• Title/Summary/Keyword: Focus 값

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A Study on Create Depth Map using Focus/Defocus in single frame (단일 프레임 영상에서 초점을 이용한 깊이정보 생성에 관한 연구)

  • Han, Hyeon-Ho;Lee, Gang-Seong;Lee, Sang-Hun
    • Journal of Digital Convergence
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    • v.10 no.4
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    • pp.191-197
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    • 2012
  • In this paper we present creating 3D image from 2D image by extract initial depth values calculated from focal values. The initial depth values are created by using the extracted focal information, which is calculated by the comparison of original image and Gaussian filtered image. This initial depth information is allocated to the object segments obtained from normalized cut technique. Then the depth of the objects are corrected to the average of depth values in the objects so that the single object can have the same depth. The generated depth is used to convert to 3D image using DIBR(Depth Image Based Rendering) and the generated 3D image is compared to the images generated by other techniques.

Optimization of optical focus of composition optical system by OSLO (합성광학계의 OSLO를 통한 optical focus의 최적화)

  • Kim, Dae Nyoun;Choi, Gei Hun
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.1
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    • pp.1-6
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    • 2000
  • This study was to calculate spot size, focus shift and optical focus by use of OSLO when 3 wavelength, ${\omega}{\upsilon}_1=0.588{\mu}$, ${\omega}{\upsilon}_2=0.486{\mu}$ and ${\omega}{\upsilon}_3=0.656{\mu}$ in composite lens optics system & ocular optical system were respectively here, Entrance Beam Radius(mm) 1 mm, Field angle(deg) 5.7296e-0.5 mm, Image Aperture 0.053055 mm, Exit Aperture 0.903711 mm, Reflective focal length 25.181544 mm, Petzval radius -19.21839 mm, n = 1.523. It was found that a range of spot size was 0.002 mm~0.07 mm when a range of back curvature radius was 1 mm~30 mm, and 0.0005 mm~0.002 mm when of it more than 50 mm. Focus shift, 50 mm a range 3 kinds of lens was small, and it saw that of all tendency was high up to 1 mm~15 mm and up to 25 mm beyond that limits, it was going down and then going up again, optical focus 100 mm lens was best and the value when optimization with this lens was $60{\pm}1mm$.

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Competition Analysis to Improve the Performance of Movie Box-Office Prediction (영화 매출 예측 성능 향상을 위한 경쟁 분석)

  • He, Guijia;Lee, Soowon
    • KIPS Transactions on Software and Data Engineering
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    • v.6 no.9
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    • pp.437-444
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    • 2017
  • Although many studies tried to predict movie revenues in the last decade, the main focus is still to learn an efficient forecast model to fit the box-office revenues. However, the previous works lack the analysis about why the prediction errors occur, and no method is proposed to reduce the errors. In this paper, we consider the prediction error comes from the competition between the movies that are released in the same period. Our purpose is to analyze the competition value for a movie and to predict how much it will be affected by other competitors so as to improve the performance of movie box-office prediction. In order to predict the competition value, firstly, we classify its sign (positive/negative) and compute the probability of positive sign and the probability of negative sign. Secondly, we forecast the competition value by regression under the condition that its sign is positive and negative respectively. And finally, we calculate the expectation of competition value based on the probabilities and values. With the predicted competition, we can adjust the primal predicted box-office. Our experimental results show that predictive competition can help improve the performance of the forecast.

Design and Implementation of Measuring Tool for the Degree of Focus on Real-Time Online Class (실시간 온라인 수업에서 수강자들의 집중력 측정 도구의 설계 및 구현)

  • Choi, Ji-Hoon;Cho, Dae-Soo
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2021.07a
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    • pp.565-566
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    • 2021
  • 최근 펜데믹으로 인하여 대부분의 교육 시스템은 비대면 수업을 통해 수업이 이루어지고 있다. 하지만 비대면 강좌는 대면 강좌와는 다르게 강의자가 수강자의 수업 상태를 파악하는데 제한이 있으며 강좌 수강 태도에 대하여 수강자를 평가하기가 어렵다. 본 논문에서는 비대면 강좌에서 사용할 수 있는 방법 중에서 실시간 화상 강의 수강자의 참여도 추정 시스템을 제안한다. 이 시스템은 기존의 화상 시스템에서 사용하는 장비를 이용하여 수강자의 얼굴, 동공 및 사용자 활동을 실시간으로 측정하여 이를 강의자에게 여러 카테고리 형태로 수업 참여도 측정값을 제공한다. 이를 통해 강의자가 수업 시 수강자들의 수업 참여 여부와 수업 평가 및 향후 수업 개선점을 확인할 수 있도록 한다.

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One dimensional inhomogeneous aperture modulation effects on the MTF of optical system II (일차원적 비균일 개구변조시 광학계의 최적상면 MTF에 미치는 영향)

  • 홍경희
    • Korean Journal of Optics and Photonics
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    • v.9 no.5
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    • pp.277-281
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    • 1998
  • One dimensional inhomogeneous aperture modulation effects on the MTF of optical system was investigated. The lens under test was a doublet made in Korea. It has 10 mm effective diameter, 87.8 mm effective focal length. The ray-fans and spot diagrams were calculated and presented on the picture for on-axis and off-axis (field of view, $1^{\circ}$ and $2^{\circ}$). Aperture modulation was carried out by positioning a aperture modulator close contacter with the lens under test. We bought two modulators from Edmud Company in U.S.A. One was linear type and the other was stepped type. The MTFs were measured on the best of focus for each modulated aperture where the MTF has the highest value for 60 line/mm and were compared with one another. For on-axis, the MTFs of some modulated apertures had higher values than the MTF of unmodulated aperture in the high frequency region. In the case of off-axis, at the field of view $1^{\circ}$, the MTF values of some modulated aperture are improved prominently and some other one are disimproved. At the field of view $2^{\circ}$ most of the MTFs of modulated apertures had lower values than the MTF of unmodulated aperture except the MTFs of linear and inverse linear type aperture in the high frequency area. But the values of MTFs in high frequency region were too low for actual use.

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Fabrication of the Plasma Focus Device for Advanced Lithography Light Source and Its Electro Optical Characteristics in Argon Arc Plasma (차세대 리소그래피 빛샘 발생을 위한 플라스마 집속 장치의 제작과 아르곤 아크 플라스마의 발생에 따른 회로 분석 및 전기 광학적 특성 연구)

  • Lee S.B.;Moon M.W.;Oh P.Y.;Song K.B.;Lim J.E.;Hong Y.J.;Yi W.J.;Choi E.H.
    • Journal of the Korean Vacuum Society
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    • v.15 no.4
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    • pp.380-386
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    • 2006
  • In this study, we had designed and fabricated the plasma focus device which can generate the light source for EUV(Extreme Ultra Violet) lithography. And we also have investigated the basic electrical characteristics of currents, voltages, resistance and inductance of this system. Voltage and current signals were measured by C-dot and B-dot probe, respectively. We applied various voltages of 1.5, 2, 2.5 and 3 kV to the anode electrode and observed voltages and current signals in accordance with various Ar pressures of 1 mTorr to 100 Torr in diode chamber. It is observed that the peak values of voltage and current signals were measured at 300 mTorr, where the inductance and impedance were also estimated to be 73 nH and $35 m{\Omega}$ respectively. The electron temperature has been shown to be 13000 K at the diode voltage of 2.5 kV and this gas pressure of 300 mTorr. It is also found that the ion density Ni and ionization rate 0 have been shown to be $N_i = 8.25{\times}10^{15}/cc$ and ${\delta}$= 77.8%, respectively by optical emission spectroscopy from assumption of local thermodynamic equilibrium(LTE) plasma.

Reproducing Summarized Video Contents based on Camera Framing and Focus

  • Hyung Lee;E-Jung Choi
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.10
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    • pp.85-92
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    • 2023
  • In this paper, we propose a method for automatically generating story-based abbreviated summaries from long-form dramas and movies. From the shooting stage, the basic premise was to compose a frame with illusion of depth considering the golden division as well as focus on the object of interest to focus the viewer's attention in terms of content delivery. To consider how to extract the appropriate frames for this purpose, we utilized elemental techniques that have been utilized in previous work on scene and shot detection, as well as work on identifying focus-related blur. After converting the videos shared on YouTube to frame-by-frame, we divided them into a entire frame and three partial regions for feature extraction, and calculated the results of applying Laplacian operator and FFT to each region to choose the FFT with relative consistency and robustness. By comparing the calculated values for the entire frame with the calculated values for the three regions, the target frames were selected based on the condition that relatively sharp regions could be identified. Based on the selected results, the final frames were extracted by combining the results of an offline change point detection method to ensure the continuity of the frames within the shot, and an edit decision list was constructed to produce an abbreviated summary of 62.77% of the footage with F1-Score of 75.9%

Efficient Distributed Conference Architecture in SIP Environment (SIP 환경에서의 효율적인 분산형 컨퍼런스 구조)

  • Jo, Hyun-Gyu;Lee, Ki-Soo;Jang, Choon-Seo
    • The Journal of the Korea Contents Association
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    • v.8 no.5
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    • pp.1-8
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    • 2008
  • The centralized conference architecture, one of the conference architectures in SIP(Session Initiation Protocol) environment, is widely used as it has the advantage of conference management and control. However it has been limited in scalability. Therefore we have proposed an efficient distributed conference architecture to improve scalability of centralized conference model. In our architecture, if the number of conference participants exceeds the predefined maximum number, a new conference server is added to the conference dynamically. In this case, the focus of existing server acts as primary focus and the focus of added server acts as secondary focus, and dynamic reallocation of participants between servers is done to equally divide the loads. This process is repeated as the number of conference participants increases. For this behavior, we have proposed procedure of adding the conference server, SIP call signal exchange, signaling procedure for RTP(Real Time Transport Protocol) sessions between conference servers, and procedure of conference event package between conference servers. The performance of our proposed model is evaluated by experiments.

Historical Sensor Data Management Using Temporal Information (센서 데이터의 시간 정보를 이용한 이력 정보 관리)

  • Lee, Yang-Koo;Ryu, Keun-Ho
    • Journal of Korea Spatial Information System Society
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    • v.10 no.4
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    • pp.97-102
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    • 2008
  • A wireless sensor network consists of many sensors that collect and transmit physical or environmental conditions at different locations to a server continuously. Many researches mainly focus on processing continuous queries on real-time data stream. However, they do not concern the problem of storing the historical data, which is mandatory to the historical queries. In this paper, we propose two time-based storage methods to store the sensor data stream and reduce the managed tuples without any loss of information, which lead to the improvement of the accuracy of query results.

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Cramér-Rao Lower Bound (CRLB) Analysis for Unmanned Aerial Vehicle (UAV) Tracking with Randomly Distributed Ground Stations Using FDOA Measurements (다수의 지상국(GS)을 이용한 무인 항공기(UAV) 추적 FDOA 기반의 CRLB 성능 분석 연구)

  • Min, Byoung-Yoon;An, Chan-Ho;Hong, Seok-Jun;Jang, Jeen-Sang;Kim, Dong-Ku
    • Journal of Advanced Navigation Technology
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    • v.15 no.2
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    • pp.234-240
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    • 2011
  • In this paper, the performances of Cram$\acute{e}$r-Rao Lower Bound (CRLB) with Frequency Difference of Arrival (FDOA) measurements for Unmanned Aerial Vehicle (UAV) tracking are investigated. We focus on two cases: the influence on CRLB with FDOA measurements collected by time, and random distribution of Ground Stations (GSs). We derived the performance by gauging the size of CRLB through Complementary Cumulative Distribution Function (CCDF). From the simulation results, broader distribution of GSs and FDOA measurements by longer time bring about better performance.