• Title/Summary/Keyword: k-convex region

Search Result 88, Processing Time 0.021 seconds

The ConvexHull using Outline Extration Algorithm in Gray Scale Image (이진 영상에서 ConvexHull을 이용한 윤곽선 추출 알고리즘)

  • Cho, Young-bok;Kim, U-ju;Woo, Sung-hee
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2017.10a
    • /
    • pp.162-165
    • /
    • 2017
  • The proposed paper extracts the region of interest from the x-lay input image and compares it with the reference image. The x-ray image has the same shape, but the size, direction and position of the object are photographed differently. In this way, we measure the erection difference of darkness and darkness using the similarity measurement method for the same object. Distance measurement also calculates the distance between two points with vector coordinates (x, y, z) of x-lay data. Experimental results show that the proposed method improves the accuracy of ROI extraction and the reference image matching time is more efficient than the conventional method.

  • PDF

The Characteristics of Soot at the Post-Flame Region in Jet Diffusion Flames Added Carbon Dioxide (이산화탄소가 첨가된 제트확산화염 후류에서의 매연 특성)

  • Ji, Jung-Hoon;Lee, Eui-Ju
    • Journal of the Korean Society of Safety
    • /
    • v.25 no.6
    • /
    • pp.9-13
    • /
    • 2010
  • An experimental study for characteristics of soot were conducted at the post-flame region in jet diffusion flames, where carbon dioxide was used as additives in oxidizer stream. Light-extinction method was performed using He-Ne laser with wave length at 632.8nm for the measurement of relative soot density and soot volume fraction with dimensionless extinction coefficient, $K_e$ and mass specific extinction coefficient, ${\sigma}_s$. To increase of resolution, laser light was modified for sheet-form using concave, convex lenses and slit. C/H ratio was introduced for quantitative analysis of soot growth which is expressed by carbonization and dehydrogen. Also transmission electron microscopy(TEM) was used for observation of morphological shape. The results show that the relative soot density in the post-flame region was lower when carbon dioxide was added in oxidizer stream because of reduction of flame temperature.

A NEW PROJECTION ALGORITHM FOR SOLVING A SYSTEM OF NONLINEAR EQUATIONS WITH CONVEX CONSTRAINTS

  • Zheng, Lian
    • Bulletin of the Korean Mathematical Society
    • /
    • v.50 no.3
    • /
    • pp.823-832
    • /
    • 2013
  • We present a new algorithm for solving a system of nonlinear equations with convex constraints which combines proximal point and projection methodologies. Compared with the existing projection methods for solving the problem, we use a different system of linear equations to obtain the proximal point; and moreover, at the step of getting next iterate, our projection way and projection region are also different. Based on the Armijo-type line search procedure, a new hyperplane is introduced. Using the separate property of hyperplane, the new algorithm is proved to be globally convergent under much weaker assumptions than monotone or more generally pseudomonotone. We study the convergence rate of the iterative sequence under very mild error bound conditions.

Hand Region Tracking and Fingertip Detection based on Depth Image (깊이 영상 기반 손 영역 추적 및 손 끝점 검출)

  • Joo, Sung-Il;Weon, Sun-Hee;Choi, Hyung-Il
    • Journal of the Korea Society of Computer and Information
    • /
    • v.18 no.8
    • /
    • pp.65-75
    • /
    • 2013
  • This paper proposes a method of tracking the hand region and detecting the fingertip using only depth images. In order to eliminate the influence of lighting conditions and obtain information quickly and stably, this paper proposes a tracking method that relies only on depth information, as well as a method of using region growing to identify errors that can occur during the tracking process and a method of detecting the fingertip that can be applied for the recognition of various gestures. First, the closest point of approach is identified through the process of transferring the center point in order to locate the tracking point, and the region is grown from that point to detect the hand region and boundary line. Next, the ratio of the invalid boundary, obtained by means of region growing, is used to calculate the validity of the tracking region and thereby judge whether the tracking is normal. If tracking is normal, the contour line is extracted from the detected hand region and the curvature and RANSAC and Convex-Hull are used to detect the fingertip. Lastly, quantitative and qualitative analyses are performed to verify the performance in various situations and prove the efficiency of the proposed algorithm for tracking and detecting the fingertip.

Feasibility for Ultrasound Pad Material for the Evaluation Axillary Region of Automated Breast Ultrasound Equipment (자동유방초음파 장비의 액와부 평가를 위한 초음파 패드 물질의 타당성)

  • Seo, Eun-Hee;Seoung, Youl-Hun
    • Journal of radiological science and technology
    • /
    • v.41 no.3
    • /
    • pp.231-240
    • /
    • 2018
  • Automated breast ultrasound (ABUS) equipment is a new innovative technique for 3D automatic breast scanning, but limited for the examination in the concave axillary region. The purpose of this study was to determine feasible candidate materials for the ultrasonic wave propagation media in ABUS, enabling the evaluation of the axillary region. Ultrasonography was performed using an ABUS system ($Invenia^{TM}ABUS$, GE, USA) on the ultrasound-specific phantom (UC-551M-0.5, ATS Laboratories, USA) covered by different candidate materials. The validity of feasible candidate materials was evaluated by image quality. Three independent radiological technologists, with more than 10 years of experience, visually assessed on the images. The inter-observer agreements according to the candidate materials were tested using Cronbach's alpha. Unenveloped solidified carrageenan can be a feasible material for the use of ABUS with excellent test reliability. Therefore, the coverage of the axillary region with carrageenan may be effective for ABUS which was originally developed for the convex anatomic structure as female breast.

Adaptive Video-Dissolve Detection Method Based on Correlation Between Two Scenes

  • Won, Jong-Un;Park, Jae-Gark;Chung, Yoon-su;Park, Kil-Houm
    • Proceedings of the IEEK Conference
    • /
    • 2002.07c
    • /
    • pp.1519-1522
    • /
    • 2002
  • In this paper, we propose a new adaptive dissolve detection method based on the analysis of a dissolve modeling error that is the difference between an ideally modeled dissolve curve without any correlation and an actual variance curve with a correlation. The dissolve modeling error is determined based on a correlation between two scenes and variances for each scene. First, Candidate regions are extracted by using the characteristics of a parabola that is downward convex, then the candidate region will be verified based on a dissolve modeling error. If a dissolve modeling error on a candidate region is less than a threshold that is defined by a dissolve modeling error with a target correlation, the candidate region should be a dissolve region with a correlation less than the target correlation. The threshold is adaptively determined based on the variances between the candidate regions and the target correlation. By considering the correlation between neighbor scenes, the proposed method is able to be a semantic scene-change detector. The proposed algorithm was tested on various types of data and its performance proved to be more accurate and reliable when compared with other commonly used methods

  • PDF

An Improved Feature Extraction Technique of Asterias Amurensis using 6-Directional Scanning and Centers of Region (6-방향 스캐닝과 영역 중심점을 이용한 아무르불가사리의 개선된 특징 추출 기법)

  • Shin, Hyun-Deok;Chu, Ran-Heui
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.13 no.2
    • /
    • pp.67-75
    • /
    • 2013
  • Korea has developed coastal farming industry due to the environmental characteristics that its three sides are surrounded by sea. The damage of coastal farming industry caused by Asterias Amurensis with very strong reproductive rate and predaciousness has increased sharply every year. Moreover, Asterias Amurensis preys on living fish and shellfish and so the damage of fishermen is vern greater. In this paper, a method is proposed to extract effectively the features from the image of Asterias Amurensis acquired in the water. Because the proposed method extracts convex features using 6-directional scanning, it selects a fewer number of feature candidates than the conventional one. In addition, after selecting candidate concave points using the extracted convex features and centers of region, the final concave features are extracted. Due to the features of the starfish which lives in groups, individuals of the starfish in the input image are concentrated. Thus, it is significant to minimize the number of feature candidates extracted from the input image. The experimental results indicate an improvement of the proposed feature extraction method over the conventional one as evidenced by the fact that the feature extract was 88 % of the feature candidates.

Face Detection Algorithm using Color and Convex-Hull Based Region Information

  • Park, Minsick;Park, Chang-Woo;Park, Mignon
    • Proceedings of the IEEK Conference
    • /
    • 2001.06c
    • /
    • pp.217-220
    • /
    • 2001
  • The detection of face in color images is important for many multimedia applications. It is the first step for face recognition and ran be used for classifying specific shots. In this paper describes a new method to detect faces in color images based on the skin color and hair color. In the first step of the processing, regions of the human skin color and head color are extracted and those regions are found by their color information. Then we converted binary scale from the image. Then we are connected regions in a binary image by label. In the next step we are found regions of interesting by their region information and some conditions.

  • PDF

Saliency Detection based on Global Color Distribution and Active Contour Analysis

  • Hu, Zhengping;Zhang, Zhenbin;Sun, Zhe;Zhao, Shuhuan
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.10 no.12
    • /
    • pp.5507-5528
    • /
    • 2016
  • In computer vision, salient object is important to extract the useful information of foreground. With active contour analysis acting as the core in this paper, we propose a bottom-up saliency detection algorithm combining with the Bayesian model and the global color distribution. Under the supports of active contour model, a more accurate foreground can be obtained as a foundation for the Bayesian model and the global color distribution. Furthermore, we establish a contour-based selection mechanism to optimize the global-color distribution, which is an effective revising approach for the Bayesian model as well. To obtain an excellent object contour, we firstly intensify the object region in the source gray-scale image by a seed-based method. The final saliency map can be detected after weighting the color distribution to the Bayesian saliency map, after both of the two components are available. The contribution of this paper is that, comparing the Harris-based convex hull algorithm, the active contour can extract a more accurate and non-convex foreground. Moreover, the global color distribution can solve the saliency-scattered drawback of Bayesian model, by the mutual complementation. According to the detected results, the final saliency maps generated with considering the global color distribution and active contour are much-improved.

Optimal Design of Composite Laminated Plates with the Discreteness in Ply Angles and Uncertainty in Material Properties Considered (섬유 배열각의 이산성과 물성치의 불확실성을 고려한 복합재료 적층 평판의 최적 설계)

  • Kim, Tae-Uk;Sin, Hyo-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.25 no.3
    • /
    • pp.369-380
    • /
    • 2001
  • Although extensive efforts have been devoted to the optimal design of composite laminated plates in recent years, some practical issues still need further research. Two of them are: the handling of the ply angle as either continuous or discrete; and that of the uncertainties in material properties, which were treated as continuous and ignored respectively in most researches in the past. In this paper, an algorithm for stacking sequence optimization which deals with discrete ply angles and that for thickness optimization which considers uncertainties in material properties are used for a two step optimization of composite laminated plates. In the stacking sequence optimization, the branch and bound method is modified to handle discrete variables; and in the thickness optimization, the convex modeling is used in calculating the failure criterion, given as constraint, to consider the uncertain material properties. Numerical results show that the optimal stacking sequence is found with fewer evaluations of objective function than expected with the size of feasible region taken into consideration; and the optimal thickness increases when the uncertainties of elastic moduli considered, which shows such uncertainties should not be ignored for safe and reliable designs.