• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.1
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• pp.677-682
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• 2009

According to the revised law of survey, all the geographic information data including 1/1,000 digital topographic maps have to be converted to world geodetic reference system by the end of 2009. National Geographic Information Institute (NGII) formulated the policy to promote the conversion from local geodetic reference system to world geodetic reference system. However, the current conversion rate is lower than planned due to some impeding factors. Therefore, in this paper, those impeding factors are investigated and then efficient conversion strategies are established and provided. The research involves the validation of affine transformation, the determination of critical value for outlier detection and optimal number of common control points for coordinate conversion, and the treatment of old and new control points.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.10a
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• pp.103-106
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• 2002

본 연구에서는 항공사진에 의한 해안선변형을 해석함에 있어서 수치정사영상 방법과 affine 변환을 이용하여 해안선변형을 분석하고, 두 가지 방법에 대한 정확도를 평가함으로써 항공사진을 이용한 해안선변형 해석의 보다 효율적인 방법을 제안하고자 하였다. 검토결과 정확도 평가 분석에서 알 수 있듯이 수치정사영상의 경우 RMS 오차가 3∼5m 정도로 나타났으며, affine 변환의 경우는 RMS 오차가 5∼8m정도인 것을 확인할 수 있었다. 정확도 평가에서 나타난 RMS 오차는 비록 수치정사영상을 이용한 해석방법보다는 정확도 면에서 약간의 차이가 발생하나 이때의 오차가 2∼3m 정도인 것으로 미루어 볼 때 affine 변환을 이용한 해석방법도 매우 정도가 높은 것이라 사료된다. 아울러, 수치정사영상의 경우 그 과정이 매우 복잡하고 어려운 점을 감안하면 affine 변환에 의한 해석방법이 항공사진을 이용한 해안선변형 해석을 수행함에 있어서 매우 효과적인 방법이라 사료된다.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.1
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• pp.60-69
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• 1999

Motion compensation by affine transform has been proposed as a solution to the artifact problems in very low bit rate video coding and a HMA(Hexagoanl Matching Algorithm) has been proposed for refine motions estimation. When dividing images with an affine transform, as image objects do not necessarily conform to triangle patterns. In this paper we propose a method that first divides an image into triangular patches according to its edge information and then further divides the image into more detailed triangular patches where more complicated edge information occurs. We image propose a PMA(Polygona Matching Algorithm) for refine motion estimation because of the different triangle pattern types of neighboring blocks and its performance is compared with H.263.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9C
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• pp.712-719
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• 2008

Temporal error concealment indicates the algorithm that restores the lost video data using temporal correlation between previous frame and current frame with lost data. It can be categorized into the methods of block-based and pixel-based concealment. The proposed method in this paper is for pixel-based temporal error concealment using affine transform. It outperforms especially when the object or background in lost block has geometric transform which can be modeled using affine transform, that is, rotation, magnification, reduction, etc. Furthermore, in order to maintain good performance even though one or more motion vector represents the motion of different objects, we defines a cost function. According to cost from the cost function, the proposed method adopts affine error concealment adaptively. Simulation results show that the proposed method yields better performance up to 1.9 dB than the method embedded in reference software of H.264/AVC.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.1
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• pp.10-17
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• 2004

In this paper, the affine transformation method that is more simpler compare with digital orthophoto method is used analyzed the long-term shoreline change, and accuracy estimation was carried out. As a result of this study, it was able to check that the shoreline change on Namhangjin coast had eroded significantly compare with the past. Moreover, as a result of accuracy estimation, it shows that the RMS error around shoreline was about 1-2 m. In consideration that maximum allowable error shown in aerial photogrammetry specification is within 2 m, therefore, analysis results of shoreline change using affine transformation method on aerial images is reliable.

• Journal of the Korea Society of Computer and Information
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• v.4 no.2
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• pp.135-140
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• 1999

This paper describes a affine transform coding which is reducing long time to take on image encoding by using scaling method and limited search area technique. For evaluating its performance, the proposed algorithm compare with Jacquin's method using traditional affine transform coding methods. Simulation results, the proposed algorithm considerably reduces encoding time by using scaling method and limited search area method. Also, the proposed algorithm provides much shorter encoding time with a little degradation of the decoded image quality than Jacquin's method.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.1 s.3
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• pp.93-98
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• 1994

This image of Kangseogu in Pusan, is a digital merge of aerial photos by scale of 1/1,200 map. The merge was carried out 2nd affine and bilinear interpolation. It can improve digital classification to help choose training sites and interprete classification results, and improve visual interpretation, as in this case, by adding detailed information to the multispectral TM data.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.06a
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• pp.181-182
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• 2014

본 논문에서는 어파인(affine) 변환에 불변하는 지역 검출기에 대하여 다양한 기술자의 성능을 비교하였다. 지난 수 년간 다양한 특징 기술자들이 연구되어 왔고, 이러한 특징 기술자들은 각각의 목적에 따라 상이한 특성을 갖고 있기 때문에 동일한 조건에서 다양한 기술자들의 성능을 비교하는 연구가 필요하다. 그러나 어파인 변환에 불변하는 지역 검출기에 대해 최적의 특징 기술자를 찾는 연구는 미흡한 실정이다. 따라서 본 논문에서는 지역적인 패치 기반의 특징 기술자뿐만 아니라 바이너리 기술자와 최근에 제안된 기술자들의 성능을 비교하였다. 제안하는 실험에서는 MSER (maximally stable extremal regions) 검출기를 이용하여 어파인 변환에 불변하는 지역을 검출하였고, 영상 확대 및 축소, 회전, 시점 변환 및 변형 가능한 물체에 대하여 각각 기술자의 성능을 비교하였다.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.79-87
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• 2008

There has been a strong demand for low altitude UAV development in rapid mapping not only to acquire high resolution image with much more low cost and weather independent, compared to satellite surveying or traditional aerial surveying, but also to meet many needs of the aerial photogrammetry. Especially, efficient geocoding of UAV imagery is the key issue. Contrary to high UAV potential for civilian applications, the technology development in photogrammetry for example direct georeferencing is in the early stage and it requires further research and additional technical development. In this study, two approaches are supposed for automatic geocoding of UAV still images by simple affine transformation and block adjustment of affine transformation using minimal ground control points and also evaluated the applicability and quality of geometric model compared to geocoded images generated by commercial S/W.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.2
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• pp.1-10
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• 2002

This paper presents the new template based human face recognition methods to improve the recognition performance against scale and in-plane rotation variations of face images. To enhance the recognition performance, the templates are generated by linear or nonlinear operation on multiple images including different scales and rotations of faces. As the invariant features to allow for scale and rotation variations of face images, we adopt the affine transformation, the log-polar mapping, and the log-polar image based FFT. The proposed recognition methods are evaluated in terms of the recognition rate and the processing time. Experimental results show that the proposed template based methods lead to higher recognition rate than the single image based one. The affine transformation based face recognition method shows marginally higher recognition rate than those of the log-polar mapping based method and the log-polar image based FFT, while, in the aspect of processing time, the log-polar mapping based method is the fastest one.