• Title/Summary/Keyword: 깊이맵

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Estimating Human Size in 2D Image for Improvement of Detection Speed in Indoor Environments (실내 환경에서 검출 속도 개선을 위한 2D 영상에서의 사람 크기 예측)

  • Gil, Jong In;Kim, Manbae
    • Journal of Broadcast Engineering
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    • v.21 no.2
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    • pp.252-260
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    • 2016
  • The performance of human detection system is affected by camera location and view angle. In 2D image acquired from such camera settings, humans are displayed in different sizes. Detecting all the humans with diverse sizes poses a difficulty in realizing a real-time system. However, if the size of a human in an image can be predicted, the processing time of human detection would be greatly reduced. In this paper, we propose a method that estimates human size by constructing an indoor scene in 3D space. Since the human has constant size everywhere in 3D space, it is possible to estimate accurate human size in 2D image by projecting 3D human into the image space. Experimental results validate that a human size can be predicted from the proposed method and that machine-learning based detection methods can yield the reduction of the processing time.

3D Model Reconstruction Algorithm Using a Focus Measure Based on Higher Order Statistics (고차 통계 초점 척도를 이용한 3D 모델 복원 알고리즘)

  • Lee, Joo-Hyun;Yoon, Hyeon-Ju;Han, Kyu-Phil
    • Journal of Korea Multimedia Society
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    • v.16 no.1
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    • pp.11-18
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    • 2013
  • This paper presents a SFF(shape from focus) algorithm using a new focus measure based on higher order statistics for the exact depth estimation. Since conventional SFF-based 3D depth reconstruction algorithms used SML(sum of modified Laplacian) as the focus measure, their performance is strongly depended on the image characteristics. These are efficient only for the rich texture and well focused images. Therefore, this paper adopts a new focus measure using HOS(higher order statistics), in order to extract the focus value for relatively poor texture and focused images. The initial best focus area map is generated by the measure. Thereafter, the area refinement, thinning, and corner detection methods are successively applied for the extraction of the locally best focus points. Finally, a 3D model from the carefully selected points is reconstructed by Delaunay triangulation.

Screen Content Coding Analysis to Improve Coding Efficiency for Immersive Video (몰입형 비디오 압축을 위한 스크린 콘텐츠 코딩 성능 분석)

  • Lee, Soonbin;Jeong, Jong-Beom;Kim, Inae;Lee, Sangsoon;Ryu, Eun-Seok
    • Journal of Broadcast Engineering
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    • v.25 no.6
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    • pp.911-921
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    • 2020
  • Recently, MPEG-I (Immersive) has been exploring compression performance through standardization projects for immersive video. The MPEG Immersion Video (MIV) standard technology is intended to provide limited 6DoF based on depth map-based image rendering (DIBR). MIV is a model that processes the Basic View and the residual information into an Additional View, which is a collection of patches. Atlases have the unique characteristics depending on the kind of the view they are included, requiring consideration of the compression efficiency. In this paper, the performance comparison analysis of screen content coding tools such as intra block copy (IBC) is conducted, based on the pattern of various views and patches repetition. It is demonstrated that the proposed method improves coding performance around -15.74% BD-rate reduction in the MIV.

A Study on Development of Program connecting with math-story books and web 2.0map(Google map) (수학교양도서와 웹 2.0지도(구글맵) 매쉬업을 통한 수학 이야기 지도 만들기 프로그램 개발)

  • Kim, Sang-Mi;Kwon, Oh-Nam
    • Journal of the Korean School Mathematics Society
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    • v.14 no.4
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    • pp.443-458
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    • 2011
  • There has been a lively discussion on improving Korean students' academic achievement and the imbalance in their recognition of the value of mathematics. In this context, there is a need for a program that enables the majority students who regards mathematics as a subject for the entrance examination to recognize the practicality and historicity of mathematics. Educational books on mathematics in everyday life or the history of mathematics are also expected to serve as an effective tool. In addition, Web 2.0 Map is another means of representing mathematics in everyday life and the history of mathematics in connection with the practical context. The active storytelling process in which mathematics in the practical context in mathematical educational books is represented in Web 2.0 Map is expected to help to understand in depth the practicality and historicity of mathematics. Nevertheless, mathematical educational books and Web 2.0 Map may lead to a considerable variety of outcomes and speeds if carrying out tasks depending on the student's competence and may have practical difficulties in being operated in class. These concerns, however, can be resolved through the creative activity programs adopted in conformance with the 2009 revised curriculum. Therefore, this study intends to develop a program for creating mathematical story maps through mathematical educational books and the Mashup of Web 2.0 Map in accordance with the process of developing activity programs. This study also intends to determine its effectiveness in enabling students to recognize the practical and historical values of mathematics.

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A Proposal of Durability Prediction Models and Development of Effective Tunnel Maintenance Method Through Field Application (내구성 예측식의 제안 및 현장적용을 통한 효율적인 터널 유지관리 기법의 개발)

  • Cho, Sung Woo;Lee, Chang Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.5
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    • pp.148-160
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    • 2012
  • This study proposed more reasonable prediction models on compressive strength and carbonation of concrete structure and developed a more effective tunnel safety diagnosis and maintenance method through field application of the proposed prediction models. For this study, the Seoul Metro's Line 1 through Line 4 were selected as target structures because they were built more than 30 years ago and have accumulated numerous diagnosis and maintenance data for about 15 years. As a result of the analysis of compressive strength and carbonation, we were able to draw prediction models with accuracy of more than 80% and confirmed the prediction model's reliability by comparing it with the existing models. We've also confirmed field suitability of the prediction models by applying field, the average error of an estimate on compressive strength and carbonation depth was about 20%, which showed an accuracy of more than 80%. We developed a more effective maintenance method using durability prediction Map before field inspection. With the durability prediction Map, diagnostic engineers and structure managers can easily detect the vulnerable points, which might have failed to reach the standard of designed strength or have a high probability of corrosion due to carbonation, therefore, it is expected to make it possible for them to diagnose and maintain tunnels more effectively and efficiently.

Rendering Quality Improvement Method based on Depth and Inverse Warping (깊이정보와 역변환 기반의 포인트 클라우드 렌더링 품질 향상 방법)

  • Lee, Heejea;Yun, Junyoung;Park, Jong-Il
    • Journal of Broadcast Engineering
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    • v.26 no.6
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    • pp.714-724
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    • 2021
  • The point cloud content is immersive content recorded by acquiring points and colors corresponding to the real environment and objects having three-dimensional location information. When a point cloud content consisting of three-dimensional points having position and color information is enlarged and rendered, the gap between the points widens and an empty hole occurs. In this paper, we propose a method for improving the quality of point cloud contents through inverse transformation-based interpolation using depth information for holes by finding holes that occur due to the gap between points when expanding the point cloud. The points on the back are rendered between the holes created by the gap between the points, acting as a hindrance to applying the interpolation method. To solve this, remove the points corresponding to the back side of the point cloud. Next, a depth map at the point in time when an empty hole is generated is extracted. Finally, inverse transform is performed to extract pixels from the original data. As a result of rendering content by the proposed method, the rendering quality improved by 1.2 dB in terms of average PSNR compared to the conventional method of increasing the size to fill the blank area.

Study on VHCF Fatigue Behaviors and UNSM Effects of Hydrogen Attacked STS 316L (수소취화된 스테인리스강 316L의 VHCF(Very High Cycle Fatigue) 피로특성과 UNSM 효과에 관한 연구)

  • Nahm, Seung-Hoon;Baek, Un-Bong;Suh, Chang-Min;Pyun, Young-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.11
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    • pp.1011-1020
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    • 2017
  • This study was conducted to investigate the material properties of stainless steel 316L specimens of untreated and UNSM treated material, hydrogen attacked material(100 bar, $300^{\circ}C$ at 120 h) and UNSM treated hydrogen attacked material at room temperature. Results demonstrated that the hydrogen attacked materials showed a tendency toward a slightly decreased fatigue strength, while the hydrogen embrittlement effect was smaller than the S-N curve of conventional untreated material. As compared to untreated material, the fatigue limit of the UNSM treated material increased by 43.8%, while it was 57.1% higher in the UNSM treated hydrogen attacked material than in untreated hydrogen attacked material. The plastic deformation layer was ${\sim}152{\mu}m$ thick, as confirmed by maps showing the level of local plastic deformation affected by the UNSM treatment in three ways: an image quality map, inverse pole figure map, and kernel average misorientation map captured via electron back scatter diffraction. Owing to hydrogen embrittlement, about 90% of surface cracks were smaller than the average grain size of $35{\mu}m$.

Fabrication of Face Molds and Silicone Masks using 3D Printing (3D 프린팅을 이용한 얼굴 몰드 및 실리콘 마스크 제작)

  • Choi, Yea-Jun;Shin, Il-Kyu;Choi, Kanghyun;Choi, Soo-Mi
    • Journal of KIISE
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    • v.43 no.5
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    • pp.516-523
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    • 2016
  • For old-age makeups, makeup artists first make a mold cast of an actor's face using plaster and then sculpt wrinkles in clay on the plaster mold. After finishing the clay sculpture, its negative plaster mold is fabricated and silicone skin patches are finally made for application to the actor's face. This process takes a few days and is tedious for actors and makeup artists. With recent advances in 3D printing and scanning technology, it is becoming easier to scan and fabricate 3D faces. This paper presents a new pipeline composed of facial scanning, interactive wrinkle modeling, and mold printing stages to easily and efficiently fabricate silicone masks for old-age makeups without the use of plaster and clay. An intuitive sketch interface based on a normal map is proposed for the creation of wrinkles in real time, even with a high-resolution face model. Then the geometry of the final wrinkles is reconstructed using a depth map and the negative mold of the wrinkled face is printed. We also show that the presented pipeline can fabricate a silicone mask more conveniently than the traditional one that consists of pouring silicone into the prepared negative mold and then overlapping the mold with the original positive one.

Deep Learning Approach for Automatic Discontinuity Mapping on 3D Model of Tunnel Face (터널 막장 3차원 지형모델 상에서의 불연속면 자동 매핑을 위한 딥러닝 기법 적용 방안)

  • Chuyen Pham;Hyu-Soung Shin
    • Tunnel and Underground Space
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    • v.33 no.6
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    • pp.508-518
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    • 2023
  • This paper presents a new approach for the automatic mapping of discontinuities in a tunnel face based on its 3D digital model reconstructed by LiDAR scan or photogrammetry techniques. The main idea revolves around the identification of discontinuity areas in the 3D digital model of a tunnel face by segmenting its 2D projected images using a deep-learning semantic segmentation model called U-Net. The proposed deep learning model integrates various features including the projected RGB image, depth map image, and local surface properties-based images i.e., normal vector and curvature images to effectively segment areas of discontinuity in the images. Subsequently, the segmentation results are projected back onto the 3D model using depth maps and projection matrices to obtain an accurate representation of the location and extent of discontinuities within the 3D space. The performance of the segmentation model is evaluated by comparing the segmented results with their corresponding ground truths, which demonstrates the high accuracy of segmentation results with the intersection-over-union metric of approximately 0.8. Despite still being limited in training data, this method exhibits promising potential to address the limitations of conventional approaches, which only rely on normal vectors and unsupervised machine learning algorithms for grouping points in the 3D model into distinct sets of discontinuities.

Bit-Map Based Hybrid Fast IP Lookup Technique (비트-맵 기반의 혼합형 고속 IP 검색 기법)

  • Oh Seung-Hyun
    • Journal of Korea Multimedia Society
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    • v.9 no.2
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    • pp.244-254
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    • 2006
  • This paper presents an efficient hybrid technique to compact the trie indexing the huge forward table small enough to be stored into cache for speeding up IP lookup. It combines two techniques, an encoding scheme called bit-map and a controlled-prefix expanding scheme to replace slow memory search with few fast-memory accesses and computations. For compaction, the bit-map represents each index and child pointer with one bit respectively. For example, when one node denotes n bits, the bit-map gives a high compression rate by consumes $2^{n-1}$ bits for $2^n$ index and child link pointers branched out of the node. The controlled-prefix expanding scheme determines the number of address bits represented by all root node of each trie's level. At this time, controlled-prefix scheme use a dynamic programming technique to get a smallest trie memory size with given number of trie's level. This paper proposes standard that can choose suitable trie structure depending on memory size of system and the required IP lookup speed presenting optimal memory size and the lookup speed according to trie level number.

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