Choose all regions containing a given pixel.

The operator select_region_point selects all regions from Regions containing the test pixel (Row,Column), i.e.:

            |Region[n] intersection {(Row,Column)}| = 1

If the regions overlap more than one region might contain the pixel. In this case all these regions are returned. If no region contains the indicated pixel the empty tuple (= no region) is returned.

read_image(Image,'fabrik')
open_window(0,0,-1,-1,'root','visible','',WindowHandle)
disp_image(Image)
regiongrowing(Image,Seg,3,3,5,0)
set_color(WindowHandle,'red')
set_draw(WindowHandle,'margin')
Button := 1
while (Button = 1)
  fwrite_string(FileId,'Select the region with the mouse (End right button)')
  fnew_line(FileId)
  get_mbutton(WindowHandle,Row,Column,Button)
  select_region_point(Seg,Single,Row,Column)
  disp_region(Single,WindowHandle)
endwhile

If F is the area of the region and N is the number of regions, the mean runtime complexity is O(ln(sqrt(F)) * N).

The operator select_region_point returns the value 2 (H_MSG_TRUE) if the parameters are correct. The behavior in case of empty input (no input regions available) is set via the operator set_system('no_object_result',<Result>). If necessary an exception handling is raised.

select_region_point is reentrant and automatically parallelized (on tuple level).

threshold, regiongrowing, connection

test_region_point

get_mbutton, get_mposition

Foundation