30 2 20124 pp. 173~180 Non-Metric Digital Camera Lens Calibration Using Ground Control Points 1) 2) 3) Abstract The most recent, 80 mega pixels digital camera appeared through the development of digital technology, and nonmetric digital cameras have been using in various field of photogrammetry. In this study, we experimented lens calibration using aerial photographs and ground control points. The aerial photographs were taken a non-metric digital camera which is CMOS(Complementary Metal Oxide Semiconductor) 21.1 mega pixels sensor and 35 lens at a helicopter. And the ground control points were selected on the 1:1,000 plotting origin data. As a result, we calculated focal length, PPA(Principal Point of Autocollimation) and symmetric radial distortion coefficients from the lens. Also, RMSE(root mean square error) and maximum residual of the ground control points from the aerial triangulation were compared before and after calibration. And we found that the accuracy of the after calibration was improved very significantly. Keywords : Non-Metric Digital Camera, Lens Calibration, Ground Control Points, Aerial Triangulation 8,000,.. 35 CMOS 2,110, 1:1,000., PPA,.,. :,,, SLR(Single-Lens Reflex) DSLR(Digital SLR).. 1) (E-mail:aerowon@nate.com) 2) (E-mail:sojk0070@gmail.com) 3) (E-mail:hcyoon@cnu.ac.kr) 173
30 2 3 (, 2006).. 1970 8 (Kenefick, 1972). Fraser(1997) x, y 10 3 ( ), ( ), ( ). Gruen (1992), (high convergence) 3.. (2010) CMOS 1,080 1,. (2009) 2,000 24.. (2008),.,... 1. 1 2(a) Canon EOS-1Ds Mark 2,110 CMOS DSLR. 6.4, 5,616 3,744. 35 36 24. (dynamic range). 2(b) Canon EF 35 f/1.4l USM 35. 174
[ ] [pixels] [ ] Canon EOS-1Ds Mark (DSLR) CMOS 6.4 5,616 3,744 35.9424 23.9616 2,110 a) [ ] [ ] Canon EF 35mm f/1.4l USM 35 f/1.4~22 (~) 0.18 72 54 /38 /63 (// ) 9 11 (8 ) b) 2 43 40~60. 9 11 (9 ).. 3(a) 3(b).. MF(manual focus). a) b) 3 175
30 2 1:1,000. 4 (DEM; Digital Elevation Model) 3. 5~15. 5(a) 575 60%, 10. 5(b) 90., 4 a) b) 5 176
3. 3, 6 1:1,000. TL1~TL25 25.. (symmetric radial distortion) (+)(-) 7. 6 (, 2008). 35..,... (radial distortion) (decentering distortion). 7 (+) pincushion, 8(a) a. (-) barrel, 8(a) b (, 2004). a) b) 8. (asymmetric radial distortion) (tangential distortion) 177
30 2 (, 2008). 8(b). (Mikhail, 2001).. (, 2010).. PPA.. ( ) 35, PPA( ) ( ) 0. ( ). 9. 1. 1. 33.558 PPA = 0.0699, = -0.3153 = 1.617980e-02, = -9.05352e-05 =1.122070e-07, = -5.33262e-11 Bingo 5.3. 2. 2. ( ) X Y Z ( ) 0.390 0.210 0.241 ( ) 0.803 0.443 0.562, PPA, 7. 3. 3. ( ) X Y Z ( ) 0.037 0.055 0.013 ( ) 0.089 0.093 0.028 9 10, 1 36 x, y +, - 178
. 16 0. X, Y, Z 11, 4, 19 12(b) 9, 5, 20. 0.146m. a) 10 25 11. 16 (+) (-). -248.97 39. b) 12 11 12. 12(a) DSLR..,. 179
30 2.., 2,110 35 1:1,000., ( ), PPA( ), ( ).,,.,.. (06 B01).,, (2010),,, 28, 6, pp. 663-668.,, (2010),,, 28, 1, pp. 93-98.,, (2006),,, 24, 3, pp. 281-288.,, (2009),,, 27, 6, pp. 741-747. (2004),,,, pp. 11-16. Fraser, C.S. (1997), Digital camera self-calibration, ISPRS Journal of Photogrammetry & Remote Sensing, Vol. 52, pp. 149-159. Gruen, A. and Beyer, H.A. (1992), System calibration through self-calibration,. Workshop on Calibration and Orientation of Cameras in Computer Vision(TU-1), ISPRS XVII Congress, Washington, D.C., pp. 33. Kenefick, J.F., Gyer, M.S. and Harp, B.F. (1972), Analytical self-calibration, Photogrammetric Engineering, Vol. 38, pp. 1117-1126. Mikhail, E. M., Bethel, J. S., McGlone, J. C. (2001), Introduction to Modern Photogrammetry, John Wiley & Sons Inc., pp. 41-44, 247-275.,, (2008),,, 26 2, pp. 103-110. ( 2012. 03. 29, 2012. 04. 07, 2012. 04. 16) 180