• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.50-54
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• 1999

This paper is proposed to image retrieval system using color and shape feature. Color feature used to four maximum value feature among the maximum value extracted from local color distribution histogram. The preprocessing of shape feature consist of edge extraction and weight central point extraction and angular sampling. The sum of distance from weight central point to contour and variation and max/min used to shape feature. The similarity is estimated compare feature of query image with the feature of images in database and the candidate of image is retrieved in order of similarity. We evaluate the effectiveness of shape feature and color feature in experiment used to two hundred of the closed image. The Recall and the Precision is each 0.72 and 0.53 in the result of average experiment. So the proposed method is presented useful method.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.144-145
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• 2008

본 연구는 라이다 자료를 이용하여 건물영역을 추출하고 건물모델을 구성하는 선형과 면요소들을 추출하는 기법을 제시하였다. 라이다 자료는 지형지물의 표고값을 정확하고 직접적인 방식으로 제공함으로써 기존의 항공사진에 비하여 매칭과정을 필요로 하지 않는 장점을 가지고 있다. 하지만 라이다 점들은 해당 수평위치에 대한 표고값만을 제공하기 때문에 지표 위의 지형지물들을 추출하기 위해서는 먼저 점들간의 기하학적인 관계를 분석하여 그들을 구성하는 선이나 면요소들을 추출해야 한다. 이를 위하여 본 연구에서는 먼저 라이다 자료를 라스터 형태로 변환한 후, 이미지 프로세싱을 통하여 상대적으로 낫은 영역과 높은 영역으로 분리하여 각각 지형과 건물영역으로 분류하였다. 다음으로 건물영역 경계로부터 건물 외곽선을 추출하고 건물영역 내에 면요소들을 통계분석을 통하여 추출하였다. 실험결과를 통하여 제시한 기법들은 비교적 복잡한 형태의 건물 지붕면과 외곽선을 성공적으로 분할하고 추출할 수 있음을 보여준다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.17-24
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• 2024

In this paper, we propose a highly secure technique to hide confidential data in image pixels using a quadruple encryption techniques. In the proposed technique, the boundary surface where the image outline exists and the flat surface with little change in pixel values are investigated. At the boundary of the image, in order to preserve the characteristics of the boundary, one bit of confidential data that has been multiply encrypted is spatially encrypted again in the LSB of the pixel located at the boundary to hide the confidential data. At the boundary of an image, in order to preserve the characteristics of the boundary, one bit of confidential data that is multiplely encrypted is hidden in the LSB of the pixel located at the boundary by spatially encrypting it. In pixels that are not on the border of the image but on a flat surface with little change in pixel value, 2-bit confidential data that is multiply encrypted is hidden in the lower 2 bits of the pixel using location-based encryption and spatial encryption techniques. When applying the proposed technique to hide confidential data, the image quality of the stego-image is up to 49.64dB, and the amount of confidential data hidden increases by up to 92.2% compared to the existing LSB method. Without an encryption key, the encrypted confidential data hidden in the stego-image cannot be extracted, and even if extracted, it cannot be decrypted, so the security of the confidential data hidden in the stego-image is maintained very strongly. The proposed technique can be effectively used to hide copyright information in general commercial images such as webtoons that do not require the use of reversible data hiding techniques.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.160-161
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• 2010

In this paper, trademark image retrieval system is proposed by using color information and shape information. We use the image for a color information by dividing into the area and extracting the area color distribution histogram. We use for the shape information by preprocessing of the boundary extraction, the centroid extraction, angular sampling etc. and calculating of the sum of the distance from the centroid to the boundary, the standard deviation, and the rate of long axis to short axis. In particular, centroid by using the angular sampling can extract feature and reduce the processing time. Users can perform searchs using the color and shape information, and also the two methods by mixing can be used by weighting.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.6
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• pp.705-716
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• 2002

This paper proposes a method which visualizes MRI head data in 3 dimensions with direct volume rendering. Though surface rendering is usually used for MRI data visualization, it has some limits of displaying little speckles because it loses the information of the speckles in the surfaces while acquiring the information. Direct volume rendering has ability of displaying little speckles, but it doesn't treat MRI data because of the data features of MRI. In this paper, we try to visualize MRI head data in 3 dimensions as follows. First, we separate the brain region from the head region of MRI head data, next increase the pixel level of the brain region, then combine the brain region with the increased pixel level and the head region without brain region, last visualizes the combined MRI head data with direct volume rendering. We segment the brain region from head region based on histogram threshold, morphology operations and snakes algorithm. The proposed segmentation method shows 91~95% similarity with a hand segmentation. The method rather clearly visualizes the organs of the head in 3 dimensions.

• Journal of Korea Multimedia Society
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• v.15 no.6
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• pp.711-721
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• 2012

The objective of this study is to propose an efficient 3D reconstruction method for developing a stereo-vision-based haptics system which can replace "robotic eyes" and "robotic touch." The haptic rendering for 3D images requires to capture depth information and edge information of stereo images. This paper proposes the 3D reconstruction methods using LoG(Laplacian of Gaussian) algorithm and DoG(Difference of Gaussian) algorithm for edge detection in addition to the basic 3D depth extraction method for better haptic rendering. Also, some experiments are performed for evaluating the CPU time and the error rates of those methods. The experimental results lead us to conclude that the DoG method is more efficient for haptic rendering. This paper may contribute to investigate the effective methods for 3D image reconstruction such as in improving the performance of mobile patrol robots.

• Journal of KIISE:Software and Applications
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• v.27 no.5
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• pp.529-542
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• 2000

Recent years, the use of multimedia information is rapidly increasing, and the video media is the most rising one than any others, and this field Integrates all the media into a single data stream. Though the availability of digital video is raised largely, it is very difficult for users to make the effective video access, due to its length and unstructured video format. Thus, the minimal interaction of users and the explicit definition of video structure is a key requirement in the lately developing image and video management systems. This paper defines the terms and hierarchical video structure, and presents the system, which construct the clustering-based video hierarchy, which facilitate users by browsing the summary and do a random access to the video content. Instead of using a single feature and domain-specific thresholds, we use multiple features that have complementary relationship for each other and clustering-based methods that use normalization so as to interact with users minimally. The stage of shot boundary detection extracts multiple features, performs the adaptive filtering process for each features to enhance the performance by eliminating the false factors, and does k-means clustering with two classes. The shot list of a result after the proposed procedure is represented as the video hierarchy by the intelligent unsupervised clustering technique. We experimented the static and the dynamic movie videos that represent characteristics of various video types. In the result of shot boundary detection, we had almost more than 95% good performance, and had also rood result in the video hierarchy.

• Journal of the Korea Society of Computer and Information
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• v.6 no.2
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• pp.14-19
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• 2001

This paper presents a new method of 3-D surface feature extraction using a quadratic pol expression. With a range image, we get an edge map through the modified scan line technique this edge map, we label a 3-dimensional object to divide object's region and extract cent corner points from it's region. Then we determine whether the segmented region is a planar or a curved from the quadric surface equation. we calculate the coefficients of the planar su the curved surface to represent regions. In this article. we prove performance of the metho synthetic and real (Odetics) range images.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.410-414
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• 2003

본 논문은 비디오 시퀀스에 카메라 패닝 보상과 2차원 시공간 엔트로피 임계법을 적용하여 추출한 객체포함영역을 대상으로 영상 분할을 수행하는 이동 객체 분할 기법에 관한 것이다. 우선, 웨이블렛 변환에 의해 구성한 피라미드 계층 구조상에서 카메라 패닝 벡터를 추정하여 전역 움직임을 보상한다. 이후, 전역 움직임이 보상된 기준영상을 대상으로 각 프레임간에서 2차원 시공간 엔트로피 임계법을 적용하여 이동 객체가 포함될 가능성이 있는 영역을 블록 단위로 추출한다. 다음으로, 2차원 시공간 엔트로피 입계법에 의해 분류된 영역을 토대로 각 블록을 움직임블록, 준 움직임 블록, 비 움직임 블록 중 어느 하나로 분류한 검색 테이블을 작성한다. 이어서, 검색 테이블을 참조하여 초기 탐색 계층 및 탐색 영역을 적응적으로 선정함으로써 피라미드 계층 구조상에서 효율적인 고속 움직임 추정을 수행하여 이동 객체에 해당하는 객체포함영역만을 추출한다. 최종적으로, 이렇게 추출된 객체포함영역에서 임계 기울기 영상을 정의한 후, 이를 기준 삼아 객체포함영역에 화소 단위의 형태학 기반 영상 분할 알고리즘을 적용함으로써 비디오 시퀀스에 포함된 이동 객체를 분할한다. 컴퓨터 시뮬레이션 결과를 통해 고찰할 때, 제안된 방법은 이동 객체에 대한 상대적으로 우수한 분할 특성을 제공할 수 있고, 특히 저대조 경계면의 분할 특성을 제고시키고 있음을 확인할 수 있다.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.729-732
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• 2000

대용량 비디오 데이터의 이용에 있어 효과적인 비디오 검색을 위해서는 비디오 데이터의 색인 과정이 필요하다. 효과적인 비디오 데이터의 색인을 위해서는 의미적 단위인 씬(Scene)으로 이루어진 비디오 데이터를 물리적인 경계면인 컷(장면전환점)으로 검출하는 기법이 필수적이며 각 샷에서의 키 프레임 추출 또한 필수적이다. 본 논문에서는 뉴스 비디오데이터의 키 프레임인 앵커 프레임의 효과적인 검색을 위해 DC 성분 추출과 이진 검색기법, 그리고 컬러 클러스터링을 이용하고 있다. 본 논문에서 제하고 있는 방법을 검증하기 위해서 47분 10초 분량의 MPEG-2 로 압축된 뉴스 비디오 데이터에 적용한 결과 91.3%의 정확도와 84.0%의 재현율을 보여 제안한 방법의 우수성을 증명하고 있다.