• Title/Summary/Keyword: Image Edge

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Optical Flow Measurement Based on Boolean Edge Detection and Hough Transform

  • Chang, Min-Hyuk;Kim, Il-Jung;Park, Jong an
    • International Journal of Control, Automation, and Systems
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    • v.1 no.1
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    • pp.119-126
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    • 2003
  • The problem of tracking moving objects in a video stream is discussed in this pa-per. We discussed the popular technique of optical flow for moving object detection. Optical flow finds the velocity vectors at each pixel in the entire video scene. However, optical flow based methods require complex computations and are sensitive to noise. In this paper, we proposed a new method based on the Hough transform and on voting accumulation for improving the accuracy and reducing the computation time. Further, we applied the Boo-lean based edge detector for edge detection. Edge detection and segmentation are used to extract the moving objects in the image sequences and reduce the computation time of the CHT. The Boolean based edge detector provides accurate and very thin edges. The difference of the two edge maps with thin edges gives better localization of moving objects. The simulation results show that the proposed method improves the accuracy of finding the optical flow vectors and more accurately extracts moving objects' information. The process of edge detection and segmentation accurately find the location and areas of the real moving objects, and hence extracting moving information is very easy and accurate. The Combinatorial Hough Transform and voting accumulation based optical flow measures optical flow vectors accurately. The direction of moving objects is also accurately measured.

Improved Edge Enhanced Error Diffusion Halftoning Using Local Mean and Spatial Variation (국부 평균과 공간 변화량을 이용한 개선된 에지 강조 오차확산법)

  • Kwak Nae-Joung
    • The Journal of the Korea Contents Association
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    • v.5 no.2
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    • pp.221-228
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    • 2005
  • The paper proposes the improved error diffusion halftoning system to enhance the edges using the spatial perceptual characteristics of the human visual system. The proposed method computes a spatial variation(SV), which is the difference between a pixel luminance and the average of its $3{\times}3$ neighborhood pixels' luminances weighted according to the spatial positioning. Information of edge enhancement(IEE) Is computed using the SV and the local average luminance. The IEE is added to the quantizer's input pixel and feeds into the halftoning quantizer. The quantizer produces the halftone image having the enhanced edge. The performance of the proposed method is compared with conventional methods by measuring the edge correlation. The halftone images by using the proposed method show better quality due to the enhanced edge. And the detailed edge is preserved in the halftone images by using the proposed method.

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An Edge Detector by Using Perfect Sharpening of Ramps (램프의 완전 선명화를 이용한 에지 검출기)

  • Lee, Jong-Gu;Yoo, Cheol-Jung;Chang, Ok-Bae
    • Journal of KIISE:Software and Applications
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    • v.34 no.11
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    • pp.961-970
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    • 2007
  • Since the usual conventional edge detectors employ the local differential derivatives, the detected edges are not uniform in their widths or some edges are missed out of the detection on magnified images. We employ a mapping from the exactly monotonic intensity distributions of ramp edges to the simple step functions of intensity, which is referred to as perfect sharpening map of ramp edges. This map is based on the non-local feature of intensity distribution and used to introduce a modified differentiation, in terms of which we can construct an efficient edge detector adaptive to the variation of edge width. By adopting the operator MADD in this paper, we developed an edge detector that works stably against the magnification of image or the variation of edge width. It is shown by comparing to the conventional algorithms that the proposed one is very excellent.

Line Edge-Based Type-Specific Corner Points Extraction for the Analysis of Table Form Document Structure (표 서식 문서의 구조 분석을 위한 선분 에지 기반의 유형별 꼭짓점 검출)

  • Jung, Jae-young
    • Journal of Digital Contents Society
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    • v.15 no.2
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    • pp.209-217
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    • 2014
  • It is very important to classify a lot of table-form documents into the same type of classes or to extract information filled in the template automatically. For these, it is necessary to accurately analyze table-form structure. This paper proposes an algorithm to extract corner points based on line edge segments and to classify the type of junction from table-form images. The algorithm preprocesses image through binarization, skew correction, deletion of isolated small area of black color because that they are probably generated by noises.. And then, it processes detections of edge block, line edges from a edge block, corner points. The extracted corner points are classified as 9 types of junction based on the combination of horizontal/vertical line edge segments in a block. The proposed method is applied to the several unconstraint document images such as tax form, transaction receipt, ordinary document containing tables, etc. The experimental results show that the performance of point detection is over 99%. Considering that almost corner points make a correspondence pair in the table, the information of type of corner and width of line may be useful to analyse the structure of table-form document.

An Efficient Contact Angle Computation using MADD Edge Detection (적응성 방향 미분의 에지 검출에 의한 효율적인 접촉각 연산)

  • Yang, Myung-Sup;Lee, Jong-Gu;Kim, Eun-Mi;Pahk, Cherl-Soo
    • Convergence Security Journal
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    • v.8 no.4
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    • pp.127-134
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    • 2008
  • In this paper, we try to improve the accuracy of automatic measurement for analysis equipment by detecting efficiently the edge of a waterdrop with transparency. In order to detect the edge of a waterdrop with transparency, we use an edge detecting technique, MADD (Modified Adaptive Directional Derivative), which can identify the ramp edges with various widths as the perfectly sharp edges and respond effectively regardless of enlarging or reducing the image. The proposed edge detecting technique by means of perfect sharpening of ramp edges employs the modified adaptive directional derivatives instead of the usual local differential operators in order to detect the edges of image. The modified adaptive directional derivatives are defined by introducing the perfect sharpening map into the adaptive directional derivatives. Finally we apply the proposed method to contact angle arithmetic and show the effiency and validity of the proposed method.

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Information extraction of the moving objects based on edge detection and optical flow (Edge 검출과 Optical flow 기반 이동물체의 정보 추출)

  • Chang, Min-Hyuk;Park, Jong-An
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.8A
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    • pp.822-828
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    • 2002
  • Optical flow estimation based on multi constraint approaches is frequently used for recognition of moving objects. However, the use have been confined because of OF estimation time as well as error problem. This paper shows a new method form effectively extracting movement information using the multi-constraint base approaches with sobel edge detection. The moving objects anr extraced in the input image sequence using edge detection and segmentation. Edge detection and difference of the two input image sequence gives us the moving objects in the images. The process of thresholding removes the moving objects detected due to noise. After thresholding the real moving objects, we applied the Combinatorial Hough Transform (CHT) and voting accumulation to find the optimal constraint lines for optical flow estimation. The moving objects found in the two consecutive images by using edge detection and segmentation greatly reduces the time for comutation of CHT. The voting based CHT avoids the errors associated with least squares methods. Calculation of a large number of points along the constraint line is also avoided by using the transformed slope-intercept parameter domain. The simulation results show that the proposed method is very effective for extracting optical flow vectors and hence recognizing moving objects in the images.

Design of New Fine Dust Measurement Method applying LoG Edge Detection Technique (LoG 윤곽선 검출 기법을 적용한 새로운 미세먼지 측정 방법 설계)

  • Jang, Taek-Jin;Lin, Chi-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.5
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    • pp.69-73
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    • 2022
  • In this paper, we propose a new method for measuring fine dust through a LoG(Laplacian of Gaussian)-based edge detection technique. CCTV-based images in a video are collected for fine dust measurement, and image ranges are designated through RoI(Region of Interest). After clustering by applying the GMM(Gaussian Mix Model) to the specified area, we detect edge through the LoG algorithm and measure the detected edge strength. The concentration of fine dust is determined based on the measured intensity data of the edge. In this paper, we propose algorithm as the effectiveness of experiment. As a result of collecting and applying CCTV image in the video installed around the laboratory of this school for a month from June to July, the measured result value was proved through this experiment to be sufficient to calculate the concentration and range of fine dust.

The Edge Enhanced Error Diffusion Appling Edge Information Weights (에지 정보 가중치를 적용한 에지 강조 오차 확산 방법)

  • 곽내정;양운모;유창연;한재혁
    • The Journal of the Korea Contents Association
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    • v.3 no.3
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    • pp.11-18
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    • 2003
  • Error diffusion is a procedure for generating high quality bilevel images from continuous-tone images but blurs the edge information. To solve this problem, we propose the improved method appling edge enhanced weights based on local characteristic of the original images. We consider edge information as local characteristic. First, we produce edges by appling 3$\times$3 sobel operator to the original image. The edge is normalized from 0 to 1. Edge information weights are computed by using sinusoidal function and the normalized edge information. The edge enhanced weights are computed by using edge information weights multiplied input pixels. The proposed method is compared with conventional methods by measuring the edge correlation and quality of the recovered images from the halftoned images. The proposed method provides better quality than the conventional method due to the enhanced edge and represents efficiently the detail edge. Also, the proposed method is improved in edge representation than the conventional method.

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Using Mean Shift Algorithm Enhance Edge Detection Effect (에지 추출 향상을 위한 Mean Shift 알고리즘의 이용)

  • Lei, Wang;Shin, Seong-Yoon;Rhee, Yang-Won
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2009.01a
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    • pp.211-214
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    • 2009
  • Edge detection always influenced by noise belong to the original image, therefore need use some methods to sort this issue, mean shift algorithm has the smooth function which suit for the edge detection purpose, so adopted to fade out the unimportant information, and the sensitive noise portions. After this section, use the Canny algorithm to pick up the contour of the objects we focus on, meanwhile select the Soble operator that has the orientation attribute to support the method work well. In final, take experiment and get the perfect result we wanted, make sure this method make sense and better than the sole Edge detection algorithm,

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Edge-Based Fast Intra Mode Decision in HEVC

  • Na, Sangkwon;Lee, Wonjae;Lee, Kyohyuk;Yoo, Kiwon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2013.06a
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    • pp.180-181
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    • 2013
  • High efficiency video coding (HEVC) appears due to the demand on high compression video coding beyond H.264/AVC in ultra-high definition (UHD) videos. As for intra prediction, HEVC has 35 prediction modes while H.264/AVC has 9 intra modes. To exploit the spatial correlation, we adopt an edge detection method, establish the edge map, and adaptively select the candidate modes using the acquired edge information in a block. The number of the candidate modes is determined through trade-off between computational complexity and coding efficiency. Besides, the range of coding unit sizes is determined using the uniqueness of the edge directions for the given image block. As a result, we reduced the encoding time by 56.8% at the cost of 2.5% BD-BR increase on average compared to Full modes at the HEVC reference software (HM 6.0 [1]).

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