In such complex histology slide, we really encourage users to explore the combination of Morph, Smooth, ImageMath, UnmixColors and MaskImage to reach a good segmentation. The best practice is to identify distinct structures in the mixtures, mask them out as separate regions, then fine tune IdentifyPrimaryObjects in each of these regions.
For your image, you should first notice that I mentioned using "Hematoxylin and Eosin" in UnmixColors , not Hematoxylin and DAB.
Then use Smooth to facilitate the segmentation of the Epithelial regions:
Then mask these region out, the remaining area is relatively clean for segmenting the brown objects:
Example pipeline maskEpi.cpproj (643.2 KB)