• Title/Summary/Keyword: Gamma 보정

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People Detection based HOG-LBP using Various Gamma Correction (다양한 Gamma 보정을 이용한 HOG-LBP 기반 사람검출)

  • Ko, Jung-Sob;Lee, Chul-Hee
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.05a
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    • pp.639-641
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    • 2012
  • People detection using HOG linear SVM classification has been successfully applied. Also, HOG combined with LBP, which reflects texture informations, shows improved performance. In this paper, we analyze various gamma correction methods. We also analyze results obtained using HOG+LBP methods.

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A CMOS Image Sensor with Analog Gamma Correction using a Nonlinear Single Slope ADC (비선형 단일 기울기 ADC를 사용하여 아날로그 감마 보정을 적용한 CMOS 이미지 센서)

  • Ham Seog-Heon;Han Gunhee
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.1 s.343
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    • pp.65-70
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    • 2006
  • An image sensor has limited dynamic range while the human eye has logarithmic response over wide range of light intensity. Although the sensor gain can be set high to identify details in darker area on the image, this results in saturation in brighter area. The gamma correction is essential to fit the human eye response. However, the digital gamma correction degrades image quality especially for darker area on the image due to the limited ADC resolution and the dynamic range. This Paper proposes a CMOS image sensor (CIS) with a nonlinear analog-to-digital converter (AU) which performs analog gamma correction. The CIS with the proposed nonlinear analog-to-digital conversion scheme was fabricated with a $0.35{\mu}m$ CMOS process. The analog gamma correction using the proposed nonlinear ADC CIS provides the 2.2dB peak-signal-to-noise-ratio(PSM) improved image qualify than conventional digital gamma correction. The PSNR of the image obtain from the digital gamma correction is 25.6dB while it is 27.8dB for analog gamma correction. The PSNR improvement over digital gamma correction is about $28.8\%$.

Determination of Attenuation Collection Methods According to the Type of Radioactive Waste Drums (방사성폐기물드럼 종류별 감쇠보정방법의 결정)

  • Kwak, Sang-Soo;Choi, Byung-I1;Yoon, Suk-Jung;Lee, Ik-Whan;Kang, Duck-Won;Sung, Ki-Bang
    • Journal of Radiation Protection and Research
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    • v.22 no.4
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    • pp.309-317
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    • 1997
  • The measured radioactivity of gamma-emitting radionuclides in each radioactive waste drum using the non-destructive waste assay method is underestimated than real radioactivity in radioactive waste drum because the gamma-rays are attenuated within the medium. Therefore, the measured radioactivity should be corrected for the attenuation of gamma-rays. For the correction of the attenuation of gamma-rays, the attenuation correction method should be applied differently by considering the distribution and density of medium in radioactive wastes drum generated from nuclear power plants. In this study, the model drums were fabricated for simulating five types of radioactive waste drums generated from nuclear power plant and the optimum methods of the attenuation correction were experimentally determined to analyze the activity of radionuclides in the waste drum accurately using the segmented gamma scanning system. With the determination of the attenuation correction methods from the experimental results the transmission method and the average density method for the miscellaneous waste drum, the transmission method and the differential peak absorption method for the shielded miscellaneous waste drum were used to measure the density of medium in waste drums. Also, the average density method and the differential peak absorption method for the spent resin drum, the paraffin solidified drum, and the spent filter drum were used.

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Shadow Reconstruction Based on Intrinsic Image and Multi-Scale Gamma Correction for Aerial Image Analysis (항공 영상 분석을 위한 고유영상과 멀티 스케일 감마 보정 기반의 그림자 복원)

  • Park, Ki-hong
    • Journal of Advanced Navigation Technology
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    • v.23 no.5
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    • pp.400-407
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    • 2019
  • In this paper, the shadow detection and reconstruction method are proposed using intrinsic image, which does not change the essential characteristics under the influence of various illuminance, and multi-scale gamma correction. The shadow detection was estimated by the pixel change information between a grayscale and an intrinsic image of the color image, and the brightness of the image were adjusted by gamma correction in the shadow restoration process. Multi-scale gamma correction is performed for each channel of a color image due to the fact that the saturation can be changed by nonlinear adjustment to individual pixel values. Multi-scale gamma values are estimated based on the information of the crossed edge between shadows and non-shadowed regions in the color image, as a result, the shadows are reconstructed by correcting different region features with multi-scale gamma values. Experimental results show that the proposed method effectively reconstructs shadows in a single natural image.

A Comparative Study of Density Compensation in Gamma-Gamma Log in PVC Casings between above and below Ground Water Tables (지하수면 상.하부 환경에서의 PVC 케이싱 이격보정 비교 연구)

  • Kim, Yeong-Hwa;Hwang, Byong-Chol;Park, Sung-Geun;Kim, Jong-Man
    • The Journal of Engineering Geology
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    • v.19 no.2
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    • pp.217-225
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    • 2009
  • A series of model borehole experiments and analyses for density compensation were performed to achieve the effective density correction of gamma-gamma log obtained from PVC cased boreholes. A follow-up survey was made for clarifying the variation property of detector responses depending on casing types, the presence of borehole fluid, and the degree of separation between probe and borehole wall. A special emphasis was placed on the comparison of gamma responses obtained from above and below ground water tables. Finally, we could quantify the detector responses as a function of separation between the probe and borehole wall, construct standoff compensation charts, and the limitations of the compensation have been discussed for the environments of both above and below ground water tables.

Spine and Ribs Techniques for Practical use of Standoff Compensation in a Density Log (밀도검층 이격보정 실용화를 위한 Spine and Ribs 기법 연구)

  • Han, Manho;Kim, Yeonghwa;Yi, Myeong-Jong;Kim, Jongman
    • Economic and Environmental Geology
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    • v.51 no.1
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    • pp.39-48
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    • 2018
  • We carried out the standoff compensation data from 2007 to 2011 into four different density borehole models to find out the most effectiveness of standoff compensation charts. First, we investigated the irregular collapse characteristics of gamma ray and cut the non-ideal gamma response to improve the effectiveness of the standoff compensation error data. Effectiveness of detector combinations, density of borehole, and spine and ribs techniques from the modified standoff compensation data was analyzed. As the result of comparison, LSD-MSD combination has been suitable for standoff compensation more than LSD-SSD combination and it is possible to do standoff compensation for soil or weathered zone under groundwater level without fatal errors. Even though error scales of density transformed spine and ribs techniques were generally large compared to the conventional standoff compensation, standoff compensation for soil and weathered zone under groundwater level were sufficiently effective.

A Preliminary Study on Correction for Density Log in Cased Boreholes (케이싱 환경에서의 밀도자료 보정을 위한 기초연구)

  • Kim, Yeong-Hwa;Kim, Ji-Hoon;Lee, Seung-Jin
    • The Journal of Engineering Geology
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    • v.16 no.4 s.50
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    • pp.429-435
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    • 2006
  • A preliminary study was made for density correction for the effect of separation between sonde and borehole wall due to the existence of casing in a borehole. Firstly, series of gamma-gamma measurements were obtained with 3 different separations in 3 different density models constructed in Kangwon National University. Secondly, density correction charts were made based on the 'spine and ribs' technique in mud cake correction. Using these charts, we could determine effectively the true density from the measurement in the thinly cased borehole.

Study of the Radioactive Source Detection and the Visualization with the Stereo Radiation Detector (스테레오 기반 감마선원 탐지 및 가시화에 관한 연구)

  • Park, Gang-teak;Lee, Nam-ho;Cha, Han-ju
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.1100-1102
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    • 2015
  • In the study, stereo-based of gamma-ray sources detector for the space including the gamma-ray source to scan in a raster scan method, and obtains a visible light image and the gamma-ray image. We went to retrieve and visualize the distance to source and the direction of the 3-dimension information from Stereo gamma-ray detectors. Configuration of the detector consisted of gamma-ray detecting sensor for gamma-ray Sources, pan-tilt for the scanning of the raster for detecting sources, and CCD camera for visible-light image. Implement a stereo structure of the device to measure the spatial distribution of source, the gamma-ray Detector and CCD camera for the stereo image acquisition was as each configuration 2. The gamma-ray detector and a visible light camera to revision the distribution of detection source, After performing each of the cameras of the stereo correction and shows the distribution of the gamma-ray Sources through 중첩 visible light image and the gamma-ray image. After Rectification process of Left and right image, we were derived visualization results of the stereo image.

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Construction of calibration models and calibrating experiment for efficient Held application of density log (밀도검층의 효과적인 현장 적용을 위한 모형 보정공 건설과 밀도 보정 기초연구)

  • Kim Ji-hoon;Kong Nam-young;Zhao Weijun;Kim Yeong-hwa
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.09a
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    • pp.73-82
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    • 2005
  • We constructed a series of calibration models in the campus of Kangwon National University. A series of experiment for calibrating sonde response as well as casing effect in field measurement. Here we explained the process of construction of calibrating facility which consists of three model holes of different density and three model holes of different diameter. It was discussed the calibration equations obtained from its sonde response calibration test. A density correction chart for different separation of detector from hole wall was suggested, and verified the possibility of determining true density from measurements in cased hole.

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A Study on FPGA Design for Rotating LED Display Available Video Output (동영상 표출이 가능한 회전 LED 전광판을 위한 FPGA 설계에 관한 연구)

  • Lim, Young-Sik;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.19 no.2
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    • pp.168-175
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    • 2015
  • In this paper, we propose FPGA design technique for rotating LED display device which is capable of displaying videos with the use of the afterimage effect. The proposed technique is made up of image data correction process based on inverse gamma correction and error diffusion, block interleaving process, and data serial output process. The data correction process based on inverse gamma correction and error diffusion is an image data correction step in which image data received are corrected by inverse gamma correction process to convert the data into linear brightness characteristics, and by error diffusion process to reduce the brightness reduction phenomenon in low-gray-level which is caused by inverse gamma correction. In the block interleaving process, the data of the frames entered transversely are first saved in accordance with entrance order, and then only the longitudinal image data are read. The data serial output process is applied to convert the parallel data in a rotating location into serial data and send them to LED Driver IC, in order to send data which will be displayed on high-speedy rotating LED Bar. To evaluate the accuracy of the proposed FPGA design technique, this paper used XC6SLX45-FG484, a Spartan 6 family of Xilinx, as FPGA, and ISE 14.5 as a design tool. According to the evaluation analysis, it was found that goal values were consistent with simulation values in terms of accurate operation of inverse gamma and error diffusion correction, block interleaving operation, and serialized operation of image data.