• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.108-115
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• 2002

In measuring step for reverse engineering of sculptured surfaces, computer vision system is used to simplify the complicated surface by boundary edge detection method that minimizes the measuring error. The measured data by Coordinate measuring machine is clouded data points of surfaces which is segmented surface using image process. In this research, the measured data is approximated as NURBS surfaces by new suggested algorithm. The position and number of control points, selection of parametric values and compensation of weight factors are proposed. Finally, surface model is simulated and improved resulting performance is obtained.

• International Journal of Contents
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• v.9 no.4
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• pp.16-21
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• 2013

Vision system is an indispensable part of constructing the chess-playing robot. Chessboard detection and pieces localization in the captured image of robot's camera are important steps for processes followed such as pieces recognition, move calculation, and robot controlling. We present a method for detecting the Janggi chessboard and pieces based on the edge and color feature. Hough transform combined with line extraction is used for segmenting the chessboard and warping it to form the rectangle shape in order to detect and interpolate the lines of chessboard. Then we detect the existence of pieces and their side by applying the saliency map and checking the color distribution at piece locations. While other methods either work only with the empty chessboard or do not care about the piece existence, our method could detect sufficiently side and position of pieces as well as lines of the chessboard even if the occlusion happens.

• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.217-227
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• 2017

Crosswalk detection is an important part of the Pedestrian Protection System in autonomous vehicles. Different methods of crosswalk detection have been introduced so far using crosswalk edge features, the distance between crosswalk blocks, laser scanning, Hough Transformation, and Fourier Transformation. However, most of these methods failed to detect crosswalks accurately, when they are damaged, faded away or partly occluded. Furthermore, these methods face difficulties when applying on real road environment where there are lot of vehicles. In this paper, we solve this problem by first using a region based binarization technique and x-axis histogram to detect the candidate crosswalk areas. Then, we apply Support Vector Machine (SVM) based classification method to decide whether the candidate areas contain a crosswalk or not. Experiment results prove that our method can detect crosswalks in different environment conditions with higher recognition rate even they are faded away or partly occluded.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.126-132
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• 2000

This paper presents a facial expression recognition based on Gabor wavelets that uses a fuzzy C-means(FCM) clustering algorithm and neural network. Features of facial expressions are extracted to two steps. In the first step, Gabor wavelet representation can provide edges extraction of major face components using the average value of the image's 2-D Gabor wavelet coefficient histogram. In the next step, we extract sparse features of facial expressions from the extracted edge information using FCM clustering algorithm. The result of facial expression recognition is compared with dimensional values of internal stated derived from semantic ratings of words related to emotion. The dimensional model can recognize not only six facial expressions related to Ekman's basic emotions, but also expressions of various internal states.

• Journal of Computing Science and Engineering
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• v.8 no.3
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• pp.149-156
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• 2014

Skeletonization is a morphological operation that transforms an original object into a subset, which is called a 'skeleton'. Skeletonization has been intensively studied for decades and is a challenging issue especially for special target objects. This paper proposes a novel approach to the skeletonization of text images based on stroke width detection. First, the preliminary skeleton is detected by using a Canny edge detector with a Tensor Voting framework. Second, the preliminary skeleton is smoothed, and junction points are connected by interpolation compensation. Experimental results show the validity of the proposed approach.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.270-273
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• 2013

잡음이 존재하는 환경에서 이미지의 경계와 디테일을 살리는 것은 잡음을 제거하는 것에 있어서 가장 중요한 요소중의 하나이다. 이를 위한 방법 중 한가지는 Bilateral 필터를 이용하여 영상 잡음 제거를 하면서 영상의 경계와 디테일을 보존하는 방법이다. Bilateral 필터의 이러한 특성 때문에 최근 Bilateral 필터를 통한 영상 잡음 제거에 대한 연구가 한창 진행되고 있다. 이에 본 논문은 Bilateral 필터의 장점인 경계와 디테일을 부각시키는 능력을 개선하기 위해 가장 간단하다고 많이 알려진 영상의 경계 검출 알고리듬을 이용하여 더욱 효과적인 Bilateral 필터를 통한 영상 잡음 제거를 연구 개발하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.134-137
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• 2014

화질의 개선을 위해 잡음을 제거하는 기술이 많이 개발되고 있으며 그 기술들 중에 효과적으로 사용되고 있는 것 하나가 양방향 필터이다. 양방향 필터는 거리에 대한 가중치와 화소 값에 대한 가중치를 모두 고려하기 때문에 경계 부분을 보존하면서 잡음을 제거하는 것이 가능하다. 필터를 적용함으로 잡음이 제거되지만 본 논문에서는 그보다 나은 결과를 위해서 경계 부분을 캐니 에지 검출기로 검출하고 강조함으로써 양방향 필터의 장점을 전보다 부각시켜 이전보다 효과적인 화질개선 방법을 제시하고자 하였다.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.527-530
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• 2012

본 논문은 윤곽선이 두드러지는 Saliency Map모델을 생성하고 객체 후보 영상을 획득하여 객체를 추출할 수 있는 기법에 관한 연구이다. 제안하는 기법은 객체의 윤곽선 정보가 두드러지는 Saliency Map을 생성하기 위해 에지(Edge), 초점(Focus), 엔트로피(Entropy)를 특징 정보로써 사용하고, 획득한 Saliency Map의 임계화 과정 및 라벨링 과정을 통해 배경 영역을 제거한 객체 후보 영상을 획득한다. 이후 Mean Shift Segmentation 알고리즘을 적용한 영상의 세그먼트별 객체 후보 영상의 픽셀 평균값을 적용한 영상을 다시 라벨링 과정을 이용하여 객체를 추출한다.

• Structural Engineering and Mechanics
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• v.15 no.3
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• pp.367-378
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• 2003

The magnitude of the plastic zone around the crack tip of DENT (Double Edge Notched Tension) specimen and the crack growth length under cyclic loading were measured by ESPI (Electronic Speckle Pattern Interferometry) system. The measured magnitude of plastic zone was compared with the proposed by Irwin and calculated by a nonlinear static method of MSC/NASTRAN. The measured crack growth length by ESPI system was also compared with the obtained data by the image analysis system. From the study, it is confirmed that the plastic zone and crack growth length can be measured accurately with the high-tech equipment (ESPI System).

• Journal of Korea Multimedia Society
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• v.6 no.4
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• pp.594-600
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• 2003

In this paper, we propose a detection method for facial features in color images with various backgrounds and face poses. To begin with, the proposed method extracts face candidacy region from images with various backgrounds, which have skin-tone color and complex objects, via the color and edge information of face. And then, by using the elliptical shape property of face, we correct a rotation, scale, and tilt of face region caused by various poses of head. Finally, we verify the face using features of face and detect facial features. In our experimental results, it is shown that accuracy of detection is high and the proposed method can be used in pose-invariant face recognition system effectively