• Title/Summary/Keyword: Gabor transform

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Authentication Performance Optimization for Smart-phone based Multimodal Biometrics (스마트폰 환경의 인증 성능 최적화를 위한 다중 생체인식 융합 기법 연구)

  • Moon, Hyeon-Joon;Lee, Min-Hyung;Jeong, Kang-Hun
    • Journal of Digital Convergence
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    • v.13 no.6
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    • pp.151-156
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    • 2015
  • In this paper, we have proposed personal multimodal biometric authentication system based on face detection, recognition and speaker verification for smart-phone environment. Proposed system detect the face with Modified Census Transform algorithm then find the eye position in the face by using gabor filter and k-means algorithm. Perform preprocessing on the detected face and eye position, then we recognize with Linear Discriminant Analysis algorithm. Afterward in speaker verification process, we extract the feature from the end point of the speech data and Mel Frequency Cepstral Coefficient. We verified the speaker through Dynamic Time Warping algorithm because the speech feature changes in real-time. The proposed multimodal biometric system is to fuse the face and speech feature (to optimize the internal operation by integer representation) for smart-phone based real-time face detection, recognition and speaker verification. As mentioned the multimodal biometric system could form the reliable system by estimating the reasonable performance.

Damage Detection in a Beam by the Wavelet Transform (웨이블렛을 이용한 보의 결함진단)

  • Kim, Eung-Hun;Kim, Yun-Yeong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.2 s.173
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    • pp.518-525
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    • 2000
  • This paper presents a new wavelet-based structural diagnostic technique. A continuous Gabor wavelet transform is shown to a very effective method in detecting damage in a beam. The beam is excited by a broad-band excitation force. For satisfactory results, the selection of an optimal wavelet is very important though the wavelet transform outperforms existing techniques such as the Wigner-Ville distribution. A specific example is given in a solid circular cylinder with a small defect.

Determination of the Group Velocity and Source Location of Dispersive Plate Waves using Wavelet Transform (Wavelet 변환을 이용한 분산성 판파의 군속도와 음원 위치 결정)

  • Jang, Yeong-Su;Jeong, Hyeon-Jo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.4 s.175
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    • pp.1024-1031
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    • 2000
  • The plate waves propagating in thin plates have dispersive nature showing the dependence of velocities on the frequency. Wavelet transform (WT) using Gabor function can be used to analyze the dispersive waves in the time-frequency domain, and then to find the arrival time of the waves propagating in the plate. Plate waves in the aluminum plate of 3 mm thickness were identified and generated by pencil lead breaks and the lowest order symmetric ($S_o$) and antisymmetric ($A_o$) modes were analyzed by the WT method. The measured group velocities agreed very well with theoretical predictions in the frequency range of 50-400 kHz. The pencil breaks were also used to simulate acoustic emission sources in the plate, and the source location algorithm using the wavelet transform of dispersive plate waves was found to give accurate results.

Implementation of Embedded System for a Fast Iris Identification Based on USN (고속의 홍채인식을 위한 USN기반의 임베디드 시스템 구현)

  • Kim, Shin-Hong;Kim, Shik
    • IEMEK Journal of Embedded Systems and Applications
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    • v.4 no.4
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    • pp.190-194
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    • 2009
  • Iris recognition is a biometric technology which can identify a person using the iris pattern. Recently, using iris information is used in many fields such as access control and information security. But Perform complex operations to extract features of the iris. Because high-end hardware for real-time iris recognition is required. This paper is appropriate for the embedded environment using local gradient histogram embedded system with iris feature extraction methods based on USN(Ubiquitous Sensor Network). Experimental results show that the performance of proposed method is comparable to existing methods using Gabor transform noticeably improves recognition performance and it is noted that the processing time of the local gradient histogram transform is much faster than that of the existing method and rotation was also a strong attribute.

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A GCST-based Digital Image Watermarking Scheme (GCST 기반 디지털 영상 워터마킹 방법)

  • Lee, Juck-Sik
    • Journal of the Institute of Convergence Signal Processing
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    • v.13 no.3
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    • pp.142-149
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    • 2012
  • Various image transformations can be used to compress images, to reduce noises in images and to extract useful features. Watermarking techniques using DCT and DWT have been a lot of research interest in the spread of multimedia contents. In this paper, Gabor cosine and sine transform considered as human visual filter is applied to embedding and extraction of watermarks for digital images. The proposed transform is used for watermarking with fifteen attacks. Randomly normal distributed noises are used as an embedded watermark. To measure the similarity between the embedded watermark and extracted one, a correlation value is computed and furthermore is compared with that of existing DCT method. Correlation values of extracted watermark are computed with randomly normal distributed noise sequences, and the sequence with the largest correlation value is declared as the embedded watermark. Frequency components are divided into various bands. Experimental results for low frequency and mid-frequency bands have shown that the proposed GCST provides a good watermarking algorithm and its performance is better than DCT.

Active Lamb Wave Propagation-based Structural Health Monitoring for Steel Plate (능동 램파 전파에 기초한 강판의 구조건전성 모니터링)

  • Jeong, Woon;Seo, Ju-Won;Kim, Hyeung-Yun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.421-431
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    • 2009
  • This paper is the study on the verification of structural health monitoring (SHM) algorithm based on the ultrasonic guided wave. An active inspection system using Lamb wave (LW) for SHM was considered. The basic study about the application of this algorithm was performed for detecting the circular notch defect in steel plate. LW testing technique, pitch-catch method, was used for interpretation of circular notch defect with depth of 50% of plate thickness and 7 mm width. Damage characterization takes place by comparing $S_0$ mode sensor signals collected before and after the damage event. By subtracting the signals of both conditions from each other, a scatter signal is produced which can be used for damage localization. The continuous Gabor wavelet transform is used to attain the time between the arrivals of the scatter and sensor signals. A new practical damage monitoring algorithm, based on damage monitoring polygon and pitch-catch method, has been proposed and verified with good accuracy. The possible damage location can be estimated by the average on calculated location points and the damage extent by the standard deviation.

Detecting the Prostate Contour in TRUS Image using Support Vector Machine and Rotation-invariant Textures (SVM과 회전 불변 텍스처 특징을 이용한 TRUS 영상의 전립선 윤곽선 검출)

  • Park, Jae Heung;Seo, Yeong Geon
    • Journal of Digital Contents Society
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    • v.15 no.6
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    • pp.675-682
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    • 2014
  • Prostate is only an organ of men. To diagnose the disease of the prostate, generally transrectal ultrasound(TRUS) images are used. Detecting its boundary is a challenging and difficult task due to weak prostate boundaries, speckle noise and the short range of gray levels. In this paper a method for automatic prostate segmentation in TRUS images using Support Vector Machine(SVM) is presented. This method involves preprocessing, extracting Gabor feature, training, and prostate segmentation. The speckle reduction for preprocessing step has been achieved by using stick filter and top-hat transform has been implemented for smoothing. Gabor filter bank for extraction of rotation-invariant texture features has been implemented. SVM for training step has been used to get each feature of prostate and nonprostate. Finally, the boundary of prostate is extracted. A number of experiments are conducted to validate this method and results shows that the proposed algorithm extracted the prostate boundary with less than 10% relative to boundary provided manually by doctors.

Wavelet Analysis of Plate Waves in Anisotropic Laminates and Acoustic Source Location (Wavelet 변환을 이용한 이방성 적층판의 판파 해석과 음원 위치 결정)

  • 장영수;정현조
    • Composites Research
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    • v.13 no.1
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    • pp.61-68
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    • 2000
  • A new approach is presented for the analysis of transient waves propagating in anisotropic composite laminates. The wavelet transform (WT) using the Gabor wavelet is applied to the time-frequency analysis of dispersive flexural waves. It is shown that the peaks of the magnitude of WT in time-frequency domain is related to the arrival times of group velocity. Experiments are performed using a lead break as the simulated fracture source on the surface of quasi-isotropic and unidirectional laminates. For predictions of the dispersion of the flexural mode, Mindlin plate theory is shown to give good agreement with the experimental results. Based on the frequency-dependent arrival times and angular dependence of group velocities of flexural waves, the problem of source location in anisotropic laminates is considered and the results are given.

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Digital Image Watermarking Schemes Based on GCST and SVD (GCST-SVD 기반 디지털 영상 워터마킹 방법)

  • Lee, Juck-Sik
    • Journal of the Institute of Convergence Signal Processing
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    • v.14 no.3
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    • pp.154-161
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    • 2013
  • In this paper, Gabor cosine and sine transform considered as human visual filter is applied to watermarking methods for digital images. Four algorithms by using singular values or principal components of SVD in the frequency domain are proposed for watermark embedding and extraction. Two dimensional image is used as an embedded watermark. To measure the similarity between the embedded watermark image and the extracted one, a normalized correlation value is computed for the comparison of the four proposed methods with various attacks. Extracted watermark images are also provided for visual inspection. The proposed GCST-SVD method which embeds a watermark image into the lowest vertical or horizontal ac frequency band can provide useful watermarking algorithm with high correlation values and visual watermark features from experimental results for various attacks.

A study on the Quality Assessment Method on Railway Video Transmission System (철도영상전송시스템의 화질평가방안에 관한 연구)

  • Chang Seok-Gahk;Cho Bong-Kwan
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1247-1252
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    • 2004
  • A objective quality assessment for the evaluation performance of a video transmission system as a basic step for construction of digital video transmission system between the spots and headquarter. Due to a limit of an analog video transmission system and the developments of various digital media and digital video standards, the need of introduce of a digital system are increased gradual1y, At this points. previously performance evaluations are performed and the quality assessment is the most important thing. We can be divided quality assessment method by the subjective quality assessment and objective quality assessment. The subjective quality assessment method has some problems which are required high cost and much time to evaluate the quality, And because existing objective quality assessment method such that PSNR are based on an analog form, the correlation with subjective data is very low. Therefore we design a new objective quality assessment method using Gabor wavelet transform reflecting HVS(Human Visual System), Designed objective quality assessment method is superior to other objective method such that PSNR or EPSNR In this paper, we proposed objective quality assessment using Gabor wavelet can be used for performance evaluation and verification of video transmission system.

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