computation of distance from shape tops to considered sphere
This measure is based on LeastSquareSphere3d measure results.
It computes, given a shape and associated sphere 3d approximation, signed distance to estimated sphere from each top of shape. An illustration of these computation is given in 2d case, please see [Concept] Roundness 2d.
Estimated sphere can be computed using a simple parametric estimation of shape tops or can be computed using a robust estimation technic. This behavior is ruled by measure parameter, see ipsdk::imaproc::attr::RobustEstimationConfig.
For more information on sphere 3d estimation please refer to LeastSquareSphere3d.