observed by 10${\times}$macrolens. The following results were obtained. I. All the materials experimented showed varying depth of dye penetration. 2. Of the material tested, caviton showed the best marginal sealing qualities regardless of the time intervals after filling and the sealing properties of the gutta percha stopping was the worst. 3. Both in zinc oxide eugenol cement and zinc oxide eugenol cement with a base of gutta percha stopping, the fillings allowed to mature for 2 days in normal saline solution showed the best sealing properties and those with no maturing time revealed the worst sealing qualities. 4. The sealing qualities of zinc oxide eugenol cement with a base of gutta percha stopping revealed slightly lower depth of dye penetration than that of zinc oxide eugenol cements.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권10호
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• pp.2663-2678
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• 2012

Due to sharp depth transition, big holes may be found in the novel view that is synthesized by depth-image-based rendering (DIBR). A hole-filling method based on disparity map is proposed. One important aspect of the method is that the disparity map of destination image is used for hole-filling, instead of the depth image of reference image. Firstly, the big hole detection based on disparity map is conducted, and the start point and the end point of the hole are recorded. Then foreground pixels and background pixels are distinguished for hole-dilating according to disparity map, so that areas with matching errors can be determined and eliminated. In addition, parallaxes of pixels in the area with holes and matching errors are changed to new values. Finally, holes are filled with background pixels from reference image according to these new parallaxes. Experimental results show that the quality of the new view after hole-filling is quite well; and geometric distortions are avoided in destination image, in contrast to the virtual view generated by depth-smoothing methods and image inpainting methods. Moreover, this method is easy for hardware implementation.