• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2018.06a
• /
• pp.173-174
• /
• 2018

배경제거는 영상에서 움직이는 객체를 분리할 때 유용한 방법이며, 대표적인 예인 Mixture of Gaussian (MOG) 알고리즘은 픽셀 당 3-5 가우스 모델을 혼합해 배경과 움직이는 객체를 구분한다. 소형 표적을 추적하기 위해서는 화소 혹은 작은 블록 단위로 시/공간적 밝기 변화량을 이용하는 옵티컬 플로우 기법이 적절하다. 본 논문에서는 소형 표적의 강인한 객체 추적을 위해 MOG2와 옵티컬 플로우의 결합 방법을 소개한다. 제안된 방법은 MOG2를 사용하여 전경 영역을 획득하고 전경 영역에만 옵티컬 플로우를 적용한다. 실험 결과는 제안 방법이 잡음과 배경의 미세 변화가 있더라도 무인 비행체를 잘 추적할 수 있음을 보여준다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2022.06a
• /
• pp.1261-1264
• /
• 2022

최근 본인에게 어울리는 색상을 배경으로 촬영하는 감성 증명사진이 유행하고 있다. 개인마다 퍼스널 컬러를 찾아 배경색에 적용하는 것은 시간, 비용, 인력적으로 어려움이 있으므로 자동으로 개인에 따른 배경색을 찾아서 사진을 합성하여 감성 증명사진을 제작해 주는 딥러닝 기반 시스템을 구축하였다. 본 논문에서는 Convolution Neural Network 를 기반으로 한 딥러닝 기술을 이용해 Image Matting 과 Multi-Label Classification 을 수행하여 기존 감성 증명사진들을 학습하여 모델을 구축하였으며, 해당 시스템으로 사용자에게 새로운 배경색이 적용된 감성 증명사진을 제공하는 웹 애플리케이션을 제안한다.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.31 no.6
• /
• pp.458-467
• /
• 2019

The purpose of this study is the suggestion of optimized parameters in OI (Optimal Interpolation) by experimental study. The observation of applying optimal interpolation is ADCP (Acoustic Doppler Current Profiler) data at the southwestern sea of Korea. FVCOM (Finite Volume Coastal Ocean Model) is used for the barotropic model. OI is to the estimation of the gain matrix by a minimum value between the background error covariance and the observation error covariance using the least square method. The scaling factor and correlation radius are very important parameters for OI. It is used to calculate the weight between observation data and model data in the model domain. The optimized parameters from the experiments were found by the Taylor diagram. Constantly each observation point requires optimizing each parameter for the best assimilation. Also, a high accuracy of numerical model means background error covariance is low and then it can decrease all of the parameters in OI. In conclusion, it is expected to have prepared the foundation for research for the selection of ocean observation points and the construction of ocean prediction systems in the future.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.54 no.8
• /
• pp.67-80
• /
• 2017

This paper presents a hole-filling method using extrapolated spatio-temporal background information to obtain a synthesized view. A new temporal background model using non-overlapped patch based background codebook is introduced to extrapolate temporal background information In addition, a depth-map driven spatial local background estimation is addressed to define spatial background constraints that represent the lower and upper bounds of a background candidate. Background holes are filled by comparing the similarities between the temporal background information and the spatial background constraints. Additionally, a depth map-based ghost removal filter is described to solve the problem of the non-fit between a color image and the corresponding depth map of a virtual view after 3-D warping. Finally, an inpainting is applied to fill in the remaining holes with the priority function that includes a new depth term. The experimental results demonstrated that the proposed method led to results that promised subjective and objective improvement over the state-of-the-art methods.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.10
• /
• pp.83-92
• /
• 2009

In this paper, an extended snake algorithm using color variance energy is proposed for segmenting an interest object in color image. General snake algorithm makes use of energy in image to segment images into a interesting area and background. There are many kinds of energy that can be used by the snake algorithm. The efficiency of the snake algorithm is depend on what kind of energy is used. A general snake algorithm based on active contour model uses the intensity value as an image energy that can be implemented and analyzed easily. But it is sensitive to noises because the image gradient uses a differential operator to get its image energy. And it is difficult for the general snake algorithm to be applied on the complex image background. Therefore, the proposed snake algorithm efficiently segment an interest object on the color image by adding a color variance of the segmented area to the image energy. This paper executed various experiments to segment an interest object on color images with simple or complex background for verifying the performance of the proposed extended snake algorithm. It shows improved accuracy performance about 12.42 %.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2016.07a
• /
• pp.101-102
• /
• 2016

본 논문에서는 차량의 특징점들 사이의 간격과 크기의 비례식으로 자동차의 차종을 식별하는 방법을 제시한다. 자동차 관련 영상은 그 편의성을 위하여 기본 RGB모델에서 Gray색상 모델로 변환시켜 사용한다. 자동차의 배경 제거는 Canny Edge Direction을 통하여 수행하고 외곽선 검을을 통하여 원하는 특징 점을 얻는다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2017.04a
• /
• pp.1010-1012
• /
• 2017

본 논문에서는 HSV, YCbCr 컬러 모델의 색상정보를 통한 화재 검출 알고리즘을 제안한다. 첫 번째 단계에서는 영상의 변화를 감지하기 위해서 입력된 영상으로부터 평균배경영상을 계산하여 전경영상을 분리한다. 그리고 차영상을 이용해 움직임을 인식하여 컬러 모델 색상정보를 비교할 영역을 구한다. 전경영상의 구해진 영역에서 컬러모델의 복합 색상정보를 이용하여 화재 영역을 검출한다.

• Review of KIISC
• /
• v.18 no.3
• /
• pp.109-117
• /
• 2008

기업의 Network 보안은 회사의 관문 방화벽에만 의존하고 있어 보안정책의 집중으로 효율성이 저하되고 이를 우회할 경우 심각한 위험에 노출될 수 있다. 본 연구는 신속성, 보안강화 측면에서 Network보안 관리 모델을 제시하여 기업의 보안 수준을 강화하는 것을 목적으로 하고 있다. 따라서 기업 비즈니스 환경 변화를 배경으로 관련 연구 결과 및 Trend에서 제시하는 이론(802.1x 사용자 인증, Virtual Backbone 등)을 조사하고 이를 바탕으로 보안 강화 측면에서의 기업의 Network 구조와 보안정책 관리모델을 제시하여 이를 실제 기업 Network에 적용하여 얻어진 효과를 검증한다.

• The Journal of the Acoustical Society of Korea
• /
• v.35 no.5
• /
• pp.340-348
• /
• 2016

Ray-based model for the calculation of the ocean surface-generated ambient noise coherence function has the form of double integral with respect to a range and a bearing angle. While the theoretical consideration about its numerical implementations was partly given in the past work of authors, the numerical results on the ocean environment have not been presented yet. In this paper, we perform numerical experiments for shallow and deep water environments. It is shown that the coherence function depends on the ocean sediment sound speed, and is more sensitive to the ocean sediment sound speed in the shallow water than in the deep water. Similar trend is also observed for varying the orientation of hydrophone pair. In addition, a post-processing technique is proposed in order to plot the noise intensity for the noise receiving angle. This procedure will supplement the weakness of the ray-based model about the output data type compared to the semi-analytic model of Harrison.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.9
• /
• pp.81-92
• /
• 2023

A privacy model is a technique that quantitatively restricts the possibility and degree of privacy breaches through privacy attacks. Representative models include k-anonymity, l-diversity, t-closeness, and differential privacy. While many privacy models have been studied, research on selecting the most suitable model for a given dataset has been relatively limited. In this study, we develop a system for recommending the suitable privacy model to prevent privacy breaches. To achieve this, we analyze the data features that need to be considered when selecting a model, such as data type, distribution, frequency, and range. Based on privacy model background knowledge that includes information about the relationships between data features and models, we recommend the most appropriate model. Finally, we validate the feasibility and usefulness by implementing a recommendation prototype system.