• Title/Summary/Keyword: 에지 방향

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A Revised Dynamic ROI Coding Method Based On The Automatic ROI Extraction For Low Depth-of-Field JPEG2000 Images (낮은 피사계 심도 JPEG2000 이미지를 위한 자동 관심영역 추출기반의 개선된 동적 관심영역 코딩 방법)

  • Park, Jae-Heung;Kim, Hyun-Joo;Shim, Jong-Chae;Yoo, Chang-Yeul;Seo, Yeong-Geon;Kang, Ki-Jun
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.10
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    • pp.63-71
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    • 2009
  • In this study, we propose a revised dynamic ROI (Region-of-Interest) coding method in which the focused ROI is automatically extracted without help from users during the recovery process of low DOF (Depth-of-Field) JPEG2000 image. The proposed method creates edge mask information using high frequency sub-band data on a specific level in DWT (Discrete Wavelet Transform), and then identifies the edge code block for a high-speed ROI extraction. The algorithm scans the edge mask data in four directions by the unit of code block and identifies the edge code block simply and fastly using a edge threshold. As the results of experimentation applying for Implicit method, the proposed method showed the superiority in the side of speed and quality comparing to the existing methods.

Effective Demosaicking Algorithm for CFA Images using Directional Interpolation and Nonlocal Means Filtering (방향성 기반 보간법과 비지역 평균 필터링에 의한 효과적인 CFA 영상 디모자이킹 알고리즘)

  • Kim, Jongho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.10
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    • pp.110-116
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    • 2017
  • This paper presents an effective demosaicking algorithm for color filter array (CFA) images acquired from single-sensor devices based on directional interpolation and nonlocal properties of the image. We interpolate the G channel considering diagonal directions as well as horizontal and vertical directions, using a small number of pixels to reflect local properties of the image. Then, we overcome image degradations, such as zipper effects near edges and false colors, by applying nonlocal means (NLM) filtering to the interpolated pixels. R and B channels are reproduced by using directional interpolation with information of the reconstructed G channel and NLM filtering. Experimental results for various McMaster images with high saturation and color changes show that the proposed algorithm accomplishes high PSNR compared with conventional methods. Moreover, the proposed method demonstrates better subjective quality compared with existing methods in terms of reduction of quality degradation, like false colors, and preservation of the image structures, such as edges and textures.

Vehicle Detection Method Using Convolution Matching Based on 8 Oriented Color Expression (8 방향 색상 표현 기반 컨벌류션 정합(Convolution Matching)을 이용한 차량 검출기법)

  • Han, Sung-Ji;Han, Young-Joon;Hahn, Hern-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.12
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    • pp.63-73
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    • 2009
  • This paper presents a vehicle detection method that uses convolution matching method based on a simple color information. An input image is expressed as 8 oriented color expression(Red, Green, Blue, White, Black, Cyan, Yellow, Magenta) considering an orientation of a pixel color vector. It makes the image very reliable and strong against changes of illumination condition or environment. This paper divides the vehicle detection into a hypothesis generation step and a hypothesis verification step. In the hypothesis generation step, the vehicle candidate region is found by vertical edge and shadow. In the hypothesis verification step, the convolution matching and the complexity of image edge are used to detect real vehicles. It is proved that the proposed method has the fast and high detection rate on various experiments where the illumination source and environment are changed.

A Study on Image Pixel Classification Using Directional Scales (방향성 정보 척도를 이용한 영상의 픽셀분류 방법에 관한 연구)

  • 박중순;김수겸
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.4
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    • pp.587-592
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    • 2004
  • Pixel classification is one of basic issues of image processing. The general characteristics of the pixels belonging to various classes are discussed and the radical principles of pixel classification are given. At the same time, a pixel classification scheme based on image information scales is proposed. The proposed method is overcome that computation amount become greater and contents easily get turned. And image directional scales has excellent anti-noise performance. In the result of experiment. good efficiency is showed compare with other methods.

A Deblurring Algorithm Combined with Edge Directional Color Demosaicing for Reducing Interpolation Artifacts (컬러 보간 에러 감소를 위한 에지 방향성 컬러 보간 방법과 결합된 디블러링 알고리즘)

  • Yoo, Du Sic;Song, Ki Sun;Kang, Moon Gi
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.7
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    • pp.205-215
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    • 2013
  • In digital imaging system, Bayer pattern is widely used and the observed image is degraded by optical blur during image acquisition process. Generally, demosaicing and deblurring process are separately performed in order to convert a blurred Bayer image to a high resolution color image. However, the demosaicing process often generates visible artifacts such as zipper effect and Moire artifacts when performing interpolation across edge direction in Bayer pattern image. These artifacts are emphasized by the deblurring process. In order to solve this problem, this paper proposes a deblurring algorithm combined with edge directional color demosaicing method. The proposed method is consisted of interpolation step and region classification step. Interpolation and deblurring are simultaneously performed according to horizontal and vertical directions, respectively during the interpolation step. In the region classification step, characteristics of local regions are determined at each pixel position and the directionally obtained values are region adaptively fused. Also, the proposed method uses blur model based on wave optics and deblurring filter is calculated by using estimated characteristics of local regions. The simulation results show that the proposed deblurring algorithm prevents the boosting of artifacts and outperforms conventional approaches in both objective and subjective terms.

Motion Map Generation for Maintaining the Temporal Coherence of Brush Strokes in the Painterly Animation (회화적 애니메이션에서 브러시 스트로크의 시간적 일관성을 유지하기 위한 모션 맵 생성)

  • Park Youngs-Up;Yoon Kyung-Hyun
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.8
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    • pp.536-546
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    • 2006
  • Painterly animation is a method that expresses painterly images with a hand-painted appearance from a video, and the most crucial element for it is the temporal coherence of brush strokes between frames. A motion map is proposed in this paper as a solution to the issue of maintaining the temporal coherence in the brush strokes between the frames. A motion map is the region that frame-to-frame motions have occurred. Namely, this map refers to the region frame-to-frame edges move by the motion information with the motion occurred edges as a starting point. In this paper, we employ the optical flow method and block-based method to estimate the motion information. The method that yielded the biggest PSNR using the motion information (the directions and magnitudes) acquired by various methods of motion estimation has been chosen as the final motion information to form a motion map. The created motion map determine the part of the frame that should be re-painted. In order to express painterly images with a hand- painted appearance and maintain the temporal coherence of brush strokes, the motion information was applied to only the strong edges that determine the directions of the brush strokes. Also, this paper seek to reduce the flickering phenomenon between the frames by using the multiple exposure method and the difference map created by the difference between images of the source and the canvas. Maintenance of the coherence in the direction of the brush strokes was also attempted by a local gradient interpolation to maintain the structural coherence.

An Automatic ROI Extraction and Its Mask Generation based on Wavelet of Low DOF Image (피사계 심도가 낮은 이미지에서 웨이블릿 기반의 자동 ROI 추출 및 마스크 생성)

  • Park, Sun-Hwa;Seo, Yeong-Geon;Lee, Bu-Kweon;Kang, Ki-Jun;Kim, Ho-Yong;Kim, Hyung-Jun;Kim, Sang-Bok
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.3
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    • pp.93-101
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    • 2009
  • This paper suggests a new algorithm automatically searching for Region-of-Interest(ROI) with high speed, using the edge information of high frequency subband transformed with wavelet. The proposed method executes a searching algorithm of 4-direction object boundary by the unit of block using the edge information, and detects ROIs. The whole image is splitted by $64{\times}64$ or $32{\times}32$ sized blocks and the blocks can be ROI block or background block according to taking the edges or not. The 4-directions searche the image from the outside to the center and the algorithm uses a feature that the low-DOF image has some edges as one goes to center. After searching all the edges, the method regards the inner blocks of the edges as ROI, and makes the ROI masks and sends them to server. This is one of the dynamic ROI method. The existing methods have had some problems of complicated filtering and region merge, but this method improved considerably the problems. Also, it was possible to apply to an application requiring real-time processing caused by the process of the unit of block.

A Technique for Image Processing of Concrete Surface Cracks (콘크리트 표면 균열의 영상 처리 기법)

  • Kim Kwang-Baek;Cho Jae-Hyun;Ahn Sang-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.7
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    • pp.1575-1581
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    • 2005
  • Recently, further study is being done on the affect of crack on concrete structure and many people have made every endeavor not to leave it unsettled but to minimize it by repair works. In this paper we propose the image processing method that do not remain manual but automatically process the length, the direction and e width of cracks on concrete surface. First, we calibrate light's affect from image by using closing operation, one of morphology methods that can extract the feature of oracle and we extract the edge of crack image by sobel mask. After it, crack image is binarized by iteration binarization. And we extract the edge of cracks using noise elimination method that use an average of adjacent pixels by 3${\times}$3 mask and Glassfire Labeling algorithm. on, in this paper we propose an image processing method which can automatically measure the length, the direction and the width of cracks using the extracted edges of cracks. The results of experiment showed that the proposed method works better on the extraction of concrete cracks. Also our method showed the possibility that inspector's decision is unnecessary.

Object Detection Method in Sea Environment Using Fast Region Merge Algorithm (해양환경에서 고속 영역 병합 알고리즘을 이용한 물표 탐지 기법)

  • Jeong, Jong-Myeon;Park, Gyei-Kark
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.5
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    • pp.610-616
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    • 2012
  • In this paper, we present a method to detect an object such as ship, rock and buoy from sea IR image for the safety navigation. To this end, we do the image smoothing first and the apply watershed algorithm to segment image into subregions. Since watershed algorithm almost always produces over-segmented regions, it requires posterior merging process to get meaningful segmented regions. We propose an efficient merger algorithm that requires only two times of direct access to the pixels regardless of the number of regions. Also by analyzing IR image obtained from sea environments, we could find out that most horizontal edge come out from object regions. For the given input IR image we extract horizontal edge and eliminate isolated edges produced from background and noises by adopting morphological operator. Among the segmented regions, the regions that have horizontal edges are extracted as final results. Experimental results show the adequacy of the proposed method.

An Efficient 3-D Deinterlacing Algorithm by Detecting Accurate Motions Using Adaptive-Thresholded Values (적응적인 임계값을 적용한 정확한 움직임 검출과 이를 이용한 효율적인 3-D 디인터레이싱 알고리즘)

  • Cho, Dae-Rim;Song, Jin-Mo;Lee, Dong-Ho
    • Journal of Korea Multimedia Society
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    • v.13 no.11
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    • pp.1610-1620
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    • 2010
  • This paper proposes a motion-adaptive 3-D deinterlacing algorithm based on an adaptive-thresholded motion detection and an interpolation method using binary patterns to compensate motion missing and false motion errors. For efficient motion detection, we adaptively decided a threshold value according to the complexity of image. Many edge-based interpolation algorithms have been proposed to improve the subjective quality. Recently, to efficiently interpolate low angle edge and line, a method using predefined binary patterns has been proposed. In this paper, we propose an improved method by modifying the binary patterns. Simulation results have shown that the proposed method provides better performance than the existing methods.