• Title/Summary/Keyword: Vertical Edge Map

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Object Detection Algorithm in Sea Environment Based on Frequency Domain (주파수 도메인에 기반한 해양 물표 검출 알고리즘)

  • Park, Ki-Tae;Jeong, Jong-Myeon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.4
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    • pp.494-499
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    • 2012
  • In this paper, a new method for detecting various objects that can be risks to safety navigation in sea environment is proposed. By analysing Infrared(IR) images obtained from various sea environments, we could find out that object regions include both horizontal and vertical direction edges while background regions of sea surface mainly include vertical direction edges. Therefore, we present an approach to detecting object regions considering horizontal and vertical edges. To this end, in the first step, image enhancement is performed by suppressing noises such as sea glint and complex clutters using a statistical filter. In the second step, a horizontal edge map and a vertical edge map are generated by 1-D Discrete Cosine Transform technique. Then, a combined map integrating the horizontal and the vertical edge maps is generated. In the third step, candidate object regions are detected by a adaptive thresholding method. Finally, exact object regions are extracted by eliminating background and clutter regions based on morphological operation.

A Scale Invariant Object Detection Algorithm Using Wavelet Transform in Sea Environment (해양 환경에서 웨이블렛 변환을 이용한 크기 변화에 무관한 물표 탐지 알고리즘)

  • Bazarvaani, Badamtseren;Park, Ki Tae;Jeong, Jongmyeon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.3
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    • pp.249-255
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    • 2013
  • In this paper, we propose an algorithm to detect scale invariant object from IR image obtained in the sea environment. We create horizontal edge (HL), vertical edge (LH), diagonal edge (HH) of images through 2-D discrete Haar wavelet transform (DHWT) technique after noise reduction using morphology operations. Considering the sea environment, Gaussian blurring to the horizontal and vertical edge images at each level of wavelet is performed and then saliency map is generated by multiplying the blurred horizontal and vertical edges and combining into one image. Then we extract object candidate region by performing a binarization to saliency map. A small area in the object candidate region are removed to produce final result. Experiment results show the feasibility of the proposed algorithm.

Localization for Mobile Robot Using Vertical Line Features (수직선 특징을 이용한 이동 로봇의 자기 위치 추정)

  • 강창훈;안현식
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.11
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    • pp.937-942
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    • 2003
  • We present a self-localization method for mobile robots using vertical line features of indoor environment. When a 2D map including feature points and color information is given, a mobile robot moves to the destination, and acquires images from the surroundings having vertical line edges by one camera. From the image, vertical line edges are detected, and pattern vectors meaning averaged color values of the left and right regions of the each line are computed by using the properties of the line and a region growing method. The pattern vectors are matched with the feature points of the map by comparing the color information and the geometrical relationship. From the perspective transformation and rigid transformation of the corresponded points, nonlinear equations are derived. Localization is carried out from solving the equations by using Newton's method. Experimental results show that the proposed method using mono view is simple and applicable to indoor environment.

Localization for Mobile Robot Using Vertical Lines

  • Kang, Chang-Hun;Ahn, Hyun-Sik
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.793-797
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    • 2003
  • In this paper, we present a self-localization method for mobile robots using vertical line features of indoor environment. When a 2D map including feature points and color information is given, a mobile robot moves to the destination, and acquires images by one camera from the surroundings having vertical line edges. From the image, vertical line edges are detected, and pattern vectors meaning averaged color values of the left and right region of each line segment are computed. The pattern vectors are matched with the feature points of the map using the color information and the geometrical relationship of the points. From the perspective transformation of the corresponded points, nonlinear equations are derived. Localization is carried out from solving the equations by using Newton's method. Experimental results show that the proposed method using mono view is simple and applicable to indoor environment.

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Text Region Detection using Adaptive Character-Edge Map From Natural Image (자연영상에서 적응적 문자-에지 맵을 이용한 텍스트 영역 검출)

  • Park, Jong-Cheon;Hwang, Dong-Guk;Jun, Byoung-Min
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.5
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    • pp.1135-1140
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    • 2007
  • This paper proposes an edge-based text region detection algorithm using the adaptive character-edge maps which are independent of the size of characters and the orientation of character string in natural images. First, labeled images are obtained from edge images and in order to search for characters, adaptive character-edge maps by way grammar are applied to labeled images. Next, selected label images are clustered as for distance of its neighbors. And then, text region candidates are obtained. Finally, text region candidates are verified by using the empirical rules and horizontal/vertical projection profiles based on the orientation of text region. As the results of experiments, a text region detection algorithm turned out to be robust in the matter of various character size, orientation, and the complexity of the background.

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A Comparative Analysis of Edge Detection Methods in Magnetic Data

  • Jeon, Taehwan;Rim, Hyoungrea;Park, Yeong-Sue
    • Journal of the Korean earth science society
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    • v.36 no.5
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    • pp.437-446
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    • 2015
  • Many edge detection methods, based on horizontal and vertical derivatives, have been introduced to provide us with intuitive information about the horizontal distribution of a subsurface anomalous body. Understanding the characteristics of each edge detection method is important for selecting an optimized method. In order to compare the characteristics of the individual methods, this study applied each method to synthetic magnetic data created using homogeneous prisms with different sizes, the numbers of bodies, and spacings between them. Seven edge detection methods were comprehensively and quantitatively analyzed: the total horizontal derivative (HD), the vertical derivative (VD), the 3D analytic signal (AS), the title derivative (TD), the theta map (TM), the horizontal derivative of tilt angle (HTD), and the normalized total horizontal derivative (NHD). HD and VD showed average good performance for a single-body model, but failed to detect multiple bodies. AS traced the edge for a single-body model comparatively well, but it was unable to detect an angulated corner and multiple bodies at the same time. TD and TM performed well in delineating the edges of shallower and larger bodies, but they showed relatively poor performance for deeper and smaller bodies. In contrast, they had a significant advantage in detecting the edges of multiple bodies. HTD showed poor performance in tracing close bodies since it was sensitive to an interference effect. NHD showed great performance under an appropriate window.

Reduced-Reference Quality Assessment for Compressed Videos Based on the Similarity Measure of Edge Projections (에지 투영의 유사도를 이용한 압축된 영상에 대한 Reduced-Reference 화질 평가)

  • Kim, Dong-O;Park, Rae-Hong;Sim, Dong-Gyu
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.3
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    • pp.37-45
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    • 2008
  • Quality assessment ai s to evaluate if a distorted image or video has a good quality by measuring the difference between the original and distorted images or videos. In this paper, to assess the visual qualify of a distorted image or video, visual features of the distorted image are compared with those of the original image instead of the direct comparison of the distorted image with the original image. We use edge projections from two images as features, where the edge projection can be easily obtained by projecting edge pixels in an edge map along vertical/horizontal direction. In this paper, edge projections are obtained by using vertical/horizontal directions of gradients as well as the magnitude of each gradient. Experimental results show the effectiveness of the proposed quality assessment through the comparison with conventional quality assessment algorithms such as structural similarity(SSIM), edge peak signal-to-noise ratio(EPSNR), and edge histogram descriptor(EHD) methods.

Salient Object Extraction from Video Sequences using Contrast Map and Motion Information (대비 지도와 움직임 정보를 이용한 동영상으로부터 중요 객체 추출)

  • Kwak, Soo-Yeong;Ko, Byoung-Chul;Byun, Hye-Ran
    • Journal of KIISE:Software and Applications
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    • v.32 no.11
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    • pp.1121-1135
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    • 2005
  • This paper proposes a moving object extraction method using the contrast map and salient points. In order to make the contrast map, we generate three-feature maps such as luminance map, color map and directional map and extract salient points from an image. By using these features, we can decide the Attention Window(AW) location easily The purpose of the AW is to remove the useless regions in the image such as background as well as to reduce the amount of image processing. To create the exact location and flexible size of the AW, we use motion feature instead of pre-assumptions or heuristic parameters. After determining of the AW, we find the difference of edge to inner area from the AW. Then, we can extract horizontal candidate region and vortical candidate region. After finding both horizontal and vertical candidates, intersection regions through logical AND operation are further processed by morphological operations. The proposed algorithm has been applied to many video sequences which have static background like surveillance type of video sequences. The moving object was quite well segmented with accurate boundaries.

Line Segments Extraction by using Chain Code Tracking of Edge Map from Aerial Images (항공영상으로부터 에지 맵의 체인코드 추적에 의한 선소추출)

  • Lee Kyu-won;Woo Dong-min
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.6
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    • pp.709-713
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    • 2005
  • A new algorithm is proposed for the extraction of line segments to construct 3D wire-frame models of building from the high-resolution aerial images. The purpose of this study Is the accurate and effective extraction of line segments, considering the problems such as discordance of lines and blurred edges existing in the conventional methods. Using the edge map extracted from aerial images, chain code tracking of edges was performed. Then, we extract the line segments considering the strength of edges and the direction of them. SUSAN (Smallest Uni-value Segment Assimilating Nucleus) algorithm proposed by Smith was used to extract an edge map. The proposed algorithm consists of 4 steps: removal of the horizontal, vertical and diagonal components of edges to reduce non-candidate point of line segments based on the chain code tracking of the edge map, removal of contiguous points, removal of the same angle points, and the extraction of the start and end points to be line segments. By comparing the proposed algorithm with Boldt algorithm, better results were obtained regarding the extraction of the representative line segments of buildings, having relatively less extraction of unnecessary line segments.

Towards an Urban Troposphere

  • Kenoff, Jeffrey A;Gross, Peter
    • International Journal of High-Rise Buildings
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    • v.11 no.1
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    • pp.15-24
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    • 2022
  • Over the past 30 years, the tall building has seen unprecedented global support. With advanced innovation and many regions around the world discovering increasing growth rates, the tall, supertall, and megatall buildings continue to drastically alter the vertical urbanism of the cities they inhabit. For centuries, urban conditions in most major territories were predominately defined by the street wall and the spaces it shapes. Giambattista Nolli's 1748 Map of Rome most clearly illustrates this significance and possibly solidifies what generations would understand to be the predominant urban condition. As architects, it has been a city's lower vertical wall fabric that has often been the primary focus of efforts to craft an urban experience, and for good reason. Through recent examples of built and unbuilt KPF projects, this paper will explore an upper vertical wall fabric, an urbanism that not only exists at the ground but also within the troposphere.