• Title/Summary/Keyword: Noise Removal

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Alpha-trimmed Mean Filter for Impulse Noise Removal (임펄스 잡음 제거를 위한 알파트림 평균 필터)

  • Kim, Kuk-Seung;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.393-396
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    • 2010
  • In this paper the process of transmitting images signal restore to image corrupted by impulse noise proposed alpha-trimmed mean filter. the proposed filter first identifies the noise pixels using the morphological noise detector and then removes the detected impulse noise using the alpha-trimmed mean filter. these proposed filter can realize the accurate noise detection and it can remove impulse noise effectively while preserving edge region in the image very well. Through the simulation, we compared with the existing methods and capabilties.

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Post Processing Noise Reduction Algorithm of SAP Using Convolution Neural Network (합성곱신경망을 이용한 SAP 잡음 제거 후처리 알고리즘)

  • Kim Donghyung
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.19 no.2
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    • pp.57-68
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    • 2023
  • Because salt and pepper noise is a type of impulse, even a small amount of noise could cause a large image degradation. In this paper, we proposed a salt-and-pepper noise removal method using the convolutional neural network. It consists of four phases. In the first step, the proposed method reconstructs noisy image using a traditional salt-and-pepper noise reduction method, and in the second step, the result image of previous step is filtered with Gaussian low pass filter. After that, we reconstruct the filtered image using convolution neural network. In the last step, the pixels with salt-and-pepper noise are replaced with the result of previous phase. Simulation results show that the proposed method yields not only objective image qualities(PSNR, SSIM) but also subjective image qualities for all SAP noise ratios.

Adaptive Noise Cancelling in ECG Signals Using System Identification Concepts (System Identification 개념을 이용한 ECG 신호의 적응 잡음 제거)

  • Nam, Hyun-Do;Ahn, Dong-Jun
    • Proceedings of the KOSOMBE Conference
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    • v.1993 no.05
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    • pp.74-77
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    • 1993
  • Estimation and removal of power line interference in the electrocardiogram using adaptive noise cancelling techniques is presented. The system identification concepts are used to design the noise cancelling filter and the prediction error method is used to adjust filter coefficients. Computer simulation were performed to compare this method with the Lekov's method.

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Salt and Pepper Noise Removal Algorithm using Directional Effective Pixels (방향성 유효 화소를 이용한 Salt and Pepper 잡음 제거 알고리즘)

  • Cheon, Bong-Won;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.05a
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    • pp.179-181
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    • 2018
  • Digital imaging equipment is used for a variety of purposes in a wide range of fields in society and is becoming an important element of the 4th industrial revolution. Imaging equipment data is exposed to noise from various causes, and this noise affects accuracy of the equipment, causing errors and lowering reliability. In the present paper, an algorithm based on directional effective pixels is proposed to effectively remove high-density Salt and Pepper noise. Conventional methods show that performance decreases as Salt and Pepper noise density increases. To the contrary, the proposed method has noise-removal performance superior to those of conventional methods, by performing de-noising which considers directional effective pixels even in a high-density Salt and Pepper noise environment. Experimental results show that the proposed algorithm is superior to the existing methods, and performance is verified through enlarged images.

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Extraction of Skin Regions through Filtering-based Noise Removal (필터링 기반의 잡음 제거를 통한 피부 영역의 추출)

  • Jang, Seok-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.12
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    • pp.672-678
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    • 2020
  • Ultra-high-speed images that accurately depict the minute movements of objects have become common as low-cost and high-performance cameras that can film at high speeds have emerged. In this paper, the proposed method removes unexpected noise contained in images after input at high speed, and then extracts an area of interest that can represent personal information, such as skin areas, from the image in which noise has been removed. In this paper, noise generated by abnormal electrical signals is removed by applying bilateral filters. A color model created through pre-learning is then used to extract the area of interest that represents the personal information contained within the image. Experimental results show that the introduced algorithms remove noise from high-speed images and then extract the area of interest robustly. The approach presented in this paper is expected to be useful in various applications related to computer vision, such as image preprocessing, noise elimination, tracking and monitoring of target areas, etc.

Adaptive Weight Filter Algorithm for Restoration Images Corrupted by High Density Impulse Noise (고밀도 임펄스 잡음에 훼손된 영상 복원을 위한 적응형 가중치 필터 알고리즘)

  • Cheon, Bong-Won;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.10
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    • pp.1483-1489
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    • 2022
  • Recently, due to the influence of the 4th industrial revolution and the development of communication media, various digital video equipment are being used in industrial fields. Image data is easily damaged by noise in the process of acquiring and transmitting and receiving from the camera and sensor, and since the damaged image has a great effect on the processing of the system, noise removal is essential. In this paper, a weight filter algorithm using a weight graph is proposed to restoration images damaged by high-density impulse noise. The proposed algorithm obtains a weight graph using pixel values inside the filtering mask of the image, and restores the image by applying the final weight to the filtering mask. Simulation was conducted to analyze the noise removal performance of the proposed algorithm, and the magnified image and PSNR were used to compare with the existing method. The resulting image of the proposed algorithm showed excellent performance by removing high-density impulse noise.

Improved Binarization and Removal of Noises for Effective Extraction of Characters in Color Images (컬러 영상에서 효율적 문자 추출을 위한 개선된 2치화 및 잡음 저거)

  • 이은주;정장호
    • Journal of Information Technology Application
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    • v.3 no.2
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    • pp.133-147
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    • 2001
  • This paper proposed a new algorithm for binarization and removal of noises in color images with characters and pictures. Binarization was performed by threshold which had computed with color-relationship relative to the number of pixel in background and character candidates and pre-threshold for dividing of background and character candidates in input images. The pre-threshold has been computed by the histogram of R, G, B In respect of the images, while background and character candidates of input images are divided by the above pre-threshold. As it is possible that threshold can be dynamically decided by the quantity of the noises, and the character images are maintained and the noises are removed to the maximum. And, in this study, we made the noise pattern table as a result of analysis in noise pattern included in the various color images aiming at removal of the noises from the Images. Noises included in the images can figure out Distribution by way of the noise pattern table and pattern matching itself. And then this Distribution classified difficulty of noises included in the images into the three categories. As removal of noises in the images is processed through different procedure according to the its classified difficulties, time required for process was reduced and efficiency of noise removal was improved. As a result of recognition experiments in respect of extracted characters in color images by way of the proposed algorithm, we conformed that the proposed algorithm is useful in a sense that it obtained the recognition rate in general documents without colors and pictures to the same level.

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A New Efficient Impulse Noise Detection based on Rank Estimation

  • Oh, Jin-Sung;Kim, You-Nam
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.3
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    • pp.173-178
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    • 2008
  • In this paper, we present a new impulsive noise detection technique. To remove the impulse noise without detail loss, only corrupted pixels must be filtered. In order to identify the corrupted pixels, a new impulse detector based on rank and value estimations of the current pixel is proposed. Based on the rank and value estimations of the current pixel, the new proposed method provides excellent statistics for detecting an impulse noise while reducing the probability of detecting image details as impulses. The proposed detection is efficient and can be used with any noise removal filter. Simulation results show that the proposed method significantly outperforms many other well-known detection techniques in terms of image restoration and noise detection.

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Image Processing for Mixed Noise Removal (복합 잡음 제거를 위한 영상처리)

  • Lee, Kyung-Hyo;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.12
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    • pp.2701-2706
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    • 2009
  • There are Impulse noise and AWGN in a general image processing. Various methods have been proposed to remove these noises. Well-known filters are Mean, Min-max and Median filter and these show different characteristics depending on the noises. When Impulse noise and AWGN are in superposition environment, single filter doesn't remove noises well. Therefore in this paper, we suggested a switching filter using a probability of noise to restore images in this environment. And we compared a filter with conventional method through simulations.

Adaptive Iterative Depeckling of SAR Imagery

  • Lee, Sang-Hoon
    • Korean Journal of Remote Sensing
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    • v.23 no.5
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    • pp.455-464
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    • 2007
  • Lee(2007) suggested the Point-Jacobian iteration MAP estimation(PJIMAP) for noise removal of the images that are corrupted by multiplicative speckle noise. It is to find a MAP estimation of noisy-free imagery based on a Bayesian model using the lognormal distribution for image intensity and an MRF for image texture. When the image intensity is logarithmically transformed, the speckle noise is approximately Gaussian additive noise, and it tends to a normal probability much faster than the intensity distribution. The MRF is incorporated into digital image analysis by viewing pixel types as states of molecules in a lattice-like physical system. In this study, the MAP estimation is computed by the Point-Jacobian iteration using adaptive parameters. At each iteration, the parameters related to the Bayesian model are adaptively estimated using the updated information. The results of the proposed scheme were compared to them of PJIMAP with SAR simulation data generated by the Monte Carlo method. The experiments demonstrated an improvement in relaxing speckle noise and estimating noise-free intensity by using the adaptive parameters for the Ponit-Jacobian iteration.