• Title/Summary/Keyword: spatial picture

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Adaptive Rate-Distortion Optimized Multiple Loop Filtering Algorithm (적응적 율-왜곡 최적 다중 루프 필터 기법)

  • Hong, Soon-Gi;Choe, Yoon-Sik;Kim, Yong-Goo
    • Journal of Broadcast Engineering
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    • v.15 no.5
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    • pp.617-630
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    • 2010
  • At 37th VCEG meeting in Jan. 2009, Toshiba proposed Quadtree-based Adaptive Loop Filter (QALF). The basic concept of QALF is to apply Wiener filter to decoded image after the conventional deblocking filter and to represent the filter on/off flag data for each basic filtering unit in a more efficient way of quadtree structure. QALF could enhance the compression performance of around more than 9%, but the structure of one filter for a decoded frame leaves room for further improvement in the sense that optimal filter for one region of a frame could quite different from the optimal filter for other parts of a picture. This paper proposes multiple adaptive loop filters for better utilization of local characteristics of decoded frame to optimize the region-based Wiener filters. Additional filters, proposed in this paper, cover separate spatial area of each decoded frame according to the performance of previously designed filter(s) to provide the flexibility of rate-distortion based selection of the number of filters.

Measurement of Flickering Artifact for H.264 with Periodic I-Frame Structure (주기적 I-프레임 구조의 H.264 부호화 동영상을 위한 플리커링 측정 알고리즘)

  • Lim, Jong-Min;Kang, Dong-Wook;Jung, Kyeong-Hoon
    • Journal of Broadcast Engineering
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    • v.15 no.3
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    • pp.321-331
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    • 2010
  • Most of multimedia video coding algorithms are lossy schemes and several kinds of spatial and temporal artifacts are inevitable. Flickering, which is the most typical coding artifact in time domain, is mainly due to fact that the quality of coded sequence fluctuates as the quantization parameter is adjusted for rate control. In this paper, we analyzed the effect of quality variation according to the characteristics of video sequence when the I-frames are periodically inserted. And we proposed the FR(Full Reference)-based assessment algorithm to measure the amount of flickering artifacts in the coded video. It is discovered that the flickering becomes critical when the level of quality is intermediate and is affected by the amount of detail or movement, the size of object, and camera parameters. The proposed measurement algorithm shows is well consistent with HVS(Human Visual System).

Detection of Red Tide Distribution in the Southern Coast of the Korea Waters using Landsat Image and Euclidian Distance (Landsat 영상과 유클리디언 거리측정 방법을 이용한 한반도 남부해역 적조영역 검출)

  • Sur, Hyung-Soo;Kim, Seok-Gyu;Lee, Chil-Woo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.4
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    • pp.1-13
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    • 2007
  • We make image that accumulate two principal component after change picture to use GLCM(Gray Level Co-Occurrence Matrix)'s texture feature information. And then these images use preprocess to achieved corner detection and area detection. Experiment results, two principle component conversion accumulation images had most informations about six kind textures by Eigen value 94.6%. When compared with red tide area that uses sea color and red tide area of image that have all principle component, displayed the most superior result. Also, we creates Euclidian space using Euclidian distance measurement about red tide area and clear sea. We identify of red tide area by red tide area and clear sea about random sea area through Euclidian distance and spatial distribution.

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A Trace of Landcover Change in a Landslide Vulnerable Area (산사태 취약지에서의 토지피복상태 변화 추적)

  • Chun, Ki-Sun;Park, Jae-Kook
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.3
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    • pp.69-76
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    • 2007
  • Kangwondo area is mountainous and landslide is easily happened easily during the rainy period in summer time. Especially, when there is torrential downpour caused by the unusual weather change, there will be greater possibility to see landslide. Another reason behind landslide is the continuous forest fire in these several years. Since the surface of the earth has been changed by the fire, when rainfall comes, landslide just happens easily. Also, it is reported that landcover condition, excepted rainfall condition, is the most effect for determining landslide susceptibility area. In this study, it is determined a landslide vulnerable area and landcover information is extracted from four satellite image(Landsat TM), about the landslide vulnerable area, which is pictured for each year. And which distribution change is analyzed. also, NDVI picture is made and distribution change of vegetation vitality is analyzed to study that change of landcover have a effect on landslide. As a result, could know that forest and NDVI are decreasing in landslide vulnerable area.

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The Study of Comparison of DCT-based H.263 Quantizer for Computative Quantity Reduction (계산량 감축을 위한 DCT-Based H.263 양자화기의 비교 연구)

  • Shin, Kyung-Cheol
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.3
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    • pp.195-200
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    • 2008
  • To compress the moving picture data effectively, it is needed to reduce spatial and temporal redundancy of input image data. While motion estimation! compensation methods is effectively able to reduce temporal redundancy but it is increased computation complexity because of the prediction between frames. So, the study of algorithm for computation reduction and real time processing is needed. This paper is presenting quantizer effectively able to quantize DCT coefficient considering the human visual sensitivity. As quantizer that proposed DCT-based H.263 could make transmit more frame than TMN5 at a same transfer speed, and it could decrease the frame drop effect. And the luminance signal appeared the difference of $-0.3{\sim}+0.65dB$ in the average PSNR for the estimation of objective image quality and the chrominance signal appeared the improvement in about 1.73dB in comparision with TMN5. The proposed method reduces $30{\sim}31%$ compared with NTSS and $20{\sim}21%$ compared to 4SS in comparition of calculation quantity.

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Characterization and Color Reproduction Based on Average Picture Level if PDP Displays (평균화면밝기에 기반한 PDP 디스플레이의 특성화 및 색 재현)

  • Kwon, Oh-Seol;Ko, Kyung-Woo;Ha, Yeong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.5
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    • pp.9-17
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    • 2008
  • This paper proposes a method of color reproduction considering the viewing conditions of a PDP TV. Because of a change of peripheral environments by a temporal and spatial location of observers, the ambient lightings should be considered in the process of color reproduction of displays. A conventional method enhances the contrast and saturation of images by controlling voltage gains in each channel, so that there is a limit to implementing the phenomenon of human adaptation. This method also faces difficulties in reproducing the perceived colors under a variety of viewing conditions. Accordingly, in order to solve this problem, we first characterize the device by considering the brightness and the flare effect. The chromatic adaptation is finally applied to reproduce colors in a PDP TV using the information from the viewing conditions by the sensor. The images reproduced by the proposed method are visually more superior to those reproduced by a conventional method in the experiments.

Language Lateralization Using Magnetoencephalography (MEG): A Preliminary Study (뇌자도를 이용한 언어 편재화: 예비 연구)

  • Lee, Seo-Young;Kang, Eunjoo;Kim, June Sic;Lee, Sang-Kun;Kang, Hyejin;Park, Hyojin;Kim, Sung Hun;Lee, Seung Hwan;Chung, Chun Kee
    • Annals of Clinical Neurophysiology
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    • v.8 no.2
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    • pp.163-170
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    • 2006
  • Backgrounds: MEG can measure the task-specific neurophysiologic activity with good spatial and time resolution. Language lateralization using noninvasive method has been a subject of interest in resective brain surgery. We purposed to develop a paradigm for language lateralization using MEG and validate its feasibility. Methods: Magnetic fields were obtained in 12 neurosurgical candidates and one volunteer for language tasks, with a 306 channel whole head MEG. Language tasks were word listening, reading and picture naming. We tested two word listening paradigms: semantic decision of meaning of abstract nouns, and recognition of repeated words. The subjects were instructed to silently name or read, and respond with pushing button or not. We decided language dominance according to the number of acceptable equivalent current dipoles (ECD) modeled by sequential single dipole, and the mean magnetic field strength by root mean square value, in each hemisphere. We collected clinical data including Wada test. Results: Magnetic fields evoked by word listening were generally distributed in bilateral temporoparietal areas with variable hemispheric dominance. Language tasks using visual stimuli frequently evoked magnetic field in posterior midline area, which made laterality decision difficult. Response during task resulted in more artifacts and different results depending on responding hand. Laterality decision with mean magnetic field strength was more concordant with Wada than the method with ECD number of each hemisphere. Conclusions: Word listening task without hand response is the most feasible paradigm for language lateralization using MEG. Mean magnetic field strength in each hemisphere is a proper index for hemispheric dominance.

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A Study on Digital Space Design Method and System using Virtual Reality (가상현실을 활용한 디지털 공간 디자인 기법과 체계 연구)

  • 김연정
    • Archives of design research
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    • v.17 no.3
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    • pp.255-262
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    • 2004
  • The history of design has been closely related with the development of technology. The digital revolution requires design to be as innovative and inventive as the Industrial Revolution had been. In the current society demanding innovation and a new role for design, a successful result can be obtained in the interrelationship between digital and physical environments. In this point of view, exhibition design as a part of space design has had the method of analogue virtual reality, which induces spectators' experiences by creating a virtual environment, as its main expression means before digital technology was introduced. This method was developed from plane images or models to picture techniques according to the development of media technology. Nowadays, the exhibition method introducing multimedia, which enables interactions, is being developed. The main purpose of this study is to identify the meaning and role of virtual space in the view of space design and to analyze its functional interaction. Through this, it attempts to actively promote organic integration and development of widely used cyber space and traditional space design.

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Improved BVP Candidate Selection Algorithm for HEVC Screen Content Coding (HEVC기반 스크린 콘텐츠 코딩을 위한 개선된 BVP 후보 선정 방법)

  • Kim, Yu-Seon;Lee, Si-Woong
    • The Journal of the Korea Contents Association
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    • v.17 no.5
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    • pp.1-7
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    • 2017
  • Joint Collaborative Team on Video Coding (JCT-VC) of ISO/IEC MPEG and ITU-T developed the HEVC Screen Content Coding (HEVC SCC) standard as the HEVC extension for the screen content video coding. The Intra Block Copy (IBC) is the most effective tool adopted in HEVC SCC and predicts current block from already reconstructed neighboring blocks in the same picture. To reduce the amount of data in BV (Block Vector) to be transmitted, a BV predictor (BVP) is used to generate the BV differences in the IBC BV coding. In this paper, we analyze the current BV prediction process using HEVC reference software SCM-2.0 and SCM-4.0. Based on the analysis results, we propose an improved BVP candidate selection algorithm by adding a search process for adjacent BVs in addition to the existing spatial BVP candidates. Experimental results show that the BD-rate reduction of our proposed improvements ranges from 0.2% to 1%.

A Study on Integration Strategies for e-Government and GIS in Korea (전자정부 구현을 위한 GIS 연계방안 연구)

  • Kim Eun-Hyung
    • Spatial Information Research
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    • v.13 no.3 s.34
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    • pp.261-281
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    • 2005
  • Geospatial information and technologies are considered as a fundamental element in the foreign advanced e-governments. Integration of e-Government and GIS technology should be an important task for the Korean e-government. Purpose of this study is to propose integration strategies for Korean e-Government and National GIS projects in a GIS perspective. For the successful integration this study analyzes the evolutional stages of e-Government and changes of GIS paradigms in a more comprehensive way. This study hypothesizes that integration of e-Government and GIS can create greater synergic effects fur the improved citizen services and increased efficiency of governmental administration. To verify the hypothesis, cases of advanced e-Governments in the foreign countries and progress of the Korean e-Government projects are compared and integration strategies are suggested. The strategies are as follows: expanded integration of geospatial and text-based information in e-Government for the greater synergic effects, implementation of GIS portal for e-Government, and development of a variety of geospatial information services for easy access and public participation. Most importantly, innovation of the institutional environments can be considered as an essential requirement to enhance and broaden interdepartmental partnerships. To realize the integration strategies suggested, this study presented the future projects under the following 5 topics: 'service', 'integration of information', 'technology', 'organization' and 'infrastructure for integration'. It is expected that results of this study can contribute to the bigger picture of Korean e-Government and the third National GIS master plan in 2006.

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