• Title/Summary/Keyword: Difference Vector

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Perceptual Color Difference based Image Quality Assessment Method and Evaluation System according to the Types of Distortion (인지적 색 차이 기반의 이미지 품질 평가 기법 및 왜곡 종류에 따른 평가 시스템 제안)

  • Lee, Jee-Yong;Kim, Young-Jin
    • Journal of KIISE
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    • v.42 no.10
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    • pp.1294-1302
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    • 2015
  • A lot of image quality assessment metrics that can precisely reflect the human visual system (HVS) have previously been researched. The Structural SIMilarity (SSIM) index is a remarkable HVS-aware metric that utilizes structural information, since the HVS is sensitive to the overall structure of an image. However, SSIM fails to deal with color difference in terms of the HVS. In order to solve this problem, the Structural and Hue SIMilarity (SHSIM) index has been selected with the Hue, Saturation, Intensity (HSI) model as a color space, but it cannot reflect the HVS-aware color difference between two color images. In this paper, we propose a new image quality assessment method for a color image by using a CIE Lab color space. In addition, by using a support vector machine (SVM) classifier, we also propose an optimization system for applying optimal metric according to the types of distortion. To evaluate the proposed index, a LIVE database, which is the most well-known in the area of image quality assessment, is employed and four criteria are used. Experimental results show that the proposed index is more consistent with the other methods.

An Abnormal Activity Monitoring System Using Sensors and Video (센서와 영상을 이용한 이상 행동 모니터링 시스템)

  • Kim, Sang-Soo;Kim, Sun-Woo;Choi, Yeon-Sung
    • Journal of KIISE
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    • v.41 no.12
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    • pp.1152-1159
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    • 2014
  • In this paper, we presents a system to ensure the safety of residents through appropriate action or alarm in case the residents occurs an emergency situation and abnormal activity. We collect and analysis real-time data of living environment of the residents using video and sensor. The existing system have been determined by using only the sensor data it have several problems. Our system attach camera to solve the existing system problem. We use weighted difference image and motion vector. The existing system, it takes about 48 hours to determine that an abnormal activity occurs. However, our system takes less than 1 hour.

Extraction of water body in before and after images of flood using Mahalanobis distance-based spectral analysis

  • Ye, Chul-Soo
    • Korean Journal of Remote Sensing
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    • v.31 no.4
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    • pp.293-302
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    • 2015
  • Water body extraction is significant for flood disaster monitoring using satellite imagery. Conventional methods have focused on finding an index, which highlights water body and suppresses non-water body such as vegetation or soil area. The Normalized Difference Water Index (NDWI) is typically used to extract water body from satellite images. The drawback of NDWI, however, is that some man-made objects in built-up areas have NDWI values similar to water body. The objective of this paper is to propose a new method that could extract correctly water body with built-up areas in before and after images of flood. We first create a two-element feature vector consisting of NDWI and a Near InfRared band (NIR) and then select a training site on water body area. After computing the mean vector and the covariance matrix of the training site, we classify each pixel into water body based on Mahalanobis distance. We also register before and after images of flood using outlier removal and triangulation-based local transformation. We finally create a change map by combining the before-flooding water body and after-flooding water body. The experimental results show that the overall accuracy and Kappa coefficient of the proposed method were 97.25% and 94.14%, respectively, while those of the NDWI method were 89.5% and 69.6%, respectively.

Vector Control of PM Motor without any Rotational Transducer PART 1 - Surface Mounted Permanent Magnet Motor (위치 검출기가 없는 영구자석 동기 전동기의 제어 PART1 - 표면부착형 영구자석 전동기)

  • Jang, Ji-Hun;Ha, Jeong-Ik;Seol, Seung-Gi
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.50 no.9
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    • pp.453-458
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    • 2001
  • This paper presents a new vector control algorithm of the surface mounted permanent magnet motor (SMPMM) without any rotational tranceducer. Originally, SMPMM does not have any magnetic saliency in structure, but it has a little magnetic saliency due to the saturation by the flux of the permanent magnet. Moreover, it varies according to the load conditions and the control performance of schematics using the saliency can be easily degraded. To prevent it and to improve the performance of the proposed algorithm, the saliency of a SMPMM under various load conditions is analyzed. In the proposed algorithm, the saliency or the impedance difference related to the saliency is utilized in order to estimate the position and speed of the rotor. And the high frequency signal is injected into the motor to measure the impedance difference and also to enhance the control performance of the system. The experimental results verify the performance of the proposed sensorless algorithm.

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Maximum A Posteriori Estimation-based Adaptive Search Range Decision for Accelerating HEVC Motion Estimation on GPU

  • Oh, Seoung-Jun;Lee, Dongkyu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.9
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    • pp.4587-4605
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    • 2019
  • High Efficiency Video Coding (HEVC) suffers from high computational complexity due to its quad-tree structure in motion estimation (ME). This paper exposes an adaptive search range decision algorithm for accelerating HEVC integer-pel ME on GPU which estimates the optimal search range (SR) using a MAP (Maximum A Posteriori) estimator. There are three main contributions; First, we define the motion feature as the standard deviation of motion vector difference values in a CTU. Second, a MAP estimator is proposed, which theoretically estimates the motion feature of the current CTU using the motion feature of a temporally adjacent CTU and its SR without any data dependency. Thus, the SR for the current CTU is parallelly determined. Finally, the values of the prior distribution and the likelihood for each discretized motion feature are computed in advance and stored at a look-up table to further save the computational complexity. Experimental results show in conventional HEVC test sequences that the proposed algorithm can achieves high average time reductions without any subjective quality loss as well as with little BD-bitrate increase.

A Predictive Model for Sensory Difference Tests Accounting for Sequence Effects

  • Lee, Hye-Seong
    • Food Science and Biotechnology
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    • v.17 no.5
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    • pp.1052-1059
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    • 2008
  • Sequential Sensitivity Analysis (SSA) and conditional stimulus model have been developed to describe sequence effects in difference tests and proposed to generate prediction of differences in sensitivity between various test protocols and to assist the appropriate selection of difference test. Yet, such models did not furnish a complete explanation of the relative sensitivity in 4 different versions of 3-alternative forced choice (AFC) tests where various interstimulus rinses were introduced. In the present study, the vector of the contrasts between various conditional stimuli were measured using same-different and 2-AFC and a new 16-distribution conditional stimulus model was developed by refining Lee and O'Mahony's contrast model. This new model gave superior predictions than previous models.

Ultrasound Image Diagnosis using Texture Analysis (TEXTURE 분석을 이용한 초음파 화상의 진단)

  • Choi, Kwang-Cheol;Kim, Sun-Il;Lee, Doo-Soo
    • Journal of Biomedical Engineering Research
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    • v.13 no.1
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    • pp.33-38
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    • 1992
  • A new approach to texture classification for quantitative ultrasound liver diagnosis using run difference matrix was developed. The run difference matrix comprised the gray level difference along with a distances. From this run difference matrix, we defined several vectors and parameters such as DOD, DGD, DAD vector, SHP, SMO, SMG, LDE, LDEL etc. Each parameter values calculated in fatty, cirrhotic, normal and chronic hepatitic liver images were plotted in a plane and we found that RDM method was more sensitive to small structural changes than the conventional run length method and showed improved classification ability between the diseases.

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An Advanced Successive Elimination Algorithm Using Mean Absolute Difference of Neighboring Search Points (경계점의 절대 오차 평균을 이용한 개선된 연속 제거 알고리즘)

  • Jung, Soo-Mok
    • Journal of the Korea Computer Industry Society
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    • v.5 no.5
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    • pp.755-760
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    • 2004
  • In this paper, an advanced successive elimination algorithm was proposed using mean absolute difference of neighboring search points. By using mean absolute difference of neighboring search points, the search point in motion estimation can be eliminated effeciently without matching evaluation that requires very intensive computations. By using adaptive MAD calculation algorithm, the candidate matching block can be eliminated early. So, the number of the proposed algrorithm was verified by experimental results.

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Numerical Analysis for Under- or Over- Expanded Supersonic Turbulence Jet Flow (초음속 불완전 팽창 난류 제트 유동에 관한 수치적 연구)

  • Kim Jae-Soo
    • 한국전산유체공학회:학술대회논문집
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    • 1999.05a
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    • pp.85-89
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    • 1999
  • Numerical Analysis has been done for the supersonic off-design jet flow due to the pressure difference between the jet and the ambient fluid. The difference of pressure generates an oblique shock or an expansion wave at the nozzle exit, The waves reflect repeatedly at the center axis and on the sonic surface in the shear layer, and the pressure difference is resolved across these waves interacted with the turbulence mixing layer. In this paper, the axi-symmetric Navier-Stokes equation has been used with two equation $k-{\varepsilon}$ turbulence closure model. The second order TVD scheme with flux limiters, based on the flux vector split by the smooth eigenvalue split, has been used to capture internal shocks and other discontinuities. The correction term for the compressible flow and the damping function are used in the turbulence model. Numerical calculations have been done to analyze the off-design jet flow due to the pressure difference. The variation of pressure along the flow axis is compared with an experimental result and other numerical result. The characteristics of the interaction between the shock cell and the turbulence mixing layer have been analyzed.

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Texture Classification Using Wavelet-Domain BDIP and BVLC Features With WPCA Classifier (웨이브렛 영역의 BDIP 및 BVLC 특징과 WPCA 분류기를 이용한 질감 분류)

  • Kim, Nam-Chul;Kim, Mi-Hye;So, Hyun-Joo;Jang, Ick-Hoon
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.2
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    • pp.102-112
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    • 2012
  • In this paper, we propose a texture classification using wavelet-domain BDIP (block difference of inverse probabilities) and BVLC (block variance of local correlation coefficients) features with WPCA (whitened principal component analysis) classifier. In the proposed method, the wavelet transform is first applied to a query image. The BDIP and BVLC operators are next applied to the wavelet subbands. Global moments for each subband of BDIP and BVLC are then computed and fused into a feature vector. In classification, the WPCA classifier, which is usually adopted in the face identification, searches the training feature vector most similar to the query feature vector. Experimental results show that the proposed method yields excellent texture classification with low feature dimension for test texture image DBs.