• Title/Summary/Keyword: Canny Edge

Search Result 208, Processing Time 0.025 seconds

Direct Measurement of Distortion of Optical System of Lithography (노광 광학계의 왜곡수차 측정에 관한 연구)

  • Joo, WonDon;Lee, JiHoon;Chae, SungMin;Kim, HyeJung;Jung, Mee Suk
    • Korean Journal of Optics and Photonics
    • /
    • v.23 no.3
    • /
    • pp.97-102
    • /
    • 2012
  • In general, one of the methods used to measure distortion is to use the full image of the regular pattern. However, because of low accuracy, this method is mainly used for an optical system such as a camera.. In order to measure distortion with high accuracy less than 1um, one can use the method of measuring the exact position of a mask image. In this case, a high accuracy stage with a laser encoder is required. In this paper, we investigate measurement of the distortion of high accuracy with a simple manual stage. The main idea is that we split and measure the mask image with the overlapping area by using CCD or CMOS, and then we get an exact position of the mask image by integrating the adjacent split images. We use the Canny Edge Detection method to get the position information of the mask image and we researched the process to exactly calculate distortion by using coordinate transformations and a least square method.

A Vehicle License Plate Recognition Using the Feature Vectors based on Mesh and Thinning (메쉬 및 세선화 기반 특징 벡터를 이용한 차량 번호판 인식)

  • Park, Seung-Hyun;Cho, Seong-Won
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.21 no.6
    • /
    • pp.705-711
    • /
    • 2011
  • This paper proposes an effective algorithm of license plate recognition for industrial applications. By applying Canny edge detection on a vehicle image, it is possible to find a connected rectangular, which is a strong candidate for license plate. The color information of license plate separates plates into white and green. Then, OTSU binary image processing and foreground neighbor pixel propagation algorithm CLNF will be applied to each license plates to reduce noise except numbers and letters. Finally, through labeling, numbers and letters will be extracted from the license plate. Letter and number regions, separated from the plate, pass through mesh method and thinning process for extracting feature vectors by X-Y projection method. The extracted feature vectors are compared with the pre-learned weighting values by backpropagation neural network to execute final recognition process. The experiment results show that the proposed license plate recognition algorithm works effectively.

A Vehicle License Plate Recognition Using the Haar-like Feature and CLNF Algorithm (Haar-like Feature 및 CLNF 알고리즘을 이용한 차량 번호판 인식)

  • Park, SeungHyun;Cho, Seongwon
    • Smart Media Journal
    • /
    • v.5 no.1
    • /
    • pp.15-23
    • /
    • 2016
  • This paper proposes an effective algorithm of Korean license plate recognition. By applying Haar-like feature and Canny edge detection on a captured vehicle image, it is possible to find a connected rectangular, which is a strong candidate for license plate. The color information of license plate separates plates into white and green. Then, OTSU binary image processing and foreground neighbor pixel propagation algorithm CLNF will be applied to each license plates to reduce noise except numbers and letters. Finally, through labeling, numbers and letters will be extracted from the license plate. Letter and number regions, separated from the plate, pass through mesh method and thinning process for extracting feature vectors by X-Y projection method. The extracted feature vectors are classified using neural networks trained by backpropagation algorithm to execute final recognition process. The experiment results show that the proposed license plate recognition algorithm works effectively.

Machine Vision-based Billiards Ball Detection (머신 비전 기반 당구공 검출)

  • SunWoo Lee;Heon Huh
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.24 no.2
    • /
    • pp.29-34
    • /
    • 2024
  • Since the outbreak of COVID-19, there has been a surge in sports conducted through online platforms due to the increase in remote and non-contact activities. Billiards, being suitable for online platforms, has received much attention, leading to research on detecting the position and trajectory of balls. In this paper, we propose a new method utilizing machine vision to detect the position of the balls accurately. The proposed method detects the outline of the ball using the Canny edge detection and then employs simple correlation to determine its position. This correlation-based approach offers satisfactory system performance and is easily applicable in practical systems due to its low implementation complexity and robustness to noise.

Text Region Detection using Edge and Regional Minima/Maxima Transformation from Natural Scene Images (에지 및 국부적 최소/최대 변환을 이용한 자연 이미지로부터 텍스트 영역 검출)

  • Park, Jong-Cheon;Lee, Keun-Wang
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.10 no.2
    • /
    • pp.358-363
    • /
    • 2009
  • Text region detection from the natural scene images used in a variety of applications, many research are needed in this field. Recent research methods is to detect the text region using various algorithm which it is combination of edge based and connected component based. Therefore, this paper proposes an text region detection using edge and regional minima/maxima transformation algorithm from natural scene images, and then detect the connected components of edge and regional minima/maxima, labeling edge and regional minima/maxima connected components. Analysis the labeled regions and then detect a text candidate regions, each of detected text candidates combined and create a single text candidate image, Final text region validated by comparing the similarity and adjacency of individual characters, and then as the final text regions are detected. As the results of experiments, proposed algorithm improved the correctness of text regions detection using combined edge and regional minima/maxima connected components detection methods.

Edge Strength Hough Transform : An Improvement on Hough Transform Using Edge Strength (경계선 강도를 이용한 허프 변환의 개선)

  • Heo, gyeong-Yong;Lee, Kwang-Eui;Woo, Young-Woon
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.10 no.11
    • /
    • pp.2055-2061
    • /
    • 2006
  • The detection of geometric primitives from a digital image is one of the basic tasks in computer vision area and the Hough transform is a well-known method for detecting analytical shape represented by a number of free parameters. However the basic property of the Hough transform, the one-to-many mapping from an image space to a Hough space, causes the innate problem, the sensitivity to noise. In this paper, we proposed Edge Strength Hough Transform which uses edge strength to reduce the sensitivity to noise and proved the insensitivity using the ratio of peaks in a Mough space. We also experimented the proposed method on lines and got small number of peaks in a Hough space compared to traditional Hough transform, which supports the noise insensitivity of the proposed method.

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
    • /
    • v.28 no.3
    • /
    • pp.332-337
    • /
    • 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.

Identification of Vehicle Using Edge Detection (에지 검출에 의한 차량 식별)

  • Shin, SY;Kim, DK;Lee, CW;Lee, HC;Lee, TW;Park, KH
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2016.10a
    • /
    • pp.382-383
    • /
    • 2016
  • Canny edge detection of the image is composed of four kinds of Gaussian filter, gradient calculation, Non-maximum suppression, and Hypothesis Thresholding. Feature is the ratio between the vehicle body, the windows, and the wheels obtained from the edge image. Features that make the proportion of these vehicles are different for each respective model. We have identified by application of this algorithm where only a small vehicle.

  • PDF

Automated Satellite Image Co-Registration using Pre-Qualified Area Matching and Studentized Outlier Detection (사전검수영역기반정합법과 't-분포 과대오차검출법'을 이용한 위성영상의 '자동 영상좌표 상호등록')

  • Kim, Jong Hong;Heo, Joon;Sohn, Hong Gyoo
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.4D
    • /
    • pp.687-693
    • /
    • 2006
  • Image co-registration is the process of overlaying two images of the same scene, one of which represents a reference image, while the other is geometrically transformed to the one. In order to improve efficiency and effectiveness of the co-registration approach, the author proposed a pre-qualified area matching algorithm which is composed of feature extraction with canny operator and area matching algorithm with cross correlation coefficient. For refining matching points, outlier detection using studentized residual was used and iteratively removes outliers at the level of three standard deviation. Throughout the pre-qualification and the refining processes, the computation time was significantly improved and the registration accuracy is enhanced. A prototype of the proposed algorithm was implemented and the performance test of 3 Landsat images of Korea. showed: (1) average RMSE error of the approach was 0.435 pixel; (2) the average number of matching points was over 25,573; (3) the average processing time was 4.2 min per image with a regular workstation equipped with a 3 GHz Intel Pentium 4 CPU and 1 Gbytes Ram. The proposed approach achieved robustness, full automation, and time efficiency.

A Combined Hough Transform based Edge Detection and Region Growing Method for Region Extraction (영역 추출을 위한 Hough 변환 기반 에지 검출과 영역 확장을 통합한 방법)

  • N.T.B., Nguyen;Kim, Yong-Kwon;Chung, Chin-Wan;Lee, Seok-Lyong;Kim, Deok-Hwan
    • Journal of KIISE:Databases
    • /
    • v.36 no.4
    • /
    • pp.263-279
    • /
    • 2009
  • Shape features in a content-based image retrieval (CBIR) system are divided into two classes: contour-based and region-based. Contour-based shape features are simple but they are not as efficient as region-based shape features. Most systems using the region-based shape feature have to extract the region firs t. The prior works on region-based systems still have shortcomings. They are complex to implement, particularly with respect to region extraction, and do not sufficiently use the spatial relationship between regions in the distance model In this paper, a region extraction method that is the combination of an edge-based method and a region growing method is proposed to accurately extract regions inside an object. Edges inside an object are accurately detected based on the Canny edge detector and the Hough transform. And the modified Integrated Region Matching (IRM) scheme which includes the adjacency relationship of regions is also proposed. It is used to compute the distance between images for the similarity search using shape features. The experimental results show the effectiveness of our region extraction method as well as the modified IRM. In comparison with other works, it is shown that the new region extraction method outperforms others.