• Title/Summary/Keyword: Noise Removal

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Adaptive Weighted Mean Filter to Remove Impulse Noise in Images (영상에서 임펄스 잡음제거를 위한 적응력 있는 가중 평균 필터)

  • Lee, Jun-Hee;Choi, Eo-Bin;Lee, Won-Yeol;Lim, Dong-Hoon
    • The Korean Journal of Applied Statistics
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    • v.21 no.2
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    • pp.233-245
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    • 2008
  • In this work, a new adaptive weighted mean filter is proposed for preserving image details while effectively suppressing impulse noise. The proposed filter is based on a noise pixel detection-estimation strategy. All the pixels are first detected using an impulse noise detector. Then the detected noise pixels are replaced with the output of the weighted mean filter over adaptive working window according to the rate of corrupted neighborhood pixels, while noise-free pixels are left unaltered. We compare the proposed filter to other existing filters in the qualitative measure and quantitative measures such as PSNR and MAE as well as computation time to verify the capability of the proposed filter. Extensive simulations show that the proposed filter performs better than other filters in impulse noise suppression and detail preservation without increasing of running time.

A Study on Nonlinear Filter for Removal of Complex Noise (복합잡음 제거를 위한 비선형필터에 관한 연구)

  • Lee, Kyung-Hyo;Ryu, Ji-Goo;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.10a
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    • pp.455-458
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    • 2008
  • Former times Information Technology generally has only depended on text or sound, while nowadays information is being moved through a variety of image media. Cell phone, TV and computer have been major elements of modem society as mediators using image signal. Therefore, image signal processing also has been treated importantly and done actively. The processing has been developed in many fields of digital image processing technologies as image data compression, recognition, restoration, etc. Noises are inevitably generated by using the signals during the processing, and typical types of the noise are Impulse(salt & pepper) and AWGN(Addiction White Gaussian Noise). To reduce the noise, various kinds of filters have been developed, and according to each noise, it is being used different filter each. However, the noise is not generated by one signal but by a complex. In this paper, I suggested an image filter to remove the complex noise, and compared with existing filters' methods for verification.

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A Study on Image Restoration Algorithm using Standard Deviation and Cubic Spline Interpolation (표준편차 및 3차 스플라인 보간법을 이용한 영상 복원 알고리즘에 관한 연구)

  • Kwon, Se-Ik;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.9
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    • pp.1689-1696
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    • 2017
  • In the process of obtaining and transmitting image, there is degradation of image due to various noise, and there have been many active studies ongoing to remove the noise added on the images. This thesis has proposed a switching filter processing by the types of noise in order to remove the complex noise added on images. When the center value of local mask is damaged by AWGN based on the noise judgment, the threshold value is applied on standard deviation of local mask to process by applying different weight of weighted mask, and if the image is damaged by the salt and pepper noise, the local mask is subdivided into 4 directions, and processed by applying cubic spine interpolation in the direction with the least slat and pepper noise. Also, in order to evaluate the performance of proposed filter algorithm, the study conducted comparison among the existing methods and proposed filter using PSNR.

Salt & Pepper Noise Removal using Bilinear Interpolation (이중 선형 보간법을 이용한 Salt & Pepper 잡음 제거)

  • Ko, You-Hak;Kwon, Se-Ik;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.05a
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    • pp.343-345
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    • 2017
  • In digital era image processing has been utilized in a variety of media such as TV, camera and smart phone. However, in the process of analyzing, recognizing, and processing image data, deterioration occurs due to various causes and Salt & Pepper noise occurs. Typical methods for removing such noise include SMF, CWMF, and SWMF. However, existing methods have a somewhat poor noise canceling characteristic in Salt & Pepper noise environment. Therefore, in this paper, we propose an algorithm to remove Salt & Pepper noise effectively by using bilinear interpolation method and median filter according to noise density of local mask. And using the PSNR(Peak Signal to Noise Ratio) it compared to the existing methods and their performance in order to determine the performance of the proposed method.

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Noise Removal of Image Signals using Inflection Points on Histogram (히스토그램의 변곡점을 이용한 영상 신호의 잡음 제거)

  • Baek, Ji-Hyeon;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.11
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    • pp.1431-1436
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    • 2020
  • In modern society, various video devices such as CCTV and black boxes are used for convenience. However, noise is frequently generated in the process of transmitting and receiving video images and video signals photographed at night. If such noise is not eliminated, the problem that the image is difficult to identify is generated. Accordingly, noise elimination of images in the image information is an indispensable step. Salt and Pepper noises are typical impulse noises among image noises. Previous research has been carried out as a method for eliminating noise, and CWMF, MMF and A-TMF are typical methods. In common, such a filter exhibits excellent performance in a low-density noise area, but a disadvantage is that noise elimination performance in a high-density noise area is somewhat insufficient. Accordingly, the proposed algorithm uses the inflection point of the histogram graph to separate areas and remove singular points, and proposes a weighting filter utilizing histogram distribution. PSNR was used for objective judgment.

Visual quality enhancement of three-dimensional photon-counting integral imaging using background noise removal algorithm (배경 잡음 제거 알고리즘을 적용한 3차원 광자 계수 집적 영상의 화질 향상)

  • Cho, Ki-Ok;Kim, Young jun;Kim, Cheolsu;Cho, Myungjin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.7
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    • pp.1376-1382
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    • 2016
  • In this paper, we present a visual quality enhancement technique for conventional three-dimensional (3D) photon counting integral imaging using background noise removal algorithm. Photon counting imaging can detect a few photons from desired objects and visualize them under severely photon-starved conditions such as low light level environment. However, when a lot of photons are generated from background, it is difficult to detect photons from desired objects. Thus, the visual quality of the reconstructed image may be degraded. Therefore, in this paper, we propose a new photon counting imaging method that removes unnecessary background noise and detects photons from only desired objects. In addition, integral imaging can be used to obtain 3D information and visualize the 3D image by statistical estimations such as maximum likelihood estimation. To prove and evaluate our proposed method, we implement the optical experiment and calculate mean square error.

Environmental IoT-Enabled Multimodal Mashup Service for Smart Forest Fires Monitoring

  • Elmisery, Ahmed M.;Sertovic, Mirela
    • Journal of Multimedia Information System
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    • v.4 no.4
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    • pp.163-170
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    • 2017
  • Internet of things (IoT) is a new paradigm for collecting, processing and analyzing various contents in order to detect anomalies and to monitor particular patterns in a specific environment. The collected data can be used to discover new patterns and to offer new insights. IoT-enabled data mashup is a new technology to combine various types of information from multiple sources into a single web service. Mashup services create a new horizon for different applications. Environmental monitoring is a serious tool for the state and private organizations, which are located in regions with environmental hazards and seek to gain insights to detect hazards and locate them clearly. These organizations may utilize IoT - enabled data mashup service to merge different types of datasets from different IoT sensor networks in order to leverage their data analytics performance and the accuracy of the predictions. This paper presents an IoT - enabled data mashup service, where the multimedia data is collected from the various IoT platforms, then fed into an environmental cognition service which executes different image processing techniques such as noise removal, segmentation, and feature extraction, in order to detect interesting patterns in hazardous areas. The noise present in the captured images is eliminated with the help of a noise removal and background subtraction processes. Markov based approach was utilized to segment the possible regions of interest. The viable features within each region were extracted using a multiresolution wavelet transform, then fed into a discriminative classifier to extract various patterns. Experimental results have shown an accurate detection performance and adequate processing time for the proposed approach. We also provide a data mashup scenario for an IoT-enabled environmental hazard detection service and experimentation results.

Noise Removal Algorithm for Accurate Mean Arterial Pressure Measurement in Pressurized Oscillometric Method (가압식 오실로메트릭 측정법에서 정확한 평균 동맥압 측정을 위한 노이즈 제거 알고리즘)

  • Joh, In-hee;Lim, Jung-hyun;Kim, Young-kil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.05a
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    • pp.184-187
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    • 2018
  • The most important factor in the prevention and treatment of cerebral infarction is to increase cerebral blood flow. Methods for increasing cerebral blood flow include drug-based methods, the surgery, invasive procedures directly inserting medical devices into the artery(NeuroFloTM) and so on. The noninvasive cerebral blood flow increasing device proposed in this paper can reduce the burden on the patient because the probability of complication is low and the treatment level can be determined according to the blood pressure state of the patient. In implementing such a noninvasive cerebral blood flow increasing device, it is important to measure the accurate mean arterial pressure for provision the appropriate level of treatment for the patient. Therefore, to remove a noise, analog and digital filters were used and algorithm for peak value detection, pump control algorithms and so on were.

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Nonlinear Anisotropic Diffusion Using Adaptive Weighted Median Filters (적응 가중 미디언 필터를 이용한 영상 확산 알고리즘)

  • Hwang, In-Ho;Lee, Kyung-Hoon;Kim, Woong-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.5C
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    • pp.542-549
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    • 2007
  • Recently, many research activities in the image processing area are concentrated on developing new algorithms by finding the solution of the 'diffusion equation'. The diffusion algorithms are expected to be utilized in numerous applications including noise removal and image restoration, edge detection, segmentation, etc. In this paper, at first, it will be shown that the anisotropic diffusion algorithms have the similar structure with the adaptive FIR filters with cross-shaped 5-tap kernel, and this relatively small-sized kernel causes many iterating procedure for satisfactory filtering effects. Moreover, it will also be shown that lots of modifications which are adopted to the conventional Gaussian diffusion method in order to weaken the edge blurring nature of the linear filtering process increases another computational burden. We propose a new Median diffusion scheme by replacing the adaptive linear filters in the diffusion process with the AWM (Adaptive Weighted Median) filters. A diffusion-equation-based adaptation scheme is also proposed. With the proposed scheme, the size of the diffusion kernel can be increased, and thus diffusion speed greatly increases. Simulation results shows that the proposed Median diffusion scheme outperforms in noise removal (especially impulsive noise), and edge preservation.

Noise Removal Algorithm using Standard Deviation and Estimation in AWGN Environment (AWGN 환경에서 표준편차 및 추정치를 통한 잡음 제거 알고리즘)

  • Cheon, Bong-Won;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.11
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    • pp.1468-1473
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    • 2018
  • The importance of communication and data processing is increasing with the advance of the Fourth Industrial Revolution. Hence, the importance of video and data processing technologies, which directly influence the accuracy and reliability of equipment, is also increasing. In this research report we propose an algorithm for calculating the final output by estimating the standard deviation and estimate required for removing AWGN while adapting to changes in the frequency factors of video. This algorithm calculates the final output by checking an estimated value against the effective pixel range, which is obtained from the standard deviation of mask factors. Subsequently, the weighted value is computed, taking into account the filter output. To evaluate the functionality of this algorithm, it is compared with the most-commonly used present method through simulation. The simulation results show that the important features of the image are preserved and efficient noise cancellation performance is demonstrated.