• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.193-202
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• 2008

In this study, we want to composite the source image and the target image when the environment includes water surface in the target image such as lake, sea, etc. The water surface is different from other common environment. On the water surface, the object must be reflected or refract and sometimes is deformed by the wave of water. In order to composite the object in the source image onto the water image, we analyze the water surface of the target image and let the object be synthesized realistically based on the wave of water. Our composite process consists of three steps. First. we use Shape-from-Shading technique to extract the normal vector of the water surface in the target image. Next, the source image is deformed according to the normal vector map. Finally, we composite the deformed object onto the target image.

• Journal of KIISE:Software and Applications
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• v.32 no.5
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• pp.449-460
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• 2005

This paper proposes a method to track persons robustly in illumination changes and partial occlusions in color video frames acquired from a fixed camera. To solve a problem of changing appearance by illumination change, a time-independent intrinsic image is used to remove noises in an frame and is adaptively updated frame-by-frame. We use a hierarchical human model including body color information in order to track persons in occlusion. The tracked human model is recorded into a persons' list for some duration after the corresponding person's exit and is recovered from the list after her reentering. The proposed method was experimented in several indoor and outdoor scenario. This demonstrated the potential effectiveness of an adaptive model-base method that corrected distorted person's color information by lighting changes, and succeeded tracking of persons which was overlapped in a frame.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.11a
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• pp.92-93
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• 2016

정확한 변위정보를 추정하기 위해 다양한 비용 값 계산함수 또는 비용 값 합산 방법들이 개발되었다. 본 논문에서는 비용 값 계산을 위해 좌, 우영상의 기울기와 SAD(Sum of Absolute Differences)를 이용하며 비용 값 합산을 위해 가이드 영상 필터링을 사용한다. 가이드 영상 필터링은 가이드 영상의 종류에 따라 필터링결과가 크게 변하게 되는데, 스테레오 정합에 사용된 원본 입력 영상을 가이드 영상으로 사용할 경우 정확한 화소 값을 가지고 있기 때문에 경계영역을 보존하며 필터링 수행이 가능하다. 하지만 가이드 필터링은 가이드 영상으로부터 미리 지정해준 이웃한 화소와의 거리와 색상차이의 분산 값만을 고려하여 필터링을 수행하기 때문에 설정 변수 값에 매우 의존적인 특성을 갖는다. 가이드 필터링 과정에서 변수에 대한 의존성을 낮추고 경계영역의 정확도를 높이기 위해 우선 평활화 필터를 이용하여 경계영역을 추출한다. 원본 입력영상을 사용하여 경계영역을 추출할 경우 객체 내부의 많은 텍스처 영역의 정보까지 추출되지만, 평활화 필터를 이용할 경우 정확한 경계 영역의 정보만을 추출 할 수 있다. 추출된 경계영역에 대해서만 높은 가중치를 사용한 뒤 기존의 가이드 영상 필터링과 혼합하여 최종 비용 값을 합산한다. 제안한 방법을 사용하여 경계영역의 정확도가 향상된 최종 변위 지도를 획득할 수 있었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.3028-3035
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• 2010

This paper propose a genetic method based on probability map to detect region of the lips on a natural image with the faces. The method has many solutions in order to detect regions such as the lips instead of one optimal solution of existing methods. To do this, it represents a pair of spatial coordinates as a chromosome, and introduces genetic operations like conservation interval, the number of generations and non-overlapping selection. By using the probability map of the HS in HSV color space, it increases adaptability to similar color that is a property of genetic algorithm. In our experiments, the optimal value of the important parameter $\beta$ was analyzed, which was used as the condition of an ending function and affected performance of the proposed algorithm. Also the algorithm was analyzed on what performance it has when its mating methods are different. The results of the experiment showed that our algorithm could be flexibly adapted for detecting other ROIs.