• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.513-518
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• 2002

This paper presents the new method for removing impulse noise using wavelet. Time and frequency-localization capabilities in denoising can provide excellent specialties comparing with the existing methods, because of including detail information of signal. The method in this paper, using denoising by threshold and slope of signal by wavelet, has superior denoising effect and can recognize edge of original signal. For objective judgement, the test signals are used HeaviSine and DTMF and this paper simulated by test signals which have added to impulse noise of different site individually.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.179-181
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• 2009

In this paper, we propose an adaptive noise detection and modified Gaussian removal algorithm using local statistics for impulse noise. In order to determine constraints for noise detection, the local mean, variance, and maximum values are used. In addition, a modified Gaussian filter that integrates the tuning parameter to remove the detected noises. Experimental results show that our method is significantly better than a number of existing techniques in terms of image restoration and noise detection.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.463-466
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• 2008

With the development of Information Technology in recent years, the image has been an important means to store or express information. Generally, during the process of acquiring and storing images, the images can be corrupted by noise of which typical types are Impulse(Impulse Noise) and AWGN(Addiction White Gaussian Noise). Impulse noise shows irregularly in black and white over the length and breadth of the image by sharp and sudden disturbance of the image signal. In the Impulse noise environment, SM(Standard Median) filter would be used because of its good noise removal performance and simple algorithm. However, when SM filter removes noise, it also produces error at the edge of image and causes whole image quality deterioration. In this paper, we propose a method based on modified nonlinear filter operation scheme which enhances the features of noise removal and detail image preservation when restoring image in Impulse noise environment. And, we compared it with existing methods and the performances through simulation.

• The Journal of the Acoustical Society of Korea
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• v.4 no.2
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• pp.26-35
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• 1985

본 논문에서는 시스템의 전달계에 있어서 추정임펄스응답신호의 정도평가법으로서 새로운 방법 을 제안한다. 이 방법의 효과에 대해서는 종래부터 이용되어온 방법들과의 논의와 컴퓨터 시뮬레이션실 험 결과를 비교하여 기술하고 있다. 추정임펄스응답의 정도는 다음의 절차에 의해 평가하고 있다. 전달 계의 입력신호는 컴퓨터가 발생하는 화이트노이즈로서 구동시키고, 그 전달계의 응답신호는 전달계를 통한 입력신호를 측정한다. 이 때 전달계에서 추정응답신호를 얻기 위하여 추정임펄스응답신호와 구동 입력신호인 화이트노이즈를 콘볼루션 계산을 행한다. 추정응답신호인 계산한 응답신호와 측정한 응답신 호는 각 샘플링 시간에 있어서 차의 신호의 파워의 합을 측정한 응답신호의 샘플값을 제곱한 신호의 합 에 대해 비를 계산한다. 이 비율이 음향전달계의 추정임펄스응답신호의 정도평가법에 사용된다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.11a
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• pp.94-95
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• 2019

본 논문에서는 에너지인터넷의 한 분야인 전력선 통신 기반 전기 자동차 충전 시스템 구축에서 발생하는 임펄스 노이즈 동기화 문제를 해결하기 위해 OFDM에서 사용하는 프레임 동기화 방식을 제안한다. Kasami sequence를 통한 동기화 방식으로 전력선 통신의 임펄스 노이즈 동기화 결과를 확인한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1251-1256
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• 2010

In the transmitting process of image signal processing system, there are several different causes of degradation that have been occuring. The main cause of degradation is attributed to the noise. The most representive method of removing noise of image, which is caused by impulse noise environment, is using the SM filter. At edge, the filter has a special feature which has a tendency to decrease. As a result, we proposed a nonlinear filter using the form of mask and the probability of the impulse noise to restore the image considering edge quality in the impulse noise environment. And through the simulation, we compared with the existings and capabilities.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.431-434
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• 2003

As a wavelet transform which is presented as a new technique of signal processing field has time and frequency localization capabilities, it's possible for multiresolution analysis as well as easy to analyze various signal. So it is being applied in many fields recently. And when two wavelet base were designed to form Hilbert transform pair, wavelet pair show superior performance than the existing DWT(discrete wavelet transform) in data detection of pulse type. Therefore in this paper, we detected position of impulse noise by using two dyadic wavelet base which is designed by truncated coefficient vector.

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.2
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• pp.75-82
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• 1994

The existence of peroodic impulse noises in distribution line carrier (DLC) communication system is known to be the most serious obstacle for improving DLC communication quality in reliability and capacity. From the spectral points, impulse noises can be divided into baseband type and modulation type the noise width of whichs are much different each other. With each nose type, this study presents the basic characteristics in relation to what they originate from and how their spectrum properties are revealed. The baseband type impulse noise is normally caused from thyristor circuit running with low switching speed and the modulation type noise from the circuit of switching power supply. The base wave of modulation noise is shown to be the pulsuatic charging current to primary condenser in switching power circuit. The study result indicates also that placing the DLC carrier frequency away the band predominated by modulated noise especially from RCC type switching power circuit is very important in DLC design.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.283-285
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• 2006

영상 개선은 영상처리의 전처리 단계로, 주로 영상필터를 사용하여 영상처리의 성능을 향상시킨다. 각종 목적에 맞는 다양한 영상 필터가 제안되고 있으며, 복수의 필터를 적응하여 보다 좋은 효과를 얻기도 한다. 다양한 영상 필터를 적절히 적용하면 하나의 필터를 사용하는 것보다 더 높은 품질을 얻을 수 있지만, 영상 필터가 다양할수록 우수한 필터 조합을 찾는 것은 매우 어렵다. 본 논문에서는 유전자 알고리즘을 이용하여 문제에 적절한 필터 조합을 찾는 방법을 제안한다. 진화에 의해 성능이 좋은 필터 조합을 자동으로 찾기 때문에, 전문가의 지식이 필요하지 않고, 영상 개선의 여러 분야에 적용될 수 있다. 제안하는 방법을 임펄스 노이즈 제거를 위해 적용하였고, 기존의 영상 개선 방법보다 높은 성능을 획득하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.149-153
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• 2004

A Impulse denosing filter design of image for the faster processing time and system compatibility using DSP processor is presented on this paper The system hardware is composed of the stand-alone board with 32 bits DSP processor and vision board for image data acquisition with NTSC CCD camera, and the host computer controls them. The denoising method uses the adaptive median filter. The experiment result is that the system leads to denosing effect as 90% and PSNR 22㏈