Return the union of all input regions.

::union1 computes the union of all input regions and returns the result in RegionUnion.

/* Union of segmentation results: */
threshold(Image,&Seg1,128.0,255.0);
dyn_threshold(Image,Mean,&Seg2,5.0,"light");
concat_obj(Seg1,Seg2,&H);
union1(H,&Seg);

Let F be the sum of all areas of the input regions. Then the runtime complexity is O(F) * F).

::union1 always returns H_MSG_TRUE. The behavior in case of empty input (no regions given) can be set via ::set_system('no_object_result',<Result>) and the behavior in case of an empty input region via ::set_system('empty_region_result',<Result>). If necessary, an exception handling is raised.

::threshold, ::connection, ::regiongrowing, ::pouring

::select_shape, ::disp_region

::union2

::intersection, ::complement

Region processing