• Title/Summary/Keyword: 멀티 스케일

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A Study on Scalable Video Coding Technique with FGS Temporal Scalability (FGST를 이용한 계층적 코딩기법에 관한 연구)

  • Kim, Jong-Uk;Kim, Jin-Cheol;Lee, Bae-Ho
    • Proceedings of the Korea Information Processing Society Conference
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    • 2002.11a
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    • pp.783-786
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    • 2002
  • 멀티미디어 컨텐트의 실시간 전송은 인터넷에서 중요한 기술영역으로 나타나고 있다. 본 논문에서는 MPEG-4 표준에서 채택된 FGS(Fine Granualrity Scalability)를 이용한 계층적 비디오 부호화 방법의 효율성 향상을 위한 방법을 제시하였다. MPEG-4 FGS는 인터넷에서 이용되는 다양한 특성의 단말기들과 대역폭 변동에서 유연성 있는 기술이다. 일반적인 계층 비디오 부호화 기법보다 PSNR값이 평균 1$\sim$2dB정도 높게 나타난다. 그러나 단일 계층 부호화 방법에 비해서는 효율성이 낮게 나타난다. 제안된 방법에서는 이런 FGS의 효율성을 높이기 위한 방법으로 시간 스케일러빌리티를 갖는 FGST(FGS temporal scalability)층을 적용하였다. 기본계층은 일반적인 FGS 부호화에 의해 이루어지고 상위계층 부호화로 시간적 스케일러빌리티를 갖는 FGST를 이용한다. 실험은 프레임율 10 fbs의 container와 mobile 영상에 대해 이루어졌고 두 영상 모두에 대해 FGS 부호화만을 적용하는 경우보다 상위계층으로서 FGST를 이용하는 경우 상당한 효율성 향상이 있음을 보인다.

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The Home Networking Service Embodiment based on Software Defined Media Platform (SDMP(Software Defined Media Platform)기반 홈 네트워킹 용 셋탑 박스 구현의 실제)

  • Moon Juneho;Cho Seongho;Kim Chong-kwon
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.07a
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    • pp.604-606
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    • 2005
  • 셋탑 박스 (Settop Box)는 다양한 가전 간의 통신을 통해 디지털 멀티미디어 서비스를 구현하는데 있어 중요한 홈 네트워킹 기술 요소 중 하나이다. 셋탑 박스의 구현을 위하여 다양한 플렛폼에서 개발이 진행되는 가운데 본 논문에서는 SDMP(Software Defined Media Platform)에 기반하여 멀티미디어를 제작하고 스트리밍 서비스를 할 수 있는 홈 네트워킹 용 셋탑 박스를 구현하였다. 본 논문에서는 다양한 인터페이스를 갖는 가전 기기를 지원할 수 있는 엑스스케일 보드 (Xscale board)를 제작하고 임베디드 리눅스 (Embedded Linux)를 포팀하여 실시간으로 인코딩된 멀티미디어를 스트리밍할 수 있는 서비스 구현의 예를 제시하였다.

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Design of Object Manager for Scalability and Scene Control of MPEG-4 Stream in Multimedia Service Environment (멀티미디어 서비스 환경에서 MPEG-4 스트림의 스케일러빌리티와 장면 제어를 위한 객체 관리기의 설계)

  • 최숙영
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2002.06a
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    • pp.266-275
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    • 2002
  • 현재 멀티미디어 서비스 분야에서 핵심적인 기술로 부상되고 있는 MPEG-4는 고압축률을 제공하며, 그 자체 구조의 모든 요소을 기술하는데 객체지향적인 기법을 사용하고 있다. 본 연구에서는 다양한 통신망과 단말 환경에 잘 대응하고 강력한 상호작용을 지원함으로서 효과적인 멀티미디어 서비스를 제공할 수 있도록, MPEG-4 시스템에 객체 관리기의 기능을 추가하도록 한다. 이 객체 관리기를 통해, 장면트리를 구성하는 객체들에 우선 순위를 부여하고 관리하며, 사용자 상호작용에 따른 장면트리의 변경 및 각 객체의 정보 및 버전들을 관리하도록 한다. 또한 객체간의 시간 관계 모델을 정의함으로서 동기화를 효과적으로 지원 할 수 있도록 한다.

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Multi-Level Digital Watermarking for Color Image of Multimedia Contents (멀티미디어 컨텐츠의 컬러 영상에 대한 다중 레벨 디지털 워터마킹)

  • Park, Hung-Bog;Seo, Jung-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.11
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    • pp.1946-1953
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    • 2006
  • Because the embedded watermark of luminance component guarantees the extraction of ownership information when the color image is converted to gray scale image, the information of ownership right as to the luminance component is embedded in the luminance-chrominance color space such as YCbCr. Therefore, this paper proposes watermark embedding, extraction and authentication algorithm of color image. which considers the device and performance of multimedia contents service by focusing on the robustness and invisibility of watermark. The color image is converted from RGB color space to YCbCr color space, and then the properties of each component of Y(Luminance), Cb(Color Differences) and Cr(Color Differences) are considered in order to embed, extract and certify multi-level watermark in the frequency domain based on the wavelet. As a result, it can guaranteed the robustness for the JPEG compression and invisibility of watermark for multi-level.

Multi-resolution Representation of 2D Point Data (2차원 점 데이터의 다중해상도 표현)

  • Yun, Seong-Min;Lee, Mun-Bae;Park, Sang-Hun
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.7
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    • pp.768-774
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    • 2010
  • Reconstruction of implicit surfaces from scattered point data sets have been developed in various engineering and scientific studies. In this paper, we represent a method to construct functions of 2D point data using multi-scale kernels and show it can be applied to graphics applications needed to access data in real-time. Our approach is similar to previous work in that a set of coefficients of the functions are calculated and stored in the preprocessing stage and function values at arbitrary positions are evaluated for real-time applications, however, it is different from others in that users can choose detail levels freely in real-time processing stage. The reason why the functions implicitly supports multi-resolution results from the mathematical properties of multi-scale kernels, and proposed method can be expanded to represent multi-resolution functions of n-dimensional data.

Performance Analysis of Scalable HEVC Coding Tools (HEVC 기반 스케일러블 비디오 부호화 툴의 성능 분석)

  • Kim, Yongtae;Choi, Jinhyuk;Choi, Haechul
    • Journal of Broadcast Engineering
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    • v.20 no.4
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    • pp.497-508
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    • 2015
  • Current communication networks consist of channels with various throughputs, protocols, and packet loss rates. Moreover, there are also diverse user multimedia consumption devices having different capabilities and screen sizes. Thus, a practical necessity of scalability on video coding have been gradually increasing. Recently, The Scalable High Efficiency Video Coding(SHVC) standard is developed by Joint Collaborative Team on Video Coding(JCT-VC) organized in cooperation with MPEG of ISO/IEC and VCEG of ITU-T. This paper introduces coding tools of SHVC including adopted and unadopted tools discussed in the process of the SHVC standardization. Furthermore, the individual tool and combined tool set are evaluated in terms of coding efficiency relative to a single layer coding structure. This analysis would be useful for developing a fast SHVC encoder as well as researching on a new scalable coding tool.

Application of Effective Regularization to Gradient-based Seismic Full Waveform Inversion using Selective Smoothing Coefficients (선택적 평활화 계수를 이용한 그래디언트기반 탄성파 완전파형역산의 효과적인 정규화 기법 적용)

  • Park, Yunhui;Pyun, Sukjoon
    • Geophysics and Geophysical Exploration
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    • v.16 no.4
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    • pp.211-216
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    • 2013
  • In general, smoothing filters regularize functions by reducing differences between adjacent values. The smoothing filters, therefore, can regularize inverse solutions and produce more accurate subsurface structure when we apply it to full waveform inversion. If we apply a smoothing filter with a constant coefficient to subsurface image or velocity model, it will make layer interfaces and fault structures vague because it does not consider any information of geologic structures and variations of velocity. In this study, we develop a selective smoothing regularization technique, which adapts smoothing coefficients according to inversion iteration, to solve the weakness of smoothing regularization with a constant coefficient. First, we determine appropriate frequencies and analyze the corresponding wavenumber coverage. Then, we define effective maximum wavenumber as 99 percentile of wavenumber spectrum in order to choose smoothing coefficients which can effectively limit the wavenumber coverage. By adapting the chosen smoothing coefficients according to the iteration, we can implement multi-scale full waveform inversion while inverting multi-frequency components simultaneously. Through the successful inversion example on a salt model with high-contrast velocity structures, we can note that our method effectively regularizes the inverse solution. We also verify that our scheme is applicable to field data through the numerical example to the synthetic data containing random noise.

Generation of High-Resolution Chest X-rays using Multi-scale Conditional Generative Adversarial Network with Attention (주목 메커니즘 기반의 멀티 스케일 조건부 적대적 생성 신경망을 활용한 고해상도 흉부 X선 영상 생성 기법)

  • Ann, Kyeongjin;Jang, Yeonggul;Ha, Seongmin;Jeon, Byunghwan;Hong, Youngtaek;Shim, Hackjoon;Chang, Hyuk-Jae
    • Journal of Broadcast Engineering
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    • v.25 no.1
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    • pp.1-12
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    • 2020
  • In the medical field, numerical imbalance of data due to differences in disease prevalence is a common problem. It reduces the performance of a artificial intelligence network, leading to difficulties in learning a network with good performance. Recently, generative adversarial network (GAN) technology has been introduced as a way to address this problem, and its ability has been demonstrated by successful applications in various fields. However, it is still difficult to achieve good results in solving problems with performance degraded by numerical imbalances because the image resolution of the previous studies is not yet good enough and the structure in the image is modeled locally. In this paper, we propose a multi-scale conditional generative adversarial network based on attention mechanism, which can produce high resolution images to solve the numerical imbalance problem of chest X-ray image data. The network was able to produce images for various diseases by controlling condition variables with only one network. It's efficient and effective in that the network don't need to be learned independently for all disease classes and solves the problem of long distance dependency in image generation with self-attention mechanism.

Development Fundamental Technologies for the Multi-Scale Mass-Deployable Cooperative Robots (멀티 스케일 다중 전개형 협업 로봇을 위한 요소 기술 개발)

  • Chu, Chong Nam;Kim, Haan;Kim, Jeongryul;Song, Sung-Hyuk;Koh, Je-Sung;Huh, Sungju;Ha, ChangSu;Kim, Jong Won;Ahn, Sung-Hoon;Cho, Kyu-Jin;Hong, Seong Soo;Lee, Dong Jun
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.1
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    • pp.11-17
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    • 2013
  • 'Multi-scale mass-deployable cooperative robots' is a next generation robotics paradigm where a large number of robots that vary in size cooperate in a hierarchical fashion to collect information in various environments. While this paradigm can exhibit the effective solution for exploration of the wide area consisting of various types of terrain, its technical maturity is still in its infant state and many technical hurdles should be resolved to realize this paradigm. In this paper, we propose to develop new design and manufacturing methodologies for the multi-scale mass-deployable cooperative robots. In doing so, we present various fundamental technologies in four different research fields. (1) Adaptable design methods consist of compliant mechanisms and hierarchical structures which provide robots with a unified way to overcome various and irregular terrains. (2) Soft composite materials realize the compliancy in these structures. (3) Multi-scale integrative manufacturing techniques are convergence of traditional methods for producing various sized robots assembled by such materials. Finally, (4) the control and communication techniques for the massive swarm robot systems enable multiple functionally simple robots to accomplish the complex job by effective job distribution.

Object Tracking Based on Centroids Shifting with Scale Adaptation (중심 이동 기반의 스케일 적응적 물체 추적 알고리즘)

  • Lee, Suk-Ho;Choi, Eun-Cheol;Kang, Moon-Gi
    • Journal of Korea Multimedia Society
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    • v.14 no.4
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    • pp.529-537
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    • 2011
  • In this paper, we propose a stable scale adaptive tracking method that uses centroids of the target colors. Most scale adaptive tracking methods have utilized histograms to determine target window sizes. However, in certain cases, histograms fail to provide good estimates of target sizes, for example, in the case of occlusion or the appearance of colors in the background that are similar to the target colors. This is due to the fact that histograms are related to the numbers of pixels that correspond to the target colors. Therefore, we propose the use of centroids that correspond to the target colors in the scale adaptation algorithm, since centroids are less sensitive to changes in the number of pixels that correspond to the target colors. Due to the spatial information inherent in centroids, a direct relationship can be established between centroids and the scale of target regions. Generally, after the zooming factors that correspond to all the target colors are calculated, the unreliable zooming factors are filtered out to produce a reliable zooming factor that determines the new scale of the target. Combined with the centroid based tracking algorithm, the proposed scale adaptation method results in a stable scale adaptive tracking algorithm. It tracks objects in a stable way, even when the background colors are similar to the colors of the object.