• Title/Summary/Keyword: Canny algorithm

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Segmentation of Scalp and Skull in brain MR Images Using CannyEdge Level Set Method

  • Du, Ruoyu;Lee, Hyo Jong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2010.11a
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    • pp.668-671
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    • 2010
  • In this paper, we present a novel automatic algorithm for scalp and skull segmentation in T1-weighted head MR images. First, the scalp and skull part are constructed by using intensity threshold. Second, the scalp outer surface is extracted based on an active level set method. Third, the skull inner surface is extracted using a canny edge detection algorithm. Finally, the fast sweeping, tagging and level set methods are applied to reconstruct surfaces from the detected points in three-dimensional space. The results of the new segmentation algorithm on MRI data acquired from eight persons were compared with manual segmented data. The average similarity indices for the scalp and skull segmented regions were equal to 84.42% for the test data.

A New Depth and Disparity Visualization Algorithm for Stereoscopic Camera Rig

  • Ramesh, Rohit;Shin, Heung-Sub;Jeong, Shin-Il;Chung, Wan-Young
    • Journal of information and communication convergence engineering
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    • v.8 no.6
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    • pp.645-650
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    • 2010
  • In this paper, we present the effect of binocular cues which plays crucial role for the visualization of a stereoscopic or 3D image. This study is useful in extracting depth and disparity information by image processing technique. A linear relation between the object distance and the image distance is presented to discuss the cause of cybersickness. In the experimental results, three dimensional view of the depth map between the 2D images is shown. A median filter is used to reduce the noises available in the disparity map image. After the median filter, two filter algorithms such as 'Gabor' filter and 'Canny' filter are tested for disparity visualization between two images. The 'Gabor' filter is to estimate the disparity by texture extraction and discrimination methods of the two images, and the 'Canny' filter is used to visualize the disparity by edge detection of the two color images obtained from stereoscopic cameras. The 'Canny' filter is better choice for estimating the disparity rather than the 'Gabor' filter because the 'Canny' filter is much more efficient than 'Gabor' filter in terms of detecting the edges. 'Canny' filter changes the color images directly into color edges without converting them into the grayscale. As a result, more clear edges of the stereo images as compared to the edge detection by 'Gabor' filter can be obtained. Since the main goal of the research is to estimate the horizontal disparity of all possible regions or edges of the images, thus the 'Canny' filter is proposed for decipherable visualization of the disparity.

A Study on Identifier Extraction from Shipping Container Image by Using Fuzzy Binarization and Contour Tracking Algorithm (퍼지 이진화와 윤곽선 추적 알고리즘을 이용한 운송 컨데이너 영상의 식별자 추출에 관한 연구)

  • 윤형근;김광백
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2003.05a
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    • pp.490-494
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    • 2003
  • 운송 컨테이너의 식별자를 추출하고 인식하는 것은 컨테이너 식별자들의 크기나 위치가 정형화되어 있지 않고 외부의 잡음으로 인하여 식별자의 형태가 훼손되어 있기 때문에 어렵다. 본 논문에서는 이러한 특성을 고려하여 컨테이너 영상에 대해 Canny 마스크를 이용하여 에지를 검출하고, Canny 마스크가 적용된 영상에서 수직·수평 히스토그램을 적용하여 컨테이너의 식별자 영역을 추출한다. 추출된 컨테이너의 식별자 영역을 삼각형 타입의 퍼지 이진화 방법을 적용하여 이진화하고 이진화된 컨테이너 식별자 영역을 윤곽선 추적 알고리즘으로 개별 식별자를 추출한다. 제안된 방법의 성능을 평가하기 위하여 실제 컨테이너 영상에 적용한 결과, 기존의 방법보다 컨테이너의 식별자 추출에서 우수한 성능이 있음을 확인하였다.

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Lane Spline Generation Using Edge Detection Robust to Environmental Changes (외부 환경 변화에 강인한 에지 검출을 통한 차선의 스플라인 생성)

  • Kwon, Bo-Chul;Shin, Dongwon
    • Journal of Broadcast Engineering
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    • v.17 no.6
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    • pp.1069-1079
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    • 2012
  • Lane detection with the use of a camera is an essential task required for the development of advanced driving assistance system. In this paper, edges of the lane are generated by applying Canny's method. The edge detection usually makes different results for several environmental conditions depending on the clearness of lane quality, so that it sometimes causes wrong lane detection. Therefore, we propose robust algorithm to environmental changes that automatically adjusts parameter for edge detection and generates edges more stably. Based on the acquired edges, we finally generate the spline curve of lane by using Catmull Rom spline.

A Novel DWT-SVD Canny-Based Watermarking Using a Modified Torus Technique

  • Lalani, Salima;Doye, D.D.
    • Journal of Information Processing Systems
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    • v.12 no.4
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    • pp.681-687
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    • 2016
  • Today's modern world requires a digital watermarking technique that takes the redundancy of an image into consideration for embedding a watermark. The novel algorithm used in this paper takes into consideration the redundancies of spatial domain and wavelet domain for embedding a watermark. Also, the cryptography-based secret key makes the algorithm difficult to hack and help protect ownership. Watermarking is blind, as it does not require the original image. Few coefficient matrices and secret keys are essential to retrieve the original watermark, which makes it redundant to various intentional attacks. The proposed technique resolves the challenge of optimizing transparency and robustness using a Canny-based edge detector technique. Improvements in the transparency of the cover image can be seen in the computed PSNR value, which is 44.20 dB.

Improvement of Power Consumption of Canny Edge Detection Using Reduction in Number of Calculations at Square Root (제곱근 연산 횟수 감소를 이용한 Canny Edge 검출에서의 전력 소모개선)

  • Hong, Seokhee;Lee, Juseong;An, Ho-Myoung;Koo, Jihun;Kim, Byuncheul
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.13 no.6
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    • pp.568-574
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    • 2020
  • In this paper, we propose a method to reduce the square root computation having high computation complexity in Canny edge detection algorithm using image processing. The proposed method is to reduce the number of operation calculating gradient magnitude using pixel's continuity using make a specific pattern instead of square root computation in gradient magnitude calculating operation. Using various test images and changing number of hole pixels, we can check for calculate match rate about 97% for one hole, and 94%, 90%, 88% when the number of hole is increased and measure decreasing computation time about 0.2ms for one hole, and 0.398ms, 0.6ms, 0.8ms when the number of hole is increased. Through this method, we expect to implement low power embedded vision system through high accuracy and a reduced operation number using two-hole pixels.

Detection and Recognition of Traffic Lights for Unmanned Autonomous Driving (무인 자율주행을 위한 신호등의 검출과 인식)

  • Kim, Jang-Won
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.6
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    • pp.751-756
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    • 2018
  • This research extracted traffic light from input video, recognized colors of traffic light, and suggested traffic light color recognizing algorithm applicable to manless autonomous vehicle or ITS by distinguishing signs. To extract traffic light, suggested algorithm extracted the outline with CEA(Canny Edge Algorithm), and applied HCT(Hough Circle Transform) to recognize colors of traffic light and improve the accuracy. The suggested method was applied to the video of stream acquired on the road. As a result, excellent rate of traffic light recognition was confirmed. Especially, ROI including traffic light in input video was distinguished and computing time could be reduced. In even area similar to traffic light, circle was not extracted or V value is low in HSV space, so it's failed in candidate area. So, accuracy of recognition rate could be improved.

Algorithm for Detecting PSD Boundary Invasion in Subway PSD using Image Processing (영상처리를 이용한 지하철 스크린 도어의 경계선 침범인식 알고리듬 연구)

  • Baek, Woon-Seok;Lee, Ha-Woon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.5
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    • pp.1051-1058
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    • 2018
  • This paper propose image processing algorithm to prevent safety accidents near by subway platform screen door(PSD). First, edges of the subway PSD images are detected and the boundary line between PSD and subway platform is detected to decide people's approach to the PSD using Hough transform. To do this, we draw the boundary line between the PSD and platform, to detect the boundary line and to decide the people's approach to the detected line is completely connected or not. Generally, edge is the basic characteristic of image; thus, edge detection is very important in image processing applications and computer vision area. The conventional edge detection methods such as Roberts, Sobel, Prewitt, and Laplacian etc, which are using a fixed value of mask, and morphological gradient from the structuring element of view and Canny edge detector are widely used. In this paper, we propose the detection algorithm about the people's approach to the subway PSD to prevent the safety accidents by using Canny edge detector and Hough transform and the computer simulation shows the results.

The Study of Pre-processing Algorithm for Improving Efficiency of Optical Flow Method on Ultrasound Image (초음파 영상에서의 Optical Flow 추적 성능 향상을 위한 전처리 알고리즘 개발 연구)

  • Kim, Sung-Min;Lee, Ju-Hwan;Roh, Seung-Gyu;Park, Sung-Yun
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.47 no.5
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    • pp.24-32
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    • 2010
  • In this study, we have proposed a pre-processing algorithm newly developed for improving the tracking efficiency of the optical flow method. The developed pre-processing algorithm consists of a median filter, binarization, morphology, canny edge, contour detecting and an approximation method. In order to evaluate whether the optical flow tracking capacity increases, this study applied the pre-processing algorithm to the Lucas-Kanade(LK) optical flow algorithm, and comparatively analyzed its images and tracking results with those of optical flow without the pre-processing algorithm and with the existing pre-processing algorithm(composed of median filter and histogram equalization). As a result, it was observed that the tracking performance derived from the LK optical flow algorithm with the pre-processing algorithm, shows better tracking accuracy, compared to the one without the pre-processing algorithm and the one with the existing pre-processing algorithm. It seems to have resulted by successful segmentation for characteristic areas and subdivision into inner and outer contour lines.

Robust Lane Detection Method Under Severe Environment (악 조건 환경에서의 강건한 차선 인식 방법)

  • Lim, Dong-Hyeog;Tran, Trung-Thien;Cho, Sang-Bock
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.5
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    • pp.224-230
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    • 2013
  • Lane boundary detection plays a key role in the driver assistance system. This study proposes a robust method for detecting lane boundary in severe environment. First, a horizontal line detects form the original image using improved Vertical Mean Distribution Method (iVMD) and the sub-region image which is under the horizontal line, is determined. Second, we extract the lane marking from the sub-region image using Canny edge detector. Finally, K-means clustering algorithm classifi left and right lane cluster under variant illumination, cracked road, complex lane marking and passing traffic. Experimental results show that the proposed method satisfie the real-time and efficient requirement of the intelligent transportation system.