• Title/Summary/Keyword: Sobel method

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The Characteristics of Edge Detection in Blurring Images by the Hybrid Functions for Local Scale Control (Local Scale변화에 대한 하이브리드 함수의 블러링 명상의 에지검출 특성)

  • 오승환;서경호;김태효
    • Journal of the Institute of Convergence Signal Processing
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    • v.2 no.1
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    • pp.53-62
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    • 2001
  • In this paper, the hybrid function by local scale control is proposed to detect the optimal edges from blurred images. In the case of image capturing, some blurring is occurred by the characteristics of the illumination and the reflected light. During processing the blurred image, it is difficult to detect perfect edges. This algorithm proposed a new hybrid function which is merged Gaussian function and the second derivative of Gaussian function. And it detects the optimal edges applying directional edge detection by Canny algorithm as the scale factor of $\sigma$ in the given local mask has been changed after convolving the hybrid function for input image. In the result, the performance is confirmed that this algorithm is better than Sobel, Robert and Canny edge detector by analyzing the some test images. And the results is obtained 0.2 ㏈ ~ 14 ㏈ of PSNR than those conventional method.

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The Effect of Trust and Customer Value on Loyalty: An Empirical Study in Indonesia

  • SOLIHA, Euis;MASKUR, Ali;WIDYASARI, Suzy;ARIYANI, Eva
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.1001-1010
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    • 2021
  • The world of tourism is a tangible form of a global business trip, which is very promising because it will be estimated to be a sector capable of driving world economic growth resulting from tourists' ever-increasing movement. Currently, in Indonesia, marketing activities in this sector are an integrated process, where the main target is providing customer satisfaction. Thus, the company's marketing activities are expected to be in accordance with customer expectations. The essential purpose of this study was to analyze the mediating role of the effect of trust and customer value on loyalty. The population of this study was users of the Lentera Wisata service in Semarang City, Indonesia. The sampling used a purposive sampling method, with the criteria of male and female customers and customers who have used the Lentera Wisata Semarang service bureau more than once. The test employed multiple regression analyses and the Sobel test. The test results revealed that trust and customer value positively and significantly affected satisfaction. However, trust did not affect customer loyalty. Meanwhile, customer value and satisfaction significantly and positively influenced loyalty. Additionally, the Sobel test results revealed that satisfaction mediated the effect of trust and customer value on customer loyalty.

A Study on Algorithm of Edge Detection in Mixed Noise Environments (복합잡음 환경에서 에지 검출에 관한 알고리즘에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.100-103
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    • 2014
  • Currently, edge detection is utilized in various areas. Edge detection is the preprocessing process for image processing in general, and this is a technology that is considered essential for image processing. According, research on this subject is carried out incessantly. Edge has important image related elements such as size, direction and location of the object of an image. Numerous methods were proposed for the detection. Among them, the representative methods are Sobel, Prewitt, Roberts, Laplacian. However, these existing methods are rather lacking when it comes to the edge detection characteristics in case of the image with mixed noise. Therefore, this study presented edge detection method that utilizes median and average values for the elements depending on the size and location of local mask.

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Colormap Construction and Combination Method between Colormaps (컬러맵의 생성과 컬러맵간의 결합 방법)

  • Kim, Jin-Hong;Jo, Cheol-Hyo;Kim, Du-Yeong
    • The Transactions of the Korea Information Processing Society
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    • v.1 no.4
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    • pp.541-550
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    • 1994
  • A true color image is needed many data on the occasion of the transmission and storage. Therefore, we want to describe color image by a minority data without unreasonableness at eyesight. In this paper, it is presented 256 colormap construction method in RGB, YIQ/YUV space and common colormap expression method at merge between colormaps by reason of dissimilar original color image to display at a monitor for each other colormap at the same time. In comparison with processed result in RGB, YIQ/YUV space, it was measured by PSNR, standard variation, and edge preservation rate using sobel operator. Process time is 3second in colormap construction and 2second in merge between colormaps. In the PSNR value, RGB space has higher 0.15, 0.34 on an average than YIQ and YUV spae. Standard variation has lower in 0.15, 0.41 on an average than Yiq and YUV space. But in the data compression, YIQ/YUV space have about 1/3 compression efficiency than RGB space by reason of use to only 4bit of 8bit in color component.

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An effective edge detection method for noise images based on linear model and standard deviation (선형모형과 표준편차에 기반한 잡음영상에 효과적인 에지 검출 방법)

  • Park, Youngho
    • The Korean Journal of Applied Statistics
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    • v.33 no.6
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    • pp.813-821
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    • 2020
  • Recently, research using unstructured data such as images and videos has been actively conducted in various fields. Edge detection is one of the most useful image enhancement techniques to improve the quality of the image process. However, it is very difficult to perform edge detection in noise images because the edges and noise having high frequency components. This paper uses a linear model and standard deviation as an effective edge detection method for noise images. The edge is detected by the difference between the standard deviation of the pixels included in the pixel block and the standard deviation of the residual obtained by fitting the linear model. The results of edge detection are compared with the results of the Sobel edge detector. In the original image, the Sobel edge detection result and the proposed edge detection result are similar. Proposed method was confirmed that the edge with reduced noise was detected in the various levels of noise images.

Development of Hough Transform for Space-Variant Image (공간 변형 영상에서의 Hough 변환)

  • 김장식;진성일
    • Proceedings of the IEEK Conference
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    • 2000.09a
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    • pp.675-678
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    • 2000
  • This paper presents a parametric line equation on the log-polar mapped plane to detect the straight lines in an original image. The log-polar edge image used in Hough transform is constructed by combining the edge images of both fovea and periphery. The foveal edge image detected by a Sobel mask on the Cartesian plane is transformed to the log-polar plane by forward mapping but the edge detection of the peripheral region is obtained by directly applying the newly developed mask to the log-polar plane. This paper also proposes a analytic method then determining a border between the fovea and the periphery regions.

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Edge Detection by Compass Gradient Masks (컴패스 그라디언트 매스크에 의한 에지 검출)

  • 김영채;김명기
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1986.10a
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    • pp.53-55
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    • 1986
  • The edge detection system makes use or 3*3 compass gradient masks, which are well suited for digital implementation. Edge angles are quantized to eight equally spaced directions, suitable for chain coding of contours. Use of edge direction msp improves the simple thresholding of gradient modulus image. The concept of local connectivity of the edge direction map is useful improving the performance of this method as well as other edge operators such as Kirsch and Sobel.

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A Method for Quantitative Performance Evaluation of Edge Detection Algorithms Depending on Chosen Parameters that Influence the Performance of Edge Detection (경계선 검출 성능에 영향을 주는 변수 변화에 따른 경계선 검출 알고리듬 성능의 정량적인 평가 방법)

  • 양희성;김유호;한정현;이은석;이준호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.6B
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    • pp.993-1001
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    • 2000
  • This research features a method that quantitatively evaluates the performance of edge detection algorithms. Contrary to conventional methods that evaluate the performance of edge detection as a function of the amount of noise added to he input image, the proposed method is capable of assessing the performance of edge detection algorithms based on chosen parameters that influence the performance of edge detection. We have proposed a quantitative measure, called average performance index, that compares the average performance of different edge detection algorithms. We have applied the method to the commonly used edge detectors, Sobel, LOG(Laplacian of Gaussian), and Canny edge detectors for noisy images that contain straight line edges and curved line edges. Two kinds of noises i.e, Gaussian and impulse noises, are used. Experimental results show that our method of quantitatively evaluating the performance of edge detection algorithms can facilitate the selection of the optimal dge detection algorithm for a given task.

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Adaptive Error Concealment Technique using a Variable Operating Region Algorithm based on MPEG-4 Coding (연산 영역 가변 알고리즘을 적용한 MPEG-4 부호화 기반의 적응적 오류 은닉 기법)

  • 김병주;권기구;이석환;권성근;김봉석;이건일
    • Journal of Korea Multimedia Society
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    • v.6 no.1
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    • pp.78-88
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    • 2003
  • A novel adaptive error concealment technique is proposed using a variable operating region algorithm based on MPEG-4 coding. In the algorithm, a missing block is classified as flat or edge block based on local information from the surrounding blocks extracted using a Sobel operation in a variable operating region (VOR). In this case, the VOR is determined adaptively according to the number of edge directions in the missing block. 1;sing the classification, the flat blocks are then concealed by the Proposed mean based weighted bilinear interpolation (MWBLI) method, and the edge blocks by the boundary directional interpolation (BDI) method. Consequently, the use of the Proposed VOR improves the subjective performance in a curved edge region, while the adaptive processing based on block classification improves the objective performance. Experimental results confirmed that the proposed algorithm produced better results than conventional algorithms, both subjectively and objectively.

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Medical Image Enhancement Using an Adaptive Nonlinear Histogram Stretching (적응적 비선형 히스트그램 스트레칭을 이용한 의료영상의 화질향상)

  • Kim, Seung-Jong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.658-665
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    • 2015
  • In the production of medical images, noise reduction and contrast enhancement are important methods to increase qualities of processing results. By using the edge-based denoising and adaptive nonlinear histogram stretching, a novel medical image enhancement algorithm is proposed. First, a medical image is decomposed by wavelet transform, and then all high frequency sub-images are decomposed by Haar transform. At the same time, edge detection with Sobel operator is performed. Second, noises in all high frequency sub-images are reduced by edge-based soft-threshold method. Third, high frequency coefficients are further enhanced by adaptive weight values in different sub-images. Finally, an adaptive nonlinear histogram stretching method is applied to increase the contrast of resultant image. Experimental results show that the proposed algorithm can enhance a low contrast medical image while preserving edges effectively without blurring the details.