• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2982-2988
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• 2014

The edge detection is a pre-processing of such as image segmentation, image recognition, etc, and many related studies are being conducted both in domestic and abroad. Representative edge detection methods are Sobel, Prewitt, Laplacian, Roberts and Canny edge detectors. Such existing methods are possible for superb detections of edges if edges are detected from videos without noises. However, for video degraded by the salt-and-pepper noise, the edge detection characteristic is shown to be insufficient due to the noise influence. Therefore, in this study, the area is separated as the top, down, left and right from the mask's center pixel first to acquire a superb edge detection characteristic from the video damaged by the salt-and-pepper noise. And the algorithm that detects the final edge by applying the directional mask on the assumed factor of mask that is obtained according to the result of determination for the noise status of representative pixel value of each area.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8B
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• pp.1480-1489
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• 1999

In this paper, we propose a new post-processing method which can solve a problem of MSDS(Mean Squared Difference of Slope) method. Using that method the blocking artifacts can significantly be reduced without any restriction, which is a major drawback of block-based DCT compression method. In this approach, the OSLD(Overlapped Sub-Laplacian Distribution) of dequantized block boundary pixel difference values is defined and used to categorize each block of an image into one of four types. Those types are also classified into one of two classes: an edge and a non-edge classes. A slope across the block boundary is used to quantify discontinuity of the image. If an absolute estimated quantization error value of a DCT coefficient is greater than the corresponding quantization step size, it is saturated to the step size in the edge class. The proposed post-processing method can improve not only the PSNR value up to 0.1~O.3 dB but visual quality without any constraints determined by ad-hoc manner.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.700-702
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• 2004

본 논문에서는 내용 기반의 화상 검색 시스템을 위한 화상 특징 추출을 고속으로 수행하기 위하여 TCP/IP 프로토콜을 사용하는 LAN 환경에서 유휴(Idle) PC들을 사용한 PC 클러스터에 관해 연구하였다. 실험에 사용한 화상 특징(Image feature)으로서는 칼라의 응집도를 사용하는 CCV(Color Coherence Vector), 화상의 엔트로피를 정량화한 PIM(Picture Information Measure), Gaussian-Laplacian 에지 검출 연산을 사용한 SEV(Spatial Edge Histogram Vector)로서 이들을 추출하기 위한 Task를 Master rude에서 Slave rude들로 전송하고, 연산에 사용 될 화상 데이터를 전송한 후 연산을 수행하고 결과를 다시 Master node로 전송하는 전통적인 Task-Farming형태의 PC Cluster를 구성하였다. 연산에 참여하는 클러스터 노드의 개수를 증가시키며 Task와 화상데이터를 전송하여 이에 따른 연산시간을 측정하고 비교하였다. 실험 결과는 유휴 PC들로 구성된 PC클러스터를 이용한 효율적인 내용기반의 화상 검색 시스템을 구성하기 위해 활용이 가능하다.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.864-869
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• 1993

This paper presents the problem of automatically recognizing embossed or molded characters which are raised from the side wall on rubber tire. In the tire image objects have approximately the same gray-value as the background and because of the tire geometry, illumination of the surface is nonhomogenous. Therefore it is difficult to recognize the raised tire character. In this paper, for describing the process of processing three steps have been proposed: 1) MIN & MAX smoothing operation filter, 2) edge detection algorithm using modified laplacian operator, 3) noise rejection. Afterwards, segmentation is done to attain characters from tire image by projection method. The recognition of the characters in the segmented image is carried out by using multilayered neural network, which is insensitive to the noise.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.8
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• pp.1238-1246
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• 1989

In this paper, a texture synthesis technique based on the NCAR(non-causal auto-regressive) model and the pyramid structure is proposed. In order to estimate the NCAR model parameters accurately from a noisy texture, the MAP(maximum a posteriori) estimation technique is also employed. In our approach, since the input texture is decomposed into the Laplacian oyramid planes first and then the NCAR model is applied to each plane, we are able to obtain a good synthesized texture even if the texture exhibits some non-random local structure or non-homogenity. The usrfulness of the proposed method is demonstrated with seveal real textures in the Brodatz album. Finally, the 2-dimensional MAP estimation technique can be used to the image restoration for noisy images as well as a texture image synthesis.

• The Transactions of the Korea Information Processing Society
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• v.6 no.8
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• pp.2222-2232
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• 1999

This paper proposed a Systolic Arrays architecture for computing edge detection on images. It is very difficult to be processed images to real time because of operations of local operators. Local operators for computing edge detection are to be used in many image processing tasks, involve replacing each pixel in an image with a value computed within a local neighborhood of that pixel. Computing such operators at the video rate requires a computing power which is not provided by conventional computer. Through computationally expensive, it is highly regular. Thus, this paper presents a systolic arrays for tasks such as edge detection and laplacian, which are defined in terms of local operators.

• Journal of Information Processing Systems
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• v.10 no.2
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• pp.223-239
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• 2014

New IIR digital differintegrators (differentiator and integrator) with very minor absolute relative errors are presented in this paper. The digital integrator is designed by interpolating some of the existing integrators. The optimum value of the interpolation ratio is obtained through linear programming optimization. Subsequently, by modifying the transfer function of the proposed integrator appropriately, new digital differentiator is obtained. Simulation results demonstrate that the proposed differintegrator are a more accurate approximation of ideal ones, than the existing differintegrators. Furthermore, the proposed differentiator has been tested in an image processing application. Edges characterize boundaries and are, therefore, a problem of fundamental importance in image processing. For comparison purpose Prewitt, Sobel, Roberts, Canny, Laplacian of Gaussian (LOG), Zerocross operators were used and their results are displayed. The results of edge detection by some of the existing differentiators are also provided. The simulation results have shown the superiority of the proposed approach over existing ones.

• Korean Journal of Remote Sensing
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• v.1 no.1
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• pp.39-51
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• 1985

The study was emphasized on application of the digital image processing techniques for lineament analysis. The major lineament of the study area belongs to Choogaryong faults which many geologists have studied since 1903. Also the lineament is so significant in geological views, because the lineament runs through Seoul area. The several image processing methods such as gradient, Laplacian and spatial filter have been applied, and the spatial filtering is most suitable method for lineament analysis among them. The lineaments distribute predominently in the N20.deg.-30.deg.E trend and N80.deg.-90.deg.W trend which have the conjugated relationship each other, and it coincides with the Gyeongsang conjugate system. The circular structure of study area was developed by cooling circular joint.

• ETRI Journal
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• v.41 no.5
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• pp.599-607
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• 2019

Although iris recognition verification is considered to be the safest method of biometric verification, studies have shown that iris features may be illegally used. To protect iris features and further improve the security of iris recognition and verification, this study applies the Gaussian and Laplacian mechanisms and to hide iris features by differentiating privacy. The efficiency of the algorithm and evaluation of the image quality by the image hashing algorithm are selected as indicators to evaluate these mechanisms. The experimental results indicate that the security of an iris image can be significantly improved using differential privacy protection.

• 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.