• Title/Summary/Keyword: 잡음 제거 필터

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Study on R-peak Detection Algorithm of Arrhythmia Patients in ECG (심전도 신호에서 부정맥 환자의 R파 검출 알고리즘 연구)

  • Ahn, Se-Jong;Lim, Chang-Joo;Kim, Yong-Gwon;Chung, Sung-Taek
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.10
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    • pp.4443-4449
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    • 2011
  • ECG consists of various types of electrical signal on the heart, and feature point of these signals can be detected by analyzing the arrhythmia. So far, feature points extraction method for the detection of arrhythmia done in the many studies. However, it is not suitable for portable device using real time operation due to complicated operation. In this paper, R-peak were extracted using R-R interval and QRS width informations on patients. First, noise of low frequency bands eliminated using butterworth filter, and the R-peak was extracted by R-R interval moving average and QRS width moving average. In order to verify, it was experimented to compare the R-peak of data in MIT-BIH arrhythmia database and the R-peak of suggested algorithm. As a results, it showed an excellent detection for feature point of R-peak, even during the process of operation could be efficient way to confirm.

Active Object Tracking based on stepwise application of Region and Color Information (지역정보와 색 정보의 단계적 적용에 의한 능동 객체 추적)

  • Jeong, Joon-Yong;Lee, Kyu-Won
    • The KIPS Transactions:PartB
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    • v.19B no.2
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    • pp.107-112
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    • 2012
  • An active object tracking algorithm using Pan and Tilt camera based in the stepwise application of region and color information from realtime image sequences is proposed. To reduce environment noises in input sequences, Gaussian filtering is performed first. An image is divided into background and objects by using the adaptive Gaussian mixture model. Once the target object is detected, an initial search window close to an object region is set up and color information is extracted from the region. We track moving objects in realtime by using the CAMShift algorithm which enables to trace objects in active camera with the color information. The proper tracking is accomplished by controlling the amount of pan and tilt to be placed the center position of object into the middle of field of view. The experimental results show that the proposed method is more effective than the hand-operated window method.

A Content-Based Image Retrieval using Object Segmentation Method (물체 분할 기법을 이용한 내용기반 영상 검색)

  • 송석진;차봉현;김명호;남기곤;이상욱;주재흠
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.1
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    • pp.1-8
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    • 2003
  • Various methods have been studying to maintain and apply the multimedia inform abruptly increasing over all social fields, in recent years. For retrieval of still images, we is implemented content-based image retrieval system in this paper that make possible to retrieve similar objects from image database after segmenting query object from background if user request query. Query image is processed median filtering to remove noise first and then object edge is detected it by canny edge detection. And query object is segmented from background by using convex hull. Similarity value can be obtained by means of histogram intersection with database image after securing color histogram from segmented image. Also segmented image is processed gray convert and wavelet transform to extract spacial gray distribution and texture feature. After that, Similarity value can be obtained by means of banded autocorrelogram and energy. Final similar image can be retrieved by adding upper similarity values that it make possible to not only robust in background but also better correct object retrieval by using object segmentation method.

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A block-based face detection algorithm for the efficient video coding of a videophone (효율적인 화상회의 동영상 압축을 위한 블록기반 얼굴 검출 방식)

  • Kim, Ki-Ju;Bang, Kyoung-Gu;Moon, Jeong-Mee;Kim, Jae-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.9C
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    • pp.1258-1268
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    • 2004
  • We propose a new fast, algorithm which is used for detecting frontal face in the frequency domain based on human skin-color using OCT coefficient of dynamic image compression and skin color information. The region where each pixel has a value of skin-color were extracted from U and V value based on DCT coefficient obtained in the process of Image compression using skin-color map in the Y, U, V color space A morphological filter and labeling method are used to eliminate noise in the resulting image We propose the algorithm to detect fastly human face that estimate the directional feature and variance of luminance block of human skin-color Then Extraction of face was completed adaptively on both background have the object analogous to skin-color and background is simple in the proposed algorithm The performance of face detection algorithm is illustrated by some simulation results earned out on various races We confined that a success rate of 94 % was achieved from the experimental results.

Improvement of Lipreading Performance Using Gabor Filter for Ship Environment (선박 환경에서 Gabor 여파기를 적용한 입술 읽기 성능향상)

  • Shin, Do-Sung;Lee, Seong-Ro;Kwon, Jang-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.7C
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    • pp.598-603
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    • 2010
  • In this paper, we work for Lipreading using visual information for ship environment. Lipreading is studied for using image information including lips of a speaker at the existing speech recognition system. This technique is a compensation method to increase recognition rate decreasing remarkably in noisy circumstances. Proposed way improved the rate of recognition improving methode of preprocessing using the Gabor Filter for Ship Environment. The experiment were carried out under changing of light with time in the ship environment with lip image. For Comparing with recognition, make a compare with between method of lip region of interest (ROI) before Gabor filtering and after Gabor filtering. In the case of using method of lip ROI before Gabor filtering, the result of the experiments applying to the proposed ways recognition resulting in 44% of recognition.

Impulse Noise Removal of LRF for 3D Map Building Using a Hybrid Median Filter (3D 맵 빌딩을 위한 하이브리드 미디언 필터를 이용한 LRF의 임펄스 잡음 제거)

  • Hwang, Yo-Seop;Kim, Hyun-Woo;Kim, Tae-Jun;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.10
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    • pp.970-976
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    • 2012
  • In this paper, a single LRF has been used to produce a 3D map for the mobile robot navigation. The 2D laser scanners are used for mobile robots navigation, where the laser scanner is applied to detect a certain level of area by the straight beam. Therefore it is limited to the usages of 2D obstacle detection and avoidance. In this research, it is designed to complement a mobile robot system to move up and down a single LRF along the yaw axis. During the up and down motion, the 2D data are stacked and manipulated to build a 3D map. Often a single LRF data are mixed with Gaussian and impulse noises. The impulse noises are removed out by the hybrid median filter designed in this research. The 2D data which are improved by deleting the impulse noises are layered to build the 3D map. Removing impulse noises while preserving the boundary is a main advantages of the hybrid median filter which has been used widely to improve the quality of images. The effectiveness of this hybrid median filter for rejecting the impulse noises has been verified through the real experiments. The performance of the hybrid median filter is evaluated in terms of PSNR (Peak Signal to Noise Ratio) and the processing time.

Pseudo-inverse-filtering type decorrelating detector for asynchronous CDMA channels (비동기 CDMA 채널을 위한 의사 역행렬 형태의 역상관 검출기)

  • 맹승주;이병기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.8
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    • pp.2072-2079
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    • 1998
  • In this paper, we propose a new decorrelating detector called pseudo-inverse-filtering type decorrelating detector for asynchronous CDMA channels. We first show that the matched filtering and decorrelating operations of the existing decorrelating detectors can be replaced with the pseudo-inverse filtering operations in synchronous channels, and using this fact we show that the decorrelating detector has the largest SNR among the linear detectors that can eliminate MAI. Then we introduce asynchronous pseudo-inverse filtering type decorrelating detector by extending this result for asynchronous channels, and discuss implementation methods of the proposed decorrelating detectors. Since the proposed scheme employs a decentralized structure for updating coefficients, it has the flexibility to add/remove users. Finally we analyze the performance of the proposed decorrelating detector in terms of the bit error rate, and examine its performance improvements over the conventional detectors through computer simulations.

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A Genetic Programming Approach to Blind Deconvolution of Noisy Blurred Images (잡음이 있고 흐릿한 영상의 블라인드 디컨벌루션을 위한 유전 프로그래밍 기법)

  • Mahmood, Muhammad Tariq;Chu, Yeon Ho;Choi, Young Kyu
    • KIPS Transactions on Software and Data Engineering
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    • v.3 no.1
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    • pp.43-48
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    • 2014
  • Usually, image deconvolution is applied as a preprocessing step in surveillance systems to reduce the effect of motion or out-of-focus blur problem. In this paper, we propose a blind-image deconvolution filtering approach based on genetic programming (GP). A numerical expression is developed using GP process for image restoration which optimally combines and exploits dependencies among features of the blurred image. In order to develop such function, first, a set of feature vectors is formed by considering a small neighborhood around each pixel. At second stage, the estimator is trained and developed through GP process that automatically selects and combines the useful feature information under a fitness criterion. The developed function is then applied to estimate the image pixel intensity of the degraded image. The performance of developed function is estimated using various degraded image sequences. Our comparative analysis highlights the effectiveness of the proposed filter.

Digital Particle Holographic System for Flow-Field Measurements (유동장 계측을 위한 디지털 입자 홀로그래피 시스템)

  • Yan, Yang;Kang, Bo-Seon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.3
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    • pp.309-316
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    • 2010
  • In this study, a digital particle holographic system and its application to channel-flow measurements were investigated. A double-exposure hologram recording system that is capable of recording digital holograms in a short time interval was developed. A correlation coefficient method was used to determine the focal plane of particles. The Wiener filter was used to remove noises and improve image quality. Two-threshold and image segmentation methods were used for binary image transformation. The cross-correlation method was used for particle pairing. The developed system was employed to study channel flow fields, and the axial velocities of channel flow were measured. The measurement errors are acceptable, and this proves the feasibility of using the digital particle holographic system as a good tool for flow-field measurements.

A Walsh-Hadamard Transform Adaptive Filter with Time-varying Step Size (가변 스텝사이즈를 적용한 월시.아다말 적응필터)

  • 오신범;이채욱
    • Journal of Korea Society of Industrial Information Systems
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    • v.5 no.2
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    • pp.32-38
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    • 2000
  • One of the most popular algorithm in adaptive signal processing is the least mean square(LMS) algorithm. The majority of these papers examine the LMS algorithm with a constant step size. The choice of the step size reflects a tradeoff between misadjustment and the speed of adaptation. Subsequent works have discussed the issue of optimization of the step size or methods of varying the step size to improve performance. However there is as yet no detailed analysis of a variable step size algorithm that is capable of giving both the adaptation speed and the convergence. In this paper we propose a new variable step size algorithm where the step size adjustment is controlled by the gradient of error square. The proposed algorithm is performed in the Walsh-Hadamard domain in real-valued orthogonal transform because of fast convergence. The simulation results using the new algorithm for noise canceller system is described. They are compared to the results obtained by other algorithms. It is shown that the proposed algorithm produces good results compared with conventional algorithms.

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