• Title/Summary/Keyword: Corner detection method

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New Gray Level Corner Point Detection Method (새로운 그레이 레벨 코너점 검출 방법)

  • 나재형;오해석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.8C
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    • pp.1062-1068
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    • 2004
  • In this paper, we introduce a new gray level comer detection method to recognize corner points accurately. The new corner detector divides the corner region into many homocentric circles according to the window size, and calculates the corner response and angle of corner area about each layer to get an accurate corner point. The new corner detector has a hierarchical structure so it can detect corner point more quickly than general gray level corner detector

Obstacle Position Detection on an Inclined Plane Using Randomized Hough Transform and Corner Detection (랜덤하프변환과 코너추출을 이용한 경사면의 장애물 위치 탐색)

  • Hwang, Sun-Min;Lee, Min-Cheol
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.5
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    • pp.419-428
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    • 2011
  • This paper suggests a judgement method for an inclined plane before entrance of it and the detection of obstacle position. Main idea is started from the assumption that obstacle is always on the bottom plane, and corner appears at this position. The process to detect the obstacle consists of three steps. First the 3D data using stereo matching is acquired to detect an obstacle. Second a bottom plane is extracted by using limit condition. Last the obstacle position is found by using Harris corner detection. Obstacle position detection on an inclined plane was verified by outdoor and indoor experiment. In error analysis, it is confirmed that an average error of obstacle detection in outdoor was larger than the error in indoor but the error are within about 0.030 m. This method will be applied to unmanned vehicles to navigate under various environment.

Accurate PCB Outline Extraction and Corner Detection for High Precision Machine Vision (고정밀 머신 비전을 위한 정확한 PCB 윤곽선과 코너 검출)

  • Ko, Dong-Min;Choi, Kang-Sun
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.3
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    • pp.53-58
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    • 2017
  • Recently, advance in technology have increased the importance of visual inspection in semiconductor inspection areas. In PCB visual inspection, accurate line estimation is critical to the accuracy of the entire process, since it is utilized in preprocessing steps such as calibration and alignment. We propose a line estimation method that is differently weighted for the line candidates using a histogram of gradient information, when the position of the initial approximate corner points is known. Using the obtained line equation of the outline, corner points can be calculated accurately. The proposed method is compared with the existing method in terms of the accuracy of the detected corner points. The proposed method accurately detects corner points even when the existing method fails. For high-resolution frames of 3.5mega-pixels, the proposed method is performed in 89.01ms.

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A Vision-Based Method to Find Fingertips in a Closed Hand

  • Chaudhary, Ankit;Vatwani, Kapil;Agrawal, Tushar;Raheja, J.L.
    • Journal of Information Processing Systems
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    • v.8 no.3
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    • pp.399-408
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    • 2012
  • Hand gesture recognition is an important area of research in the field of Human Computer Interaction (HCI). The geometric attributes of the hand play an important role in hand shape reconstruction and gesture recognition. That said, fingertips are one of the important attributes for the detection of hand gestures and can provide valuable information from hand images. Many methods are available in scientific literature for fingertips detection with an open hand but very poor results are available for fingertips detection when the hand is closed. This paper presents a new method for the detection of fingertips in a closed hand using the corner detection method and an advanced edge detection algorithm. It is important to note that the skin color segmentation methodology did not work for fingertips detection in a closed hand. Thus the proposed method applied Gabor filter techniques for the detection of edges and then applied the corner detection algorithm for the detection of fingertips through the edges. To check the accuracy of the method, this method was tested on a vast number of images taken with a webcam. The method resulted in a higher accuracy rate of detections from the images. The method was further implemented on video for testing its validity on real time image capturing. These closed hand fingertips detection would help in controlling an electro-mechanical robotic hand via hand gesture in a natural way.

Detection of Junctions via Accumulation of Connectivity-based Weight in Image Space : Applications for Locating 2D Barcode (영상 공간에서의 연결성 기반 가중치 누적을 통한 코너점 검출: 이차원 바코드 검출에의 응용)

  • Kim, Jeong-Tae;Song, Jin-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.10
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    • pp.1865-1867
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    • 2007
  • We propse a novel corner detection algorithm for locating 2D Data Matrix barcode in an image. The proposed method accumulates weight for each cross point defined by every combination of edge points in the image, and detects the corner point of the barcode L-pattern by determining the location of the highest accumulated weight. By designing the weight considering the connectivity of two lines around the cross point, we were able to detect the corner of L-pattern even for the cases that the lines of L-patterns are short. In the experiments, the proposed method showed improved performance compared with the conventional Hough transform based method in terms of detectability and computation time.

Comer Detection in Gray Lavel Images for Wafer Die Position Recognition (웨이퍼 다이 위치 인식을 위한 명암 영상 코너점 검출)

  • 나재형;오해석
    • Journal of KIISE:Software and Applications
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    • v.31 no.6
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    • pp.792-798
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    • 2004
  • In this paper, we will introduce a new corner detector for the wafer die position recognition. The die position recognition procedure is necessary for WSCSP(Wafer Scale Chip Scale Packaging) technology, decide the accuracy of post-procedure. We present a hierarchical gray level corner detection method for the recognition of the die position from a wafer image. The new corner detector divides the corner region into many homocentric circles, and calculates the comer response and the angle of direction about each circle to get an accurate toner point. The new corner detector has a hierarchical structure so it can detect comer point more quickly than general gray level corner detector.

Comparative Study of Corner and Feature Extractors for Real-Time Object Recognition in Image Processing

  • Mohapatra, Arpita;Sarangi, Sunita;Patnaik, Srikanta;Sabut, Sukant
    • Journal of information and communication convergence engineering
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    • v.12 no.4
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    • pp.263-270
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    • 2014
  • Corner detection and feature extraction are essential aspects of computer vision problems such as object recognition and tracking. Feature detectors such as Scale Invariant Feature Transform (SIFT) yields high quality features but computationally intensive for use in real-time applications. The Features from Accelerated Segment Test (FAST) detector provides faster feature computation by extracting only corner information in recognising an object. In this paper we have analyzed the efficient object detection algorithms with respect to efficiency, quality and robustness by comparing characteristics of image detectors for corner detector and feature extractors. The simulated result shows that compared to conventional SIFT algorithm, the object recognition system based on the FAST corner detector yields increased speed and low performance degradation. The average time to find keypoints in SIFT method is about 0.116 seconds for extracting 2169 keypoints. Similarly the average time to find corner points was 0.651 seconds for detecting 1714 keypoints in FAST methods at threshold 30. Thus the FAST method detects corner points faster with better quality images for object recognition.

A Fast Adaptive Corner Detection Based on Curvature Scale Space

  • Nguyen, Van Hau;Woo, Kyung-Haeng;Choi, Won-Ho
    • Journal of Korea Multimedia Society
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    • v.14 no.5
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    • pp.622-631
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    • 2011
  • Corners play an important role in describing object features for pattern recognition and identification. This paper proposed a fast and adaptive corner detector in both coarse and fine scale, followed by the framework of the curvature scale space (CSS). An adaptive curvature threshold and evaluating of angles of corner candidates are added to original CSS to remove round corners and false corners in the detecting process. The efficiency of proposed method is compared to other popular detectors in both accuracy criteria, stability and time consuming. Results illustrate that the proposed method performs extremely surpass in both areas.

Post-Processing for Reducing Corner Outliers (Corner outlier 제거를 위한 후처리 기법)

  • 홍윤표;전병우
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.11-14
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    • 2003
  • In block-based lossy video compression, severe quantization causes discontinuities along block boundaries so that annoying blocking artifacts are visible in decoded video imases. These blocking artifacts significantly decrease the subjective image quality. In order to reduce the blocking artifacts in decoded images, many algorithms have been proposed However studies on so called, corner outliers, have been very limited. Corner outliers make image edges look disconnected from those of neighboring blocks at cross block boundary. In order to solve this problem, we propose a corner outlier detection and compensation algorithm as post-processing in spatial domain The experiment results show that the proposed method provides much improved subjective image quality.

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Accurate Corner Detection using 4-directional Edge Labeling and Corner Positioning Templates

  • Park, Eun-Jin;Choi, Doo-Hyun
    • Journal of Electrical Engineering and Technology
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    • v.6 no.4
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    • pp.580-584
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    • 2011
  • Corner positioning templates are proposed in order to detect the accurate positions of corners that are extracted using 4-directional edge labeling. Top-down and bottom-up directional labeling are used to label the edge segments with four kinds of labels according to their directions. The points whose labels have changed are then determined as corners. The exact positions of the missing corners due to the disconnected edges are detected through the corner positioning templates that are determined according to the labels of start-points and end-points after the two-pass edge labeling. Experiment results show that the proposed method can detect the exact positions of the real corners.