• Title/Summary/Keyword: high-pass filtering

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Adaptive Histogram Projection And Detail Enhancement for the Visualization of High Dynamic Range Infrared Images

  • Lee, Dong-Seok;Yang, Hyun-Jin
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.11
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    • pp.23-30
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    • 2016
  • In this paper, we propose an adaptive histogram projection technique for dynamic range compression and an efficient detail enhancement method which is enhancing strong edge while reducing noise. First, The high dynamic range image is divided into low-pass component and high-pass component by applying 'guided image filtering'. After applying 'guided filter' to high dynamic range image, second, the low-pass component of the image is compressed into 8-bit with the adaptive histogram projection technique which is using global standard deviation value of whole image. Third, the high-pass component of the image adaptively reduces noise and intensifies the strong edges using standard deviation value in local path of the guided filter. Lastly, the monitor display image is summed up with the compressed low-pass component and the edge-intensified high-pass component. At the end of this paper, the experimental result show that the suggested technique can be applied properly to the IR images of various scenes.

Fast Preprocessing Technique based on High-Pass Filtering for Spool Rate Extraction of Weak JEM Signals (약한 제트 엔진 변조 신호의 Spool Rate 추출을 위한 High-Pass Filtering 기반의 빠른 전처리 기법)

  • Song, Won-Young;Kim, Hyung-Ju;Kim, Sung-Tai;Shin, In-Seon;Myung, Noh-Hoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.30 no.5
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    • pp.380-388
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    • 2019
  • Jet engine modulation(JEM) signals are widely used for target recognition. These signals coming from a potentially hostile aircraft provide specific information about the jet engine. In order to obtain the number of blades, which is uniquely provided by the JEM signal, one must extract the spool rate, which is the rotation speed of the blades. In this paper, we propose an algorithm to extract the spool rate from a weak JEM signal. A criterion is developed to extract the spool rate from the JEM signal by analyzing the intensity of the JEM signal component. The weak signal is first subjected to a high-pass filtering-based process, which modifies it to facilitate spool rate extraction. We then apply a peak detection process and extract the spool rate. The technique is simpler than the existing CEMD or WD method, is accurate, and greatly reduces the time required.

Motor noise removal for determining gait events over treadmill walking using wavelet filter

  • Yeom, Ho-Jun;Selgrade, Brian P.;Chang, Young-Hui;Kim, Jung-Lae
    • International journal of advanced smart convergence
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    • v.1 no.1
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    • pp.48-51
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    • 2012
  • The conventional method for filtering force plate data, low-pass filtering, does not always give accurate results when applied to force data from a custom-made, instrumented treadmill. Therefore, this study compares low-pass filtered data to the same data passed through a wavelet filter. We collected data with the treadmill running. However these include motor noise with ground reaction force at two force plates. We found that he proposed wavelet method eliminated motor noise to result in more accurate force plate data than the conventional low-pass filter, particularly at high speed motor operation. In this study we suggested the convolution wavelet (CNW) which was compared to that of a low-pass filter. The CNW showed better performance as compared to band-pass filtering particularly for low signal-to-noise ratios, and a lower computational load.

Comparative Analysis of LPF and HPF for Roads Edge Detection from High Resolution Satellite Imagery (고해상도위성영상에서 도로 경계 검출을 위한 고주파와 저주파 필터링 비교분석에 관한 연구)

  • Choi, Hyun;Kang, In-Joon
    • Journal of Korean Society for Geospatial Information Science
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    • v.14 no.3 s.37
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    • pp.3-11
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    • 2006
  • The need for edge detection about topography data from the high resolution satellite imagery is happening with increasing frequency according to many people utilize the its imagery as various fields recently. Many experts is recognizing of other GIS will make use of the road detection from the high resolution satellite imagery, including ITS (Intelligent Transportation Systems) and urban planning. This paper is comparative analysis of LPF (Low Pass Filtering) and HPF (High Pass Filtering) for roads edge detection from high resolution satellite imagery. As a result, LPF and HPF can be highlight selective pixels at edge area about input data. In case or applying to other techniques such as LPF for the same purpose, they aye more effective for wide road width which often cause the slight distortion of boundary or overall change of brightness values on the whole Image. Whereas, HPF has ability to enhance selectively detailed components in a target image.

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Application of the Band-pass Filtering for Improving 3D Tomogram of Micron-thick Sections of Biological Specimens (생물시료의 3D Tomogram 정밀도 개선을 위한 Band-pass Filtering 활용)

  • Ryu, Keun-Yong;Kim, Mi-Jeong;Choi, Ki-Joo;Je, A-Reum;Kim, Soo-Jin;Lee, Chul-hyun;Jung, Hyun-Suk;Park, Jong-Won;Kweon, Hee-Seok
    • Applied Microscopy
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    • v.42 no.2
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    • pp.105-109
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    • 2012
  • Electron tomography (ET) of biological specimens is performed from a series of images obtained over a range of tilt angles in a transmission electron microscope. When using the high voltage electron microscope (HVEM), various noises appear in EM images acquired from thick sections by high voltage electron beam. In order to obtain an adequate result in electron tomograms that allow visualization of rather complex and mega-cellular structure such as brain tissue, it is necessary to remove the noise in each original tilt images of thick section. Using band-pass filtering of original tilt images, the filtered images are obtained and used to assemble a reconstructed tomogram. The qualified 3D tomogram from filtered images results in a considerable reduction of the noises compared to conventional tomogram. In conclusion, this study suggests that band-pass filtering is effective to improve the brightness and intensity of HVEM produced tomograms acquired from micron-thick sections of biological specimens.

Pre-filtering of Images Considering Human Visual Perception (시각특성을 고려한 영상의 전처리 필터링)

  • 권효섭;조남익
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.4
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    • pp.706-713
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    • 1997
  • In this paper, we propose a band stop filter(BSF) for reducing drag-like effect of the low pass filter(LPF), a block by block adaptive filtering method, and a motion adaptive filtering method, which show better results in terms of PSNR or human visual perception compared to the conventional method using LPF. The BSF improves the draglike effects of the low pass filter by passing temporal high frequency components of video sequences which correspond to objects with large motion. The proposed adaptive methods also improve the conventional adaptive filtering by modifying the conventional algorithm and applying the algorithms for small blocks. The simulation results show that the proposed filtering methods show better results in terms of PSNR and subjective tests in most cases. Also in case of block by block adaptive filtering, it is verified that the application of the algorithm for smaller block gives better results.

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A Study on the Edge Detection for Road Information based on the IKONOS (IKONOS 영상에서 도로정보추출을 위한 경계검출에 관한 연구)

  • Choi, Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.3
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    • pp.593-598
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    • 2006
  • High-resolution satellite imagery has many benefits, compared to aerial photo in the wide area as well as multi-spectral character. So, it can be used well for constructing GIS data when making digital map. This study analysed the possibilities that road information derived automatically from IKONOS can be used for making ITS system or updating digital map of the urban areas where change frequently and producing satellite image map. In this study, Sobel was applied for road edge dectection after low pass filtering. As the results, it's possible for low pass filtering and high pass filtering to be used as the basic data for ITS construction when extracting edge roads and constructs according to the characteristic of high-resolution satellite imagery.

Electrooculography Filtering Model Based on Machine Learning (머신러닝 기반의 안전도 데이터 필터링 모델)

  • Hong, Ki Hyeon;Lee, Byung Mun
    • Journal of Korea Multimedia Society
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    • v.24 no.2
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    • pp.274-284
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    • 2021
  • Customized services to a sleep induction for better sleepcare are more effective because of different satisfaction levels to users. The EOG data measured at the frontal lobe when a person blinks his eyes can be used as biometric data because it has different values for each person. The accuracy of measurement is degraded by a noise source, such as toss and turn. Therefore, it is necessary to analyze the noisy data and remove them from normal EOG by filtering. There are low-pass filtering and high-pass filtering as filtering using a frequency band. However, since filtering within a frequency band range is also required for more effective performance, we propose a machine learning model for the filtering of EOG data in this paper as the second filtering method. In addition, optimal values of parameters such as the depth of the hidden layer, the number of nodes of the hidden layer, the activation function, and the dropout were found through experiments, to improve the performance of the machine learning filtering model, and the filtering performance of 95.7% was obtained. Eventually, it is expected that it can be used for effective user identification services by using filtering model for EOG data.

A Study of Vein Identification System using 2D-Gabor Filter for the Vessel USN Entrance/Exit Management (선박USN 출입관리를 위한 2차원 Gabor 필터를 이용한 정맥 인식 방법에 관한 연구)

  • Choi, Myeong-Soo;Lee, Seong-Ro;Sin, Sang-Woo;Jang, Kyung-Sik;Jung, Min-A
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.11A
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    • pp.1190-1196
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    • 2007
  • In this paper, we propose the biometrics system using hand vein pattern. This system is for management about person's entrance/exit in vessel USN. we select the biometrics method using hand vein pattern as adoptable method to vessel USN environment. Our experimental results show that preprocessing using two dimensional gabor filter achieves performance improvements over high pass filtering. Also, we compared our method with measured FAR(False Acceptance Rate) and FRR(False Rejection Rate) using pattern matching, the results show low error rate over high pass filtering. As a result, we verify the adoptability of biometrics system using hand vein pattern in management of person's entrance/exit in vessel.

Real-Time Continuous-Scale Image Interpolation with Directional Smoothing

  • Yoo, Yoonjong;Shin, Jeongho;Paik, Joonki
    • IEIE Transactions on Smart Processing and Computing
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    • v.3 no.3
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    • pp.128-134
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    • 2014
  • A real-time, continuous-scale image interpolation method is proposed based on a bilinear interpolation with directionally adaptive low-pass filtering. The proposed algorithm was optimized for hardware implementation. The ordinary bi-linear interpolation method has blocking artifacts. The proposed algorithm solves this problem using directionally adaptive low-pass filtering. The algorithm can also solve the severe blurring problem by selectively choosing low-pass filter coefficients. Therefore, the proposed interpolation algorithm can realize a high-quality image scaler for a range of imaging systems, such as digital cameras, CCTV and digital flat panel displays.