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OME-TIFF Loading

Source: dev_note/topic_ome_tiff_loading.md

Context

OME-TIFF support adds a parallel data-loading path that operates alongside the existing per-FOV TIFF folder layout.

Key Decisions

  • Auto-detection. OME-TIFF datasets are detected automatically from .ome.tif, .ome.tiff, or suffix-less OME TIFF files. No manual flag is required.
  • OMEFovWrapper. Channel access is lazy and downsample-aware; the wrapper presents the same interface as the folder-based loader.
  • Pyramid level selection. The coarsest pyramid level that meets the requested downsample factor is used to minimize I/O without over-fetching pixels.
  • Frame-aware access. Stacked OME files (multiple Z-planes or time points) are accessed by frame index; slices are cached per frame.

Rendering

OME-TIFF images share the same compositor pipeline as standard TIFFs. Viewport alignment and downsample factor handling have specific fixes:

  • Keyframe compatibility — fallbacks for metadata edge cases.
  • Lazy max computation — avoids loading full-resolution data to find the channel maximum.
  • Memory usage regression addressed for large pyramid levels.

Usage

To open an OME-TIFF dataset, point base_folder (or the equivalent runner argument) at the directory containing the .ome.tiff file(s). The viewer detects and loads them automatically.