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Morpho line

A morpho line is the border of a morpho set. Assuming a right choice of grid and point connectivity so that a Jordan's theorem follows, a morpho line is a closed curve dividing the grid in two connected components : the interior of the morpho set and the exterior one. Actually, because an image has a finite support, a morpho line may also intersects the image border : in such case, the curve remains open. There is another restriction to the Jordan's theorem : most of modules using morpho lines (such as ml_extract) consider the 4-connectivity only in the square grid, so the border may cut the connected component to several pieces and the corresponding morpho lines may be self-intersecting. Notice that if the morpho set is a level set, the corresponding border is a level line. And if the morpho set is an iso set, its border is an iso line.

The structure Morpho_line can be used to handle such morpho line. First a Morpho_line is a curve, so the Point_curve structure is used to record it (field first_point). There are additional fields, to give information on the line (type of the points, closed or open curve) and to allow the reconstruction of the morpho set (minvalue, maxvalue).



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next up previous contents index
Next: The structure Morpho_line Up: Level sets and morphological Previous: Functions Summary   Contents   Index
mw 2004-05-05