• Title/Summary/Keyword: Otsu algorithm

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A Binarization Technique using Histogram Matching for License Plate with a Shadow (그림자가 있는 자동차 번호판을 위한 히스토그램 매칭 기반의 이진화)

  • Kim, Jung Hun;Kim, Gibak
    • Journal of Broadcast Engineering
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    • v.19 no.1
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    • pp.56-63
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    • 2014
  • This paper deals with a binarization for plate number recognition. The binarization process converts an image into a binary image and plays an important role for automatically recognizing plate number. The rear license plate has often a shadowed image which causes erroneous binarized image due to non-uniform illumination. In this paper, a binarization method is proposed in which the shadow line is detected in a rear plate with a shadow. And then the histogram matching is conducted for the two image separated by the shadow line. After histogram matching, two images are joined and finally Otsu method is applied for the binarization. In the experiment, the proposed algorithm shows robust performance compared to the conventional method in the presence of estimation error in the shadow line.

Satellite-based Forest Withering Index for Detection of Fire Burn Area: Its Development and Application to 2019 Kangwon Wildfires (산불피해지 탐지를 위한 위성기반 산림고사지수 개발 및 2019년 4월 강원 산불 사례에의 적용)

  • Park, Seong-Wook;Lee, Soo-Jin;Chung, Chu-Yong;Chung, Sung-Rae;Shin, Inchul;Jung, Won-Chan;Mo, Hee-Sook;Kim, Sang-Il;Lee, Yang-Won
    • Korean Journal of Remote Sensing
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    • v.35 no.2
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    • pp.343-346
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    • 2019
  • This letter describes a development of satellite-based forest withering index for detection of fire burn area and its application to the Goseong-Sokcho and Gangneung-Donghae wildfires in April 4, 2019. Withered forest has very different spectral characteristics from healthy forest. In particular, a false color composite of R-NIR-G represents such difference very clearly. Using Sentinel-2 images with the forest withering index, we derived the area burned by the wildfires: approximately 701.16 ha for Goseong-Sokcho and approximately 710.60 ha for Gangneung-Donghae, although official record will be announced by the Korean government later.

3D Film Image Inspection Based on the Width of Optimized Height of Histogram (히스토그램의 최적 높이의 폭에 기반한 3차원 필름 영상 검사)

  • Jae-Eun Lee;Jong-Nam Kim
    • Journal of the Institute of Convergence Signal Processing
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    • v.23 no.2
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    • pp.107-114
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    • 2022
  • In order to classify 3D film images as right or wrong, it is necessary to detect the pattern in a 3D film image. However, if the contrast of the pixels in the 3D film image is low, it is not easy to classify as the right and wrong 3D film images because the pattern in the image might not be clear. In this paper, we propose a method of classifying 3D film images as right or wrong by comparing the width at a specific frequency of each histogram after obtaining the histogram. Since, it is classified using the width of the histogram, the analysis process is not complicated. From the experiment, the histograms of right and wrong 3D film images were distinctly different, and the proposed algorithm reflects these features, and showed that all 3D film images were accurately classified at a specific frequency of the histogram. The performance of the proposed algorithm was verified to be the best through the comparison test with the other methods such as image subtraction, otsu thresholding, canny edge detection, morphological geodesic active contour, and support vector machines, and it was shown that excellent classification accuracy could be obtained without detecting the patterns in 3D film images.

Object Segmentation for Detection of Moths in the Pheromone Trap Images (페로몬 트랩 영상에서 해충 검출을 위한 객체 분할)

  • Kim, Tae-Woo;Cho, Tae-Kyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.157-163
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    • 2017
  • The object segmentation approach has the merit of reducing the processing cost required to detect moths of interest, because it applies a moth detection algorithm to the segmented objects after segmenting the objects individually in the moth image. In this paper, an object segmentation method for moth detection in pheromone trap images is proposed. Our method consists of preprocessing, thresholding, morphological filtering, and object labeling processes. Thresholding in the process is a critical step significantly influencing the performance of object segmentation. The proposed method can threshold very elaborately by reflecting the local properties of the moth images. We performed thresholding using global and local versions of Ostu's method and, used the proposed method for the moth images of Carposina sasakii acquired on a pheromone trap placed in an orchard. It was demonstrated that the proposed method could reflect the properties of light and background on the moth images. Also, we performed object segmentation and moth classification for Carposina sasakii images, where the latter process used an SVM classifier with training and classification steps. In the experiments, the proposed method performed the detection of Carposina sasakii for 10 moth images and achieved an average detection rate of 95% of them. Therefore, it was shown that the proposed technique is an effective monitoring method of Carposina sasakii in an orchard.