• Title/Summary/Keyword: Adaptive feature extraction

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Robust Extraction of Facial Features under Illumination Variations (조명 변화에 견고한 얼굴 특징 추출)

  • Jung Sung-Tae
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.6 s.38
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    • pp.1-8
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    • 2005
  • Facial analysis is used in many applications like face recognition systems, human-computer interface through head movements or facial expressions, model based coding, or virtual reality. In all these applications a very precise extraction of facial feature points are necessary. In this paper we presents a method for automatic extraction of the facial features Points such as mouth corners, eye corners, eyebrow corners. First, face region is detected by AdaBoost-based object detection algorithm. Then a combination of three kinds of feature energy for facial features are computed; valley energy, intensity energy and edge energy. After feature area are detected by searching horizontal rectangles which has high feature energy. Finally, a corner detection algorithm is applied on the end region of each feature area. Because we integrate three feature energy and the suggested estimation method for valley energy and intensity energy are adaptive to the illumination change, the proposed feature extraction method is robust under various conditions.

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Novel Detection Algorithm of The Upstroke of Pulse Waveform for Continuously Varying Contact Pressure Method (연속 가압방식의 맥파 측정방법을 위한 시작점 검출 알고리즘 개발)

  • Bae, Jang-Han;Jeon, Young-Ju;Kim, Jong-Yeol;Kim, Jae-Uk
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.49 no.2
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    • pp.46-54
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    • 2012
  • We propose a continuously varying contact pressure(CVCP)-adaptive feature extraction algorithm for pulse diagnostic analysis. The CVCP method measures the pulse waveform with continuously increasing contact pressure(CP). This method offer a high resolution signal of the pulse waveform amplitude(PWA) as a function of the contact pressure. Therefore it enables us to overcome the limitation of commercially available pulse-taking devices whose analysis rely on a few number of PWA-CP pairs. We show that an efficient feature extraction algorithm which covers the features of the CVCP-method can be developed by sequentially applying Fast Fourier Transform, peak detection by center-to-edges method, baseline drift removal, detection of the percussion wave upstroke by intersecting tangent method and detection of the analysis region. Finally, by a clinical study with 30 subjects, we show that our CVCP-adaptive feature extraction algorithm detected the upstroke with accuracy of 99.46% and sensitivity of 99.51%, which were about 4.82% and 2.46% increases respectively, compared to a conventional feature extraction method. The proposed CVCP method and the CVCP-adaptive feature extraction algorithm are expected to improve the accuracy in the pulse diagnostic algorithms such as floating/sunken pulse qualities and deficient/excess pulse qualities.

CutPaste-Based Anomaly Detection Model using Multi Scale Feature Extraction in Time Series Streaming Data

  • Jeon, Byeong-Uk;Chung, Kyungyong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.8
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    • pp.2787-2800
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    • 2022
  • The aging society increases emergency situations of the elderly living alone and a variety of social crimes. In order to prevent them, techniques to detect emergency situations through voice are actively researched. This study proposes CutPaste-based anomaly detection model using multi-scale feature extraction in time series streaming data. In the proposed method, an audio file is converted into a spectrogram. In this way, it is possible to use an algorithm for image data, such as CNN. After that, mutli-scale feature extraction is applied. Three images drawn from Adaptive Pooling layer that has different-sized kernels are merged. In consideration of various types of anomaly, including point anomaly, contextual anomaly, and collective anomaly, the limitations of a conventional anomaly model are improved. Finally, CutPaste-based anomaly detection is conducted. Since the model is trained through self-supervised learning, it is possible to detect a diversity of emergency situations as anomaly without labeling. Therefore, the proposed model overcomes the limitations of a conventional model that classifies only labelled emergency situations. Also, the proposed model is evaluated to have better performance than a conventional anomaly detection model.

Binary classification by the combination of Adaboost and feature extraction methods (특징 추출 알고리즘과 Adaboost를 이용한 이진분류기)

  • Ham, Seaung-Lok;Kwak, No-Jun
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.49 no.4
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    • pp.42-53
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    • 2012
  • In pattern recognition and machine learning society, classification has been a classical problem and the most widely researched area. Adaptive boosting also known as Adaboost has been successfully applied to binary classification problems. It is a kind of boosting algorithm capable of constructing a strong classifier through a weighted combination of weak classifiers. On the other hand, the PCA and LDA algorithms are the most popular linear feature extraction methods used mainly for dimensionality reduction. In this paper, the combination of Adaboost and feature extraction methods is proposed for efficient classification of two class data. Conventionally, in classification problems, the roles of feature extraction and classification have been distinct, i.e., a feature extraction method and a classifier are applied sequentially to classify input variable into several categories. In this paper, these two steps are combined into one resulting in a good classification performance. More specifically, each projection vector is treated as a weak classifier in Adaboost algorithm to constitute a strong classifier for binary classification problems. The proposed algorithm is applied to UCI dataset and FRGC dataset and showed better recognition rates than sequential application of feature extraction and classification methods.

Text Extraction Algorithm in Complex Images using Adaptive Edge detection (복잡한 영상에서 적응적 에지검출을 이용한 텍스트 추출 알고리즘 연구)

  • Shin, Seong;Kim, Sung-Dong;Baek, Young-Hyun;Moon, Sung-Ryong
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.251-252
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    • 2007
  • The thesis proposed the Text Extraction Algorithm which is a text extraction algorithm which uses the Coiflet Wavelet, YCbCr Color model and the close curve edge feature of adaptive LoG Operator in order to complement the demerit of the existing research which is weak in complexity of background, variety of light and disordered line and similarity of text and background color. This thesis is simulated with natural images which include naturally text area regardless of size, resolution and slant and so on of image. And the proposed algorithm is confirmed to an excellent by compared with an existing extraction algorithm in same image.

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Real-Time Head Tracking using Adaptive Boosting in Surveillance (서베일런스에서 Adaptive Boosting을 이용한 실시간 헤드 트래킹)

  • Kang, Sung-Kwan;Lee, Jung-Hyun
    • Journal of Digital Convergence
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    • v.11 no.2
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    • pp.243-248
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    • 2013
  • This paper proposes an effective method using Adaptive Boosting to track a person's head in complex background. By only one way to feature extraction methods are not sufficient for modeling a person's head. Therefore, the method proposed in this paper, several feature extraction methods for the accuracy of the detection head running at the same time. Feature Extraction for the imaging of the head was extracted using sub-region and Haar wavelet transform. Sub-region represents the local characteristics of the head, Haar wavelet transform can indicate the frequency characteristics of face. Therefore, if we use them to extract the features of face, effective modeling is possible. In the proposed method to track down the man's head from the input video in real time, we ues the results after learning Harr-wavelet characteristics of the three types using AdaBoosting algorithm. Originally the AdaBoosting algorithm, there is a very long learning time, if learning data was changes, and then it is need to be performed learning again. In order to overcome this shortcoming, in this research propose efficient method using cascade AdaBoosting. This method reduces the learning time for the imaging of the head, and can respond effectively to changes in the learning data. The proposed method generated classifier with excellent performance using less learning time and learning data. In addition, this method accurately detect and track head of person from a variety of head data in real-time video images.

Shape Extraction of Near Target Using Opening Operator with Adaptive Structure Element in Infrared hnages (적응적 구조요소를 이용한 열림 연산자에 의한 적외선 영상표적 추출)

  • Kwon, Hyuk-Ju;Bae, Tae-Wuk;Kim, Byoung-Ik;Lee, Sung-Hak;Kim, Young-Choon;Ahn, Sang-Ho;Sohng, Kyu-Ik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.9C
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    • pp.546-554
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    • 2011
  • Near targets in the infrared (IR) images have the steady feature for inner region and the transient feature for the boundary region. Based on these features, this paper proposes a new method to extract the fine target shape of near targets in the IR images. First, we detect the boundary region of the candidate targets using the local variance weighted information entropy (WIE) of the original images. And then, a coarse target region can be estimated based on the labeling of the boundary region. For the coarse target region, we use the opening filter with an adaptive structure element to extract the fine target shape. The decision of the adaptive structure element size is optimized for the width information of target boundary by calculating the average WIE in the enlarged windows. The experimental results show that a proposed method has better extraction performance than the previous threshold algorithms.

Adaptive Shot Change Detection Technique Using Mean of Feature Value on Variable Reference Block (가변 참조 구간의 평균 특징값을 이용한 적응적인 장면 전환 검출 기법)

  • Kim, Won-Hee;Moon, Kwang-Seok;Kim, Jong-Nam
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.4
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    • pp.272-279
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    • 2008
  • Shot change detection is an important technique for effective management of video data, so detection scheme requires adaptive detection techniques to be used actually in various video. In this paper, we propose an adaptive shot change detection algorithm using the mean of feature value on variable reference blocks. Our algorithm determines shot change detection by defining adaptive threshold values with the feature value extracted from video frames and comparing the feature value and the threshold value. We obtained better detection ratio than the conventional methods maximally by 15% in the experiment with the same test sequence. We also had good detection ratio for other several methods of feature extraction and could see realtime operation of shot change detection in the hardware platform with low performance was possible by implementing it in TVUS model of HOMECAST company. Thus, our algerian in the paper can be useful in PMP(portable multimedia player) or other portable players.

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Development of surface defect inspection algorithms for cold mill strip using tree structure (트리 구조를 이용한 냉연 표면흠 검사 알고리듬 개발에 관한 연구)

  • Kim, Kyung-Min;Jung, Woo-Yong;Lee, Byung-Jin;Ryu, Gyung;Park, Gui-Tae
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.365-370
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    • 1997
  • In this paper we suggest a development of surface defect inspection algorithms for cold mill strip using tree structure. The defects which exist in a surface of cold mill strip have a scattering or singular distribution. This paper consists of preprocessing, feature extraction and defect classification. By preprocessing, the binarized defect image is achieved. In this procedure, Top-hit transform, adaptive thresholding, thinning and noise rejection are used. Especially, Top-hit transform using local min/max operation diminishes the effect of bad lighting. In feature extraction, geometric, moment, co-occurrence matrix, histogram-ratio features are calculated. The histogram-ratio feature is taken from the gray-level image. For the defect classification, we suggest a tree structure of which nodes are multilayer neural network clasifiers. The proposed algorithm reduced error rate comparing to one stage structure.

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Design of Hierarchical Classifier for Classifying Defects of Cold Mill Strip using Neural Networks (신경회로망을 이용한 냉연 표면흠 분류를 위한 계층적 분류기의 설계)

  • Kim, Kyoung-Min;Lyou, Kyoung;Jung, Woo-Yong;Park, Gwi-Tae;Park, Joong-Jo
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.4
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    • pp.499-505
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    • 1998
  • In developing an automated surface inspect algorithm, we have designed a hierarchical classifier using neural network. The defects which exist on the surface of cold mill strip have a scattering or singular distribution. We have considered three major problems, that is preprocessing, feature extraction and defect classification. In preprocessing, Top-hit transform, adaptive thresholding, thinning and noise rejection are used Especially, Top-hit transform using local minimax operation diminishes the effect of bad lighting. In feature extraction, geometric, moment, co-occurrence matrix, and histogram ratio features are calculated. The histogram ratio feature is taken from the gray-level image. For defect classification, we suggest a hierarchical structure of which nodes are multilayer neural network classifiers. The proposed algorithm reduced error rate by comparing to one-stage structure.

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