Reconstruction of 3-dimension image from topographic map and satellite image
Cubic Spline Interpolation
To create a 3-dimentional graphic of DTM data, it should know the height of each pixel. Therefore, the cubic spline interpolation is applied to the contour map. The height of each pixel will be calculated by third degree polynomial (4) which shows in the following equation.
Si(x) = aix3 + bix2 +cix + di ; i = 1,2,…,N - 1
With S
i (x) defined as the cubic polynomial to be used in interval between pixel x
i and pixel x
i + 1. The spline coefficients a,b,c and d are computed by the given x pixels and y values.
By applying the cubic spline interpolation to contour map of Fig. 5. The resulting of 3-dimensional graphic is ploted as Fig.6
Figure 6. 3-dimensional image, (a) MOS-1 MESSR image,
(b) -dimensional graphic of DTM data,
(c) results of -dimension image by combining Fig 6(a) and 6(b) together.
Reconstruction of 3-dimensional image
The DTM data will be combined with the satellite imagery data to reconstruct a 3-dimensional image. The result of 3-dimensional image will be shown in Fig 6. The satelline image of Fig 6 (a) is obtained by MOS-I MESSR over Lunta Island which is in the southern part of Thailand. The Fig 6(b) is the 3-dimensional graphic. The result of 3-dimensional image is shown in Fig 6 (c).
Conclusions
This paper presents a method for generating DTM data and reconstruction of 3-D image, the complete process can be presented the flow charge of Fig. 7. This kind of image is very useful in widely application such as for establishing the microwave repeater station, determining the slope of mountain in order to find away to tidal wave and etc.
Figure 7 Block diagram of 3-dimensional image reconstruction
References
- D.F Rogers and J.A Adams, Mathematical Elements for Computer graphics Mc Graw-Hill New York 976.
- K.S Fu, RC Gonzalez and C.S.G Lee, Robotic : Control sensing vision and intelligence Mc GrawHill NEW York 1987
- R.C Gonzalez R.E Woods, Digital Image Processing", Addision Wesley Publishing company Inc. 1992.
- R. Sedgewick,. Algorithms Addison -Wesley Publishing Company Inc. 1988
- S. Nakamura, Applied Numerical Moethosin C, Prentice Hall International 1993.
- S. Rimmer, Supercharged Bitmapped graphics, Windcrest Books 1992.
- S. Viseshisin, T. Hashimoto and S. Murai, Interactive System for Automated Generation of DTM from existing Topographic Map of Thailkand in 9th ACRS pp.s-5-1-2-5-6 Bangkok 1988.
