Fig. 1: Diverse annotation styles across ground-truth datasets.

These are examples of images that the human annotators chose to segment a certain way, where another equally valid segmentation style exists. All these examples were chosen to be representative of large categories of images in their respective datasets. a, Annotation examples from the Cellpose dataset. From left to right, these show: (i) nuclei without cytoplasm are not labeled, (ii) diffuse processes are not labeled, (iii) outlines biased toward the outside of cells and (iv) dense areas with unclear boundaries are nonetheless segmented. b, Annotation examples from the TissueNet dataset. These illustrate: (i) outlines follow membrane/cytoplasm for some image types, and include nuclei without a green channel label, (ii) outlines do not follow cytoplasm for other image types, (iii) slightly out of focus cells are not segmented and (iv) outlines drawn just around nucleus for some image types. c, Annotation examples from the LiveCell dataset. These illustrate: (i) dense labeling for some image types, (ii) no labeling in dense areas for other image types, (iii) same as (ii) and (iv) no labeling in some image areas for unknown reasons.