• Title/Summary/Keyword: Standard Hough Transform

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A Self-Organizing Map Based Hough Transform for Detecting Straight Lines (직선 추출을 위한 자기조직화지도 기반의 허프 변환)

  • Lee, Moon-Kyu
    • Journal of Korean Institute of Industrial Engineers
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    • v.28 no.2
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    • pp.162-170
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    • 2002
  • Detecting straight lines in an image is frequently required for various machine vision applications such as restoring CAD drawings from scanned images and object recognition. The standard Hough transform has been dominantly used to that purpose. However, massive storage requirement and low precision in estimating line parameters due to the quantization of parameter space are the major drawbacks of the Hough transform technique. In this paper, to overcome the drawbacks, an iterative algorithm based on a self-organizing map is presented. The self-organizing map can be adaptively learned such that image points are clustered by prominent lines. Through the procedure of the algorithm, a set of lines are sequentially detected one at a time. The algorithm can produce highly precised estimates of line parameters using very small amount of storage memory. Computational results for synthetically generated images are given. The promise of the algorithm is also demonstrated with its application to two natural images of inserts.

The automatic recognition of the plate of vehicle using the correlation coefficient and hough transform (상관계수와 하프변환을 이용한 차량번호판 자동인식)

  • Kim, Kyoung-Min;Lee, Byung-Jin;Lyou, Kyoung;Park, Gwi-Tae
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.5
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    • pp.511-519
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    • 1997
  • This paper presents the automatic recognition algorithm of the license number in on vehicle image. The proposed algorithm uses the correlation coefficient and Hough transform to detect license plate. The m/n ratio reduction is performed to save time and memory. By the correlation coefficient between the standard pattern and the target pattern, licence plate area is roughly extracted. On the extracted local area, preprocessing and binarization is performed. The Hough transform is applied to find the extract outline of the plate. If the detection fails, a smaller or a larger standard pattern is used to compute the correlation coefficient. Through this process, the license plate of different size can be extracted. Two algorithms to each separate number are proposed. One segments each number with projection-histogram, and the other segments each number with the label. After each character is separated, it is recognized by the neural network. This research overlomes the problems in conventional methods, such as the time requirement or failure in extraction of outlines which are due to the processing of the entire image, and by processing in real time, the practical application is possible.

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Line Segment Detection Algorithm Using Improved PPHT (개선된 PPHT를 이용한 선분 인식 알고리즘)

  • Lee, Chanho;Moon, Ji-hyun;Nguyen, Duy Phuong
    • Journal of IKEEE
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    • v.20 no.1
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    • pp.82-88
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    • 2016
  • The detection rate of Progressive Probability Hough Transform(PPHT) is decreased when a lot of noise components exist due to an unclear or complex original image although it is quite a good algorithm that detects line segments accurately. In order to solve the problem, we propose an improved line detecting algorithm which is robust to noise components and recovers slightly damaged edges. The proposed algorithm is based on PPHT and traces a line segments by pixel and checks of it is straight. It increases the detection rate by reducing the effect of noise components and by recovering edge patterns within a limited pixel size. The proposed algorithm is applied to a lane detection method and the false positive detection rate is decreased by 30% and the line detection rate is increased by 15%.

A Selection of Threshold for the Generalized Hough Transform: A Probabilistic Approach (일반화된 허프변환의 임계값 선택을 위한 확률적 접근방식)

  • Chang, Ji Y.
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.1
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    • pp.161-171
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    • 2014
  • When the Hough transform is applied to identify an instance of a given model, the output is typically a histogram of votes cast by a set of image features into a parameter space. The next step is to threshold the histogram of counts to hypothesize a given match. The question is "What is a reasonable choice of the threshold?" In a standard implementation of the Hough transform, the threshold is selected heuristically, e.g., some fraction of the highest cell count. Setting the threshold too low can give rise to a false alarm of a given shape(Type I error). On the other hand, setting the threshold too high can result in mis-detection of a given shape(Type II error). In this paper, we derive two conditional probability functions of cell counts in the accumulator array of the generalized Hough transform(GHough), that can be used to select a scientific threshold at the peak detection stage of the Ghough.

Objective Measurement of Water Repellency of Fabric Using Image Analysis (I) - Methodology of Image Processing -

  • Jeong Young Jin;Jang Jinho
    • Fibers and Polymers
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    • v.6 no.2
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    • pp.162-168
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    • 2005
  • A methodology for the objective evaluation of water repellency is studied using image analysis of the sprayed pattern on woven fabrics according to a standard spray test (AATCC Test Method 22-2001). The wet area ratio obtained from the spray standard test ranking is found to be exponentially related with its water repellency rating. Mean filtering is used to remove the effect of weave texture and the transmitted light through interyarn spaces. The ring frame of the instrument and wet region are recognized using Otsu thresholding technique. And Hough transform and outline operation are used to obtain the size and position of the ring frame. The objective assessment of the water repellency using image processing can reduce unnecessary confusion in the subjective determination of the water repellency.

A Straight-Line Detecting Algorithm Using a Self-Organizing Map (자기조직화지도를 이용한 직선 추출 알고리즘)

  • Lee Moon-Kyu
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2002.05a
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    • pp.886-893
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    • 2002
  • The standard Hough transform has been dominantly used to detect straight lines in an image. However, massive storage requirement and low precision in estimating line parameters due to the quantization of parameter space are the major drawbacks of the Hough transform technique. In this paper, to overcome the drawbacks, an iterative algorithm based on a self-organizing map is presented. The self-organizing map can be adaptively learned such that image points are clustered by prominent lines. Through the procedure of the algorithm, a set of lines are sequentially detected one at a time. Computational results for synthetically generated images are given. The promise of the algorithm is also demonstrated with its application to two natural images of inserts.

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Global Map Building and Navigation of Mobile Robot Based on Ultrasonic Sensor Data Fusion

  • Kang, Shin-Chul;Jin, Tae-Seok
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.7 no.3
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    • pp.198-204
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    • 2007
  • In mobile robotics, ultrasonic sensors became standard devices for collision avoiding. Moreover, their applicability for map building and navigation has exploited in recent years. In this paper, as the preliminary step for developing a multi-purpose autonomous carrier mobile robot to transport trolleys or heavy goods and serve as robotic nursing assistant in hospital wards. The aim of this paper is to present the use of multi-sensor data fusion such as ultrasonic sensor, IR sensor for mobile robot to navigate, and presents an experimental mobile robot designed to operate autonomously within both indoor and outdoor environments. The global map building based on multi-sensor data fusion is applied for recognition an obstacle free path from a starting position to a known goal region, and simultaneously build a map of straight line segment geometric primitives based on the application of the Hough transform from the actual and noisy sonar data. We will give an explanation for the robot system architecture designed and implemented in this study and a short review of existing techniques, Hough transform, since there exist several recent thorough books and review paper on this paper. Experimental results with a real Pioneer DX2 mobile robot will demonstrate the effectiveness of the discussed methods.

Fast Decision Method of Geometric Partitioning Mode and Block Partitioning Mode using Hough Transform in VVC (허프 변환을 이용한 VVC의 기하학 분할 모드 및 블록 분할 고속 결정 방법)

  • Lee, Minhun;Park, Juntaek;Bang, Gun;Lim, Woong;Sim, Donggyu;Oh, Seoung-Jun
    • Journal of Broadcast Engineering
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    • v.25 no.5
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    • pp.698-708
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    • 2020
  • VVC (Versatile Video Coding), which has been developing as a next generation video coding standard. Compared to HEVC (High Efficiency Video Coding), VVC is improved by about 34% in RA (Random Access) configuration and about 30% in LDB (Low-Delay B) configuration by adopting various techniques such as recursive block partitioning structure and GPM (Geometric Partitioning Mode). But the encoding complexity is increased by about 10x and 7x, respectively. In this paper, we propose a fast decision method of GPM mode and block partitioning using directionality of block to reduce encoding complexity of VVC. The proposed method is to apply the Hough transform to the current block to identify the directionality of the block, thereby determining the GPM mode and the specific block partitioning method to be skipped in the rate-distortion cost search process. As a result, compared to VTM8.0, the proposed method reduces about 31.01% and 29.84% encoding complexity for RA and LDB configuration with 2.48% and 2.69% BD-rate loss, respectively.

Iris Recognition using MPEG-7 Homogeneous Texture Descriptor (MPEG-7 Homogeneous Texture 기술자를 이용한 홍채인식)

  • 이종민;한일호;김희율
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.45-48
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    • 2002
  • In this paper, we propose an iris recognition system using Homogeneous Texture descriptor of MPEG-7 standard. The texture of iris is generally used in iris recognition system. We segment the pupil with Hough transform and the boundary of iris with it's gray level difference between the white of the eye. To extract Homogeneous Texture descriptor, this iris image is transformed into polar coordinates. The extracted descriptor is then compared with the reference in DB. If their distance is larger than threshold, they are recognized as different iris. Test results will show that Homogeneous Texture descriptor can be a good measure for iris recognition system.

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Radius-Measuring Algorithm for Small Tubes Based on Machine Vision using Fuzzy Searching Method (퍼지탐색을 이용한 머신비전 기반의 소형 튜브 내경측정 알고리즘)

  • Naranbaatar, Erdenesuren;Lee, Sang-Jin;Kim, Hyoung-Seok;Bae, Yong-Hwan;Lee, Byung-Ryong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.11
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    • pp.1429-1436
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    • 2011
  • In this paper, a new tube-radius-measuring algorithm has been proposed for effectively measuring the radii of small tubes under severe noise conditions that can also perform well when metal scraps that make it difficult to measure the radius correctly are inside the tube hole. In the algorithm, we adopt a fuzzy searching method that searches for the center of the inner circle by using fuzzy parameters for distance and orientation from the initial search point. The proposed algorithm has been implemented and tested on both synthetic and real-world tube images, and the performance is compared to existing circle-detection algorithms, such as the Hough transform and RANSAC methods, to prove the accuracy and effectiveness of the algorithm. From this comparison, it is concluded that the proposed algorithm has excellent performance in terms of measurement accuracy and computation time.