• Fisheries and Aquatic Sciences
• /
• 제4권1호
• /
• pp.1-9
• /
• 2001

This paper describes a procedure extracting feature vector of a target cell more precisely in the case of identifying specified cell. The classification of object type is based on feature vector such as area, complexity, centroid, rotation angle, effective diameter, perimeter, width and height of the object So, the feature vector plays very important role in classifying objects. Because the feature vectors is affected by noises and holes, it is necessary to remove noises contaminated in original image to get feature vector extraction exactly. In this paper, we propose the following method to do to get feature vector extraction exactly. First, by Otsu's optimal threshold selection method and morphological filters such as cleaning, filling and opening filters, we separate objects from background an get rid of isolated particles. After the labeling step by 4-adjacent neighborhood, the labeled image is filtered by the area filter. From this area-filtered image, feature vector such as area, complexity, centroid, rotation angle, effective diameter, the perimeter based on chain code and the width and height based on rotation matrix are extracted. To prove the effectiveness, the proposed method is applied for yeast Zygosaccharomyces rouxn. It is also shown that the experimental results from the proposed method is more efficient in measuring feature vectors than from only Otsu's optimal threshold detection method.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제18권1호
• /
• pp.27-41
• /
• 2014

In this paper, we present an efficient numerical method for multiphase image segmentation using a multiphase-field model. The method combines the vector-valued Allen-Cahn phase-field equation with initial data fitting terms containing prescribed interface width and fidelity constants. An efficient numerical solution is achieved using the recently developed hybrid operator splitting method for the vector-valued Allen-Cahn phase-field equation. We split the modified vector-valued Allen-Cahn equation into a nonlinear equation and a linear diffusion equation with a source term. The linear diffusion equation is discretized using an implicit scheme and the resulting implicit discrete system of equations is solved by a multigrid method. The nonlinear equation is solved semi-analytically using a closed-form solution. And by treating the source term of the linear diffusion equation explicitly, we solve the modified vector-valued Allen-Cahn equation in a decoupled way. By decoupling the governing equation, we can speed up the segmentation process with multiple phases. We perform some characteristic numerical experiments for multiphase image segmentation.

• 대한의용생체공학회:의공학회지
• /
• 제10권2호
• /
• pp.173-178
• /
• 1989

A vector quantization technique using a variable block size was applied to image compression of digitized X -ray films. Whether the size of VQ block should be subdivided or not is determined experimentally by the threshold value. The simulation result shows that the performance of the proposed vector quantizer is suitable for the medical image coding, which is applicable to PACS( Picture Archiving and Communication System).

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
• /
• pp.669-672
• /
• 2001

We propose an efficient algorithm for an interactive content-based image retrieval using relevance feedback. In the proposed algorithm, a new query feature vector first is yielded from the average feature vector of the relevant images that is fed back from the result images of the previous retrieval. Each component weight of a feature vector is computed from an inverse of standard deviation for each component of the relevant images. The updated feature vector of the query and the component weights are used in the iterative retrieval process. In addition, the irrelevant images are excluded from object images in the next iteration to obtain additional performance improvement. In order to evaluate the retrieval performance of the proposed method, we experiment for three image databases, that is, Corel, Vistex, and Ultra databases. We have chosen wavelet moments, BDIP and BVLC, and MFS as features representing the visual content of an image. The experimental results show that the proposed method yields large precision improvement.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
• /
• pp.211-221
• /
• 1998

A digital image processing technique which is able to get the velocity vector distribution of a surface of the spilled oil in the ocean without contacting the flow itself. This technique is based upon the PIV(Particle Imaging Velocimetry) technique and its system mainly consists of a high sensitive camera, a CCD camera, an image grabber, and a host computer in which an image processing algorithm is adopted for velocity vector acquisition. For the acquisition of the advective velocity vector of floating matters on the ocean, a new multi-frame tracking algorithm is proposed, and for the acquisition of the diffusion velocity vector distribution of the spilt oil onto the water surface, a high sensitive gray-level cross-correlation algorithm is proposed.

• 한국항만학회지
• /
• 제12권2호
• /
• pp.291-302
• /
• 1998

A digital image processing technique which is able to be used for getting the velocity vector distribution of a surface of the spilt oil in the ocean without contacting the flow itself. This technique is based upon the PIV(Particle Imaging Velocimetry) technique and its system mainly consists of a high sensitive camera, a CCD camera, an image grabber, and a host computer in which an image processing algorithm is adopted for velocity vector acquisition. For the acquisition of the advective velocity vector of floating matters on the ocean, a new multi-frame tracking algorithm is proposed, and for the acquisition of the diffusion velocity vector distribution of the spilt oil onto the water surface, a high sensitive gray-level cross-correlation algorithm is proposed.

• 디지털콘텐츠학회 논문지
• /
• 제2권2호
• /
• pp.157-166
• /
• 2001

본 논문은 내용 기반 이미지 검색 시스템에서 이미지의 위치 및 모양 정보에 의한 회귀선을 추정하여 효율적으로 특징 벡터 추출함과 동시에 같은 도메인상의 특징 벡터가 일정 수준보다 많아질 경우 효율적으로 특징 벡터의 차원을 줄이는 기법을 제안한다. 특히, 특징 벡터의 차원을 줄이는 제안된 기법은 특징 벡터의 수에 관계없이 특정한 n개의 특징 벡터로의 변환이 가능하다. 본 논문에서 제안된 기법들은 실제 내용 기반 이미지 검색 시스템의 구현을 통해 기존의 방법보다 효율적인 검색은 물론 다차원 특징 벡터를 특정 n차원의 특징 벡터로 변환함으로써 다차원 색인 기법이 가지고 있는 가장 큰 단점인 '차원의 저주' 문제를 근본적으로 해결할 수 있는 방법임을 보인다.

• 전자공학회논문지
• /
• 제52권6호
• /
• pp.79-84
• /
• 2015

디지털 영상의 배포에서, 위 변조자에 의해 영상이 변조되는 심각한 문제가 있다. 이러한 문제를 해결하기 위하여, 본 논문에서는 영상의 픽셀값 경사도에 따른 특징벡터를 이용한 미디언 필터링 영상 포렌식 판정 알고리즘을 제안한다. 제안된 알고리즘에서, 원영상의 픽셀값 경사도로부터 자기회귀 계수를 1~6차까지의 6 Dim.을 계산한다. 그리고 경사도를 Poisson 방정식의 해에 의한 재구성 영상과 원영상과의 차영상으로 부터, 4 Dim. (평균값, 최대값 그리고 최대값의 좌표 i,j)의 특징벡터를 추출한다. 2 종류의 특징벡터는 10 Dim.으로 조합되어 변조된 영상의 미디언 필터링 (Median Filtering: MF) 검출기의 SVM (Support Vector Machine) 분류를 위한 학습에 사용된다. 제안된 미디언 필터링 검출 알고리즘은 동일 10 Dim. 특징벡터의 MFR (Median Filter Residual) 스킴과 비교하여 원영상, 평균필터링 ($3{\times}3$) 영상 그리고 JPEG (QF=90) 영상에서는 성능이 우수하며, Gaussian 필터링 ($3{\times}3$) 영상에서는 성능이 다소 낮지만, 성능평가 전체항목에서 민감도 (Sensitivity; TP: True Positive rate)와 1-특이도 (1-Specificity; FP: False Positive rate)의 AUC (Area Under Curve)가 모두 1에 수렴하여 'Excellent (A)' 등급임을 확인하였다.

• 한국컴퓨터정보학회:학술대회논문집
• /
• 한국컴퓨터정보학회 2020년도 제61차 동계학술대회논문집 28권1호
• /
• pp.27-28
• /
• 2020

본 논문에서는 초음파 영상의 통계적 특징벡터를 활용하여 폐암 분류를 제안한다. 폐암의 초음파 사진들을 비교 분석하여 각각의 label에 맞는 feature vector를 선별한다. 선택된 feature vector는 SVM을 이용하여 훈련 시킨 후, 최종적으로 폐암을 구별한다.

• 대한의용생체공학회:의공학회지
• /
• 제26권3호
• /
• pp.129-132
• /
• 2005

It is one of the most important issues to determine a target brain image that gives a common coordinate system for a constructing population-based brain atlas. The purpose of this study is to provide a simple and reliable procedure that determines the target brain image among the group based on the inherent structural information of three-dimensional magnetic resonance (MR) images. It uses only 11 lines defined automatically as a feature vector representing structural variations based on the Talairach coordinate system. Average characteristic vector of the group and the difference vectors of each one from the average vector were obtained. Finally, the individual data that had the minimum difference vector was determined as the target. We determined the target brain image by both our algorithm and conventional visual inspection for 20 healthy young volunteers. Eighteen fiducial points were marked independently for each data to evaluate the similarity. Target brain image obtained by our algorithm showed the best result, and the visual inspection determined the second one. We concluded that our method could be used to determine an appropriate target brain image in constructing brain atlases such as disease-specific ones.