• Journal of Information Processing Systems
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• 제16권5호
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• pp.1129-1144
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• 2020

The thangka image inpainting method based on wavelet transform is not ideal for contour curves when the high frequency information is repaired. In order to solve the problem, a new image inpainting algorithm is proposed based on edge structural constraints and wavelet transform coefficients. Firstly, a damaged thangka image is decomposed into low frequency subgraphs and high frequency subgraphs with different resolutions using wavelet transform. Then, the improved fast marching method is used to repair the low frequency subgraphs which represent structural information of the image. At the same time, for the high frequency subgraphs which represent textural information of the image, the extracted and repaired edge contour information is used to constrain structure inpainting in the proposed algorithm. Finally, the texture part is repaired using texture synthesis based on the wavelet coefficient characteristic of each subgraph. In this paper, the improved method is compared with the existing three methods. It is found that the improved method is superior to them in inpainting accuracy, especially in the case of contour curve. The experimental results show that the hierarchical method combined with structural constraints has a good effect on the edge damage of thangka images.

• Journal of Information Processing Systems
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• 제14권6호
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• pp.1405-1419
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• 2018

An image fusion method is proposed on the basis of depth model segmentation to overcome the shortcomings of noise interference and artifacts caused by infrared and visible image fusion. Firstly, the deep Boltzmann machine is used to perform the priori learning of infrared and visible target and background contour, and the depth segmentation model of the contour is constructed. The Split Bregman iterative algorithm is employed to gain the optimal energy segmentation of infrared and visible image contours. Then, the nonsubsampled contourlet transform (NSCT) transform is taken to decompose the source image, and the corresponding rules are used to integrate the coefficients in the light of the segmented background contour. Finally, the NSCT inverse transform is used to reconstruct the fused image. The simulation results of MATLAB indicates that the proposed algorithm can obtain the fusion result of both target and background contours effectively, with a high contrast and noise suppression in subjective evaluation as well as great merits in objective quantitative indicators.

• Nuclear Engineering and Technology
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• 제39권4호
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• pp.313-326
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• 2007

In this paper, an algorithm to reconstruct two orthogonal images into a three-dimensional image is developed in order to measure the bubble size and volume in a two-phase boiling flow. The central-active contour model originally proposed by P. $Szczypi\'{n}ski$ and P. Strumillo is modified to reduce the dependence on the initial reference point and to increase the contour stability. The modified model is then applied to the algorithm to extract the object boundary. This improved central contour model could be applied to obscure objects using a variable threshold value. The extracted boundaries from each image are merged into a three-dimensional image through the developed algorithm. It is shown that the object reconstructed using the developed algorithm is very similar or identical to the real object. Various values such as volume and surface area are calculated for the reconstructed images and the developed algorithm is qualitatively verified using real images from rubber clay experiments and quantitatively verified by simulation using imaginary images. Finally, the developed algorithm is applied to measure the size and volume of vapor bubbles condensing in a subcooled boiling flow.

• 한국항행학회논문지
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• 제13권2호
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• pp.257-261
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• 2009

본 논문은 형태학 이론을 이용하여 이미지의 윤곽선을 추출하는 새로운 방법을 제안한다. 제안된 방법은 분할된 이미지를 형태학 기반의 근접성, 유사성, 연속성을 사용하여 객체들로 그룹화 한다. 즉, 이미지의 시각 계층에서 지각적 방법과 하향식 피드백을 이용하여 이질적인 시각적 형태들을 하나의 시각적 형태로 구체화 시킨다. 실험 결과 다른 방법에 비하여 좋은 성능을 보인다.

• 디지털융복합연구
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• 제10권3호
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• pp.167-172
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• 2012

본 논문에서는 단일 프레임 영상에 존재하는 객체를 Active Contour 기반의 영역 분할 과정을 거쳐 분할하였다. Active Contour는 영상에서 객체의 윤곽 형태를 검출해내는 것으로 다중 객체 분할을 위해 각 객체의 윤곽 형태를 검출해 낼 수 있도록 다중 탐색 시작점을 갖도록 하였다. 생성된 객체 별 윤곽 정보를 기반으로 이진화하여 초기 객체 영역을 생성하였다. 초기 객체 영역 내부의 홀 영역과 픽셀 값의 변화로 인한 내부 분할을 hole filling을 수행하여 보정함으로써 최종 객체 영역을 생성하였다. 제안한 기법은 기존 영역 기반 분할의 문제점인 잡음이나 경계선 부근에서 객체 분할이 정확히 이루어지지 않는 부분을 보완하였다. 제안 방법을 비교하기 위해 실제 영상에 기존에 제안된 객체 분할 방법과 제안한 방법을 각각 적용하여 비교하였다.

• 대한전자공학회논문지SP
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• 제47권1호
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• pp.1-8
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• 2010

얼굴의 윤곽선을 검출하기 위해서는 일반적으로 입력 영상에 직접 동적 윤곽선 모델(Active Contour Model)을 적용하는 방법을 많이 사용한다. 그러나 동적 윤곽선 모델은 초기의 위치 설정과 사용되는 에너지 함수의 계수 값에 따라 성능에 영향을 받기 때문에, 다양한 조명조건과 환경조건에 따라 최적화된 파라미터들을 설정해야 하는 번거로움이 있다. 또한 섬세한 윤곽선의 검출을 위해서는 모델에서 사용되는 정점의 수를 증가시켜야 하는 단점이 있다. 이러한 단점들을 해결하기 위해, 본 논문에서는 입력영상의 분할된 영역에서의 히스토그램 분석을 통하여, 얼굴 영역과 배경 영역의 픽셀 값을 구분할 수 있는 임계값을 자동으로 찾아, 얼굴의 윤곽선 영역을 검출하는 접근 방법을 제안한다. 제안된 방법은 입력 영상의 분석을 통하여 얼굴의 윤곽선 영역을 검출하기 때문에 다양한 조명과 배경 조건하에서도 높은 성능으로 얼굴의 윤곽선 영역을 검출하였다.

• 전자공학회논문지T
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• 제36T권4호
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• pp.24-29
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• 1999

In this paper, a simple contour-preserving filtering algorithm is proposed. The goal of the contour-preserving filtering method is to remove noise ad granularity as the preprocessing for the image segmentation procedure. Our method finds edge map and separates the image into the edge region and the non-edge region using this edge map. For the non-edge region, typical smoothing filters could be used to remove the noise and the small areas during the segmentation procedure. The result of simulation shows that our method is slightly better than the typical methods such as the median filtering and gradient inverse weighted filtering in the point of view of analysis of variance (ANOVA).

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.554-559
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• 1999

The purpose of this study is the machining of texture shapes by the contour fitting data. The hardware of the system comprises PC and scanning system, CO2 laser machine. There are four steps, (1) text image loading using scanning shapes or 2D image files, (2) generation of contour fitting data by the line and arc, cubic Bezier curve, (3) generation of NC code from the contouring fitting data, (4) machining by the DNC system. It is developed a software package, with which can conduct a micro CAM system of CNC laser machine in the PC without economical burden.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1748-1751
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• 1991

Generally, we can't acquire clear boundary or area from an image having obscure boundary like allergy image by using Sobel or Lapalace operator. Also, when the image not uniform in some part of a image in brightness, there are difficulties to use the global operator such as histogram, for the contour line doesn't have the same grey level. In this paper, we will propose an algorithm to improve those difficulties. The main idea of the algorithm is that we divide the image into many rectangular parts like a chess board, calculate the average of each part, and decide the local threshold for each pixel on the calculated value. In experiment, we can get the contour and area by this algorithm which is much like to the contour and area measured by a doctor. Also, This algorithm has many advantages such as short processing time and little influences of noises and can be used in the robot vision, etc..

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 춘계학술대회
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• pp.27-31
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• 1994

Intravascular ultrasound images of coranary artery contain very important informations on heart disease. The intimal contours on the image show informations and data to examine intravascular problems of patients. A new computation algorithm to detect the intimal and adventitial contours from the intravascular images was developed. An Image processing on gray level image was used. It uses arrays of pixels in each radial lines on the images. A "Robert" filter was adopted at first step for one dimensional image processing. Some other calculation techniques were developed to inclose the accuracy of automatically detected contours. The standard contour data to compare with automatically detected contour data were obtained through manually tracing by experienced cardiological medical doctors. The result of the new algorithm shows high accuracy of 80 % matching with the standard contour data.