• 제목/요약/키워드: color contrast

검색결과 802건 처리시간 0.03초

영상 선명화를 위한 개선된 Retinex 알고리즘 (Advanced Retinex Algorithm for Image Enhancement)

  • 차효상;홍성훈
    • 한국멀티미디어학회논문지
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    • 제16권1호
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    • pp.29-41
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    • 2013
  • 디지털 카메라는 제한된 크기의 다이내믹레인지를 갖는 이미지 센서의 한계로 인하여 인간의 눈으로 보는 것과 동일한 화질의 영상을 얻을 수 없기 때문에 이를 개선해야 할 필요성이 있다. 기존의 화질개선방법으로는 Land의 인간의 시각적 모델을 바탕으로 한 Retinex 알고리즘이 대표적이다. Retinex 알고리즘은 칼라의 일관성과 시각적인 개선을 제공하지만, 전역적인 contrast 감소와 후광효과 및 색왜곡 문제를 발생시키기도 한다. 이러한 문제를 개선하기 위해 본 논문에서는 YCbCr 색공간에서 휘도성분의 주파수성분에 대한 처리를 통해 전역적 contrast를 향상시키고, 색차성분에 대한 처리를 통해 칼라 선명도를 향상시키는 방법을 제안한다. 실험 결과영상의 비교를 통해 제안된 알고리즘이 기존의 알고리즘에 비해 연산량 감소효과가 뛰어나며 전역적 contrast 향상과 색상 보전 성능이 우수하고 후광효과를 효과적으로 제거함을 확인하였다.

중국 청대 복식에 사용된 색채에 관한 연구 (A Research on the Chinese Color through the Costume of Qing Dynasty)

  • 금기숙;정현
    • 복식
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    • 제54권4호
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    • pp.41-53
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    • 2004
  • The significant role of colors in fashion design is not enough to emphasize in terms of one of the important design elements and its influences on the behaviors of the people. The purpose of this research is to examine the traditional Chinese colors and its ways of color combinations to appreciate the Chinese culture and its people. The Chinese traditional costume of Ching Dynasty were investigated through historic records, historic nobles, costume accessories and so on. The results of the study were summarized as follows: (1) The Blue was the most favoured color for clothing among men and women during Ching dynasty and various blues in terms of hue, value and intensities were used. (2) The bright Yellow which had been a symbol of Emperor were prohibited being used among people. Though, the late period of Dynasty, the regulation became not to strict and various shades of yellow families were adapted among People. (3) The Red which had been preferred during Ming Dynasty were constantly favoured for the formal wears of auspicious events such as weddings. (4) Dark color groups were loved for the clothing which were used as a ground colors against the flamboyant patterns revealing strong visual effects through value contrast or primary color combinations. (5) The White had a symbol of mourning and there were some intentions to adopt pale color groups such as mint, jade, gray, moon whit,. silver white to make up for white. (6) Contrast color combinations were one of the basic ways of color combination in Chinese traditional costume. Therefore Chinese color combinations has a strong visual effect and easy to draw attention of people by the contrast of the hue, value or intensity of color. (7) Multi-color combinations were another characteristics of Chinese costume in the formal wears which bears many surface designs. The surface decorated with full of motifs, were appreciated by the people expressing their longings and hopes through the auspicious meanings of patterns and striking visual effects of color combinations.

어린이병원 방문자의 색채지각에 나타난 시각적 주의에 관한 연구 (A Study on Visual Attention on Color Perception by Visitors of Children's Hospital)

  • 조은길;손광호
    • 한국실내디자인학회논문집
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    • 제25권2호
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    • pp.50-58
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    • 2016
  • The design of children's hospitals is highly dependent on color schemes. As a space shared together by both adults and children, the design of children's hospitals require color coordination that takes account of the users' characteristics. Visual perception tracking experiment was conducted on the 2 chosen experimental images with a target group made up of adults and children, the following results were found. First, visual attention characteristics of spatial elements' colors were found. The contrast of colors were discovered to effect attention, especially the information desk region showed highest attention. Pillars are subjected to a higher attention relative to other spatial elements, it is suggested when using accent colors to use it only when it is absolutely necessary in partial areas. In contrast, floor patterns were found to be subjected to very low attention relative to other elements. Second, effects of color contrast on visual attention were uncovered. Although color contrast effects attention for both adults and children, children were found to be more effected by color contrast than adults. Especially, children's tendency to rely on color contrast for visual recognition was higher than adults. Since when using only one type on a wide surface children show higher attention on the < vivid > colors than adults, when planning a color coordination for children using < pale > colors instead of < vivid > ones in background for a large surface is seen as a more desired method to increase attention by putting emphasis on the [sharply contrasting] colors.

Improved Human Factors of Electroluminescent Displays using Optical Interference Effect

  • Krasnov, Alexey N.;Kim, Woo-Young
    • Journal of Information Display
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    • 제4권2호
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    • pp.7-12
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    • 2003
  • We discuss main techniques to improve legibility of electroluminescent displays. Emphasis is placed on use of destructive optical interference to cancel ambient light reflected from the back electrode of the device. Basic optical principles and material composition of the optical interference contrast-enhancing stack (CES) are presented. We also describe the improved human factors of electroluminescent devices assisted with a CES. Achromatic contrast is the most important contributor to display's legibility. In some conditions color contrast may also be important. Contributing to both luminance and color contrast enhancement, the contrast-enhancing stack may play an important role in various display applications.

Underwater image quality enhancement through Rayleigh-stretching and averaging image planes

  • Ghani, Ahmad Shahrizan Abdul;Isa, Nor Ashidi Mat
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제6권4호
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    • pp.840-866
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    • 2014
  • Visibility in underwater images is usually poor because of the attenuation of light in the water that causes low contrast and color variation. In this paper, a new approach for underwater image quality improvement is presented. The proposed method aims to improve underwater image contrast, increase image details, and reduce noise by applying a new method of using contrast stretching to produce two different images with different contrasts. The proposed method integrates the modification of the image histogram in two main color models, RGB and HSV. The histograms of the color channel in the RGB color model are modified and remapped to follow the Rayleigh distribution within certain ranges. The image is then converted to the HSV color model, and the S and V components are modified within a certain limit. Qualitative and quantitative analyses indicate that the proposed method outperforms other state-of-the-art methods in terms of contrast, details, and noise reduction. The image color also shows much improvement.

Prediction of successful caudal epidural injection using color Doppler ultrasonography in the paramedian sagittal oblique view of the lumbosacral spine

  • Yoo, Seon Woo;Ki, Min-Jong;Doo, A Ram;Woo, Cheol Jong;Kim, Ye Sull;Son, Ji-Seon
    • The Korean Journal of Pain
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    • 제34권3호
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    • pp.339-345
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    • 2021
  • Background: Ultrasound-guided caudal epidural injection (CEI) is limited in that it cannot confirm drug distribution at the target site without fluoroscopy. We hypothesized that visualization of solution flow through the inter-laminar space of the lumbosacral spine using color Doppler ultrasound alone would allow for confirmation of drug distribution. Therefore, we aimed to prospectively evaluate the usefulness of this method by comparing the color Doppler image in the paramedian sagittal oblique view of the lumbosacral spine (LS-PSOV) with the distribution of the contrast medium observed during fluoroscopy. Methods: Sixty-five patients received a 10-mL CEI of solution containing contrast medium under ultrasound guidance. During injection, flow was observed in the LSPSOV using color Doppler ultrasonography, following which it was confirmed using fluoroscopy. The presence of contrast image at L5-S1 on fluoroscopy was defined as "successful CEI." We then calculated prediction accuracy for successful CEI using color Doppler ultrasonography in the LS-PSOV. We also investigated the correlation between the distribution levels measured via color Doppler and fluoroscopy. Results: Prediction accuracy with color Doppler ultrasonography was 96.9%. The sensitivity, specificity, positive predictive value, and negative predictive value were 96.7%, 100%, 100%, and 60.0%, respectively. In 52 of 65 patients (80%), the highest level at which contrast image was observed was the same for both color Doppler ultrasonography and fluoroscopy. Conclusions: Our findings demonstrate that color Doppler ultrasonography in the LS-PSOV is a new method for determining whether a drug solution reaches the lumbosacral region (i.e., the main target level) without the need for fluoroscopy.

Image Enhancement Method by Saturation and Contrast Improvement

  • Park, Gyu-Hee;Cho, Hwa-Hyun;Yun, Jong-Ho;Choi, Myung-Ryul
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1139-1142
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    • 2007
  • In this paper, an image enhancement method by saturation and contrast improvement is proposed. Histogram equalization with color difference makes higher contrast. By generating saturation amplification ratio with color difference, the saturation improves effectively. The experimental results show that the proposed algorithm has higher contrast and more natural - look than the conventional methods.

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색의대비 기반 템플릿을 이용한 색상 변환 (Color Transfer using Color Contrast Based Templates)

  • 박영섭;윤경현;이은석
    • 한국멀티미디어학회논문지
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    • 제12권5호
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    • pp.633-643
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    • 2009
  • 본 논문에서는 다양한 색상을 가지는 입력 영상의 화질올 잘 유지하면서, 객체들 간 시각적인 차이를 뚜렷하게 표현하기 위해 색의대비 기반 템플릿을 이용하는 색상 변환 알고리즘을 제안한다. 이 방법은 CIE $L^{\ast}a^{\ast}b^{\ast}$색상 공간 중 유채색의 $a^{\ast}b^{\ast}$평면상에 분포된 입력 영상파 템플릿의 색상 데이터를 이용한다. 템플릿은 색상간의 대비효과를 고려하여 만들어지며, 사용자가 임의로 지정한 가준 색상들을 기반한 그라데이션 영상의 색상 분포를 표시하는 칙선 또는 곡선의 형태를 가진다. 또한, 만들어진 템플릿을 스플라인 곡선으로 모델링하고, 모텔링된 곡선의 제어점을 변형함으로써 간단하게 다른 기준 색상을 가지는, 새로운 탱플릿을 만들 수도 있다. 탬플릿을 이용한 색상 변환은 회귀분석과 칼라 매칭을 통해 이루어지며, 입력 영상의 색상분포를 템플릿의 색상 분포와 유사하게 변형함으로써 입력 영상의 색상 일관성올 유지하였다.

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에코 패션디자인에 나타난 색채 배색 연구 (The Research of Color Combination Presented in Eco Fashion Design)

  • 최정윤;이경희;김새봄
    • 복식문화연구
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    • 제20권1호
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    • pp.62-71
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    • 2012
  • The purpose of this research is to analyze the characteristics of the color combination in Eco fashion design. 532 pictures related to eco was collected through Eco brand web sites from 2008 through 2011. The characteristics for analysis include color combination and tone. The method of research is content and statistical analysis. The result of the research is summed up below. First, achromatic color was most frequently presented in Eco fashion. Also monotone color or single color combination were displayed often. Secondly, many dresses were of single color combination and T-shirt items displayed contrast color combination created by luminosity difference. Third, the outcome of comparing seasons was that both seasons presented single color and contrast color combination. The difference between countries proved slight as single color coloration dominated. This considered the process which was non-chemical manufacture for eco-friendly. For the combination of colors, the same coloration with single colors or contrast coloration due to the differences of brightness were presented quite often, generally, the modern image fashion without fancy factors have shown a lot. These results that minimalism trend was included in eco-friendly image.