• Title/Summary/Keyword: Otsu 알고리즘

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Building Dataset of Sensor-only Facilities for Autonomous Cooperative Driving

  • Hyung Lee;Chulwoo Park;Handong Lee;Junhyuk Lee
    • Journal of the Korea Society of Computer and Information
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    • v.29 no.1
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    • pp.21-30
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    • 2024
  • In this paper, we propose a method to build a sample dataset of the features of eight sensor-only facilities built as infrastructure for autonomous cooperative driving. The feature extracted from point cloud data acquired by LiDAR and build them into the sample dataset for recognizing the facilities. In order to build the dataset, eight sensor-only facilities with high-brightness reflector sheets and a sensor acquisition system were developed. To extract the features of facilities located within a certain measurement distance from the acquired point cloud data, a cylindrical projection method was applied to the extracted points after applying DBSCAN method for points and then a modified OTSU method for reflected intensity. Coordinates of 3D points, projected coordinates of 2D, and reflection intensity were set as the features of the facility, and the dataset was built along with labels. In order to check the effectiveness of the facility dataset built based on LiDAR data, a common CNN model was selected and tested after training, showing an accuracy of about 90% or more, confirming the possibility of facility recognition. Through continuous experiments, we will improve the feature extraction algorithm for building the proposed dataset and improve its performance, and develop a dedicated model for recognizing sensor-only facilities for autonomous cooperative driving.

Hierarchical Watermarking Technique Combining Error Correction Codes (오류 정정 부호를 결합한 계층적 워터마킹 기법)

  • Do-Eun Kim;So-Hyun Park;Il-Gu Lee
    • The Transactions of the Korea Information Processing Society
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    • v.13 no.10
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    • pp.481-491
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    • 2024
  • Digital watermarking is a technique for embedding information into digital content. Digital watermarking has attracted attention as a technique to combat piracy and identify artificially generated content, but it is still not robust in various situations. In this paper, we propose a frequency conversion-based hierarchical watermarking technique capable of attack detection, error correction, and owner identification. By embedding attack detection and error correction signatures in hierarchical watermarking, the proposed scheme maintains invisibility and outperforms the existing methods in capacity and robustness. We also proposed a framework to evaluate the performance of the image quality and error correction according to the type of error correction signature and the number of signature embeddings. We compared the visual quality and error correction performance of the conventional model without error correction signature and the conventional model with hamming and BCH signatures. We compared the quality by the number of signature embeddings and found that the quality deteriorates as the number of embeddings increases but is robust to attacks. By analyzing the quality and error correction ability by error correction signature type, we found that hamming codes showed better error correction performance than BCH codes and 41.31% better signature restoration performance than conventional methods.

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.

Sinkhole Tracking by Deep Learning and Data Association (딥 러닝과 데이터 결합에 의한 싱크홀 트래킹)

  • Ro, Soonghwan;Hoai, Nam Vu;Choi, Bokgil;Dung, Nguyen Manh
    • The Journal of Korean Institute of Information Technology
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    • v.17 no.6
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    • pp.17-25
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    • 2019
  • Accurate tracking of the sinkholes that are appearing frequently now is an important method of protecting human and property damage. Although many sinkhole detection systems have been proposed, it is still far from completely solved especially in-depth area. Furthermore, detection of sinkhole algorithms experienced the problem of unstable result that makes the system difficult to fire a warning in real-time. In this paper, we proposed a method of sinkhole tracking by deep learning and data association, that takes advantage of the recent development of CNN transfer learning. Our system consists of three main parts which are binary segmentation, sinkhole classification, and sinkhole tracking. The experiment results show that the sinkhole can be tracked in real-time on the dataset. These achievements have proven that the proposed system is able to apply to the practical application.

A Study on Recognition of Both of PCA and LAD Using Types of Vehicle Plate (PCA와 LDA을 이용한 차량 번호판 통합 인식에 관한 연구)

  • Lee, Jin-Ki;Kim, Hyun-Yul;Lee, Seung-Kyu;Lee, Geon-Wha;Park, Yung-Rok;An, Ki-Nam;Bae, Cheol-Su;Park, Young-Cheol
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.6 no.1
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    • pp.6-17
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    • 2013
  • Recently, the color of vehicle license plate has been changed from green to white. Thus the vehicle plate recognition system used for parking management systems, speed and signal violation detection systems should be robust to the both colors. This paper presents a vehicle license plate recognition system, which works on both of green and white plate at the same time. In the proposed system, the image of license plate is taken from a captured vehicle image by using morphological information. In the next, each character region in the license plate image is extracted based on the vertical and horizontal projection of plate image and the relative position of individual characters. Finally, for the recognition process of extracted characters, PCA(Principal Component Analysis) and LDA(Linear Discriminant Analysis) are sequentially utilized. In the experiment, vehicle license plates of both green background and white background captured under irregular illumination conditions have been tested, and the relatively high extraction and recognition rates are observed.

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.