The osteoclast has tricky brightness that is lower than the “noisy” surrounded mononuclear cells and merely brighter than background.
If you look for precise segmentation, please follow this lead https://blog.cellprofiler.org/2017/01/19/cellprofiler-ilastik-superpowered-segmentation/
You can try use the following CellProfiler-only pipeline, however you may not obtain perfect segmentation:
Use module “EnhanceOrSuppressFeatures” to neglect small mononuclear cells.
Note: you may have to fine-tune the size of small objects to-be-neglect, which is around 20-45.
Then do a series of ImageMath to improve the signal of osteoclast
Use IdentifyPrimaryObject to identify osteoclast region.
Then shrink primary objects for about 30 pixels
Use IdentifyTertiaryObjects to define a “peripheral”.
I attach here a primitive pipeline, please modify to get better result.
Osteoclast.cpproj (641.6 KB)