fetch_convex ( Region : : : Rows, Columns )

Access convex hull as contour.

The operator fetch_convex returns the convex hull of a region as polygon. The polygon is the minimum result of line (Rows) and column coordinates (Columns) describing the hull of the region. The polygon pixels lie on the region. The polygon starts at the smallest line number; in this line at the pixel with the largest column index. The rotation direction is clockwise. The first pixel of the polygon is identical with the last. The operator fetch_convex returns the coordinates in the form of tuples. An empty region is passed as empty tuple.


Parameters

Region (input_object)
region -> object
Output region.

Rows (output_control)
contour.y-array -> integer
Line numbers of contour pixels.

Columns (output_control)
contour.x-array -> integer
Column numbers of the contour pixels.
Number of elements: Columns == Rows


Result

The operator fetch_convex returns the value TRUE.


Possible Predecessors

threshold__, skeleton, dyn_threshold__


Possible Successors

disp_polygon


Alternatives

shape_trans


See also

select_obj, fetch_contour



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