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http://dx.doi.org/10.3741/JKWRA.2008.41.8.855

A Surface Image Velocimetry Algorithm for Analyzing Swaying Images  

Yu, Kwonk-Yu (Dept. of Civil Eng.)
Yoon, Byung-Man (Dept. of Civil & Environmental Engr.)
Jung, Beom-Seok (Dept. of Civil Eng.)
Publication Information
Journal of Korea Water Resources Association / v.41, no.8, 2008 , pp. 855-862 More about this Journal
Abstract
Surface Image Velocimetry (SIV) is an instrument to measure water surface velocity by using image processing techniques. To improve its measuring accuracy, it is essential to get high quality images with low skewness. A truck-mounted SIV system would be a good way to get images, since its crane gives high altitude to the images. However, the images taken with a truck-mounted SIV would be swayed due to the movement of crane and the camera by winds. In that case, to analyze the images, it is necessary to compensate the side sway in the images. The present study is to develop an algorithm to analyze the swayed images by combining common image processing techniques and coordinate transform techniques. The system follows the traces of some selected fixed points and calculates the displacements of the video camera. By subtracting the average velocity of the fixed points from that of grid points, the velocity fields of the flow can be corrected. To evaluate the system's performance, two image sets were used, one image set without side sway and another set with side sway. The comparison of their results showed very close with the error of around 6 %.
Keywords
Surface Image Velocimetry; image processing; image correction; velocity measurement;
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  • Reference
1 김서준, 윤병만, 류권규, 주용우 (2007). “LSPIV기법을 이용한 탄천(대곡교) 유량측정.” 한국수자원학회 학술발표대회 개요집, p. 205
2 노영신 (2005). 영상해석 기술을 이용한 하천 유량측정 기법 개발, 명지대학교 박사학위논문
3 Kim, Y. S., Muste, M., Kruger, A., Krajewski, W., Bradley, A., and Weber, L. (2005). "Real-time stream monitoring using mobile large-scale particle image velocimetry." Proc. of XXXI IAHR Congress, Sep. 11-16, Seoul
4 Yu, K. (2004). Particle tracking of suspendedsediment velocities in open-channel flow. Ph.D thesis, Univ. of Iowa, Iowa city, IOWA
5 김서준 (2008). 표면 영상 유속계를 이용한 유량측정기법의 정확도 분석, 명지대학교 석사학위논문
6 Fujita, I. Aya, S., and Deguchi, T. (1997). "Surface velocimetry measurement of river flow using video images of an oblique angle." Proc. XXVII IAHR Conference, Thema B, Vol.1, San Francisco, CA., pp. 227-232