Elliptical shape and size approximation of a particle contour

The paper presents an approximation of the particle contour by means of an ellipse with equivalent moments of inertia along both axes perpendicular to each other. This method ensures higher accuracy of size approximation than circular and rectangular approximation methods. The proposed method can be applied to machine vision systems used for particle size distribution analysis. In this method, there are simultaneously determined two (instead of one) characteristic dimensions. From these two dimensions as a decisive criterion there is chosen the smaller one, because it has the greatest importance for the particle behavior of the grain in the screening process.