# Help with flood filling segmentation

**URL:** <https://discourse.slicer.org/t/help-with-flood-filling-segmentation/14349>\
**Category:** Support\
**Tags:** segmentation\
**Created:** [October 31, 2020, 6:14pm UTC](https://discourse.slicer.org/t/help-with-flood-filling-segmentation/14349 "2020-10-31T18:14:21Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![carlos.rinaldi](https://avatars.discourse-cdn.com/v4/letter/c/46a35a/32.png) [@carlos.rinaldi](https://discourse.slicer.org/u/carlos.rinaldi)\
**Post date:** [October 31, 2020, 6:14pm UTC](https://discourse.slicer.org/t/help-with-flood-filling-segmentation/14349/1 "2020-10-31T18:14:21Z")

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I am new to slicer. Working on segmentation using the SegmentEditorExtraEffects on Slicer build 4.10.2 on a Mac running 10.13.6.

I am trying to use flood filling to create a segmentation. I create a new segment, choose Flood Filling and leave default values (Int Tol 10, Neighborhood 1) and click on a pixel in the axial slice, get the spinning wheel but nothing happens (no region is selected for the segment). I change around the values and click and sometimes it processes with nothing happening and other times it gets stuck processing.

What does the “neighborhood size” parameter mean? What does increasing/decreasing it do?

Ultimately, I am trying to create a segment for a region where the intensity is above a certain value (a tumor region), but trying to avoid another region where there is also high intensity (other organs). Perhaps I should try another tool, like watershed, but I can’t figure out how to use that one.

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [November 1, 2020, 8:10pm UTC](https://discourse.slicer.org/t/help-with-flood-filling-segmentation/14349/2 "2020-11-01T20:10:54Z")

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Please use the latest stable release (Slicer-4.11.20200930), as it has greatly improved segmentation tools.

Flood filling is inherently a very fragile, unreliable operation on realistic images, and especially in 3D.

Grow from seeds, Watershed, and Local threshold effects all work much better. You can find detailed, step-by-step slide-based and video tutorials and segmentation recipes here: [https://www.slicer.org/wiki/Documentation/Nightly/Training#Segmentation](https://www.slicer.org/wiki/Documentation/Nightly/Training#Segmentation). For example, see this recipe: [https://lassoan.github.io/SlicerSegmentationRecipes/AortaMaskedGrowFromSeeds/](https://lassoan.github.io/SlicerSegmentationRecipes/AortaMaskedGrowFromSeeds/)

If you get stuck at any point then let us know.