• Title/Summary/Keyword: 초점정합

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Precise Rectification of Misaligned Stereo Images for 3D Image Generation (입체영상 제작을 위한 비정렬 스테레오 영상의 정밀편위수정)

  • Kim, Jae-In;Kim, Tae-Jung
    • Journal of Broadcast Engineering
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    • v.17 no.2
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    • pp.411-421
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    • 2012
  • The stagnant growth in 3D market due to 3D movie contents shortage is encouraging development of techniques for production cost reduction. Elimination of vertical disparity generated during image acquisition requires heaviest time and effort in the whole stereoscopic film-making process. This matter is directly related to competitiveness in the market and is being dealt with as a very important task. The removal of vertical disparity, i.e. image rectification has been treated for a long time in the photogrammetry field. While computer vision methods are focused on fast processing and automation, photogrammetry methods on accuracy and precision. However, photogrammetric approaches have not been tried for the 3D film-making. In this paper, proposed is a photogrammetry-based rectification algorithm that enable to eliminate the vertical disparity precisely by reconstruction of geometric relationship at the time of shooting. Evaluation of proposed algorithm was carried out by comparing the performance with two existing computer vision algorithms. The epipolar constraint satisfaction, epipolar line accuracy and vertical disparity of result images were tested. As a result, the proposed algorithm showed excellent performance than the other algorithms in term of accuracy and precision, and also revealed robustness about position error of tie-points.

Automatic Registration between Multiple IR Images Using Simple Pre-processing Method and Modified Local Features Extraction Algorithm (단순 전처리 방법과 수정된 지역적 피쳐 추출기법을 이용한 다중 적외선영상 자동 기하보정)

  • Kim, Dae Sung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.6
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    • pp.485-494
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    • 2017
  • This study focuses on automatic image registration between multiple IR images using simple preprocessing method and modified local feature extraction algorithm. The input images were preprocessed by using the median and absolute value after histogram equalization, and it could be effectively applied to reduce the brightness difference value between images by applying the similarity of extracted features to the concept of angle instead of distance. The results were evaluated using visual and inverse RMSE methods. The features that could not be achieved by the existing local feature extraction technique showed high image matching reliability and application convenience. It is expected that this method can be used as one of the automatic registration methods between multi-sensor images under specific conditions.

Convergence of Broadcasting and Communication in Home Network using E-PON based Home Gateway (EPON 기반 홈게이트웨이를 이용한 댁내 망에서의 방송통신 융합 서비스)

  • Park Wanki;Kim Daeyoung
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.6 s.336
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    • pp.9-16
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    • 2005
  • In this paper, we focus on supporting the convergence of broadcasting and communication in home network systems with E-PON based home gateway. We propose a new architecture to provide broadcasting and data services in integrated home network using overlay transport mechanism in access network and If multicast techniques of IGMP and IGMP snooping in home network. We also detail a set of mechanisms and procedures for home broadcasting service through the home gateway system. Our new scheme is composed of three parts: a) an overlay transmission model of video broadcasting signals (satellite and/or cable TV) and Internet data, b) to select a specific video broadcasting channel and to make of the selected video broadcasting stream into IP multicast packets in tuner/conversion module using multiple tuner system and c) to transfer the converted If multicast packets to L2 switch of home gateway's core module and to send them out to target port(s) by L2 multicast using IGMP snooping.

Augmented Reality Using Projective Information (비유클리드공간 정보를 사용하는 증강현실)

  • 서용덕;홍기상
    • Journal of Broadcast Engineering
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    • v.4 no.2
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    • pp.87-102
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    • 1999
  • We propose an algorithm for augmenting a real video sequence with views of graphics ojbects without metric calibration of the video camera by representing the motion of the video camera in projective space. We define a virtual camera, through which views of graphics objects are generated. attached to the real camera by specifying image locations of the world coordinate system of the virtual world. The virtual camera is decomposed into calibration and motion components in order to make full use of graphics tools. The projective motion of the real camera recovered from image matches has a function of transferring the virtual camera and makes the virtual camera move according to the motion of the real camera. The virtual camera also follows the change of the internal parameters of the real camera. This paper shows theoretical and experimental results of our application of non-metric vision to augmented reality.

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Interactive VFX System for TV Virtual Studio (TV 가상 스튜디오용 인터랙티브 VFX 시스템)

  • Byun, Hae Won
    • Journal of the Korea Computer Graphics Society
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    • v.21 no.5
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    • pp.21-27
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    • 2015
  • In this paper, we presents visual effect(water, fire, smoke) simulation and interaction system for TV virtual studio. TV virtual studio seamlessly synthesizes CG background and a live performer standing on a TV green studio. Previous virtual studios focus on the registration of CG background and a performer in real world. In contrast to the previous systems, we can afford to make new types of TV scenes more easily by simulating interactive visual effects according to a performer. This requires the extraction of the performer motion to be transformed 3D vector field and simulate fluids by applying the vector field to Navier Stokes equation. To add realism to water VFX simulation and interaction, we also simulate the dynamic behavior of splashing fluids on the water surface. To provide real-time recording of TV programs, real-time VFX simulation and interaction is presented through a GPU programming. Experimental results show this system can be used practically for realizing water, fire, smoke VFX simulation and the dynamic behavior simulation of fish flocks inside ocean.

Design of the Parabolic Reflector Antenna with Bended Elliptical Conductor Plate Feed (절곡된 타원형 도체평판 급전부를 갖는 포물선 반사판 안테나 설계)

  • Kim, Byung-Mun;Yun, Li-Ho;Hong, Jae-Pyo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.6
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    • pp.989-996
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    • 2017
  • The proposed directional pencil beam antenna consists of a waveguide feeder with bended elliptical conductor plate feed and a parabolic curved reflector. Two rectangular apertures located at the broad wall near the end of the feed waveguide inserted from behind the reflector are located at the focus of the reflector and emit electromagnetic energy with bended elliptical conductor plate. This plate is designed to reflect electromagnetic energy primarily and to face the main reflector. The two rectangular apertures located at the waveguide end have inwardly protruding tabs for impedance matching of the antenna system, the shape of the tabs is a truncated oval. The proposed parabolic reflector antenna has a diameter of 400 mm and a focal length of 134.23 mm. The antenna gain is 33.68 dBi at the center frequency of 16.5 GHz, the beam width is $3.3^{\circ}$ and the reflection loss is -15 dB. Using the HFSS-IE, simulation results are performed to validate the proposed antennas.

Design of W-band Cascode Mixer with High Conversion Gain using 0.1-μm GaAs pHEMT Process (0.1-μm GaAs pHEMT 공정을 이용한 높은 변환이득을 가지는 W-대역 캐스코드 혼합기 설계)

  • Choe, Wonseok;Kim, HyeongJin;Kim, Wansik;Kim, Jongpil;Jeong, Jinho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.6
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    • pp.127-132
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    • 2018
  • In this paper, a high conversion gain cascode mixer was designed in W-band and verified by the fabrication and measurements. In the high frequency band such as a W-band, the conversion loss of a mixer is increased because of the poor performance of transistors. This high conversion loss of the mixer requires additional circuits which can give an extra gain such as an RF buffer amplifier, and this can affects the linearity and stability of the overall systems. Therefore, it is necessary to maximize the conversion gain of the mixer. To maximize the conversion gain of the mixer, biases of the transistor were optimized, and output load impedance was optimized by the load-pull simulations. The designed mixer was fabricated in $0.1-{\mu}m$ GaAs pHEMT technology and verified by the measurements. The measurement results shows a maximum conversion gain of -4.7 dB at W-band and an input 1-dB compression point of 2.5 dBm.

Signal-to-noise Ratio in Time- and Frequency-domain Photoacoustic Measurements by Different Frequency Filtering (주파수 필터링 함수에 따른 시간 및 주파수 영역 광음향 측정에 대한 신호 대 잡음비 분석)

  • Kang, DongYel
    • Korean Journal of Optics and Photonics
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    • v.30 no.2
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    • pp.48-58
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    • 2019
  • We investigate the signal-to-noise ratios (SNRs) of time-domain (i.e. pulsed illumination) and frequency-domain (i.e. chirped illumination) photoacoustic signals measured by a spherically focused ultrasound transducer for spherical absorbers. The simulation results show that the time-domain photoacoustic SNR is higher than that of frequency-domain photoacoustic signals, as reported in the previous literature. We understand the reason for this SNR gap between the two measurement modes by analyzing photoacoustic-signal spectra, considering the incident beam energy controlled by the maximum permissible exposure. As the result of this approach, we find that filtering off the DC term in the chirped signal's spectrum improves frequency-domain photoacoustic SNRs by up to approximately 5 dB. In particular, it is observed that photoacoustic SNRs are highly sensitive to an upper-frequency value of frequency filtering functions, and the optimal upper-frequency values maximizing the SNR are different in time- and frequency-domain photoacoustic measurements.

Custom Metadata Storage Method Using XMP (XMP를 이용한 커스텀 메타데이터 저장 방법)

  • Hyun, Chang-Jong;Kim, Dong-Ho
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.2
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    • pp.323-330
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    • 2019
  • Recently, as the growth of the Internet has led to a rapid increase in the consumption of multimedia such as photographs and moving images, the importance of metadata has been emphasized. In the case of existing metadata, only limited information such as GPS value or focal length according to the format is stored. However, with the development of mobile devices and multimedia acquisition devices, various sensors can be used in the devices. Therefore, this paper describes a method that can store not only the existing metadata format information at the time of multimedia acquisition but also another existing format of metadata such as information of various sensors which is the gyroscope and acceleration sensor of the device. We propose an application program that provides moving location information. The proposed method is expected to provide various applications such as image matching and effective image classification.

A study on Practical Countermeasures of Copyright Appraisal with the Amendment of Civil Procedure Act in 2016 (민사소송법 개정에 따른 저작권 감정 제도의 실무적 대응 방안)

  • Kim, Si Yeol
    • Journal of Software Assessment and Valuation
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    • v.16 no.1
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    • pp.1-11
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    • 2020
  • The March 29, 2016, amendment to the Civil Procedure Act introduced changes to the appraisal procedures, including new obligations for appraisers, changes in the modes of appraiser testimony, and questioning of appraisers through video conferencing, with all seemingly aimed at procedurally addressing the issues with appraisal in the context of court proceedings. The changes introduced by the amendment also affect the appraisal procedures for copyrights. In light of the above, this article examines how the amendment to the Civil Procedure Act affects the appraisal procedures for copyrights. Specific issues covered by this paper include: appointment of additional appraisers, prohibition of delegated appraisal, operation of the multiple appraisal system, disclosure of participating experts, proximity of the appraiser system, and congruence of areas of expertise.