• Progress in Medical Physics
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• v.7 no.2
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• pp.79-90
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• 1996

In this paper, we present an automatic threshold decision method to detect the contour of the a 2-D echocarodiogram by using the Bayes estimator for the boundary-like region. The boundary-like region is constructed from the conduction coefficient of the heat anisotro-pic diffusion method which enforces the blurred image during the preprocessing step. For the boundary-like region, we used the Bayes estimator to select an optimal threshold level. From this threshold value, the contour of the echocardigrams can be detected automatically Finally by overlapping the estimated contour to the original echocardiogram, we can obtain the contour enforced ultrasound echocardiogram.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.4
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• pp.663-670
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• 2019

The modified Canny edge detection algorithm that can detect the boundary between screen door and platform in the subway is proposed in this paper. Generally, in the subway, the boundary line between the platform and the screen door is darker than the surrounding area. Therefore, an edge image is using the modified bottom-hat transform by considering its characteristics. Double thresholded images with strong edge and weak edge through double thresholding are obtained. An algorithm that detects the boundary invasion between the platform and the screen door is proposed by calculating the length by applying the Hough transform to the double thresholded image and comparing the boundary line length between when there is an object such as a person and when there is no object. In this paper, the results of the proposed modified Canny edge detection algorithm using two different input images according to camera height position are shown by computer simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.171-174
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• 2010

본 논문에서는 렌즈의 흠집을 추출할 수 있는 퍼지 기법을 이용한 렌즈 흠집 검출 방법을 제안한다. 제안된 방법은 렌즈 영상을 그레이 영상으로 변환한 후, 캐니 마스크를 이용하여 렌즈의 경계선을 추출한다. 추출된 렌즈의 경계선에 대해 평균 이진화와 모폴로지를 이용하여 렌즈 경계선을 보정한다. 렌즈 경계선이 보정된 영상에서 Seed Fill 알고리즘을 적용하여 렌즈의 내부 영역만을 추출한다. 추출된 렌즈의 내부 영역에 해당하는 원 영상에서 소벨 마스크를 적용하여 렌즈 내부 영역의 에지를 추출한다. 렌즈 내부 영역에서 추출된 에지 객체들의 정보를 이용하여 흠집과 비흠집을 분류하는 퍼지 기법을 적용하여 흠집 영역을 추출한다. 본 논문에서 제안된 렌즈의 흠집 검출 방법의 성능을 평가하기 위해 CHEMI, MID, HL, HM 시력 보정용 렌즈를 대상으로 실험한 결과, 제안된 방법이 흠집을 효과적으로 검출하는 것을 확인하였다.

• Journal of the Korea Society of Computer and Information
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• v.14 no.6
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• pp.59-64
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• 2009

Edge detection always influenced by the noise of original image, therefore need some methods to eliminate them in advance, and the Mean Shift algorithm has the smooth function which suit for this purpose, so adopt it to fade out the unimportant information and the sensitive noise portions. Above all, we use the Canny algorithm to pick up the contour of the objects we focus on. And, take tests and get better result than the former sole Canny algorithm. This combination method of Mean Shift algorithm and Canny algorithm is suitable for the edge detection processing.

• Journal of the Korea Society of Computer and Information
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• v.17 no.7
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• pp.67-76
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• 2012

This paper proposes an efficient method that helps a visually impaired person to detect a pavement borderline. A pedestrian is equipped with a camera so that the front view of a natural scene is captured. Our approach analyzes the captured image and detects the borderline of a pavement in a very robust manner. Our approach performs the task in two steps. In a first step, our approach detects a vanishing point and vanishing lines by applying an edge operator. The edge operator is designed to take a threshold value adaptively so that it can handle a dynamic environment robustly. The second step is to determine the borderlines of a pavement based on vanishing lines detected in the first step. It analyzes the vanishing lines to form VRays that confines the pavement only. The VRays segments out the pavement region in a radial manner. We compared our approach against Canny edge detector. Experimental results show that our approach detects borderlines of a pavement very accurately in various situations.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.10
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• pp.1244-1251
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• 1988

Edge is one of the primitive features of an image and is widely used in image classification and analysis. New edge extration methods using central moments are presented and show various characteristics according to the order of moment, definition of both random variables and probability density functions. The proposed methods use the integral of differences between local mean and pixels in the window whereas most of conventional edge operators use only differential concepts. This gives good noise immunity and extracts fine edges.

• Journal of Korea Game Society
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• v.10 no.4
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• pp.63-71
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• 2010

In this paper, we propose a boundary based marker binary coding method for augmented reality games, which enables the marker-area to be binary coded well in any lighting environments. First, it detects the boundary after transforming an original marker image to a gray scale image, and it executes 4 way pixel extensions for all boundary pixels in order to make the boundary to closed area. Next, for all boundary pixels it compares the brightness of right and left ones of each pixel and allocates black for the lower side and white for the higher side by filling inside area thru the seeded region growing. Experimental results showed that our proposed method produces a good binary marker image recognizable in various light environments. In addition, it showed the possibility of real-time calculation by considering the result of operation speed which is 51 fps for VGA image.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.3184-3190
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• 2011

In this paper, we propose a method to detect Iris Round wipe transitions with circular moving borders in digital video data. The suggested method robustly extracts circular moving borders from the input image using improved Hough transform, and finally detects Iris Round wipes by effectively analyzing their moving directions and shapes. In order to evaluate the performance of the suggested algorithm, the experimental results show that the proposed method can effectively detect Iris Rounds with circular moving borders in various video data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.865-871
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• 2022

In this paper, we propose a method of extracting prostate region using morphological characteristics of ultra-sonic image of prostate. In the first step of the proposed method, the edge area of the prostate image is extracted. The histogram of ultra-sonic image is used to extract base objects to detect the upper edge of prostate region by altering the contrast of the image, then, the lower edges of the extracted base objects are connected by using monotone cubic spline interpolation to extract the upper edge. Step 2, Otsu's binarization is applied to the region under the extracted upper edge of the prostate ultra-sonic image to extract the lower edge of prostate. In the last step, the upper and the lower edges are connected to extract prostate region and by comparing the extracted region of prostate with the one measured manually, the result showed that the morphological characteristics of prostate in ultrasonic image can be utilized to extract the prostate region.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.6
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• pp.21-27
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• 2018

Wearing degree and uneven wearing detection algorithm using horizontal edge information is proposed in this paper. The noise in the input image is removed by bilateral filter, and then edges are extracted from the filtered image by using the proposed mask. As the tire is worn, grooves of tire shoulder or sipes are changed more than the vertical grooves. Therefore the edges from grooves of tire shoulder or sipes have more information about the tire wearing than the edges from vertical grooves. Proposed mask that is reflected this feature is used to extract the horizontal edges. After edge extraction, the edge image is represented in two-level system. The edge pixels of the binarization image are used to decide the wearing degree and uneven wearing. This proposed method can be used easily without any other equipments. The proposed method is conducted with a real vehicle, and the experimental results show the good performance of the proposed method in detecting wearing degree and uneven wearing.