Split XLD contours at dominant points.

::split_contours_xld splits the contours which were used to generate the polygons Polygons at prominent points. If the mode 'polygon' is selected, the contours are split at the polygons' control points. In mode 'dominant', they are split at dominant points, i.e., at points for which the calculated change of direction is larger than the (empirically determined) threshold Weight * 2 * PI / contour length, and for which in the (empirically determined) neighborhood of sqrt(Smooth) * ln(contour length) points no larger change of direction occurs. The contour direction is determined from the direction of the regression line (i.e. the least-squares approximating line) through all points in a neighborhood of Smooth points around a contour point. The directions thus determined are smoothed with a Gaussian of width Smooth. Weight is a weighting factor for the sensitiveness of the operator. The larger Weight is selected, the less dominant points are found.

::gen_polygons_xld

::regress_contours_xld

::gen_contours_skeleton_xld, ::lines_gauss, ::lines_facet, ::edges_sub_pix

Sub-pixel operators