Measurement Accuracy of Center Location of a Circle by Centroid Method

This paper reports an investigation of the effect of digitization on the measurement accuracy of the center location of a circle by a centroid method. Although general expressions representing the measurement accuracy of the center location of a circle by the centroid method are unable to be obtained analytically, we have succeeded in obtaining the variances V of measurement errors for 39 quantization bits n ranging from one to infinity by numerical integration. We have succeeded in obtaining the effective approximation formulae of V as a function of the diameter d of the circle for any n as well. The results show that V would oscillate on an approximate one-pixel cycle in d for any n and decrease as n increases. The differences of V among the different n would be negligible when n ≥ 6. Some behaviors of V with an increase in n are demonstrated. This contribution was selected in a double blind review process to be published within the Lecture Notes in Computer Science series (Springer-Verlag, Heidelberg). Photogrammetric Image Analysis Volume Editors: Stilla U, Rottensteiner F, Mayer H, Jutzi B, Butenuth M LNCS Volume: 6952 Series Editors: Hutchison D, Kanade T, Kittler J, Kleinberg JM, Kobsa A, Mattern F, Mitchell JC, Naor M, Nierstrasz O, Pandu Rangan C, Steffen B, Sudan M, Terzopoulos D, Tygar D, Weikum G ISSN: 0302-9743 The article is accessible online through www.springerlink.com. 63 In: Stilla U et al (Eds) PIA11. International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences 38 (3/W22)