• Title/Summary/Keyword: Automatic thresholding

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Destination address block locating algorithm for automatic classification of packages (택배 자동 분류를 위한 주소영역 검출 알고리즘)

  • Kim, Bong-Seok;Kim, Seung-Jin;Jung, Yoon-Su;Im, Sung-Woon;Ro, Chul-Kyun;Won, Chul-Ho;Cho, Jin-Ho;Lee, Kuhn-Il
    • Journal of Sensor Science and Technology
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    • v.12 no.3
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    • pp.128-138
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    • 2003
  • In this paper, we proposed the algorithm for locating destination address block (DAB) from automatic system to classify packages. For locating DAB, because the size of obtained images is are very large, we select the region of interesting (ROI) to reduce time carrying into algorithm. After selecting the ROI, proposed algorithm is carried out within the ROI. We extract the outline of the handwriting part of the DAB and the rest components within the obtained ROI using thresholding. We carry out labeling to extract each connected component for extracted outline and the rest components. We extract the outline of the handwriting part of the DAB using the geometrical characteristic of the outline of the handwriting part of the DAB among many connected components. The last, we extract the locating DAB using the outline of the handwriting part of the DAB.

Automatic Segmentation of Pulmonary Structures using Gray-level Information of Chest CT Images (흉부 CT 영상의 밝기값 정보를 사용한 폐구조물 자동 분할)

  • Yim, Ye-Ny;Hong, Helen
    • Journal of KIISE:Software and Applications
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    • v.33 no.11
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    • pp.942-952
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    • 2006
  • We propose an automatic segmentation method for identifying pulmonary structures using gray-level information of chest CT images. Our method consists of following five steps. First, to segment pulmonary structures based on the difference of gray-level value, we select the threshold using optimal thresholding. Second, we separate the thorax from the background air and then the lungs and airways from the thorax by applying the inverse operation of 2D region growing in chest CT images. To eliminate non-pulmonary structures which has similar intensities with the lungs, we use 3D connected component labeling. Third, we segment the trachea and left and right mainstem bronchi using 3D branch-based region growing in chest CT images. Fourth, we can obtain accurate lung boundaries by subtracting the result of third step from the result of second step. Finally, we select the threshold in accordance with histogram analysis and then segment radio-dense pulmonary vessels by applying gray-level thresholding to the result of the second step. To evaluate the accuracy of proposed method, we make a visual inspection of segmentation result of lungs, airways and pulmonary vessels. We compare the result of the conventional region growing with the result of proposed 3D branch-based region growing. Experimental results show that our proposed method extracts lung boundaries, airways, and pulmonary vessels automatically and accurately.

Automatic Recognition of the Front/Back Sides and Stalk States for Mushrooms(Lentinus Edodes L.) (버섯 전후면과 꼭지부 상태의 자동 인식)

  • Hwang, H.;Lee, C.H.
    • Journal of Biosystems Engineering
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    • v.19 no.2
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    • pp.124-137
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    • 1994
  • Visual features of a mushroom(Lentinus Edodes, L.) are critical in grading and sorting as most agricultural products are. Because of its complex and various visual features, grading and sorting of mushrooms have been done manually by the human expert. To realize the automatic handling and grading of mushrooms in real time, the computer vision system should be utilized and the efficient and robust processing of the camera captured visual information be provided. Since visual features of a mushroom are distributed over the front and back sides, recognizing sides and states of the stalk including the stalk orientation from the captured image is a prime process in the automatic task processing. In this paper, the efficient and robust recognition process identifying the front and back side and the state of the stalk was developed and its performance was compared with other recognition trials. First, recognition was tried based on the rule set up with some experimental heuristics using the quantitative features such as geometry and texture extracted from the segmented mushroom image. And the neural net based learning recognition was done without extracting quantitative features. For network inputs the segmented binary image obtained from the combined type automatic thresholding was tested first. And then the gray valued raw camera image was directly utilized. The state of the stalk seriously affects the measured size of the mushroom cap. When its effect is serious, the stalk should be excluded in mushroom cap sizing. In this paper, the stalk removal process followed by the boundary regeneration of the cap image was also presented. The neural net based gray valued raw image processing showed the successful results for our recognition task. The developed technology through this research may open the new way of the quality inspection and sorting especially for the agricultural products whose visual features are fuzzy and not uniquely defined.

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Adaptive Automatic Thresholding in Infrared Image Target Tracking (적외선 영상 표적추적 성능 개선을 위한 적응적인 자동문턱치 산출 기법 연구)

  • Kim, Tae-Han;Song, Taek-Lyul
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.6
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    • pp.579-586
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    • 2011
  • It is very critical for image processing of IIR (Imaging Infrared) seekers to achieve improved guidance performance for missile systems to determine appropriate thresholds in various environments. In this paper, we propose automatic threshold determination methods for proper thresholds to extract definite target signals in an EOCM (Electro-Optical Countermeasures) environment with low SNR (Signal-to-Noise Ratios). In particular, thresholds are found to be too low to extract target signals if one uses the Otsu method so that we suggest a Shifted Otsu method to solve this problem. Also we improve extracting target signal by changing Shifted Otsu thresholds according to the TBR (Target to Background Ratio). The suggested method is tested for real IIR images and the results are compared with the Otsu method. The HPDAF (Highest Probabilistic Data Association Filter) which selects the target originated measurements by taking into account of both signal intensity and statistical distance information is applied in this study.

Automatic Edge Detection Method for Mobile Robot Application (이동로봇을 위한 영상의 자동 엣지 검출 방법)

  • Kim Dongsu;Kweon Inso;Lee Wangheon
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.5
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    • pp.423-428
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    • 2005
  • This paper proposes a new edge detection method using a $3{\times}3$ ideal binary pattern and lookup table (LUT) for the mobile robot localization without any parameter adjustments. We take the mean of the pixels within the $3{\times}3$ block as a threshold by which the pixels are divided into two groups. The edge magnitude and orientation are calculated by taking the difference of average intensities of the two groups and by searching directional code in the LUT, respectively. And also the input image is not only partitioned into multiple groups according to their intensity similarities by the histogram, but also the threshold of each group is determined by fuzzy reasoning automatically. Finally, the edges are determined through non-maximum suppression using edge confidence measure and edge linking. Applying this edge detection method to the mobile robot localization using projective invariance of the cross ratio. we demonstrate the robustness of the proposed method to the illumination changes in a corridor environment.

Navigation and Find Co-location of ATSR Images

  • Shin, Dong-Seok;Pollard, John-K.
    • Korean Journal of Remote Sensing
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    • v.10 no.2
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    • pp.133-160
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    • 1994
  • In this paper, we propose a comprehensive geometric correction algorithm of Along Track Scanning Radiometer(ATSR) images. The procedure consists of two cascaded modules; precorrection and fine co-location. The pre-correction algorithm is based on the navigation model which was derived in mathematical forms. This model was applied for correction raw(un-geolocated) ATSR images. The non-systematic geometric errors are also introduced as the limitation of the geometric correction by this analytical method. A fast and automatic algorithm is also presented in the paper for co-locating nadir and forward views of the ATSR images by using a binary cross-correlation matching technique. It removes small non-systematic errors which cannot be corrected by the analytic method. The proposed algorithm does not require any auxiliary informations, or a priori processing and avoiding the imperfect co-registratio problem observed with multiple channels. Coastlines in images are detected by a ragion segmentation and an automatic thresholding technique. The matching procedure is carried out with binaty coastline images (nadir and forward), and it gives comparable accuracy and faster processing than a patch based matching technique. This technique automatically reduces non-systematic errors between two views to .$\pm$ 1 pixel.

Extraction of Heart Region in EBT Images (EBT 영상에서 심장 영역의 추출)

  • Kim, Hyun-Soo;Lee, Sung-Kee
    • Journal of KIISE:Software and Applications
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    • v.27 no.6
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    • pp.651-659
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    • 2000
  • It is very important to extract the heart region in the medical images. In this paper, we present the automatic heart region extraction in the EBT (electron beam tomography) images. We use contrast thresholding, anatomic knowledge, and mathematical morphology to extract the heart region. Using these results, we applied the active contour models (snakes) to search the exact region. We analyzed the experimental results by comparing the results with the results made by medical experts.

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Night-time Vehicle Detection Method Using Convolutional Neural Network (합성곱 신경망 기반 야간 차량 검출 방법)

  • Park, Woong-Kyu;Choi, Yeongyu;KIM, Hyun-Koo;Choi, Gyu-Sang;Jung, Ho-Youl
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.2
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    • pp.113-120
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    • 2017
  • In this paper, we present a night-time vehicle detection method using CNN (Convolutional Neural Network) classification. The camera based night-time vehicle detection plays an important role on various advanced driver assistance systems (ADAS) such as automatic head-lamp control system. The method consists mainly of thresholding, labeling and classification steps. The classification step is implemented by existing CIFAR-10 model CNN. Through the simulations tested on real road video, we show that CNN classification is a good alternative for night-time vehicle detection.

Vision Sensing for the Ego-Lane Detection of a Vehicle (자동차의 자기 주행차선 검출을 위한 시각 센싱)

  • Kim, Dong-Uk;Do, Yongtae
    • Journal of Sensor Science and Technology
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    • v.27 no.2
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    • pp.137-141
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    • 2018
  • Detecting the ego-lane of a vehicle (the lane on which the vehicle is currently running) is one of the basic techniques for a smart car. Vision sensing is a widely-used method for the ego-lane detection. Existing studies usually find road lane lines by detecting edge pixels in the image from a vehicle camera, and then connecting the edge pixels using Hough Transform. However, this approach takes rather long processing time, and too many straight lines are often detected resulting in false detections in various road conditions. In this paper, we find the lane lines by scanning only a limited number of horizontal lines within a small image region of interest. The horizontal image line scan replaces the edge detection process of existing methods. Automatic thresholding and spatiotemporal filtering procedures are also proposed in order to make our method reliable. In the experiments using real road images of different conditions, the proposed method resulted in high success rate.

APPLICATION OF NEURAL NETWORK FOR THE CLOUD DETECTION FROM GEOSTATIONARY SATELLITE DATA

  • Ahn, Hyun-Jeong;Ahn, Myung-Hwan;Chung, Chu-Yong
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.34-37
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    • 2005
  • An efficient and robust neural network-based scheme is introduced in this paper to perform automatic cloud detection. Unlike many existing cloud detection schemes which use thresholding and statistical methods, we used the artificial neural network methods, the multi-layer perceptrons (MLP) with back-propagation algorithm and radial basis function (RBF) networks for cloud detection from Geostationary satellite images. We have used a simple scene (a mixed scene containing only cloud and clear sky). The main results show that the neural networks are able to handle complex atmospheric and meteorological phenomena. The experimental results show that two methods performed well, obtaining a classification accuracy reaching over 90 percent. Moreover, the RBF model is the most effective method for the cloud classification.

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