• 한국정보통신학회논문지
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• 제13권10호
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• pp.1981-1986
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• 2009

본 논문은 인공신경망을 이용한 새로운 매팅 기법을 제안한다. 매팅이란 영상에서 객체의 불투명도를 추정하는 기술이다. 매팅 기법을 이용하면 객체를 자연스럽게 추출할 수 있다. 먼저 trimap을 이용하여 영상을 배경 영역, 전경 영역, 미지 영역으로 구분한다. 배경 영역과 전경 영역의 정보를 이용하여 미지 영역 화소의 불투명도를 추정한다. 제안하는 알고리즘은 배경 영역과 전경 영역의 정보를 SOM을 이용하여 학습하고 그 결과를 이용하여 미지 영역의 각 화소의 불투명도를 추정한다. 본 논문에서는 배경 영역과 전경 영역의 정보를 학습하는 방법에 따라서 전역적 SOM matting과 지역적 SOM matting으로 구별한다. 제안하는 알고리즘의 성능을 평가하기 위하여 영상에 적용해보았다. 이를 통해 제안하는 알고리즘이 객체를 영상에서 분리 가능함을 확인 할 수 있다.

• ETRI Journal
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• 제36권3호
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• pp.450-459
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• 2014

In this paper, we present a new, easy-to-generate system that is capable of creating virtual 3D tree models and simulating a variety of growth processes of a tree from a single, real tree image. We not only construct various tree models with the same trunk through our proposed digital image matting method and skeleton-based abstraction of branches, but we also animate the visual growth of the constructed 3D tree model through usage of the branch age information combined with a scaling factor. To control the simulation of a tree growth process, we consider tree-growing attributes, such as branching orders, branch width, tree size, and branch self-bending effect, at the same time. Other invisible branches and leaves are automatically attached to the tree by employing parametric branch libraries under the conventional procedural assumption of structure having a local self-similarity. Simulations with a real image confirm that our system makes it possible to achieve realistic tree models and growth processes with ease.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.281-282
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• 2007

In this paper, we propose a method for digital matting using a multi-view camera system. In order to generate multi-view synthetic aperture images, we first move all images obtained from the multi-view camera according to their disparities. After we obtain corresponding trimaps by taking a variance of the synthetic aperture images, we convert the trimaps into multi-view alpha mattes. Experimental results show that the proposed scheme can create the composite images successfully by combining foreground objects with multi-view background images.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2011년도 춘계 종합학술대회 논문집
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• pp.51-52
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• 2011

We introduce a novel complete framework for contructing realistic facial animations given just one facial photo as an input in this paper. Our approach is carried on in 2D photo spacem not 3D space. Moreover, we utilize computer vision-based technique (digital matting) as well as conventional image processing methods (image warping and texture synthesis) for expressing more realistic facial animations. Simulated results show that our scheme produces high quality facial animations very efficiently.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2022년도 제66차 하계학술대회논문집 30권2호
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• pp.233-234
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• 2022

본 논문에서는 영상합성 방법들 중 하나인 로토스코핑에 대해서, 그 중 현장에서 수작업으로 수행되어온 키잉 작업의 단계별 과정을 살펴본 후 이들을 영상처리 알고리즘 등을 활용하여 반자동 혹은 자동화를 할 수 있는 방법을 모색해 본다.

• 디지털산업정보학회논문지
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• 제8권4호
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• pp.159-165
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• 2012

The accurate focusing position should be determined for accurate measurements In VMS. Camera lens focusing is an important problem in computer vision and video measuring systems (VMS) that use CCD cameras and high precision XYZ stages. Camera focusing is a very important step in high precision measurement systems that use computer vision technique. The auto focusing process consists of two steps, the focus value measurement step and the exact focusing position determination step. It is suitable for eliminating high frequency noises with lower processing time and without blurring. An automatic focusing technique is applied to measure a crater with a one-dimensional search algorithm for finding the best focus. Throughout this paper, the suggested algorithm for the Auto focusing was combined with the learning. As a result, it is expected that such a combination would be expanded into the system of recognizing voices in a noisy environment.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.87-91
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• 2022

Bokeh effect is a stylistic technique that can produce blurring the background of photos. This paper implements to produce a bokeh effect with a single image by post processing. Generating depth map is a key process of bokeh effect, and depth map is an image that contains information relating to the distance of the surfaces of scene objects from a viewpoint. First, this work presents algorithms to determine the depth map from a single input image. Then, we obtain a sparse defocus map with gradient ratio from input image and blurred image. Defocus map is obtained by propagating threshold values from edges using matting Laplacian. Finally, we obtain the blurred image on foreground and background segmentation with bokeh effect achieved. With the experimental results, an efficient image processing method with bokeh effect applied using a single image is presented.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권12호
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• pp.3345-3363
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• 2023

Developers often use cross-platform frameworks to create mobile apps that can run on multiple platforms with minimal code changes. However, these frameworks may not suit all the needs of a specific app, so developers may also use native APIs to add platform-specific features. This method eventually dilutes the advantages of cross-platform development methodology that aims to reduce development costs and time, and often leads to a decision to return back to the original native mobile development methodology. In this study, we explore a different approach: combining different cross-platform tools to develop a storybook mobile app that meets various requirements. We have demonstrated that integrating two cross-platform solutions can be used reliably to develop complex mobile applications. However, we also report that this approach can introduce unforeseen issues such as sandbox redundancy, unexpected functional burdens, and redundant permission requests. Despite these challenges, we believe that combining two cross-platform solutions can be applied to a variety of functional and performance requirements, enabling the development of more sophisticated mobile applications at lower costs and with shorter development timelines than traditional mobile app development methodologies.

• 디지털산업정보학회논문지
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• 제7권4호
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• pp.81-88
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• 2011

Mini Double Gears Frame is critical part of PDP and also produces couple hundred thousand every month. In the process of mass production, product inspection is very important process. Double Gear, one of the part of machine, was inspected by human eyes which caused mistakes and slow progress. To achieve the speed and accuracy the system was compensated by vision system which is inspecting automatically. The focus value is measured based on the fact that high contrast images have much high frequency edge information. High frequency term of the image is extracted using the high-pass filter and the sum of the high frequency term is used as the focus value. We used a Gaussian smoothing filter to reduce the noise and then measures the focus value using the modified Laplacian filter called a Sum modified Laplacian Focus values for the various lens positions are calculated and the position with the maximum focus value is decided as the focused position. The focus values calculated in various lens position showed the Gaussian distribution. We proposed a method to estimate the best focus position using the Gaussian curve fitting. Focus values of the uniform interval lens positions are calculated and the values are used to estimate the Gaussian distribution parameters to find the best focus position.

• 디지털산업정보학회논문지
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• 제10권4호
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• pp.29-35
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• 2014

The formula contains up between the text and the structural information, as well as their mathematical symbols. Research on-line or off-line recognition formula is underway actively used in various fields, and various forms of the equation are implemented recognition system. Although many documents are included in the various formulas, it is not easy to enter a formula into the computer. Recognition of the expression is divided into two processes of symbol recognition and structural analysis. After analyzing the location information of each character is specified to recognize the effective area after each symbol, and to the structure analysis based on the proximity between the characters is recognized as an independent single formula. Furthermore, analyzing the relationship between the front and back each time a combination of the position relationship between each symbol, and then to add the symbol which was able to easily update the structure of the entire formula. In this paper, by using a scanner to scan the book formula was used to interpret the meaning of the recognized symbol has a relative size and location information of the expression symbol. An algorithm to remove the formulas for calculation of the number of formula is present at the same time is proposed. Using the proposed algorithms to scan the books in the formula in order to evaluate the performance verification as 100% separation and showed the recognition rate equation.