Work Done
Inspected histo PR 343 and local branch. write_mask_pyramid samples each output level directly from a coarse binary mask. Existing ZarrImage.make_pyramidal reads the previous stored level through Dask. The PR already extracts shared allocation and metadata into ZarrImage.add_level. Remaining reuse opportunity: centralize level shapes, factors and stopping rule in virdx-ome without replacing the direct coarse-source sampling. No histo files changed; tests inspected, not executed.
Pitfalls
Existing data.ome_reading.downsample_mask uses endpoint-aligned linspace indices, not this writer’s floor-scaled grid, and materializes its output. It is not a drop-in replacement.
Improvements
Keep pyramid geometry policy in virdx-ome while preserving the coarse-mask fast path. The current equivalence test compares pixels and level resolutions against make_pyramidal.