• Title/Summary/Keyword: Noise Removal

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Depth map temporal consistency compensation using motion estimation (움직임 추정을 통한 깊이 지도의 시간적 일관성 보상 기법)

  • Hyun, Jeeho;Yoo, Jisang
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.2
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    • pp.438-446
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    • 2013
  • Generally, a camera isn't located at the center of display in a tele-presence system and it causes an incorrect eye contact between speakers which reduce the realistic feeling during the conversation. To solve this incorrect eye contact problem, we newly propose an intermediate view reconstruction algorithm using both a color camera and a depth camera and applying for the depth image based rendering (DIBR) algorithm. In the proposed algorithm, an efficient hole filling method using the arithmetic mean value of neighbor pixels and an efficient boundary noise removal method by expanding the edge region of depth image are included. We show that the generated eye-contacted image has good quality through experiments.

Curved Feature Modeling and Accuracy Analysis Using Point Cloud Data (점군집 데이터를 이용한 곡면객체 모델링 및 정확도 분석)

  • Lee, Dae Geon;Yoo, Eun Jin;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.3
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    • pp.243-251
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    • 2016
  • LiDAR data processing steps include noise removal, filtering, classification, segmentation, shape recognition, modeling, and quality assessment. This paper focuses on modeling and accuracy evaluation of 3D objects with curved surfaces. The appropriate modeling functions were determined by analyzing surface patch shape. Existing methods for modeling curved surface features require linearization, initial approximation, and iteration of the non-linear functions. However, proposed method could directly estimate the unknown parameters of the modeling functions. The results demonstrate feasibility of the proposed method. The proposed method was applied to the simulated and real building data of hemi-spherical and semi-cylindrical surfaces. The parameters and accuracy of the modeling functions were estimated. It is expected that the proposed method would contribute to automatic modeling of various objects.

Text Area Extraction Method for Color Images Based on Labeling and Gradient Difference Method (레이블링 기법과 밝기값 변화에 기반한 컬러영상의 문자영역 추출 방법)

  • Won, Jong-Kil;Kim, Hye-Young;Cho, Jin-Soo
    • The Journal of the Korea Contents Association
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    • v.11 no.12
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    • pp.511-521
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    • 2011
  • As the use of image input and output devices increases, the importance of extracting text area in color images is also increasing. In this paper, in order to extract text area of the images efficiently, we present a text area extraction method for color images based on labeling and gradient difference method. The proposed method first eliminates non-text area using the processes of labeling and filtering. After generating the candidates of text area by using the property that is high gradient difference in text area, text area is extracted using the post-processing of noise removal and text area merging. The benefits of the proposed method are its simplicity and high accuracy that is better than the conventional methods. Experimental results show that precision, recall and inverse ratio of non-text extraction (IRNTE) of the proposed method are 99.59%, 98.65% and 82.30%, respectively.

Small Target Detection Method Using Bilateral Filter Based on Surrounding Statistical Feature (주위 통계 특성에 기초한 양방향 필터를 이용한 소형 표적 검출 기법)

  • Bae, Tae-Wuk;Kim, Young-Taeg
    • Journal of Korea Multimedia Society
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    • v.16 no.6
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    • pp.756-763
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    • 2013
  • Bilateral filter (BF), functioning by two Gaussian filters, domain and range filter is a nonlinear filter for sharpness enhancement and noise removal. In infrared (IR) small target detection field, the BF is designed by background predictor for predicting background not including small target. For this, the standard deviations of the two Gaussian filters need to be changed adaptively in background and target region of an infrared image. In this paper, the proposed bilateral filter make the standard deviations changed adaptively, using variance feature of mean values of surrounding block neighboring local filter window. And, in case the variance of mean values for surrounding blocks is low for any processed pixel, the pixel is classified to flat background and target region for enhancing background prediction. On the other hand, any pixel with high variance for surrounding blocks is classified to edge region. Small target can be detected by subtracting predicted background from original image. In experimental results, we confirmed that the proposed bilateral filter has superior target detection rate, compared with existing methods.

The efficient IR-UWB Radar System for Reflective Wave Removal in a Short Distance Environments (근거리 환경에서 반사파 제거를 위한 효율적인 IR-UWB Radar 시스템)

  • Kim, Sueng-Woo;Jeong, Won-Ho;Yeo, Bong-Gu;Kim, Kyung-Seok
    • Journal of Satellite, Information and Communications
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    • v.12 no.1
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    • pp.64-71
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    • 2017
  • In this paper, Kalman filter and RRWA algorithm are used to estimate the accurate target in IR-UWB (Impulse-Radio Ultra Wideband) radar system, which enables accurate location recognition of indoors and outdoors with low cost and low power consumption. In the signal reflected by the target, unnecessary signals exist in addition to the target signal. We have tried to remove unnecessary signals and to derive accurate target signals and improve performance. The location of the targets is estimated in real time with one transmitting antenna and one receiving antenna. The Kalman filter was used to remove the background noise and the RRWA algorithm was used to remove the reflected signal. In this paper, we think that it will be useful to study the accurate distance estimation and tracking in future target estimation.

An Efficient Vehicle Image Compensation Algorithm based on Histogram Equalization (히스토그램 균등화 기반의 효율적인 차량용 영상 보정 알고리즘)

  • Hong, Sung-Il;Lin, Chi-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.2192-2200
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    • 2015
  • In this paper, we propose an efficient vehicle image compensation algorithm based on Histogram Equalization. The proposed a vehicle image compensation algorithm was elimination to the vehicle image shake using motion compensation and motion estimation. And, algorithm was calculated the histogram of pixel values from each sub-image by dividing the image as the constant size areas in order to image enhancement. Also, it had enhancement to the image by adjusting the gradient. The proposed algorithm was evaluate the difference between of performance and time, image by applied to the IP, and were confirmed the image enhancement with removing of vehicle camera image shake. In this paper, the proposed vehicle image enhancement algorithm was demonstrated effectiveness when compared to existing vehicle image stabilization, because the elimination of shake for the vehicle images used real-time processing without using a memory. And it was obtained the reduction effect of the computation time by the calculated through block matching, and obtained the better restoration result for naturalness of the image with the lowest noise.

Noise Removal Using Complex Wavelet and Bernoulli-Gaussian Model (복소수 웨이블릿과 베르누이-가우스 모델을 이용한 잡음 제거)

  • Eom Il-Kyu;Kim Yoo-Shin
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.5 s.311
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    • pp.52-61
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    • 2006
  • Orthogonal wavelet tansform which is generally used in image and signal processing applications has limited performance because of lack of shift invariance and low directional selectivity. To overcome these demerits complex wavelet transform has been proposed. In this paper, we present an efficient image denoising method using dual-tree complex wavelet transform and Bernoulli-Gauss prior model. In estimating hyper-parameters for Bernoulli-Gaussian model, we present two simple and non-iterative methods. We use hypothesis-testing technique in order to estimate the mixing parameter, Bernoulli random variable. Based on the estimated mixing parameter, variance for clean signal is obtained by using maximum generalized marginal likelihood (MGML) estimator. We simulate our denoising method using dual-tree complex wavelet and compare our algorithm to well blown denoising schemes. Experimental results show that the proposed method can generate good denoising results for high frequency image with low computational cost.

A Study on Expanding Participation in and Raising Awareness of the Green Parking Project for Improvement of Parking Conditions in Urban Residential Areas (도시주거지 주차환경개선을 위한 녹색주차사업 참여확대 및 인식제고 방안)

  • Kim, Myo-Jung
    • Journal of the Korean housing association
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    • v.26 no.1
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    • pp.61-70
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    • 2015
  • The purpose of this study was to provide information on how to expend participation in and raise awareness of the Green Parking Project. A survey was conducted for this study among two groups. One group consisted of 38 residents of the Green Parking Zone in Nam-gu, Ulsan, and the other group consised 129 residents with no experience with the Green Parking Project. For analysis, the frequency and means were calculated, and t-test, analysis of variance, and chi-square test were performed. The results showed, first, that general residents tended to think that parking on the street in front of one's house is a divine right, while residents living the Green Parking Zone thought that the street is a public space. Second, general residents regarded fences as means of security to protect their private property, while people living in the Green Parking Zone tended to think of their yards as semi-private spaces and allowed access to neighbors. Third, general residents had concerns about maintenance and administration fees, noise and dust, security of houses, and privacy. However, residents of the Green Parking Zone evaluated those conditions positively. Fourth, people who were well-informed about the Green Parking Project had low anxiety about security and invasion of privacy, results from the project. Therefore, effective public relations are very important for expanding participation and raising awareness.

Generation of an eye-contacted view using color and depth cameras (컬러와 깊이 카메라를 이용한 시점 일치 영상 생성 기법)

  • Hyun, Jee-Ho;Han, Jae-Young;Won, Jong-Pil;Yoo, Ji-Sang
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.8
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    • pp.1642-1652
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    • 2012
  • Generally, a camera isn't located at the center of display in a tele-presence system and it causes an incorrect eye contact between speakers which reduce the realistic feeling during the conversation. To solve this incorrect eye contact problem, we newly propose an intermediate view reconstruction algorithm using both a color camera and a depth camera and applying for the depth image based rendering (DIBR) algorithm. In the proposed algorithm, an efficient hole filling method using the arithmetic mean value of neighbor pixels and an efficient boundary noise removal method by expanding the edge region of depth image are included. We show that the generated eye-contacted image has good quality through experiments.

Multi-Modal User Distance Estimation System based on Mobile Device (모바일 디바이스 기반의 멀티 모달 사용자 거리 추정 시스템)

  • Oh, Byung-Hun;Hong, Kwang-Seok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.2
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    • pp.65-71
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    • 2014
  • This paper present the multi-modal user distance estimation system using mono camera and mono microphone basically equipped with a mobile device. In case of a distance estimation method using an image, we is estimated a distance of the user through the skin color region extraction step, a noise removal step, the face and eyes region detection step. On the other hand, in case of a distance estimation method using speech, we calculates the absolute difference between the value of the sample of speech input. The largest peak value of the calculated difference value is selected and samples before and after the peak are specified as the ROI(Region of Interest). The samples specified perform FFT(Fast Fourier Transform) and calculate the magnitude of the frequency domain. Magnitude obtained is compared with the distance model to calculate the likelihood. We is estimated user distance by adding with weights in the sorted value. The result of an experiment using the multi-modal method shows more improved measurement value than that of single modality.