• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.165-169
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• 2004

Recently remote sensing technology is applied for construction projects planning and design areas by use of high resolution satellite images according to engineering application technology in the various experimental tasks. In this study, It was applied for optimum route selection methods and basic design by comparing to present railway and new expand dual railway route on the new construction plan path of 20km at national railway lines, and then showed 3-dimensional images and fly simulation images to possibility for various application as low cost and short time compare to airplane and helicopters survey methods. As a results of its applied, It gained the results not only improvement of present methods but also real various application possibilities.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.3
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• pp.175-182
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• 2017

In this paper, we present a multi-depth generation method using a time-of-flight (ToF) fusion camera system. Multi-view color cameras in the parallel type and ToF depth sensors are used for 3D scene capturing. Although each ToF depth sensor can measure the depth information of the scene in real-time, it has several problems to overcome. Therefore, after we capture low-resolution depth images by ToF depth sensors, we perform a post-processing to solve the problems. Then, the depth information of the depth sensor is warped to color image positions and used as initial disparity values. In addition, the warped depth data is used to generate a depth-discontinuity map for efficient stereo matching. By applying the stereo matching using belief propagation with the depth-discontinuity map and the initial disparity information, we have obtained more accurate and stable multi-view disparity maps in reduced time.

• Journal of IKEEE
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• v.15 no.1
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• pp.10-14
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• 2011

In this paper, we present an efficient hardware architecture of unrolling image mapper of catadioptric omnidirectional imaging systems. The catadioptric omnidirectional imaging systems generate images of 360 degrees of view and need to be transformed into panorama images in rectangular coordinate. In most application, it has to perform the panorama unrolling in real-time and at low-cost, especially for high-resolution images. The proposed hardware architecture adopts a software/hardware cooperative structure and employs several optimization schemes using look-up-table(LUT) of coordinate conversion. To avoid the on-line division operation caused by the coordinate transformation algorithm, the proposed architecture has the LUT which has pre-computed division factors. And then, the amount of memory used by the LUT is reduced to 1/4 by using symmetrical characteristic compared with the conventional architecture. Experimental results show that the proposed hardware architecture achieves an effective real-time performance and lower implementation cost, and it can be applied to other kinds of catadioptric omnidirectional imaging systems.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.721-724
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• 2000

This paper presents fingerprint authentication method based on minutiae quadrangle definded by neighboring two Delaunay triangles. In this method, we first make minutiae triangle through Delaunay triangulation which adaptively connect neighboring minutiae according to the local minutiae density distribution, and then use feature vectors in authentication which is extracted from the minutiae quadrangle formed by neighboring two minutiae triangles. This prevents the degradation of matching ratio caused by the errors in image processing or local deformation of the fingerprint, and we can authenticate more discriminately as this method reflects wider local area's topological features than the features extracted from the individual minutiae triangles. To evaluate the proposed algorithm's performance, experiment are conducted on 120 fingerprints, of which size is 256 ${\times}$ 364 with 500dpi resolution. Robust authentications are possible with low FRR.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.628-631
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• 2003

In this paper, we present real-time, accurate face region detection and tracking technique for an intelligent surveillance system. It is very important to obtain the high-resolution images, which enables accurate identification of an object-of-interest. Conventional surveillance or security systems, however, usually provide poor image quality because they use one or more fixed cameras and keep recording scenes without any cine. We implemented a real-time surveillance system that tracks a moving person using four pan-tilt-zoom (PTZ) cameras. While tracking, the region-of-interest (ROI) can be obtained by using a low-pass filter and background subtraction. Color information in the ROI is updated to extract features for optimal tracking and zooming. The experiment with real human faces showed highly acceptable results in the sense of both accuracy and computational efficiency.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.345-352
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• 2010

Korea multi-purpose satellite-5 (KOMPSAT-5) is a low earth orbit (LEO) satellite scheduled to be launched in 2010. To satisfy the precision orbit determination (POD) requirement for a high resolution synthetic aperture radar image of KOMPSAT-5, KOMPSAT-5 has atmosphere occultation POD (AOPOD) system which consists of a space-borne dual frequency global positioning system (GPS) receiver and a laser retro reflector array. A space-borne dual frequency GPS receiver on a LEO satellite provides position data for the POD and radio occultation data for scientific applications. This paper describes an overview of AOPOD system and operation concepts of the radio occultation mission in KOMPSAT-5. We showed AOPOD system satisfies the requirements of KOMPSAT-5 in performance and stability.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.342-345
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• 1993

In this paper, we study the structure of the hierarchical coding method of video signal which can contain the multi resolution video signals. To preserve the compatibility with the conventional coding methods. we accomplished a scalable structure using the subband coding, maintaining enoughly the international coding structure. The proposed scheme showed the low PSNR, a little, when compared with the conventional scheme, but showed a good image quality perceptually and proved to have a advantage in the H/W implementation in a view of processing speed.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.235-236
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• 2007

CCD(Charge-Coupled Device) 혹은 CMOS (Complementary Metal Oxide Semiconductor)와 같은 소자를 이용하여 빛을 전기적 신호인 Image로 재구성하는 촬상소자(Color Capture Device)는 촬영환경이 어두워지면 Dynamic Range가 작아지고, Noise가 상대적으로 심해진다[1][2]. 본 논문에서는 촬영 환경이 어두울 때, Resolution을 Preserving하는 Pixel Pitch가 큰 촬상 소자와 Motion Blur를 억제하는 Exposure Time이 긴 촬상 소자의 조합을 신호처리로 구현하여, 신호의 Power를 향상시켜 Dynamic Range를 키우고 Noise의 Boost-up을 억제하여 SNR(Signal to Noise Ratio)을 향상시키는 방식으로, 촬상 장치의 감도를 향상시켜 화질을 개선하는 방법을 제안한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.8-11
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• 2013

We implement the foveation and frequency sensitivity feature of human visual system in discrete cosine transform (DCT) domain. Resolution of human visual perception decays as distance from the eye-focused point, known as foveation property, and the middle frequency components give most pleasant image quality to human than the low and high frequency components, which is the frequency sensitivity property of human visual system. For satisfying the foveation property, we enhanced the local contrast at the focused regions and smoothed local contrast at the non-focused regions in the DCT domain without bringing the blocking and ringing artifacts. Moreover, the energies at each DCT frequency components is modified with various degree to fulfill the frequency sensitivity property. The proposed method is verified by the subjective and objective evaluations that it can the improve the human perceptual visual quality.

• Annual Conference of KIPS
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• 2004.11a
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• pp.839-842
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• 2004

자연영상에서 문자를 인식하는 연구는 활발히 진행되고 있지만 대부분 디지털 카메라나 캠코더 등으로 획득한 고해상도의 영상에서의 연구에 국한되어 있다. 휴대폰 카메라로 획득된 저해상도의 영상은 아주 적은 수의 픽셀로 정보를 표현하기 때문에 기존의 이진화 알고리즘으로는 문자와 배경을 깨끗하게 분리해 낼 수 없다. 본 논문은 영상의 칼라정보를 K-Means 클러스터링을 이용하여 전경과 배경으로 이진화 하였으며, 이진화 성능을 향상시키기 위해 지능형 주파수 필터와 비등방성 확산 필터를 사용하였다. 또한 입력영상을 파이프라인 구조의 이진화 및 인식 시스템에 인식시킴으로써 인식성능을 향상시켰다.