• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.11a
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• pp.200-203
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• 2019

영상처리 분야에서 이미지 샤프닝 기법은 주관적 화질 향상에 큰 역할을 하고 있다. 본 논문에서는 모폴로지 기법을 이용한 향상된 이미지 샤프닝 알고리듬을 제안한다. 기존의 Sobel이나 Laplacian 연산자는 에지 검출에 있어서 잡음에 취약하다는 단점이 있다. 이를 해결하기 위해 잡음에 상대적으로 민감하지 않은 모폴로지 기법을 이용했다. 우선, 침식 연산을 수행한 이미지와 원본 이미지와의 차를 통해 에지를 얻는다. 이 에지는 원본 이미지의 히스토그램의 표준 편자 값을 기반으로 원본 이미지와 가중합을 통해 에지를 중점적으로 선명하게 만든다. 실험을 통해 제안하는 알고리듬은 기존의 Sobel이나 Laplacian 연산자 보다 우수한 성능을 보임을 알 수 있었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.10
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• pp.1546-1552
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• 1993

We proposed an adaptive block truncation coding(BTC) using gradient and a new initial value. We used gradient of sobel operator as a new category classification coefficient to reduce Jagged appearance at edge part. We defined a new initial value to reduce large quantization error in the 4-level quantizer block including edge part. By computer simulations, we showed that the proposed method less computation load, reduced jagged appearance at edge part, also improved PSNR more than the conventional adaptive BTC.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.31.2-31.2
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• 2010

본 연구의 목적은 태양 코로나 구조를 분석하기에 적합한 영상처리 기법을 찾는 것이다. 이를 위하여 우리는 IDL(Interactive Data Language)에 내장된 여러 가지 영상처리방법을 SOHO EIT 영상에 적용하였다. 우리는 영상처리를 위하여 단일 영상처리 방법과 2단계 영상 처리 방법을 사용하였다. 단일 영상처리 방법으로 히스토그램 평활화(Equalization), 주파수 필터링, 경계선 강화기법(Sobel, Robert) 등을 사용하였다. 2단계 영상처리 방법은 단일 영상 처리 방법에서 효과적이었던 방법들을 두 가지 이상 순차적으로 적용하는 것이다. 본 연구를 통하여 우리는 2단계 영상처리 방법(예, 저주파 필터 + Sobel + 히스토그램 평활화)이 단일 영상처리 방법 보다 코로나 루프 구조를 잘 보여주는 것을 확인하였다. 이 연구 결과가 태양 코로나 구조 연구에 유용하게 사용될 수 있을 것으로 기대된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.892-894
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• 2013

Edge has been utilized in various application fields with development of technique of digital image processing. In conventional edge detection methods, there are some methods using mask including Sobel, Prewitt, Roberts and Laplacian operator. Those methods are that implement is simple but generates errors of edge detection in images added AWGN(additive white Gaussian noise). Therefore, to compensate the defect of those methods, in this paper, an edge detection algorithm using modified mask is proposed, and it showed superior edge detection property in AWGN.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.404-406
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• 2013

An image edge has been utilized as preprocessing procedure in various field such as object detection, object recognition. there are Sobel, Prewitt, Roberts, Laplacian as conventional edge detection methods. existing methods are implement is simple, but edge detection characteristics is insufficient in impulse noise area. Therefore, to compensate the defect of conventional methods, in this paper, an edge detection algorithm using modified mask is proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.886-888
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• 2013

An edge includes information of objects such as magnitude, orientation, and location. Conventional edge detection methods to detect those edge are methods using Sobel, Prewitt, Roberts, Laplacian operator. Existing methods use fixed weighted mask to detect edges, and their edge detection characteristics are insufficient. Therefore, to remedy weakness of conventional methods, in this paper, an edge detection algorithm using weight with standard deviation and thresholds is proposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.4
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• pp.405-413
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• 1987

In this paper, we have discussed three-type median filters(SQUARE, CROSS, X-SHAPE) that preserving edge in an original image while reducing random noise was introduced for image enhancement and edge detection on radar image. Since radar image have a number of parts of curve, we compared results produced by edge detection operater proposed for improving the parts of curve with results of using the existing edge detection methods, such as Roberts, Sobel, Prewitt, Laplacian and Kirsch.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.3
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• pp.238-245
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• 2001

This paper describes a method for detecting a close leading vehicle using the contour of the vehi-cles rear wheels. The contour of a leading vehicles rear wheels in 속 front road image from a B/W CCD camera mounted on the central front bumper of the vehicle, has vertical components and can be discerned clearly in contrast to the road surface. After extracting positive edges and negative edges using the Sobel op-erator in the raw image, every point that can be recognized as a feature of the contour of the leading vehicle wheel is determined. This process can detect the presence of a close leading vehicle, and it is also possible to calculate the distance to the leading vehicle and the lateral deviation angle. This method might be useful for developing and LSA (Low Speed Automation) system that can relieve drivers stress in the stop-and-go traffic conditions encoun-tered on urban roads.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.215-218
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• 2002

The edges of an image hold much of the information in that image. The edges tell where objects are, their shape and size, and something about their texture. An edge is where the intensity of an image moves from a low value to a high value. We introduce the edge detection using the differential operator with Sobel operator and describe a nonparametric Wilcoxon test based on statistical hypothesis testing for the detection of edges. This paper proposes an efficient edge detection using Van der Waerden's statistic in original and noisy images. We use the threshold determined by specifying significance level a and an edge-height parameter. Comparison with our statistical test and Sobel operator shows that Van der Waerden method perform more effectively in both noisy and noise-free images.

• Journal of the Korea Society of Computer and Information
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• v.21 no.9
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• pp.45-49
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• 2016

In this study, an image processing algorithm was developed to increase readability of the images of specific parts of a KTX train acquired by using a mobile digital radiographic testing device in a situation where a running train is stopped. The image processing algorithm was realized by using a Visual C++ development tool. The algorithm developed in this study allows to select an interested region in the acquired images when the interested region is suspected to cause a problem, and applies a thinning process based Sobel operators to the selected region. The experimental results show that the readability of defect parts that are not visible to naked eyes was increased through edge detector. Application of the algorithm developed in this study may help to accurately read non-destructive inspection images.