• 제목/요약/키워드: Visual sensitivity

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경관영향평가 기법을 통한 댐건설에 대한 경관영향평가 (The Visual Impact Assessment in Dam Construction Using Visual Impact Assessment Method)

  • 김대현;구본학
    • 한국조경학회지
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    • 제27권4호
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    • pp.80-86
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    • 1999
  • The purpose of this study was to suggest a case study and anlaysis of the visual impact in dam construction through visual impact assessment method in Dong-sang river. The results can be summarized as follows; 1) For the evaluation of the visual impact of dam construction, five steps such as field analysis of visual status, finding visual sensitivity area and visual control point, making visual simulation material and evaluation, and visual impact analysis and assessment were suggested as desirable. 2) In the case study, the visual impact of dam construction was evaluated to be simple, unique, modern, static, cool and unfamiliar. 3) There was a few difference between the pre-construction and post-construction in statistical test. Especially, The dam in Man-Jee area was evaluated to be artificial, unique and destroyed in statistical difference, and then we design dam structure with visual friendliness. 4) In conclusion, there was high correlation between pre-construction landscape and post-construction landscape through semantic differential scale method using eleven adjectives. Therefore, we state that there is no visual impact for the dam construction for the moment.

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DCT영역에서의 국부 Contrast 조절 기법 (Method for Local Contrast Control in DCT Domain)

  • ;;김원하;김선국
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 2013년도 추계학술대회
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    • pp.8-11
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    • 2013
  • We implement the foveation and frequency sensitivity feature of human visual system in discrete cosine transform (DCT) domain. Resolution of human visual perception decays as distance from the eye-focused point, known as foveation property, and the middle frequency components give most pleasant image quality to human than the low and high frequency components, which is the frequency sensitivity property of human visual system. For satisfying the foveation property, we enhanced the local contrast at the focused regions and smoothed local contrast at the non-focused regions in the DCT domain without bringing the blocking and ringing artifacts. Moreover, the energies at each DCT frequency components is modified with various degree to fulfill the frequency sensitivity property. The proposed method is verified by the subjective and objective evaluations that it can the improve the human perceptual visual quality.

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Contrast Sensitivity 함수를 이용한 영상화질 개선 방법 (Image Enhancement Using The Contrast Sensitivity Function)

  • 방성배;김원하
    • 방송공학회논문지
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    • 제20권2호
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    • pp.238-247
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    • 2015
  • 본 논문은 영상 신호의 방향을 고려하여 기존의 multiband energy scaling 방법의 문제점을 보완하면서 human visual system(HVS)에 적합한 영상 local contrast 향상 방법을 개발하였다. 기존의 multiband energy scaling 방법은 신호 방향에 대한 고려 없이 화질을 향상시켜 ringing artifact가 발생하였으나 본 논문에서는 block gradient를 사용하여 신호의 방향을 측정하고 측정된 신호 방향에 따라 주파수 신호를 향상시켜 ringing artifact의 발생 없이 화질을 향상시켰다. 또한 본 논문은 human visual system(HVS)은 각 신호의 값 하나하나 보다는 각 신호가 가지는 주파수에 성분에 민감하게 반응한다는 것을 이용하여 주파수 성분에 대한 인간 시각의 민감도를 모델링한 contrast sensitivity function(CSF)에 따라 영상의 화질을 향상시켰다. 결국 본 논문에서 제안하는 방법은 신호의 특성과 인간 시각의 특성을 모두 고려하여 영상의 화질을 향상시키기 때문에 기존의 화질 향상 방법들에 비해 영상 신호와 인간 시각 특성에 더욱 적합하게 화질을 향상시킬 수 있다.

LED 광원에 대한 암순응시 볼락 (Sebastes inermis)의 시각 스펙트럼 민감도 (Visual spectral sensitivity of dark-adapted rockfish (Sebastes inermis) in LED light source)

  • 허민아;강경미;신현옥
    • 수산해양기술연구
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    • 제51권1호
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    • pp.102-110
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    • 2015
  • The characteristics of aquatic light fields are generally reflected in the visual systems of fishes inhabiting them. Therefore, research on light sensitivity of fish is useful to explain the correlation between the visual function and habitat, behavior and distribution of fish. Rockfish is an important species in coastal ecology and also one of the main species for culturing in Korea. To make a contribution on the maintenance of the fish resources and understanding the ecology of the rockfish, the visual spectral sensitivities of the dark-adapted rockfishes were measured in the range of visible light (405~660 nm) using a light source of light-emitting diodes (LEDs). In order to assess electrophysiological response of the fish, the ERGs (electroretinograms) of the dark-adapted rockfishes were recorded on a data logger (12 bits) and a laptop computer. Juvenile (n=5; weight: $20.3{\pm}5.2g$; total length: $10.3{\pm}0.7cm$) and adult (n=5; weight: $87.8{\pm}21.8g$; total length: $18.1{\pm}1.3cm$) rockfishes were used in experiment. The visual threshold of juvenile and adult rockfish were 11.66 (log quanta/$cm^2/s$) and 11.81 (log quanta/$cm^2/s$) in 574 nm, respectively. The peak wavelength of the spectral sensitivity in the dark-adapted juvenile and adult rockfish was commonly 551 nm (series of green color). Collectively, these results demonstrate that the rockfish has suitable visual capabilities for inhabiting coastal water in Korea.

외인성 주의 유도에 의한 시야의 시각 민감도 변화 (Changes in sensitivity across visual field induced by exogenous attention)

  • 정상철;현주석;정찬섭
    • 인지과학
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    • 제8권4호
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    • pp.63-75
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    • 1997
  • 주의 위치로부터의 거리에 따른 시각 민감도 변화를 조사하였다. 피험자가 시야 평면의 한 점을 응시하는 동안 응시점에서 좌우 대칭으로 4。 떨어져 있는 주의 유도점중 하나를 깜빡인 다음 주의 유도점 부근에 표적 자극을 제시하였다. 피험자의 과제는 그 표적이 나타났는지의 여부를 판단하여 보고하는 것이었다. 표적 자극의 탐지율은 주의 유도점 인접한 곳에서 가장 높았으며 그곳으로부터 멀어질수록 점진적으로 감소하였다. 이러한 결과는 주의 유도에 의한 시각 민감도의 점진적 변화 모형(gradient model)을 지지하는 것이다.

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인간 시각의 인지 특성을 이용한 영상 화질 향상 방법 (Image Enhancement Using Human Visual Perception)

  • 방성배;김원하
    • 방송공학회논문지
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    • 제23권2호
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    • pp.206-217
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    • 2018
  • 본 논문은 영상 신호의 방향을 고려하여 기존의 multiband energy scaling 방법의 문제점을 보완하면서 human visual system(HVS)에 적합한 영상 local contrast 향상 방법을 개발하였다. 기존의 multiband energy scaling 방법은 신호 방향에 대한 고려 없이 화질을 향상시켜 ringing artifact가 발생하였으나 본 논문에서는 block gradient를 사용하여 신호의 방향을 측정하고 측정된 신호 방향에 따라 주파수 신호를 향상시켜 ringing artifact의 발생 없이 화질을 향상시켰다. 또한 본 논문은 human visual system(HVS)은 각 신호의 값 하나하나 보다는 각 신호가 가지는 주파수에 성분에 민감하게 반응한다는 것을 이용하여 주파수 성분에 대한 인간 시각의 민감도를 모델링한 contrast sensitivity function(CSF)에 따라 영상의 화질을 향상시켰다. 결국 본 논문에서 제안하는 방법은 신호의 특성과 인간 시각의 특성을 모두 고려하여 영상의 화질을 향상시키기 때문에 기존의 화질 향상 방법들에 비해 영상 신호와 인간 시각 특성에 더욱 적합하게 화질을 향상시킬 수 있다.

Stereo Image Quality Assessment Using Visual Attention and Distortion Predictors

  • Hwang, Jae-Jeong;Wu, Hong Ren
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제5권9호
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    • pp.1613-1631
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    • 2011
  • Several metrics have been reported in the literature to assess stereo image quality, mostly based on visual attention or human visual sensitivity based distortion prediction with the help of disparity information, which do not consider the combined aspects of human visual processing. In this paper, visual attention and depth assisted stereo image quality assessment model (VAD-SIQAM) is devised that consists of three main components, i.e., stereo attention predictor (SAP), depth variation (DV), and stereo distortion predictor (SDP). Visual attention is modeled based on entropy and inverse contrast to detect regions or objects of interest/attention. Depth variation is fused into the attention probability to account for the amount of changed depth in distorted stereo images. Finally, the stereo distortion predictor is designed by integrating distortion probability, which is based on low-level human visual system (HVS), responses into actual attention probabilities. The results show that regions of attention are detected among the visually significant distortions in the stereo image pair. Drawbacks of human visual sensitivity based picture quality metrics are alleviated by integrating visual attention and depth information. We also show that positive correlation with ground-truth attention and depth maps are increased by up to 0.949 and 0.936 in terms of the Pearson and the Spearman correlation coefficients, respectively.

시각적 공간자극에 나타난 뇌파반응의 자극 정도와 만족도 변화특성 - 할로겐 조명과 벽의 영향을 중심으로 - (The Change Characteristic of the Stimulation and Satisfaction of the Brain Wave Reaction to the Visual Stimulation in the Space - Focus on the Influence of the Halogen and Wall -)

  • 서지은
    • 한국실내디자인학회논문집
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    • 제24권5호
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    • pp.99-107
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    • 2015
  • The purpose of this study is to analyze the change of visual stimulus of users to the space through the experiment of EEG and the satisfaction of users depends on the lighting. To do that, the results measured with EEG experiment focusing on Beta ${\beta}$ were compared to each other to figure out difference in the changes of the activation of human brain on lighting's situation as the lighting off and on in the same space. The difference in the results was verified according to the characteristic of users which classified with 4 types of the spatial sensitivities. The results of this study are as following. Firstly, the spacial sensitivity of user is to communicate well with the different senses with stimulus through interaction among the elements. At this time, the brain plays a major role in build the spacial sensitivity of users as the place to make form. Secondly, there are the differences in the activation of brain depends on lighting situation even in the same space. The stimulus into the brain became generally stronger in images with lighting on than off. Especially, the response in the occipital lobe which connected with the visual center turn out strongly in the image of 'modern natural'. Because the visual stimulus interact well with the bright color, the reflectional texture and the rough texture painted the dark color. Thirdly, the satisfaction of users changed with lighting in the space. But we could know that the satisfaction of users isn't be related to the visual stimulus through the results of this study. Finally, there isn't the difference in the activation degree of brain according to the characteristic which are preference of users into 4 types of the spatial sensitivity through the results came from ANCOVA(analysis of covariance) with SPSS Program 22.

음주 후 시간경과에 따른 시력의 변화 (Time-dependent Changes of Visual Acuity After Alcohol Ingestion)

  • 김상엽;이선행;문병연;유동식;조현국
    • 한국안광학회지
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    • 제13권2호
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    • pp.59-62
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    • 2008
  • 목적: 알코올 섭취 후 시간경과에 따른 시력변화를 알아보고자 하였다. 방법: 음주 1시간 및 3시간 후의 자각적 타각적 굴절검사, 원거리 대비감도 검사, 그리고 세막대 입체시 검사를 실시하였다. 결과: 혈중 알코올 농도의 상승과 비례하여 평균 -0.25D ~ -0.35D의 근시성 변화를 일으켰고, 동적입체시 기능이 저하되는 것으로 나타났다. 그러나 대비감도는 모든 공간주파수에서 큰 변화가 없는 것으로 나타났다. 결론: 알코올이 일반적인 시력검사 및 기능검사에 영향을 끼친다는 사실을 숙지하고 피검자의 검사 전 알코올 음용에 대해 문진할 필요성이 있다.

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QR분해와 외란관측기를 이용한 시각구동 방법 (A Novel Visual Servoing Method Using QR Decomposition and Disturbance Observer)

  • 이준수;서일홍;유범재;오상록
    • 제어로봇시스템학회논문지
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    • 제6권6호
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    • pp.462-470
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    • 2000
  • This paper proposes a visual servoing method based on QR decomposition and disturbance observer. The QR decomposition factors the image feature Jacobian into a unitary matrix and an upper triangular matrix. And it is shown that several performance indices such as measurement sensitivity of visual features, sensitivity of the control to noise and controllability can be improved for any general image feature Jacobian by QR decomposition and disturbance observer. To show the validity of the proposed approach, visual servoing with stereo vision is carried out for a Samsung FARAMAN 6-axis industrial robot manipulator.

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