• Title/Summary/Keyword: Local edge pattern

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A Study of Evaluation System for Facial Expression Recognition based on LDP (LDP 기반의 얼굴 표정 인식 평가 시스템의 설계 및 구현)

  • Lee, Tae Hwan;Cho, Young Tak;Ahn, Yong Hak;Chae, Ok Sam
    • Convergence Security Journal
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    • v.14 no.7
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    • pp.23-28
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    • 2014
  • This study proposes the design and implementation of the system for a facial expression recognition system. LDP(Local Directional Pattern) feature computes the edge response in a different direction from a pixel with the relationship of neighbor pixels. It is necessary to be estimated that LDP code can represent facial features correctly under various conditions. In this respect, we build the system of facial expression recognition to test LDP performance quickly and the proposed evaluation system consists of six components. we experiment the recognition rate with local micro patterns (LDP, Gabor, LBP) in the proposed evaluation system.

Local Prominent Directional Pattern for Gender Recognition of Facial Photographs and Sketches (Local Prominent Directional Pattern을 이용한 얼굴 사진과 스케치 영상 성별인식 방법)

  • Makhmudkhujaev, Farkhod;Chae, Oksam
    • Convergence Security Journal
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    • v.19 no.2
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    • pp.91-104
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    • 2019
  • In this paper, we present a novel local descriptor, Local Prominent Directional Pattern (LPDP), to represent the description of facial images for gender recognition purpose. To achieve a clearly discriminative representation of local shape, presented method encodes a target pixel with the prominent directional variations in local structure from an analysis of statistics encompassed in the histogram of such directional variations. Use of the statistical information comes from the observation that a local neighboring region, having an edge going through it, demonstrate similar gradient directions, and hence, the prominent accumulations, accumulated from such gradient directions provide a solid base to represent the shape of that local structure. Unlike the sole use of gradient direction of a target pixel in existing methods, our coding scheme selects prominent edge directions accumulated from more samples (e.g., surrounding neighboring pixels), which, in turn, minimizes the effect of noise by suppressing the noisy accumulations of single or fewer samples. In this way, the presented encoding strategy provides the more discriminative shape of local structures while ensuring robustness to subtle changes such as local noise. We conduct extensive experiments on gender recognition datasets containing a wide range of challenges such as illumination, expression, age, and pose variations as well as sketch images, and observe the better performance of LPDP descriptor against existing local descriptors.

Edge-Directed Color Interpolation on Disjointed Color Filter Array (분리된 컬러 필터 배열을 이용한 에지 방향 컬러 보간 방법)

  • Oh, Hyun-Mook;Yoo, Du-Sic;Kang, Moon-Gi
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.1
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    • pp.53-61
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    • 2010
  • In this paper, we present a color interpolation algorithm that uses novel edge direction estimator and region classifier. The proposed edge direction estimator accurately determines the edge direction based on the correlation between the images obtained by the channel separated and down-sampled Bayer color filter array(CFA) pattern. The correlation is defined based on the similarity between the edge direction in the local region of the image and the shifting direction of the images. Also, the region of an image is defined as the flat, the edge, and the pattern-edge regions, where the edges are appeared repeatedly. When all the pixels in the image are classified into the three different regions, each pixel is interpolated horizontally or vertically according to the estimated direction. Experimental results show that the proposed algorithm outperforms the conventional edge-directed methods on objective and subjective criteria.

Texture Classification Using Rotation Invariant Local Directional Pattern (Rotation Invariant Local Directional Pattern을 이용한 텍스처 분류 방법)

  • Lee, Tae Hwan;Chae, Ok Sam
    • Convergence Security Journal
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    • v.17 no.3
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    • pp.21-29
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    • 2017
  • Accurate encoding of local patterns is a very important factor in texture classification. However, LBP based methods w idely studied have fundamental problems that are vulnerable to noise. Recently, LDP method using edge response and dire ction information was proposed in facial expression recognition. LDP is more robust to noise than LBP and can accommod ate more information in it's pattern code, but it has drawbacks that it is sensitive to rotation transforms that are critical to texture classification. In this paper, we propose a new local pattern coding method called Rotation Invariant Local Direc tional Pattern, which combines rotation-invariant transform to LDP. To prove the texture classification performance of the proposed method in this paper, texture classification was performed on the widely used UIUC and CUReT datasets. As a result, the proposed RILDP method showed better performance than the existing methods.

Enhancement of the Ultrasonic Image Using the Adaptive Window Log Filter for NDI of Aircraft Composite Materials (항공기 복합 재료의 비파괴 검사(NDI)를 위한 가변 창 필터를 이용한 초음파 영상 개선)

  • Hong, G.Y.;Hong, S.B.
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.11 no.2
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    • pp.33-42
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    • 2003
  • In this paper, we propose an enhancement of the ultrasonic image for non-destructive inspection of aircraft composite materials. The ultrasonic images are corrupted by a speckle noise which has the characteristic of granular pattern noise and is in all types of coherent imaging systems, the signal independent and multiplicative noise. In this paper, we derive a filter, called the AWLF(Adaptive Window Log Filter), from the nature of the speckle. The filter is made of the MEAN Filter in the edge region and Log Filter in the flat or noise region. To make a distinction between edge and flat region, we calculate the inclination around the local window instead of computing the local statistics of pixels such as local mean ${\bar{M}}$ and standard deviation ${\sigma}_s$. According to the obtained region, edge region is performed by the mean filter and flat region by the Log filter. Performance of the proposed filter is evaluated by the Enhanced Factor$(F_e)$ and the Speckle Index(SI).

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A study on the micro pattern replication difference in injection molding (사출성형시 미세패턴 전사성 차이에 관한 연구)

  • Kim, Tae-Hoon;Yoo, Yeong-Eun;Je, Tae-Jin;Park, Yeong-Woo;Roh, Seung- Hwan;Choi, Doo-Sun
    • Design & Manufacturing
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    • v.2 no.4
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    • pp.48-53
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    • 2008
  • We injection molded a thin type of plate and wedge type of plate with micro prizm patterns on its surface and investigated the fidelity of replication of the micro pattern depending on the process parameter such as mold temperature, melt temperature, injection rate or packing pressure. The size of the $90^{\circ}$ prizm pattern is $50{\mu}m$ and the size of the plate is about $335mm{\times}213mm$ and $400mm{\times}400mm$. The thicknesses are 2.6mm and 0.7mm at each edge of the wedge type of plate and 1mm at each edge of the thin type of plate. The fidelity of the replication turned out quite different according to the process parameters and location of the patterns on the plate. We measured the cavity pressure and temperature in real-time during the molding to analyze the effect of the local melt pressure and temperature on the micro pattern replication.

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Edge Detection in Blurred and Noisy Image Using Fuzzy Method (퍼지 기법을 이용한 열화된 영상에서의 에지 검출)

  • Jung, Jae-Woo;Chung, Tae-Yun;Jung, Jin-Yang;Huh, Jae-Man;Han, Young-Oh;Park, Sang-Hui
    • Proceedings of the KIEE Conference
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    • 1996.11a
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    • pp.294-296
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    • 1996
  • The process of detecting edge in an image is an important component of many Pattern Recognition and Computer Vision applications. In many practical cases, there exist blurred images due to defocussing, movement of an object and so on. In addition, local perturbation noise can be added to the images. We propose the edge detection technique in blurred and noisy image. For this, we use Fuzzy pyramid linking mothod to remove noise and enhance the edge in images. We develop contrast intensifier using the concept of Fuzzy sets as a postprocessing.

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A study on the prizm pattern replication in injection molding (사출 도광판의 프리즘 패턴 전사성에 관한 실험적 연구)

  • Kim, Chang-Wan;Yoo, Yeong-Eun;Kim, Tae-Hoon;Je, Tae-Jin;Choi, Doo-Sun
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1537-1541
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    • 2007
  • We injection molded a wedge type of plate with micro prizm patterns on its surface and investigated the fidelity of replication of the micro pattern depending on the process parameter such as mold temperature, melt temperature, injection rate or packing pressure. The size of the size of the $90^{\circ}$ prizm pattern is $50{\mu}m$ and the size of the plate is about 300㎜${\times}$200㎜. The thicknesses are 2.6㎜. and 0.7mm at each edge of the wedge type of plate. The fidelity of the replication turned out quite different according to the process parameters and location of the patterns on the plate. We measured the cavity pressure and temperature in real-time during the molding to analyze the effect of the local melt pressure and temperature on the micro pattern replication.

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An experimental-computational investigation of fracture in brittle materials

  • De Proft, K.;Wells, G.N.;Sluys, L.J.;De Wilde, W.P.
    • Computers and Concrete
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    • v.1 no.3
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    • pp.227-248
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    • 2004
  • A combined experimental-computational study of a double edge-notched stone specimen subjected to tensile loading is presented. In the experimental part, the load-deformation response and the displacement field around the crack tip are recorded. An Electronic Speckle Pattern Interferometer (ESPI) is used to obtain the local displacement field. The experimental results are used to validate a numerical model for the description of fracture using finite elements. The numerical model uses displacement discontinuities to model cracks. At the discontinuity, a plasticity-based cohesive zone model is applied for monotonic loading and a combined damage-plasticity cohesive zone model is used for cyclic loading. Both local and global results from the numerical simulations are compared with experimental data. It is shown that local measurements add important information for the validation of the numerical model. Consequently, the numerical models are enhanced in order to correctly capture the experimentally observed behaviour.