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2.2.A. Choice of the Step of the Start Positions for the Procedure of the Contour Boundary Representation in Terms of the Contiguous Segments.

A beforehand value of the least radius of neighbourhoods R_min among radii of neighbourhoods R_c of all contour segments of the treated image was estimated. The radius of the neighbourhood is a radius of the greatest circle with the center on the given segment, intercrossed by it and not containing points of other segments (fig.27).

Fig.27

Parameters of X, Y initial sets were defined by nodes of some grid on the image plane. Density of the grid was chosen so that in any circle in radius R_min/2 one node of this grid hitted even. In the case of a square grid its step should be less, than R_min/sqrt(2). Remaining parameters were prescribed identical to all sets. A value of parameter B corresponding to length of initial contiguous segments was chosen smaller than (R_min/2)*sqrt(3). This choice is caused by the obtained theoretical estimation for a resolving power of the suggested approximation method. Parameter D was chosen equal 0.5*B, A - arbitrary, P1 = P2 = 0.