• Title/Summary/Keyword: Feature extraction algorithm

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Online Face Pose Estimation based on A Planar Homography Between A User's Face and Its Image (사용자의 얼굴과 카메라 영상 간의 호모그래피를 이용한 실시간 얼굴 움직임 추정)

  • Koo, Deo-Olla;Lee, Seok-Han;Doo, Kyung-Soo;Choi, Jong-Soo
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.47 no.4
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    • pp.25-33
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    • 2010
  • In this paper, we propose a simple and efficient algorithm for head pose estimation using a single camera. First, four subimages are obtained from the camera image for face feature extraction. These subimages are used as feature templates. The templates are then tracked by Kalman filtering, and camera projective matrix is computed by the projective mapping between the templates and their coordinate in the 3D coordinate system. And the user's face pose is estimated from the projective mapping between the user's face and image plane. The accuracy and the robustness of our technique is verified on the experimental results of several real video sequences.

EMD based Cardiac Arrhythmia Classification using Multi-class SVM (다중 클래스 SVM을 이용한 EMD 기반의 부정맥 신호 분류)

  • Lee, Geum-Boon;Cho, Beom-Joon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.1
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    • pp.16-22
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    • 2010
  • Electrocardiogram(ECG) analysis and arrhythmia recognition are critical for diagnosis and treatment of ill patients. Cardiac arrhythmia is a condition in which heart beat may be irregular and presents a serious threat to the patient recovering from ventricular tachycardia (VT) and ventricular fibrillation (VF). Other arrhythmias like atrial premature contraction (APC), Premature ventricular contraction (PVC) and superventricular tachycardia (SVT) are important in diagnosing the heart diseases. This paper presented new method to classify various arrhythmias contrary to other techniques which are limited to only two or three arrhythmias. ECG is decomposed into Intrinsic Mode Functions (IMFs) by Empirical Mode Decomposition (EMD). Burg algorithm was performed on IMFs to obtain AR coefficients which can reduce the dimension of feature vector and utilized as Multi-class SVM inputs which is basically extended from binary SVM. We chose optimal parameters for SVM classifier, applied to arrhythmias classification and achieved the accuracies of detecting NSR, APC, PVC, SVT, VT and VP were 96.8% to 99.5%. The results showed that EMD was useful for the preprocessing and feature extraction and multi-class SVM for classification of cardiac arrhythmias, with high usefulness.

Efficient R Wave Detection based on Subtractive Operation Method (차감 동작 기법 기반의 효율적인 R파 검출)

  • Cho, Ik-Sung;Kwon, Hyeog-Soong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.4
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    • pp.945-952
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    • 2013
  • The R wave of QRS complex is the most prominent feature in ECG because of its specific shape; therefore it is taken as a reference in ECG feature extraction. But R wave detection suffers from the fact that frequency bands of the noise/other components such as P/T waves overlap with that of QRS complex. ECG signal processing must consider efficiency for hardware and software resources available in processing for miniaturization and low power. In other words, the design of algorithm that exactly detects QRS region using minimal computation by analyzing the person's physical condition and/or environment is needed. Therefore, efficient QRS detection based on SOM(Subtractive Operation Method) is presented in this paper. For this purpose, we detected R wave through the preprocessing method using morphological filter, empirical threshold, and subtractive signal. Also, we applied dynamic backward searching method for efficient detection. The performance of R wave detection is evaluated by using MIT-BIH arrhythmia database. The achieved scores indicate the average of 99.41% in R wave detection.

Content-based Image Retrieval using the Color and Wavelet-based Texture Feature (색상특징과 웨이블렛 기반의 질감특징을 이용한 영상 검색)

  • 박종현;박순영;조완현;오일석
    • Journal of KIISE:Databases
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    • v.30 no.2
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    • pp.125-133
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    • 2003
  • In this paper we propose an efficient content-based image retrieval method using the color and wavelet based texture features. The color features are obtained from soft-color histograms of the global image and the wavelet-based texture features are obtained from the invariant moments of the high-pass sub-band through the spatial-frequency analysis of the wavelet transform. The proposed system, called a color and texture based two-step retrieval(CTBTR), is composed of two-step query operations for an efficient image retrieval. In the first-step matching operation, the color histogram features are used to filter out the dissimilar images quickly from a large image database. The second-step matching operation applies the wavelet based texture features to the retained set of images to retrieve all relevant images successfully. The experimental results show that the proposed algorithm yields more improved retrieval accuracy with computationally efficiency than the previous methods.

Automatic Segmentation of Cellular Images for High-Throughput Genome-Wide RNA Interference Screening (고속 Genome-Wide RNA 간섭 스크리닝을 위한 세포영상의 자동 분할)

  • Han, Chan-Hee;Song, In-Hwan;Lee, Si-Woong
    • The Journal of the Korea Contents Association
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    • v.10 no.4
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    • pp.19-27
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    • 2010
  • In recent years, high-throughput genome-wide RNA interference screening is emerging as an essential tool to biologists in understanding complex cellular processes. The manual analysis of the large number of images produced in each study spends much time and the labor. Hence, automatic cellular image analysis becomes an urgent need, where segmentation is the first and one of the most important steps. However, those factors such as the region overlapping, a variety of shapes, and non-uniform local characteristics of cellular images become obstacles to efficient cell segmentation. To avoid the problem, a new watershed-based cell segmentation algorithm using a localized segmentation method and a feature vector is proposed in this paper. Localized approach in segmentation resolves the problems caused by a variety of shapes and non-uniform characteristics. In addition, the poor performance of segmentation in overlapped regions can be improved by taking advantage of a feature vector whose component features complement each other. Simulation results show that the proposed method improves the segmentation performance compared to the method in Cellprofiler.

Facial Expression Recognition using Face Alignment and AdaBoost (얼굴정렬과 AdaBoost를 이용한 얼굴 표정 인식)

  • Jeong, Kyungjoong;Choi, Jaesik;Jang, Gil-Jin
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.11
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    • pp.193-201
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    • 2014
  • This paper suggests a facial expression recognition system using face detection, face alignment, facial unit extraction, and training and testing algorithms based on AdaBoost classifiers. First, we find face region by a face detector. From the results, face alignment algorithm extracts feature points. The facial units are from a subset of action units generated by combining the obtained feature points. The facial units are generally more effective for smaller-sized databases, and are able to represent the facial expressions more efficiently and reduce the computation time, and hence can be applied to real-time scenarios. Experimental results in real scenarios showed that the proposed system has an excellent performance over 90% recognition rates.

A Classification of lschemic Heart Disease using Neural Network in Magnetocardiogram (심자도에서 신경회로망을 이용한 허혈성 심장질환 분류)

  • Eum, Sang-hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.11
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    • pp.2137-2142
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    • 2016
  • The electrical current generated by heart creates not only electric potential but also a magnetic field. In this study, the signals obtained magnetocardiogram(MCG) using 61 channel superconducting quantum interference device(SQUID) system, and the clinical significance of various feature parameters has been developed MCG. Neural network algorithm was used to perform the classification of ischemic heart disease. The MCG signal was obtained to facilitate the extraction of parameters through a process of pre-processing. The data used to research the normal group 10 and ischemic heart disease group 10 with visible signs of stable angina patients. The available clinical indicators were extracted by characteristic point, characteristic interval parameter, and amplitude ratio parameter. The extracted parameters are determined to analysis the significance and clinical parameters were defined. It is possible to classify ischemic heart disease using the MCG feature parameters as a neural network input.

The Verification of Image Merging for Lumber Scanning System (제재목 화상입력시스템의 화상병합 성능 검증)

  • Kim, Byung Nam;Kim, Kwang Mo;Shim, Kug-Bo;Lee, Hyoung Woo;Shim, Sang-Ro
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.6
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    • pp.556-565
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    • 2009
  • Automated visual grading system of lumber needs correct input image. In order to create a correct image of domestic red pine lumber 3.6 m long feeding on a conveyer, part images were captured using area sensor and template matching algorithm was applied to merge part images. Two kinds of template matching algorithms and six kinds of template sizes were adopted in this operation. Feature extracted method appeared to have more excellent image merging performance than fixed template method. Error length was attributed to a decline of similarity related by difference of partial brightness on a part image, specific pattern and template size. The mismatch part was repetitively generated at the long grain. The best size of template for image merging was $100{\times}100$ pixels. In a further study, assignment of exact template size, preprocessing of image merging for reduction of brightness difference will be needed to improve image merging.

SuperDepthTransfer: Depth Extraction from Image Using Instance-Based Learning with Superpixels

  • Zhu, Yuesheng;Jiang, Yifeng;Huang, Zhuandi;Luo, Guibo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.10
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    • pp.4968-4986
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    • 2017
  • In this paper, we primarily address the difficulty of automatic generation of a plausible depth map from a single image in an unstructured environment. The aim is to extrapolate a depth map with a more correct, rich, and distinct depth order, which is both quantitatively accurate as well as visually pleasing. Our technique, which is fundamentally based on a preexisting DepthTransfer algorithm, transfers depth information at the level of superpixels. This occurs within a framework that replaces a pixel basis with one of instance-based learning. A vital superpixels feature enhancing matching precision is posterior incorporation of predictive semantic labels into the depth extraction procedure. Finally, a modified Cross Bilateral Filter is leveraged to augment the final depth field. For training and evaluation, experiments were conducted using the Make3D Range Image Dataset and vividly demonstrate that this depth estimation method outperforms state-of-the-art methods for the correlation coefficient metric, mean log10 error and root mean squared error, and achieves comparable performance for the average relative error metric in both efficacy and computational efficiency. This approach can be utilized to automatically convert 2D images into stereo for 3D visualization, producing anaglyph images that are visually superior in realism and simultaneously more immersive.

Fast Extraction of Edge Histogram in DCT Domain based on MPEG-7 (MPEG-7 기반 DCT영역에서의 에지히스토그램 고속 추출 기법)

  • Eom Min-Young;Choe Yoon-Sik;Won Chee-Sun;Nam Jae-Yeal
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.4 s.310
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    • pp.19-26
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    • 2006
  • In these days, multimedia data is transmitted and processed in compressed format. Due to the decoding procedure and filtering for edge detection, the feature extraction process of MPEG-7 Edge Histogram Descriptor (EHD) is time consuming as well as computationally expensive. To improve efficiency of compressed image retrieval, we propose a new edge histogram generation algorithm in DCT domain in this paper. Using the edge information provided by the only two AC coefficients of DCT coefficients, we can get edge directions and strengths directly in DCT domain. The experimental results demonstrate that our system has good performance in terms of retrieval efficiency and effectiveness.