• Title/Summary/Keyword: Contour Extraction

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Contour Extraction Method using p-Snake with Prototype Energy (원형에너지가 추가된 p-Snake를 이용한 윤곽선 추출 기법)

  • Oh, Seung-Taek;Jun, Byung-Hwan
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.4
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    • pp.101-109
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    • 2014
  • It is an essential element for the establishment of image processing related systems to find the exact contour from the image of an arbitrary object. In particular, if a vision system is established to inspect the products in the automated production process, it is very important to detect the contours for standardized shapes such lines and curves. In this paper, we propose a prototype adaptive dynamic contour model, p-Snake with improved contour extraction algorithms by adding the prototype energy. The proposed method is to find the initial contour by applying the existing Snake algorithm after Sobel operation is performed for prototype analysis. Next, the final contour of the object is detected by analyzing prototypes such as lines and circles, defining prototype energy and using it as an additional energy item in the existing Snake function on the basis of information on initial contour. We performed experiments on 340 images obtained by using an environment that duplicated the background of an industrial site. It was found that even if objects are not clearly distinguished from the background due to noise and lighting or the edges being insufficiently visible in the images, the contour can be extracted. In addition, in the case of similarity which is the measure representing how much it matches the prototype, the prototype similarity of contour extracted from the proposed p-ACM is superior to that of ACM by 9.85%.

A license plate detection method based on contour extraction that adapts to environmental changes (주변 환경 변화에 적응하는 윤곽선 추출 기반의 자동차 번호판 검출 기법)

  • Pyo, Sung-Kook;Lee, Gang-seong;Park, Young-Soo;Lee, Sang-Hun
    • Journal of the Korea Convergence Society
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    • v.9 no.9
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    • pp.31-39
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    • 2018
  • In this paper, we proposed a license plate detection method based on contour extraction that adapts to environmental changes. The proposed method extracts contour lines using DoG (Difference of Gaussian) to remove unnecessary noise parts in the contour extraction process. Binarization was applied in ugly outline images, and erosion and dilation operations were used to emphasize the contour of the character part. Then, only the outline of the ratio of the characters of the plate was extracted through the ratio of the width and height of the characters. And the case where the outline is the longest is estimated by estimating the characters of the license plate. For the experiment, we applied 130 image data to license plate on the front of the vehicle, oblique environment, and environment images with various backgrounds. I also experimented with motorcycle images of different license plate patterns. Experimental results showed that the detection rate of the oblique image was 93% and that of the various background environment was 70% in the motorcycle image but 98% in the front image.

Facial Contour Extraction in PC Camera Images using Active Contour Models (동적 윤곽선 모델을 이용한 PC 카메라 영상에서의 얼굴 윤곽선 추출)

  • Kim Young-Won;Jun Byung-Hwan
    • Proceedings of the Korea Contents Association Conference
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    • 2005.11a
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    • pp.633-638
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    • 2005
  • The extraction of a face is a very important part for human interface, biometrics and security. In this paper, we applies DCM(Dilation of Color and Motion) filter and Active Contour Models to extract facial outline. First, DCM filter is made by applying morphology dilation to the combination of facial color image and differential image applied by dilation previously. This filter is used to remove complex background and to detect facial outline. Because Active Contour Models receive a large effect according to initial curves, we calculate rotational degree using geometric ratio of face, eyes and mouth. We use edgeness and intensity as an image energy, in order to extract outline in the area of weak edge. We acquire various head-pose images with both eyes from five persons in inner space with complex background. As an experimental result with total 125 images gathered by 25 per person, it shows that average extraction rate of facial outline is 98.1% and average processing time is 0.2sec.

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Image Contour Extraction Method base on Gestalt Theory (형태 이론에 기반한 이미지 윤곽선 추출 방법)

  • Ha, Chu-Ja;Kim, Cheol-Won
    • Journal of Advanced Navigation Technology
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    • v.13 no.2
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    • pp.257-261
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    • 2009
  • This paper propose a new method using Gestalt theory to extract image contour. The proposed method use Gestalt theory based on proximity, similarity and continuation for grouping objects from image segmentation. It use downward feedback and perception to materialize one visual level in image from heterogeneity visual levels in image. The experimental result show that the proposed method achieves better performance than other methods.

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Automated Silhouette Extraction Method for Generating a Blueprint from 3D Scan Data of Cultural Asset (문화재의 3D 스캔 데이터로부터 도면을 생성하기 위한 자동화된 실루엣 추출 방법)

  • Jung, Jung-Il;Cho, Jin-Soo;WhangBo, Tae-Keun
    • The Journal of the Korea Contents Association
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    • v.8 no.12
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    • pp.10-19
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    • 2008
  • In this paper, we propose an automated silhouette extraction method that can effectively extract inner-patterns and silhouettes from 3D scan data of cultural asset. First of all, after creating the edge list of 3D vector data, we decide contour edge and crease edge according to viewpoint. In the next step, after extracting surface silhouette by investigating the vector variation of adjacent faces in crease edge, we finally extract the contour silhouette and surface silhouette for generating the blueprint of cultural asset. To evaluate the performance of the proposed silhouette extraction method, we performed experiments of silhouette extraction using a traditional tile model, a car model and a stone monument model. Comparing with the conventional threshold-based silhouette extraction method, the proposed method extracted more distinct and clear surface silhouettes and inner-patterns by effectively removing meaningless edges, such as noise.

An Extraction of Moving Object Contour Using Active Contour Model (능동 윤곽선 모델을 이용한 이동 물체 윤곽선 추출)

  • 이상욱;권태하
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.1
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    • pp.123-130
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    • 2000
  • In this paper, we propose an extracting method of moving object contour using active contour model from image sequences acquired by fixed camera. We use an adaptive background model for robust processing in surrounding conditions. Object segmentation model detects pixels thresholded from local difference image between background and current image and extracts connected regions. Noises in boundary area of moving object we eliminated by morphological filter. The contour of segmented object is corrected by using active contour model for extracting accurate boundary of moving object. We apply the proposed method to highway image sequences and show the results of simulation.

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Tumor boundary extraction from brain MRI images using active contour models (Snakes) (스네이크를 이용한 뇌 자기 공명 영상에서 종양의 경계선 추출)

  • Ryeong-Ju Kim;Young-Chul Kim;Heung-Kook Choi
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.2
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    • pp.1-6
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    • 2003
  • The study is to automatically or semi-automatically detect the accurate contour of tumors or lesions using active contour models (Snakes) in the MRI images of the brain. In the study we have improved the energy-minimization problem of snakes using dynamic programming and have utilized the values of the canny edge detector by the image force to make the snake less sensitive in noises. For the extracted boundary, the inside area, the perimeter and its center coordinates could be calculated. In addition, the multiple 2D slices with the contour of the lesion wore combined to visualized the shape of the lesion in 3D. We expect that the proposed method in this paper will be useful to make a treatment plan as well as to evaluate the treatments.

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Active Contour Model for Boundary Detection of Multiple Objects (복수 객체의 윤곽 검출 방법에 대한 능동윤곽모델)

  • Jang, Jong-Whan
    • The KIPS Transactions:PartB
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    • v.17B no.5
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    • pp.375-380
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    • 2010
  • Most of previous algorithms of object boundary extraction have been studied for extracting the boundary of single object. However, multiple objects are much common in the real image. The proposed algorithm of extracting the boundary of each of multiple objects has two steps. In the first step, we propose the fast method using the outer and inner products; the initial contour including multiple objects is split and connected and each of new contours includes only one object. In the second step, an improved active contour model is studied to extract the boundary of each object included each of contours. Experimental results with various test images have shown that our algorithm produces much better results than the previous algorithms.

Contour Extraction of Facial Features Based on the Enhanced Snake (개선된 스네이크를 이용한 얼굴 특징요소의 윤곽 추출)

  • Lee, Sung Soo;Jang, JongWhan
    • KIPS Transactions on Software and Data Engineering
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    • v.4 no.8
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    • pp.309-314
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    • 2015
  • One of typical methods for extracting facial features from face images may be snake. Although snake is simple and fast, performance is very much affected by the initial contour and the shape of object to be extracted. In this paper, the enhanced snake is proposed to extract better facial features from 6 lip and mouth images as snake point is added to the midpoint of snake segment. It is shown that RSD of the proposed method is about 2.8% to 5.8% less than that of Greedy snake about 6 test face images. Since lesser RSD is especially obtained for contours with highly concavity, the contour is more accurately extracted.

A TRUS Prostate Segmentation using Gabor Texture Features and Snake-like Contour

  • Kim, Sung Gyun;Seo, Yeong Geon
    • Journal of Information Processing Systems
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    • v.9 no.1
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    • pp.103-116
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    • 2013
  • Prostate cancer is one of the most frequent cancers in men and is a major cause of mortality in the most of countries. In many diagnostic and treatment procedures for prostate disease accurate detection of prostate boundaries in transrectal ultrasound(TRUS) images is required. This is a challenging and difficult task due to weak prostate boundaries, speckle noise and the short range of gray levels. In this paper a method for automatic prostate segmentation in TRUS images using Gabor feature extraction and snake-like contour is presented. This method involves preprocessing, extracting Gabor feature, training, and prostate segmentation. The speckle reduction for preprocessing step has been achieved by using stick filter and top-hat transform has been implemented for smoothing the contour. A Gabor filter bank for extraction of rotation-invariant texture features has been implemented. A support vector machine(SVM) for training step has been used to get each feature of prostate and nonprostate. Finally, the boundary of prostate is extracted by the snake-like contour algorithm. A number of experiments are conducted to validate this method and results showed that this new algorithm extracted the prostate boundary with less than 10.2% of the accuracy which is relative to boundary provided manually by experts.