• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.6
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• pp.77-87
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• 2011

In this paper, we propose a disparity correction technique to reduce the inherent visual discomfort while watching stereoscopic videos. The visual discomfort must be solved for commercial 3D display systems to provide natural stereoscopic videos to human eyes. The proposed disparity correction technique consists of horizontal and vertical disparity corrections. The horizontal disparity correction is implemented by controlling the depth budget of stereoscopic video using the geometric relations of a stereoscopic camera system. In addition, the vertical disparity correction is implemented by using a feature-based stereo matching algorithm. Conventional vertical disparity corrections have been done by only using camera calibration parameters, which still cause systematic errors in vertical disparities. In this paper, we minimize the vertical disparity as small as possible by using a feature-based correction algorithm. Through the comparisons of conventional feature-based correction algorithms, we analyze the performance of the proposed technique.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.647-660
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• 2022

To prepare an atmospheric correction model suitable for CAS500-4 (Compact Advanced Satellite 500-4), this letter examined an atmospheric correction experiment using Sentinel-2 images having similar spectral characteristics to CAS500-4. Studies to compare the atmospheric correction results depending on different Aerosol Optical Depth (AOD) data are rarely found. We conducted a comparison of Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH), Sen2Cor, and Second Simulation of the Satellite Signal in the Solar Spectrum - Vector (6SV) version 1.1 and 2.1, using Geo-Kompsat 2A (GK2A) Advanced Meteorological Imager (AMI) and Aerosol Robotic Network (AERONET) AOD data. In this experiment, 6SV2.1 seemed more stable than others when considering the correlation matrices and the output images for each band and Normalized Difference Vegetation Index (NDVI).

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.1
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• pp.70-79
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• 2017

This study proposes a method to quickly and accurately acquire distance information on direction signs. The proposed method is composed of the recognition of the sign, pre-processing to facilitate the acquisition of the road sign distance, and the acquisition of the distance data. The road sign recognition uses color detection including gamma correction in order to mitigate various noise issues. In order to facilitate the acquisition of distance data, this study applied tilt correction using linear factors, and resolution correction using Fourier transform. To acquire the distance data, morphological operation was used to highlight the area, along with labeling and template matching. By acquiring the distance information on the direction sign through such a processes, the proposed system can be output the distance remaining to the next junction. As a result, when the proposed method is applied to system it can process the data in real-time using the fast calculation speed, average speed was shown to be 0.46 second per frame, with accuracy of 0.65 in similarity value.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05c
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• pp.365-370
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• 2002

본 논문은 차량의 번호판 인식 시스템을 구축할 목적으로 번호판 추출을 컬러 정보를 이용하여 구현하였다. 본 실험은 특히 번호판 추출에 많은 장애 요인, 즉, 흐린날, 늦은 오후에 촬영된 차량, 번호판과 같은 색상을 가지는 차량, 그늘진 곳에 주차된 차량 그리고, 운행중인 차량에 대해서도 실험 대상으로 하였다. 그리고, 본 논문에서는 빠른 번호판 검출을 위하여 부분 영역에 대한 특정 픽셀을 추출하였고, 변형 모폴로지와 레이블링의 반복 적용을 통하여 번호판을 검출하며, 후처리를 통하여 보다 정확한 영역을 재보정 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1487-1494
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• 2012

This paper proposes an algorithm detecting the skew of the degraded as well as the clear document images using edge and correcting it. The proposed algorithm detects edges in a character region selected by image complexity and generates projection histograms by projecting them to various directions. And then it detects the document skew by estimating the edge concentrations in the histograms and corrects the skewed document image. For the fast skew detection, the proposed algorithm uses downsampling and 3 step coarse-to-fine searching. In the skew detection of the clear and the degraded images, the maximum and the average detection errors in the proposed algorithm are about 50% of one in a conventional similar algorithm and the processing time is reduced to about 25%. In the non-uniform luminance images acquired by a mobile device, the conventional algorithm can't detect skews since it can't get valid binary images, while the proposed algorithm detect them with the average detection error of 0.1o or under.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.49-54
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• 2007

Flow analysis in a turbine cascade by Euler or Navier-Stokes equation gives relatively accurate solution, however, those method require large computer memory or computing time. on contrast, the panel method， which is applied to incompressible and inviscid flow, provides fast and reasonal solution but the compressibility correction is required for a high air velocity case. In this paper, the compressibility corrected panel method was applied in order to find velocity distribution on turbine blades. Results showed that the calculated velocity in a turbine cascade by the compressibility corrected panel method gave good agreement with experimental results or the solution by finite volume method for compressible flow.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.1
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• pp.23-28
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• 2008

Flow analysis in a turbine cascade by Euler or Navier-Stokes equation gives relatively accurate solution, however, those method require large computer memory or computing time. On contrast, the panel method, which is applied to incompressible and inviscid flow, provides fast and reasonal solution but the compressibility correction is required for a high air velocity case. In this paper, the compressibility corrected panel method was applied in order to find velocity distribution on turbine blades. Results showed that the calculated velocity in a turbine cascade by the compressibility corrected panel method gave good agreement with the solution by finite volume method for compressible flow.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.2
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• pp.165-170
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• 2002

For the inaccessible area where the field verification is unable, it is difficult to obtain the ground control points (GCPs) or the acquired GCPs may be inaccurate. In general systematic geometric correction is achieved by utilizing orbit ephemeris and three axis attitude data of the satellite. however, this method results to poor accuracy of the imagery's absolute coordinates. To improve the absolute accuracy as well as the relative accuracy, we added the accessible region into the inaccessible area. We obtained GCPs in the accessible region by the fast static GPS survey and made geometric corrections with these biased GCPs. Because the biased GCPs show a pattern of coordinate errors, we analyzed this tendency to track the estimated errors in the inaccessible area.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.630-638
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• 2016

In this paper, a feature based panorama image generation algorithm using FAST(Features from Accelerated Segment Test) method that is faster than SIFT(Scale Invariant Feature Transform) and SURF(Speeded Up Robust Features) is proposed. Cylindrical projection is performed to generate natural panorama images with numerous images as input. The occurred error can be minimized by applying RANSAC(Random Sample Consensus) for the matching process. When we synthesize numerous images acquired from different camera angles, we use blending techniques to compensate the distortions by the heterogeneity of border line. In that way, we could get more natural synthesized panorama image. The proposed algorithm can generate natural panorama images regardless the order of input images and tilted images. In addition, the image matching can be faster than the conventional method. As a result of the experiments, distortion was corrected and natural panorama image was generated.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.617-619
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• 2004

Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time in. Today any data storage system can not satisfy these conditions, but holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System architecture without mechanical actuating part is possible, so fast data transfer rate and high storage capacity about $1Tb/cm^3$ can be realized. In this paper, to correct errors of binary data stored in holographic digital data storage system, find cluster centers using subtractive clustering and reduce intensities of pixels around centers, so the intensify profile of data rare will be uniform and the better data storage system can be realized.