• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.739-742
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• 2005

In this paper, an efficient detection algorithm for the flicker, which is caused by mismatching between light frequency and exposure time at CMOS image sensor (CIS), is proposed. The flicker detection can be implemented by specific hardware or complex signal processing logic. However it is difficult to implement on single chip image sensor, which has pixel, CDS, ADC, and ISP on a die, because of limited die area. Thus for the flicker detection, the simple algorithm and high accuracy should be achieved on single chip image sensor,. To satisfy these purposes, the proposed algorithm organizes only simple operation, which calculates the subtraction of horizontal luminance mean between continuous two frames. This algorithm was verified with MATLAB and Xilinx FPGA, and it is implemented with Magnachip 0.18 standard cell library. As a result, the accuracy is 95% in average on FPGA emulation and the consumed gate count is about 7,500 gates (@40MHz) for implementation using Magnachip 0.18 process.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.641-644
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• 2005

This paper introduces an Interactive Feature Extraction (!FE) approach for the registration of satellite imagery by matching extracted point and line features. !FE method contains both point extraction by cross-correlation matching of singular points and line extraction by Hough transform. The purpose of this study is to minimize user's intervention in feature extraction and easily apply the extracted features for image registration. Experiments with these imagery dataset proved the feasibility and the efficiency of the suggested method.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.303-307
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• 2002

Although Synthetic Aperture Radar(SAR) is a very powerful and attractive tool, automatic interpretation of SAR images is extremely difficult because of several reason. Spatially, speckle noise reduction in SAR images is important step to interpret the SAR image at the preprocessing step. The speckle noise in SAR images is modeled to be multiplicative, and therefore, a signal-dependent noise. So, it has deflated many image-denoising algorithms that are based on additive noise model. In this paper, we propose an adaptive wavelet shrinkage method for speckle noise reduction in SAR images by analyzing the high frequency level in detail. We first decompose minutely the high frequency level to analyze the noise level. And then, we determine the weighting threshold value per the level, and layer. Finally, using those weighting threshold, we produce the efficient wavelet shrinkage method. So, this method not only reduces the speckle noise, but also preserves image detail and sharpness.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.401-404
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• 2004

SAR (Synthetic Aperture Radar) signal data need a focusing procedure to make the information available to the user. In recent SAR systems, various sensing modes and mission operations are applied to acquire high-resolution SAR images. Therefore, in order to develop generalized focusing software for multi-satellites, a regularized parameter configuration that sufficiently represents sensor and platform characteristics of the SAR system is required. The objective of this paper is to introduce the consideration of parameter definition for developing a generalized SAR processor and to discuss the flexibility and extensibility of defined parameters. The proposed parameter configuration can be applied to a SAR processor. Experiments based on real data will show the suitability of the suggested processing parameters.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.19-22
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• 2000

지리 정보와 속성 정보를 바탕으로 사용자에게 다양한 분석 기능을 제공하는 지리정보시스템은 많은 기능적인 향상과 사용자 인터페이스에서의 편리성을 제공하고 있다. 그러나, 초기의 지리정보 시스템 소프트웨어들은 패키지 형태로 제공되어 구축비용 및 다양한 사용자 요구 사항을 충족시키기에 많은 어려움을 가지고 있다. 본 논문에서는, OGC(Open GIS Consortium)의 개방형 지리정보시스템 서비스 아키텍쳐에 기반을 둔 지리정보시스템 서비스 컴포넌트의 설계 및 구현에 대하여 서술한다. 각 서비스 컴포넌트는 단위 기능을 컴포넌트 형태로 제공함으로써 구축비용 및 다양한 사양한 요구사항을 효율적으로 충족시킬 수 있다. 개발된 서비스 컴포넌트는 객체 지향형 모델링 툴인 UML(Unified Modeling Language)로 설계되었고, ATL/COM 과 C++ 환경에서 구축되었다. 이는 재사용성 뿐만 아니라 상호 운용성, 언어 독립성, 쉬운 개발환경 등을 제공한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.405-408
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• 2001

지리 정보와 속성 정보를 바탕으로 사용자에게 다양한 분석 기능을 제공하는 인터넷 지리정보시스템은 지리정보서비스 사용자 층을 더욱 확대 시키고 있다. 그러나 이들 시스템은 개방성, 상호운용성을 지원하지 않으며 기능 및 데이터 지원 확장, 다양한 데이터 소스로의 접근 등의 어려움을 가지고 있다. 본 논문에서는, OGC(Open GIS Consortium)의 웹 지리정보서비스 아키텍쳐에 기반을 둔 상호운용성과 XML 기반 데이터서비스 등 개방형 웹 지리정보서비스 시스템을 설계, 구현한다. 또한, 컴포넌트 기반의 아키텍쳐를 바탕으로 단위 기능을 컴포넌트 형태로 제공함으로써 구축 비용 및 다양한 사양한 요구사항을 효율적으로 충족시킬 수 있다. 개발된 서비스 컴포넌트는 객체 지향형 모델링 툴인 UML(Unified Modeling Language)로 설계되었고, ATL/COM 과 C++ 환경에서 구축되었다. 이는 재사용성 뿐만 아니라 상호 운용성, 언어 독립성, 쉬운 개발환경 등을 제공한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11a
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• pp.775-778
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• 2002

영상 이진화란 명도 영상(gray-scaled image)을 이진 영상(bi-leveled image)으로 변환하는 것을 말한다. 영상 이진화는 문서 인식, 비디오 영상 분석 등과 같이 영상처리 분야에서 많이 사용되는 기본적인 영상 처리 과정에 해당한다. 본 논문은 Intel 사의 Pentium 계열 프로세서에서 지원하는 SIMD(Single-Instruction Multiple-Data) 기술을 이용하여 영상 이진화를 고속으로 수행하는 방법을 소개한다. 우편영상에 대하여 실험한 결과, SSE2 명령어로 구현된 프로그램은 기존의 C 언어로 구현된 프로그램에 비하여 4배 이상의 속도 향상을 보였다.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.59-64
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• 2002

This paper presents a method for line segment extraction for 3-d building reconstruction. Building roofs are described as a set of planar polygonal patches, each of which is extracted by watershed-based image segmentation, line segment matching and coplanar grouping. Coplanar grouping and polygonal patch formation are performed per region by selecting 3-d line segments that are matched using epipolar geometry and flight information. The algorithm has been applied to high resolution aerial images and the results show accurate 3-d building reconstruction.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.81-81
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• 2002

Classification is considered as one of the processes of extracting attributes from satellite imagery and is one of the usual functions in the commercial satellite image processing software. Accuracy of classification plays a key role in deciding the usage of its results. Many tremendous efforts far the higher accuracy have been done in such fields; training area selection, classification algorithm. Our research is one of these effort in different manners. In this research, we conduct classification using multiple satellite image data and evidential approach. We statistically consider the posterior probabilities and certainty in maximum likelihood classification and methodologically Dempster's orthogonal sums. Unfortunately, accuracy for the whole data sets has not assessed yet, but accuracy assessments in training fields and check fields shows accuracy improvement over 10% in overall accuracy and over 0.1 in kappa index.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.29-33
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• 2002

In order to utilize remote sensed images widely, it is necessary to correct geometrically. Traditional approaches to geometric correction require substantial human operations. Such substantial human operations make geometric correction a laborious and tedious process. In this paper, We introduce concept of GCP(Ground Control Point) Chip and generate a GCP Chip for automatic geometric correction. GCP Chip is small image patch which has a GCP in reference coordinate image. GCP Chip will be used to match new images in geometric correction. We generated GCP chip using Landsat-7 ETM+ panchromatic band image in this study. Henceforth this result will support automatic process in geometric correction.