• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.593-598
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• 2006

High-resolution satellite imagery has many benefits, compared to aerial photo in the wide area as well as multi-spectral character. So, it can be used well for constructing GIS data when making digital map. This study analysed the possibilities that road information derived automatically from IKONOS can be used for making ITS system or updating digital map of the urban areas where change frequently and producing satellite image map. In this study, Sobel was applied for road edge dectection after low pass filtering. As the results, it's possible for low pass filtering and high pass filtering to be used as the basic data for ITS construction when extracting edge roads and constructs according to the characteristic of high-resolution satellite imagery.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.2
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• pp.93-98
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• 2013

Multi-temporal high resolution satellite images are essential data for efficient city analysis and monitoring. Yet even when acquired from the same location, identical sensors as well as different sensors, these multi-temporal images have a geometric inconsistency. Matching points between images, therefore, must be extracted to match the images. With images of an urban area, however, it is difficult to extract matching points accurately because buildings, trees, bridges, and other artificial objects cause shadows over a wide area, which have different intensities and directions in multi-temporal images. In this study, we analyze a shadow effect on image matching of high resolution satellite images in urban area using Scale-Invariant Feature Transform(SIFT), the representative matching points extraction method, and automatic shadow extraction method. The shadow segments are extracted using spatial and spectral attributes derived from the image segmentation. Also, we consider information of shadow adjacency with the building edge buffer. SIFT matching points extracted from shadow segments are eliminated from matching point pairs and then image matching is performed. Finally, we evaluate the quality of matching points and image matching results, visually and quantitatively, for the analysis of shadow effect on image matching of high resolution satellite image.

• Smart Media Journal
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• v.2 no.4
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• pp.60-65
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• 2013

In this paper, we propose a high-resolution disparity map generation method using a low-resolution time-of-flight (TOF) depth camera and color camera. The TOF depth camera is efficient since it measures the range information of objects using the infra-red (IR) signal in real-time. It also quantizes the range information and provides the depth image. However, there are some problems of the TOF depth camera, such as noise and lens distortion. Moreover, the output resolution of the TOF depth camera is too small for 3D applications. Therefore, it is essential to not only reduce the noise and distortion but also enlarge the output resolution of the TOF depth image. Our proposed method generates a depth map for a color image using the TOF camera and the color camera simultaneously. We warp the depth value at each pixel to the color image position. The color image is segmented using the mean-shift segmentation method. We define a cost function that consists of color values and segmented color values. We apply a weighted average filter whose weighting factor is defined by the random walk probability using the defined cost function of the block. Experimental results show that the proposed method generates the depth map efficiently and we can reconstruct good virtual view images.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06b
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• pp.256-260
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• 2008

위성영상으로부터 적절한 정보를 추출하여 GIS(지리정보시스템)의 기반자료로 활용하기 위해서는 공간해상도와 분광해상도가 모두 우수한 양질의 고해상 영상을 확보해야 한다. 그러나 현재 운영되고 있는 위성영상은 이 두가지를 모두 만족시키지 못하므로 본 연구에서는 위성영상 융합기술을 사용할 것을 제안하였다. 그리하여 IHS PCA Wavelet 등의 융합기술들을 실험하였고 두가지 해상도를 모두 만족시키는 고해상 영상을 생산할 수 있음을 보였다. 또한, 실험 결과를 시각적 정량적으로 평가하여 IHS 융합기법이 가장 우수한 결과를 나타냄을 보였다.

• 한국지형공간정보학회:학술대회논문집
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• 2004.10a
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• pp.33-37
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• 2004

고해상 입체 위성영상 엄밀 모델링(Rigorous Modeling)을 구현하고, 이를 기반으로 각 입체시 영상을 제작하여 3차원 정확도 평가를 수행하였다. 본 연구 지역으로 진주지역의 SPOTS 입체영상을 이용하였으며, 각 영상별 기준점 자료는 1/5000 수치지도를 이용하여 입체영상의 중복영역 내에 균등하게 지상기준점 40점을 추출하였다. 추출된 점을 각각 기준점과 검사점으로 구분하여 엄밀 모델링의 정확도를 분석하였다. 또한, 입체시 제작시에 기준점으로 사용된 지상좌표와 이에 대응하는 영상점을 이용하여 입체시 영상을 제작하였다. 제작된 입체시 영상에서 동일점을 획득하기 위해 영상 매칭 및 수치해석도화기(Helava System)를 이용하여 정확한 영상점을 획득하여 3차원 좌표를 계산하여 정확도 평가를 수행하였다.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.3
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• pp.252-262
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• 2020

In Remote Sensing, a machine learning based SVM model is typically utilized for land cover classification. And study using neural network models is also being carried out continuously. But study using high-resolution imagery of KOMPSAT is insufficient. Therefore, the purpose of this study is to assess the accuracy of land cover classification by neural network models using high-resolution KOMPSAT-3 satellite imagery. After acquiring satellite imagery of coastal areas near Gyeongju City, training data were produced. And land cover was classified with the SVM, ANN and DNN models for the three items of water, vegetation and land. Then, the accuracy of the classification results was quantitatively assessed through error matrix: the result using DNN model showed the best with 92.0% accuracy. It is necessary to supplement the training data through future multi-temporal satellite imagery, and to carry out classifications for various items.

• Spatial Information Research
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• v.13 no.4 s.35
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• pp.345-354
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• 2005

Super resolution image reconstruction method refers to image processing algorithms that produce a high resolution(HR) image from observed several low resolution(LR) images of the same scene. This method has proven to be useful in many practical cases where multiple frames of the same scene can be obtained, such as satellite imaging, video surveillance, video enhancement and restoration, digital mosaicking, and medical imaging. In this paper, we applied the super resolution reconstruction method in spatial domain to video sequences. Test images are adjacently sampled images from continuous video sequences and are overlapped at high rate. We constructed the observation model between the HR images and LR images applied with the Maximum A Posteriori(MAP) reconstruction method which is one of the major methods in the super resolution grid construction. Based on the MAP method, we reconstructed high resolution images from low resolution images and compared the results with those from other known interpolation methods.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.06a
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• pp.107-108
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• 2014

부화소 기반 영상 축소기법은 각각의 부화소를 조절함으로써 픽셀 기반 영상 축소기법보다 해상도를 향상시킬 수 있는 방법이다. 그러나 부화소에 의한 해상도의 증가는 종종 색상정보의 왜곡을 발생시킨다. 부화소 랜더링의 주요과제는 선명도를 유지함과 동시에 색조왜곡현상을 억제하는 것이다. 선행연구들은 부화소랜더링을 위해 1 차원 혹은 2 차원 필터를 최적화 하였지만, 지역적인 특성을 고려하지 않았기 때문에 출력영상의 화질이 저하되는 현상이 발생한다. 본 논문은 위와 같은 문제를 해결하기 위해 내용적응형 2D FIR 필터를 제작방법을 제안한다. 제안필터는 충분한 수의 저해상도 패치와 고해상도 패치 쌍을 이용하여 임의의 고해상도 패치로부터 고화질의 저해상도 패치를 만들기 위한 최적의 내용적응형 2D FIR 필터를 학습한다. 학습된 필터에 의한 실험결과 제안하는 필터가 종례기법들 보다 색조왜곡현상이 현저히 줄어들고, 출력영상의 선명도를 유지함을 보여준다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.733-735
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• 2014

Example based Super Resolution(SR) is using the correspondence between the low and high resolution image from a database. This method uses only one image to estimate a high resolution image and can get the larger image than 2 times. Example based SR is proposed to solve the problem of classical SR. Neighbor embedding(NE) has been inspired by manifold learning method, particularly locally linear embedding. However, the poor generalization of NE decreases the performance of such algorithm. The sizes of local training sets are always too small to improve the performance of NE. We propose the advanced NE baesd on SVR having an excellent generalization ability to solve this problem. Given a low resolution image, we estimate a pixel in its high resolution version by using SVR based NE. Through experimental results, we quantitatively and qualitatively confirm the improved results of the proposed algorithm when comparing with conventional interpolation methods and NE.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.121-124
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• 2008

2000 년대 들어 방송통신융합의 흐름에 따라 등장한 IT 기반의 Non Linear 제작공정은 2005 년까지 IMX-50, DV25/50 포맷 등 50Mbps 급 이하의 동영상 Data 를 중심으로 영상 콘텐츠 제작을 위해 부분적인 프로그램 장르에 국한하여 구축, 운용되어 왔다. 최근 초고속 네트워크를 통해 대용량의 고해상도 영상데이터를 안정적으로 수용 처리하는, 상대적으로 저렴하면서 효과적인 기능을 보유한 컴퓨터 기술 기반 단위 Application 들이 등장함에 따라 고해상도 프로그램 제작을 지향하는 Contents 생산기지들을 중심으로 IT 기반 제작공정으로의 전환과 차세대 제작시스템으로 HD 급 NPS 구축 필요성이 대두되었다. 본 논문에서는 IT 기반의 방송 시스템 구축의 단초로서 최초로 HD 급 대용량 구축모델의 프로토 타입을 설계하고 발전 로드맵을 분석, 최적화를 위한 방안을 제시한다.