• 제목/요약/키워드: Weber's contrast

검색결과 4건 처리시간 0.018초

이미지 화질개선을 위한 Weber-Fechner 법칙을 적용한 가중 히스토그램 균등화 기법 (Weighted Histogram Equalization Method adopting Weber-Fechner's Law for Image Enhancement)

  • 김동형
    • 한국산학기술학회논문지
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    • 제15권7호
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    • pp.4475-4481
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    • 2014
  • 저화질 이미지의 화질 개선에는 전통적으로 히스토그램균등화 기법이 사용되어 왔다. 히스토그램균등화 기법은 입력 이미지의 누적밀도함수를 변환함수로 사용하는 기법으로 이는 이론상 최대의 엔트로피를 가지지만 주관적 화질 측면에서는 백화현상이 나타나는 문제점이 있다. 본 논문에서는 히스토그램균등화 기법 기반의 가중 히스토그램 균등화 기법을 제안한다. 이는 인간의 시각특성을 반영한 Weber-Fechner 법칙을 사용하며 입력영상에 독립적인 변환함수를 제공하는 여러 이미지 화질 개선 기법들이 가지는 문제점을 해결하기 위해서 동적영역 재조정 과정을 포함한다. 최종적으로 재조정된 동적영역 범위 내에서 Weber-Fechner 법칙을 적용한 변환함수와 히스토그램균등화 기법을 통해 얻어진 변환함수간의 가중 평균을 통하여 변환함수를 생성한다. 실험결과 제안하는 알고리즘은 주관적 화질 측면에서 대비비를 효과적으로 향상시키는 것을 보여주며, 엔트로피 또한 비교에 사용된 여러 이전의 방법들과 비교하여 유사하거나 높은 값을 가지는 것을 볼 수 있었다.

엔트로피 가중치와 웨버 법칙을 이용한 세일리언시 검출 (Saliency Detection Using Entropy Weight and Weber's Law)

  • 이호상;문상환;엄일규
    • 전자공학회논문지
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    • 제54권1호
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    • pp.88-95
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    • 2017
  • 본 논문에서는 웨이블릿 변환 영역에서 엔트로피 가중치와 웨버 대비 도를 이용한 세일리언시 검출 방법을 제안한다. 본 논문의 방법은 기존의 일반적인 방법과 마찬가지로 국부적인 세일리언시를 결정하는 상향식 검출과 전역적인 세일리언시를 구성하는 하향식 검출을 결합하는 구조를 가진다. 먼저, CIE Lab 컬러 영상에 대하여 웨이블릿 변환을 수행하고, 저주파 부밴드에 대하여 웨버 대비도 계산하고 이를 저주파 계수에 부가하여 전역 세일리언시를 구한다. 다음으로, 고주파 부밴드의 엔트로피를 이용한 가중치를 가우시안 필터에 적용하여 국부 세일리언시를 구한다. 마지막으로 국부 세일리언시와 전역 세일리언시의 비선형 결합을 통하여 최종 세일리언시를 검출한다. 제안 방법의 성능 평가를 위해 2개의 영상 데이터베이스에 대하여 모의실험을 수행하였다. 기존의 방법과 비교하여 본 논문의 방법은 우수한 세일리언시 검출 결과를 나타내었다.

Face Recognition based on Weber Symmetrical Local Graph Structure

  • Yang, Jucheng;Zhang, Lingchao;Wang, Yuan;Zhao, Tingting;Sun, Wenhui;Park, Dong Sun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권4호
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    • pp.1748-1759
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    • 2018
  • Weber Local Descriptor (WLD) is a stable and effective feature extraction algorithm, which is based on Weber's Law. It calculates the differential excitation information and direction information, and then integrates them to get the feature information of the image. However, WLD only considers the center pixel and its contrast with its surrounding pixels when calculating the differential excitation information. As a result, the illumination variation is relatively sensitive, and the selection of the neighbor area is rather small. This may make the whole information is divided into small pieces, thus, it is difficult to be recognized. In order to overcome this problem, this paper proposes Weber Symmetrical Local Graph Structure (WSLGS), which constructs the graph structure based on the $5{\times}5$ neighborhood. Then the information obtained is regarded as the differential excitation information. Finally, we demonstrate the effectiveness of our proposed method on the database of ORL, JAFFE and our own built database, high-definition infrared faces. The experimental results show that WSLGS provides higher recognition rate and shorter image processing time compared with traditional algorithms.

네트워크 구조와 조직학습문화, 지식경영참여가 개인창의성 및 성과에 미치는 영향에 관한 실증분석: SI제안팀과 R&D팀의 비교연구 (Exploring Influence of Network Structure, Organizational Learning Culture, and Knowledge Management Participation on Individual Creativity and Performance: Comparison of SI Proposal Team and R&D Team)

  • 이건창;서영욱;채성욱;송석우
    • Asia pacific journal of information systems
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    • 제20권4호
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    • pp.101-123
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    • 2010
  • Recently, firms are operating a number of teams to accomplish organizational performance. Especially, ad hoc teams like proposal preparation team are quite different from permanent teams like R&D team in the sense of how the team forms network structure and deals with organizational learning culture and knowledge management participation efforts. Moreover, depending on the team characteristics, individual creativity will differ from each other, which will lead to organizational performance eventually. Previous studies in the field of creativity are lacking in this issue. So main objectives of this study are organized as follows. First, the issue of how to improve individual creativity and organizational performance will be analyzed empirically. This issue will be performed depending on team characteristics such as ad hoc team and permanent team. Antecedents adopted for this research objective are cultural and knowledge factors such as organizational learning culture, and knowledge management participation. Second, the network structure such as degree centrality, and structural hole is used to analyze its influence on individual creativity and organizational performance. SI (System Integration) companies are facing severely tough requirements from clients to submit very creative proposals. Also, R&D teams are widely accepted as relatively creative teams because their responsibilities are focused on suggesting innovative techniques to make their companies remain competitive in the market. SI teams are usually ad hoc, while R&D teams are permanent on an average. By taking advantage of these characteristics of the two kinds of teams, we will prove the validity of the proposed research questions. To obtain the survey data, we accessed 7 SI teams (74 members), and 6 R&D teams (63 members), collecting 137 valid questionnaires. PLS technique was applied to analyze the survey data. Results are as follows. First, in case of SI teams, organizational learning culture affects individual creativity significantly. Meanwhile, knowledge management participation has a significant influence on Individual creativity for the permanent teams. Second, degree centrality Influences individual creativity significantly in case of SI teams. This is comparable with the fact that structural hole has a significant impact on individual creativity for the R&D teams. Practical implications can be summarized as follows: First, network structure of ad hoc team should be designed differently from one of permanent team. Ad hoc team is supposed to show a high creativity in a rather short period, implying that network density among team members should be improved, and those members with high degree centrality should be encouraged to show their Individual creativity and take a leading role by allowing them to get heavily engaged in knowledge sharing and diffusion. In contrast, permanent team should be designed to take advantage of structural hole instead of focusing on network density. Since structural hole can be utilized very effectively in the permanent team, strong arbitrators' merits in the permanent team will increase and therefore helps increase both network efficiency and effectiveness too. In this way, individual creativity in the permanent team is likely to lead to organizational creativity in a seamless way. Second, way of Increasing individual creativity should be sought from the perspective of organizational culture and knowledge management. Organization is supposed to provide a cultural atmosphere in which Innovative idea suggestions and active discussion among team members are encouraged. In this way, trust builds up among team members, facilitating the formation of organizational learning culture. Third, in the ad hoc team, organizational looming culture should be built such a way that individual creativity can grow up fast in a rather short period. Since time is tight, reasonable compensation policy, leader's Initiatives, and learning culture formation should be done In a short period so that mutual trust is built among members quickly, and necessary knowledge and information can be learnt rapidly. Fourth, in the permanent team, it should be kept in mind that the degree of participation in knowledge management determines level of Individual creativity. Therefore, the team ought to facilitate knowledge circulation process such as knowledge creation, storage, sharing, utilization, and learning among team members, which will lead to team performance. In this way, firms must control knowledge networks in permanent team and ad hoc team in a way mentioned above so that individual creativity as well as team performance can be maximized.