Image Processing and Concentric Ellipse Fitting to Estimate the Ellipticity of Steel Coils
Daniel C. H. Schleicher, G. Bernhard · InTech eBooks · 2009
This chapter introduced the problem of ellipticity estimation on hand of a practical problem. To obtain a good ellipticity estimation proper datasets must be obtained. These datasets are generally not very easy to obtain, for which reason also the preprocessing to extract the datasets was discussed in detail. Since only arc segments could be used for the ellipticity estimation, normal ellipticy fits fail. Hence the estimation was split into two parts, first to estimate the center of the coil with the concentric ellipticity estimator and then to estimate the ellipticity of the arc segments. Using the general approach for the ellipse fit, enables also to use different solver implementations for fitting problems. When discussing the errors, it was accented that a lot of error sources affect the final result. The correct understanding of the partial errors helps to optimize the corresponding section of the algorithm.