• Title/Summary/Keyword: Contrast Scale

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Face Recognition Robust to Brightness, Contrast, Scale, Rotation and Translation (밝기, 명암도, 크기, 회전, 위치 변화에 강인한 얼굴 인식)

  • 이형지;정재호
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.6
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    • pp.149-156
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    • 2003
  • This paper proposes a face recognition method based on modified Otsu binarization, Hu moment and linear discriminant analysis (LDA). Proposed method is robust to brightness, contrast, scale, rotation, and translation changes. Modified Otsu binarization can make binary images that have the invariant characteristic in brightness and contrast changes. From edge and multi-level binary images obtained by the threshold method, we compute the 17 dimensional Hu moment and then extract feature vector using LDA algorithm. Especially, our face recognition system is robust to scale, rotation, and translation changes because of using Hu moment. Experimental results showed that our method had almost a superior performance compared with the conventional well-known principal component analysis (PCA) and the method combined PCA and LDA in the perspective of brightness, contrast, scale, rotation, and translation changes with Olivetti Research Laboratory (ORL) database and the AR database.

A Study of the Differing Images of Wearers according to Differences of Chroma Contrast Coloration and Stripe Patterns (채도 콘트라스트 배색과 스트라이프 무의 변화에 따른 의복착용자의 이미지 연구)

  • Moon, Ju-Young
    • Journal of the Korean Society of Costume
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    • v.60 no.1
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    • pp.28-42
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    • 2010
  • A purpose of this study is to 6nd out how the casual and formal style clothes of stripe pattern giving variety by pattern direction, pattern width, and contrast coloration have an effect on image of wearers. For this, 192 stimuli were made and 1200 testee evaluated them using semantic differential scale. As a result, five image dimensions were drawn as a factor of attractiveness, gracefulness, activeness, visibility, and tenderness. Unlike the value contrast previously researched, it showed that chroma contrast coloration which was interacted with a color tone contrast coloration had an effect on all the 5 image dimensions. This result was recognized as significant clothes dues in evaluating the image of stripe wearers. Besides, clothing style, stripe pattern, and contrast coloration were made clear as an efficient parameter in image presentation of clothing wearers.

An Adaptive Dynamic Range Linear Stretching Method for Contrast Enhancement (영상 강조를 위한 Adaptive Dynamic Range Linear Stretching 기법)

  • Kim, Yong-Min;Choi, Jae-Wan;Kim, Yong-Il
    • Korean Journal of Remote Sensing
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    • v.26 no.4
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    • pp.395-401
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    • 2010
  • Image enhancement algorithm aims to improve the visual quality of low contrast image through eliminating the noise and blurring, increasing contrast, and raising detail. This paper proposes adaptive dynamic range linear stretching(ADRLS) algorithm based on advantages of existing methods. ADRLS method is focused on generating sub-histograms of the majority through partitioning the histogram of input image and applying adaptive scale factor. Generated sub-histograms are finally applied by linear stretching(LS) algorithm. In order to validate proposed method, it is compared with LS and histogram equalization(HE) algorithm generally used. As the result, the proposed method show to improve contrast of input image and to preserve distinct characteristics of histogram by controlling excessive change of brightness.

The Study of the Image and Positioning according to Stripe Pattern and Clothing Style (스트라이프 문양과 의복스타일에 따른 이미지 차이와 포지셔닝 연구)

  • Moon, Ju-Young
    • The Korean Fashion and Textile Research Journal
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    • v.12 no.1
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    • pp.1-9
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    • 2010
  • A purpose of this study was to find out how the casual and formal style clothes of stripe pattern giving variety by pattern direction, pattern width, and contrast coloration have an effect on image of wearers. 432 stimuli were made and 2,800 testee evaluated them using semantic differential scale. As a result, five image dimensions were drawn as a factor of attractiveness, activeness, gracefulness, visibility, and tenderness. In consequence of analysing the image difference by stripe pattern and clothing style, the stripe pattern and clothing style affect image presentation as a significant clue. And besides, as a result of positioning stimuli by image, pattern direction, coloration, and tone combination were important clues that decide image. Consequently, clothing style, stripe pattern, and contrast coloration were made clear as an efficient parameter in image presentation of clothing wearers.

Enhancement of Image Contrast in Linacgram through Image Processing (전산처리를 통한 Linacgram의 화질개선)

  • Suh, Hyun-Suk;Shin, Hyun-Kyo;Lee, Re-Na
    • Radiation Oncology Journal
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    • v.18 no.4
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    • pp.345-354
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    • 2000
  • Purpose : Conventional radiation therapy Portal images gives low contrast images. The purpose of this study was to enhance image contrast of a linacgram by developing a low-cost image processing method. Materials and Methods : Chest linacgram was obtained by irradiating humanoid Phantom and scanned using Diagnostic-Pro scanner for image processing. Several types of scan method were used in scanning. These include optical density scan, histogram equalized scan, linear histogram based scan, linear histogram independent scan, linear optical density scan, logarithmic scan, and power square root scan. The histogram distribution of the scanned images were plotted and the ranges of the gray scale were compared among various scan types. The scanned images were then transformed to the gray window by pallette fitting method and the contrast of the reprocessed portal images were evaluated for image improvement. Portal images of patients were also taken at various anatomic sites and the images were processed by Gray Scale Expansion (GSE) method. The patient images were analyzed to examine the feasibility of using the GSE technique in clinic. Results :The histogram distribution showed that minimum and maximum gray scale ranges of 3192 and 21940 were obtained when the image was scanned using logarithmic method and square root method, respectively. Out of 256 gray scale, only 7 to 30$\%$ of the steps were used. After expanding the gray scale to full range, contrast of the portal images were improved. Experiment peformed with patient image showed that improved identification of organs were achieved by GSE in portal images of knee joint, head and neck, lung, and pelvis. Conclusion :Phantom study demonstrated that the GSE technique improved image contrast of a linacgram. This indicates that the decrease in image quality resulting from the dual exposure, could be improved by expanding the gray scale. As a result, the improved technique will make it possible to compare the digitally reconstructed radiographs (DRR) and simulation image for evaluating the patient positioning error.

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The improved contrast control method for LCD monitor

  • Kwon, Byong-Heon;Park, Myung-Ryul;Youn, Jin-Suk
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1811-1814
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    • 2002
  • In this paper, we propose an improved contrast control method f9r image improvement of multi-gray scale image. The proposed contrast control method can improve contrast of image by changing gradient of weight as the type of input image. In addition, the proposed method does not require field and frame memory for large amount of computed data. And, the proposed method can be easily applied to the FPD fur real-time processing because of its less hardware complexity than that of the conventional methods. Also it can flexibly control the contrast of input gray level by varying the weight values that control the contrast range. The operation and performance of the proposed controller have been verified using computer simulation.

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Measuring the matter energy density and Hubble parameter from Large Scale Structure

  • Lee, Seokcheon
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.57.1-57.1
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    • 2013
  • We investigate the method to measure both the present value of the matter energy density contrast and the Hubble parameter directly from the measurement of the linear growth rate which is obtained from the large scale structure of the Universe. From this method, one can obtain the value of the nuisance cosmological parameter $\Omo$ (the present value of the matter energy density contrast) within 3% error if the growth rate measurement can be reached $z >3.5$. One can also investigate the evolution of the Hubble parameter without any prior on the value of $H_0$ (the current value of the Hubble parameter). Especially, estimating the Hubble parameter are insensitive to the errors on the measurement of the normalized growth rate $f \sigma_8$. However, this method requires the high $z$ ($z >3.5$) measurement of the growth rate in order to get the less than 5% errors on the measurements of $H(z)$ at $z \leq 1.2$ with the redshift bin $\Delta z = 0.2$. Thus, this will be suitable for the next generation large scale structure galaxy surveys like WFMOS and LSST.

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Compensation of Correlated Color Temperature of Gray Scale in LCD (LCD의 Gray Scale 상관 색온도 보정)

  • 구병준;이상훈;정재영;한찬호;이건일;송규익
    • Proceedings of the IEEK Conference
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    • 2000.09a
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    • pp.705-708
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    • 2000
  • 일반적인 LCD의 색 재현 특성은 입력 디지털 값이 낮을수록 gray scale의 상관색온도가 상승하여 정확한 색 재현이 불가능하다. 본 논문에서는 LCD의 입력 디지털 값의 변화에 따른 특성을 조사하고, luminance, contrast 비 등의 특성에 열화없이 gray scale의 입력 잘 변화에 따른 상관색온도의 변화를 보정하기 위해서 입력 디지털 값을 조정하는 새로운 LUT를 제안하였다.

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The Image of the Stripe Clothes according to Value Contrast Coloration (명도 콘트라스트 배색에 따른 스트라이프 의복 착용자의 이미지 연구)

  • Moon, Ju-Young;Kang, Kyung-Ja
    • The Research Journal of the Costume Culture
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    • v.16 no.6
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    • pp.992-1007
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    • 2008
  • This study was meant to offer the data for predicting the product plan answering the diverse demands for consumers based on the results of analyzing the image and formative property by transforming the stripe patterns. The concrete study way is composed of the collected stimulus centering on the interval of the stripe pattern and value contrast coloration. Consequently 192 stimuli, changed by the pattern direction and pattern interval, clothing style, and contrast coloration, are selected. The experimental materials made for this study are a set of stimuli and response scale. The statistics way used in analysis was factor analysis, ANOVA, dispersion analysis, multiple classification analysis. The results of this study were summed as following. Firstly, In the value contrast, a pair of 27 adjectives were made of attractiveness, activeness, gracefulness, visibility, and tenderness dimension. Secondly, the direction of the pattern, interval, clothing style, and contrast coloration were respectively transformed according to value contrast.

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