• Title/Summary/Keyword: canny edge detector

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An adaptive method of multi-scale edge detection for underwater image

  • Bo, Liu
    • Ocean Systems Engineering
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    • v.6 no.3
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    • pp.217-231
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    • 2016
  • This paper presents a new approach for underwater image analysis using the bi-dimensional empirical mode decomposition (BEMD) technique and the phase congruency information. The BEMD algorithm, fully unsupervised, it is mainly applied to texture extraction and image filtering, which are widely recognized as a difficult and challenging machine vision problem. The phase information is the very stability feature of image. Recent developments in analysis methods on the phase congruency information have received large attention by the image researchers. In this paper, the proposed method is called the EP model that inherits the advantages of the first two algorithms, so this model is suitable for processing underwater image. Moreover, the receiver operating characteristic (ROC) curve is presented in this paper to solve the problem that the threshold is greatly affected by personal experience when underwater image edge detection is performed using the EP model. The EP images are computed using combinations of the Canny detector parameters, and the binaryzation image results are generated accordingly. The ideal EP edge feature extractive maps are estimated using correspondence threshold which is optimized by ROC analysis. The experimental results show that the proposed algorithm is able to avoid the operation error caused by manual setting of the detection threshold, and to adaptively set the image feature detection threshold. The proposed method has been proved to be accuracy and effectiveness by the underwater image processing examples.

Development of Brazing Robot System using Camera and IR Sensor (카메라와 적외선 센서를 이용한 브레이징 로봇시스템 개발)

  • Kim, Young-Tak;Lim, Mee-Seub;Lim, Joon-Hong
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1729-1730
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    • 2008
  • In the industry, the automation of brazing system is very important using the vision senor and the edge detection of the bronze pipe. And also, the accurate coordination is needed for the finding of the precise location. In this paper, we propose an algorithm for the measurement of 3D information of the brazing material and the detection algorithm of soldering area using the camera and IR sensor. We use Canny edge detector in noisy environments. The experimental study shows that camera and IR sensor is useful for the measurement of distance in the brazing work.

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Region Extraction Using Edge Information and watershed segmentation (윤곽선 정보와 watershed segmentation을 이용한 영역 추출)

  • 이원효;주동현;염동훈;고기영;김두영
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2003.06a
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    • pp.90-93
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    • 2003
  • 본 논문에서는 watershed segmentation을 이용해서 특정한 영역의 윤곽선정보를 바탕으로 영상을 추출하는 방법을 제안한다. 일반적인 영역추출방법에는 폐곡선을 이용한 영역추출방법, snake라 불리는 에너지 최소화를 이용한 active contour 방법 등 여러 가지가 있다. 특히 이러한 방법에는 연산시간이 많이 걸린다는 단점이 있는데, 이러한 문제점을 해결하기 위해서 canny edge detector를 사용하여 윤곽선 정보를 추출하고, watershed segmentation으로 영상을 분할한 후 윤곽선 정보를 이용해서 특정 영상의 영역에 대한 부분을 병합하여 추출하는 방법을 사용하였다. 제안하는 방법으로 기존의 추출 방법중의 하나인 levelset과 비교 실험한 결과 거의 동일한 영상의 결과를 얻을 수 있었으며 연산시간을 줄일 수 있었다.

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A Study on Efficient Watershed Algorithm by Using Improved SUSAN Algorithm

  • Choi, Yong-Hwan;Kim, Yong-Ho;Kim, Joong-Kyu
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.05b
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    • pp.431-434
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    • 2003
  • In this paper, we propose an efficient method not only f3r producing accurate region segmentation, solving the over-segmentation problem of watershed algorithm but also f3r reducing post-processing time by reducing computation loads. Through this proposed method, region segmentation of neighboring objects and discrimination of similar intensities were effectively obtained. Input image of watershed algorithm has used the derivative-based detectors such as Sobel and Canny. But proposed method uses the pixels-similarity-based detector, that is, SUSAN. By adopting this proposed method, we can reduce the noise problem and solve the problem of over-segmentation and not lose the edge information of objects. We also propose Zero-Crossing SUSAN. With Zero-Crossing SUSAN, the edge localization, times and computation loads can be improved over those obtained from existing SUSAN

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Edge based Interactive Segmentation (경계선 기반의 대화형 영상분할 시스템)

  • Yun, Hyun Joo;Lee, Sang Wook
    • Journal of the Korea Computer Graphics Society
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    • v.8 no.2
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    • pp.15-22
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    • 2002
  • Image segmentation methods partition an image into meaningful regions. For image composition and analysis, it is desirable for the partitioned regions to represent meaningful objects in terms of human perception and manipulation. Despite the recent progress in image understanding, however, most of the segmentation methods mainly employ low-level image features and it is still highly challenging to automatically segment an image based on high-level meaning suitable for human interpretation. The concept of HCI (Human Computer Interaction) can be applied to operator-assisted image segmentation in a manner that a human operator provides guidance to automatic image processing by interactively supplying critical information about object boundaries. Intelligent Scissors and Snakes have demonstrated the effectiveness of human-assisted segmentation [2] [1]. This paper presents a method for interactive image segmentation for more efficient and effective detection and tracking of object boundaries. The presented method is partly based on the concept of Intelligent Scissors, but employs the well-established Canny edge detector for stable edge detection. It also uses "sewing method" for including weak edges in object boundaries, and 5-direction search to promote more efficient and stable linking of neighboring edges than the previous methods.

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Image noise reduction algorithms using nonparametric method (비모수 방법을 사용한 영상 잡음 제거 알고리즘)

  • Woo, Ho-young;Kim, Yeong-hwa
    • The Korean Journal of Applied Statistics
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    • v.32 no.5
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    • pp.721-740
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    • 2019
  • Noise reduction is an important field in image processing and requires a statistical approach. However, it is difficult to assume a specific distribution of noise, and a spatial filter that reflects regional characteristics is a small sample and cannot be accessed in a parametric manner. The first order image differential and the second order image differential show a clear difference according to the noise level included in the image and can be more clearly understood using the canyon edge detector. The Fligner-Killeen test was performed and the bootstrap method was used to statistically check the noise level. The estimated noise level was set between 0 and 1 using the cumulative distribution function of the beta distribution. In this paper, we propose a nonparametric noise reduction algorithm that accounts for the noise level included in the image.

Carpal Bone Segmentation Using Modified Multi-Seed Based Region Growing

  • Choi, Kyung-Min;Kim, Sung-Min;Kim, Young-Soo;Kim, In-Young;Kim, Sun-Il
    • Journal of Biomedical Engineering Research
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    • v.28 no.3
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    • pp.332-337
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    • 2007
  • In the early twenty-first century, minimally invasive surgery is the mainstay of various kinds of surgical fields. Surgeons gave percutaneously surgical treatment of the screw directly using a fluoroscopic view in the past. The latest date, they began to operate the fractured carpal bone surgery using Computerized Tomography (CT). Carpal bones composed of wrist joint consist of eight small bones which have hexahedron and sponge shape. Because of these shape, it is difficult to grasp the shape of carpal bones using only CT image data. Although several image segmentation studies have been conducted with carpal bone CT image data, more studies about carpal bone using CT data are still required. Especially, to apply the software implemented from the studies to clinical fIeld, the outcomes should be user friendly and very accurate. To satisfy those conditions, we propose modified multi-seed region growing segmentation method which uses simple threshold and the canny edge detector for finding edge information more accurately. This method is able to use very easily and gives us high accuracy and high speed for extracting the edge information of carpal bones. Especially, using multi-seed points, multi-bone objects of the carpal bone are extracted simultaneously.

Text Region Extraction using Pattern Histogram of Character-Edge Map in Natural Images (문자-에지 맵의 패턴 히스토그램을 이용한 자연이미지에서의 텍스트 영역 추출)

  • Park, Jong-Cheon;Hwang, Dong-Guk;Lee, Woo-Ram;Kwon, Kyo-Hyun;Jun, Byoung-Min
    • Proceedings of the KAIS Fall Conference
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    • 2006.11a
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    • pp.220-224
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    • 2006
  • The text to be included in the natural images has many important information in the natural image. Therefore, if we can extract the text in natural images, It can be applied to many important applications. In this paper, we propose a text region extraction method using pattern histogram of character-edge map. We extract the edges with the Canny edge detector and creates 16 kind of edge map from an extracted edges. And then we make a character-edge map of 8 kinds that have a character feature with a combination of an edge map. We extract text region using 8 kinds of character-edge map and 16 kind of edge map. Verification of text candidate region uses analysis of a character-edge map pattern histogram and structural feature of text region. The method to propose experimented with various kind of the natural images. The proposed approach extracted text region from a natural images to have been composed of a complex background, various letters, various text colors effectively.

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Accurate Spatial Information Mapping System Using MMS LiDAR Data (MMS LiDAR 자료 기반 정밀 공간 정보 매핑 시스템)

  • CHOUNG, Yun-Jae;CHOI, Hyeoung-Wook;PARK, Hyeon-Cheol
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.1
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    • pp.1-11
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    • 2018
  • Mapping accurate spatial information is important for constructing three-dimensional (3D) spatial models and managing artificial facilities, and, especially, mapping road centerlines is necessary for constructing accurate road maps. This research developed a semi-automatic methodology for mapping road centerlines using the MMS(Mobile Mapping System) LiDAR(Light Detection And Ranging) point cloud as follows. First, the intensity image was generated from the given MMS LiDAR data through the interpolation method. Next, the line segments were extracted from the intensity image through the edge detection technique. Finally, the road centerline segments were manually selected among the extracted line segments. The statistical results showed that the generated road centerlines had 0.065 m overall accuracy but had some errors in the areas near road signs.

A Study on Enhancing the Performance of Detecting Lip Feature Points for Facial Expression Recognition Based on AAM (AAM 기반 얼굴 표정 인식을 위한 입술 특징점 검출 성능 향상 연구)

  • Han, Eun-Jung;Kang, Byung-Jun;Park, Kang-Ryoung
    • The KIPS Transactions:PartB
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    • v.16B no.4
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    • pp.299-308
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    • 2009
  • AAM(Active Appearance Model) is an algorithm to extract face feature points with statistical models of shape and texture information based on PCA(Principal Component Analysis). This method is widely used for face recognition, face modeling and expression recognition. However, the detection performance of AAM algorithm is sensitive to initial value and the AAM method has the problem that detection error is increased when an input image is quite different from training data. Especially, the algorithm shows high accuracy in case of closed lips but the detection error is increased in case of opened lips and deformed lips according to the facial expression of user. To solve these problems, we propose the improved AAM algorithm using lip feature points which is extracted based on a new lip detection algorithm. In this paper, we select a searching region based on the face feature points which are detected by AAM algorithm. And lip corner points are extracted by using Canny edge detection and histogram projection method in the selected searching region. Then, lip region is accurately detected by combining color and edge information of lip in the searching region which is adjusted based on the position of the detected lip corners. Based on that, the accuracy and processing speed of lip detection are improved. Experimental results showed that the RMS(Root Mean Square) error of the proposed method was reduced as much as 4.21 pixels compared to that only using AAM algorithm.