- Add type hints for Python 3.10 (WIP).
- Fix Mypy errors (breaking).
- Mark many parameters positional-only or keyword-only (breaking).
- Remove deprecated pages parameter from imread (breaking).
- Remove deprecated compress and ijmetadata write parameters (breaking).
- Remove deprecated fastij and movie parameters from TiffFile (breaking).
- Remove deprecated multifile parameters from TiffFile (breaking).
- Remove deprecated tif parameter from TiffTag.overwrite (breaking).
- Remove deprecated file parameter from FileSequence.asarray (breaking).
- Remove option to pass imread class to FileSequence (breaking).
- Remove optional parameters from __str__ functions (breaking).
- Rename TiffPageSeries.offset to dataoffset (breaking)
- Change TiffPage.pages to None if no SubIFDs are present (breaking).
- Change TiffPage.index to int (breaking).
- Change TiffPage.is_contiguous, is_imagej, and is_shaped to bool (breaking).
- Add TiffPage imagej_description and shaped_description properties.
- Add TiffFormat abstract base class.
- Deprecate lazyattr and use functools.cached_property instead (breaking).
- Julian_datetime raises ValueError for dates before year 1 (breaking).
- Regressed import time due to typing.