- Tiffwrite is now fully typed.

.github/workflows/mypy.yml

@@ -0,0 +1,21 @@
+name: MyPy
+
+on: [push, pull_request]
+
+jobs:
+  mypy:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.10", "3.12"]
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: pip install mypy lxml geojson maturin python-dateutil types-python-dateutil lxml-stubs
+      - name: Test with mypy
+        run: mypy

.github/workflows/pytest.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: ["3.10"]
+        python-version: ["3.10", "3.12"]
         os: [ubuntu-20.04, windows-2019, macOS-11]
 
     steps:

README.md

@@ -1,3 +1,4 @@
+[![mypy](https://github.com/wimpomp/tiffwrite/actions/workflows/mypy.yml/badge.svg)](https://github.com/wimpomp/tiffwrite/actions/workflows/mypy.yml)
 [![pytest](https://github.com/wimpomp/tiffwrite/actions/workflows/pytest.yml/badge.svg)](https://github.com/wimpomp/tiffwrite/actions/workflows/pytest.yml)
 
 # Tiffwrite

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "tiffwrite"
-version = "2024.2.2"
+version = "2024.3.0"
 description = "Parallel tiff writer compatible with ImageJ."
 authors = ["Wim Pomp, Lenstra lab NKI <w.pomp@nki.nl>"]
 license = "GPL-3.0-or-later"
@@ -9,22 +9,30 @@ packages = [{include = "tiffwrite"}]
 repository = "https://github.com/wimpomp/tiffwrite"
 
 [tool.poetry.dependencies]
-python = "^3.8"
+python = "^3.10"
 tifffile = "*"
 imagecodecs = "*"
 numpy = "*"
 tqdm = "*"
 colorcet = "*"
 matplotlib = "*"
-parfor = ">=2023.10.1"
+parfor = ">=2024.3.0"
 pytest = { version = "*", optional = true }
 
 [tool.poetry.extras]
-test = ["pytest"]
+test = ["pytest", "mypy"]
 
 [tool.pytest.ini_options]
 filterwarnings = ["ignore:::(?!tiffwrite)"]
 
+[tool.isort]
+line_length = 119
+
+[tool.mypy]
+disable_error_code = ["import-untyped", "return"]
+implicit_optional = true
+exclude = ["build"]
+
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"

tests/test_multiple.py

@@ -1,12 +1,14 @@
 from contextlib import ExitStack
 from itertools import product
+from pathlib import Path
 
 import numpy as np
-from tiffwrite import IJTiffFile
 from tqdm.auto import tqdm
 
+from tiffwrite import IJTiffFile
 
-def test_mult(tmp_path):
+
+def test_mult(tmp_path: Path) -> None:
     shape = (2, 3, 5)
     paths = [tmp_path / f'test{i}.tif' for i in range(6)]
     with ExitStack() as stack:

tests/test_single.py

@@ -1,10 +1,12 @@
 from itertools import product
+from pathlib import Path
 
 import numpy as np
+
 from tiffwrite import IJTiffFile
 
 
-def test_single(tmp_path):
+def test_single(tmp_path: Path) -> None:
     path = tmp_path / 'test.tif'
     with IJTiffFile(path, (3, 4, 5)) as tif:
         for c, z, t in product(range(3), range(4), range(5)):

tiffwrite/__init__.py

@@ -1,4 +1,5 @@
-import os
+from __future__ import annotations
+
 import struct
 import warnings
 from collections.abc import Iterable
@@ -10,12 +11,14 @@ from hashlib import sha1
 from importlib.metadata import version
 from io import BytesIO
 from itertools import product
-from numbers import Number
+from pathlib import Path
+from typing import Any, BinaryIO, Callable, Generator, Literal, Optional, Sequence
 
 import colorcet
 import numpy as np
 import tifffile
 from matplotlib import colors as mpl_colors
+from numpy.typing import DTypeLike
 from parfor import ParPool, PoolSingleton
 from tqdm.auto import tqdm
 
@@ -28,7 +31,8 @@ except Exception:  # noqa
     __version__ = "unknown"
 
 
-def tiffwrite(file, data, axes='TZCXY', dtype=None, bar=False, *args, **kwargs):
+def tiffwrite(file: str | Path, data: np.ndarray, axes: str = 'TZCXY', dtype: DTypeLike = None, bar: bool = False,
+              *args: Any, **kwargs: Any) -> None:
     """ file:       string; filename of the new tiff file
         data:       2 to 5D numpy array
         axes:       string; order of dimensions in data, default: TZCXY for 5D, ZCXY for 4D, CXY for 3D, XY for 2D data
@@ -47,20 +51,36 @@ def tiffwrite(file, data, axes='TZCXY', dtype=None, bar=False, *args, **kwargs):
             data = np.expand_dims(data, axis)
 
     shape = data.shape[:3]
-    with IJTiffFile(file, shape, data.dtype if dtype is None else dtype, *args, **kwargs) as f:
+    with IJTiffFile(file, shape, data.dtype if dtype is None else dtype, *args, **kwargs) as f:  # type: ignore
         at_least_one = False
-        for n in tqdm(product(*[range(i) for i in shape]), total=np.prod(shape), desc='Saving tiff', disable=not bar):  # noqa
+        for n in tqdm(product(*[range(i) for i in shape]), total=np.prod(shape), desc='Saving tiff', disable=not bar):
-            if np.any(data[n]) or not at_least_one:   # noqa
+            if np.any(data[n]) or not at_least_one:
-                f.save(data[n], *n)  # noqa
+                f.save(data[n], *n)
                 at_least_one = True
 
 
 class Header:
-    def __init__(self, *args):
+    def __init__(self, filehandle_or_byteorder: BinaryIO | Literal['>', '<'] | None = None,
-        if len(args) == 1:
+                 bigtiff: bool = True) -> None:
-            fh = args[0]
+        if filehandle_or_byteorder is None or isinstance(filehandle_or_byteorder, str):
+            self.byteorder = filehandle_or_byteorder or '<'
+            self.bigtiff = bigtiff
+            if self.bigtiff:
+                self.tagsize = 20
+                self.tagnoformat = 'Q'
+                self.offsetsize = 8
+                self.offsetformat = 'Q'
+                self.offset = 16
+            else:
+                self.tagsize = 12
+                self.tagnoformat = 'H'
+                self.offsetsize = 4
+                self.offsetformat = 'I'
+                self.offset = 8
+        else:
+            fh = filehandle_or_byteorder
             fh.seek(0)
-            self.byteorder = {b'II': '<', b'MM': '>'}[fh.read(2)]
+            self.byteorder = '>' if fh.read(2) == b'MM' else '<'
             self.bigtiff = {42: False, 43: True}[struct.unpack(self.byteorder + 'H', fh.read(2))[0]]
             if self.bigtiff:
                 self.tagsize = 20
@@ -75,22 +95,8 @@ class Header:
                 self.offsetformat = 'I'
                 self.offsetsize = 4
                 self.offset = struct.unpack(self.byteorder + self.offsetformat, fh.read(self.offsetsize))[0]
-        else:
-            self.byteorder, self.bigtiff = args if len(args) == 2 else ('<', True)
-            if self.bigtiff:
-                self.tagsize = 20
-                self.tagnoformat = 'Q'
-                self.offsetsize = 8
-                self.offsetformat = 'Q'
-                self.offset = 16
-            else:
-                self.tagsize = 12
-                self.tagnoformat = 'H'
-                self.offsetsize = 4
-                self.offsetformat = 'I'
-                self.offset = 8
 
-    def write(self, fh):
+    def write(self, fh: BinaryIO) -> None:
         fh.write({'<': b'II', '>': b'MM'}[self.byteorder])
         if self.bigtiff:
             fh.write(struct.pack(self.byteorder + 'H', 43))
@@ -103,28 +109,34 @@ class Header:
 
 
 class Tag:
+    Value = bytes | str | float | Fraction | Sequence[bytes | str | float | Fraction]
     tiff_tag_registry = tifffile.TiffTagRegistry({key: value.lower() for key, value in tifffile.TIFF.TAGS.items()})
 
     @staticmethod
-    def to_tags(tags):
+    def from_dict(tags: dict[str | int, Value | Tag]) -> dict[int, Tag]:
-        return {(key if isinstance(key, Number) else (int(key[3:]) if key.lower().startswith('tag')
+        return {(key if isinstance(key, int)
-                                       else Tag.tiff_tag_registry[key.lower()])):
+                 else (int(key[3:]) if key.lower().startswith('tag')
-                    tag if isinstance(tag, Tag) else Tag(tag) for key, tag in tags.items()}
+                       else Tag.tiff_tag_registry[key.lower()])): tag if isinstance(tag, Tag) else Tag(tag)
+                for key, tag in tags.items()}
 
     @staticmethod
-    def fraction(numerator=0, denominator=None):
+    def fraction(numerator: float = 0, denominator: int = None) -> Fraction:
-        return Fraction(numerator, denominator).limit_denominator(2 ** (31 if numerator < 0 or
+        return Fraction(numerator, denominator).limit_denominator(  # type: ignore
-                                                             (denominator is not None and denominator < 0) else 32) - 1)
+            2 ** (31 if numerator < 0 or (denominator is not None and denominator < 0) else 32) - 1)
 
-    def __init__(self, ttype, value=None, offset=None):
+    def __init__(self, ttype_or_value: str | Value, value: Value = None,
-        self.fh = None
+                 offset: int = None) -> None:
-        self.header = None
+        self._value: bytes | str | Sequence[bytes | str | float | Fraction]
-        self.bytes_data = None
+        self.fh: Optional[BinaryIO] = None
+        self.header: Optional[Header] = None
+        self.bytes_data: Optional[bytes] = None
         if value is None:
-            self.value = ttype
+            self.value = ttype_or_value  # type: ignore
-            if all([isinstance(value, int) for value in self.value]):
+            if isinstance(self.value, (str, bytes)) or all([isinstance(value, (str, bytes)) for value in self.value]):
-                min_value = np.min(self.value)
+                ttype = 'ascii'
-                max_value = np.max(self.value)
+            elif all([isinstance(value, int) for value in self.value]):
+                min_value: int = np.min(self.value)  # type: ignore
+                max_value: int = np.max(self.value)  # type: ignore
                 type_map = {'uint8': 'byte', 'int8': 'sbyte', 'uint16': 'short', 'int16': 'sshort',
                             'uint32': 'long', 'int32': 'slong', 'uint64': 'long8', 'int64': 'slong8'}
                 for dtype, ttype in type_map.items():
@@ -132,16 +144,14 @@ class Tag:
                         break
                     else:
                         ttype = 'undefined'
-            elif isinstance(self.value, (str, bytes)) or all([isinstance(value, (str, bytes)) for value in self.value]):
-                ttype = 'ascii'
             elif all([isinstance(value, Fraction) for value in self.value]):
-                if all([value.numerator < 0 or value.denominator < 0 for value in self.value]):
+                if all([value.numerator < 0 or value.denominator < 0 for value in self.value]):  # type: ignore
                     ttype = 'srational'
                 else:
                     ttype = 'rational'
             elif all([isinstance(value, (float, int)) for value in self.value]):
-                min_value = np.min(np.asarray(self.value)[np.isfinite(self.value)])
+                min_value = np.min(np.asarray(self.value)[np.isfinite(self.value)])  # type: ignore
-                max_value = np.max(np.asarray(self.value)[np.isfinite(self.value)])
+                max_value = np.max(np.asarray(self.value)[np.isfinite(self.value)])  # type: ignore
                 type_map = {'float32': 'float', 'float64': 'double'}
                 for dtype, ttype in type_map.items():
                     if np.finfo(dtype).min <= min_value and max_value <= np.finfo(dtype).max:
@@ -152,53 +162,54 @@ class Tag:
                 ttype = 'complex'
             else:
                 ttype = 'undefined'
-            self.ttype = tifffile.TIFF.DATATYPES[ttype.upper()]
+            self.ttype = tifffile.TIFF.DATATYPES[ttype.upper()]  # noqa
         else:
-            self.value = value
+            self.value = value  # type: ignore
-            self.ttype = tifffile.TIFF.DATATYPES[ttype.upper()] if isinstance(ttype, str) else ttype
+            self.ttype = tifffile.TIFF.DATATYPES[ttype_or_value.upper()] if isinstance(ttype_or_value, str) \
+                else ttype_or_value  # type: ignore
         self.dtype = tifffile.TIFF.DATA_FORMATS[self.ttype]
         self.offset = offset
         self.type_check()
 
     @property
-    def value(self):
+    def value(self) -> bytes | str | Sequence[bytes | str | float | Fraction]:
         return self._value
 
     @value.setter
-    def value(self, value):
+    def value(self, value: Value) -> None:
         self._value = value if isinstance(value, Iterable) else (value,)
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         if self.offset is None:
-            return f'{tifffile.TIFF.DATATYPES(self.ttype).name}: {self.value}'
+            return f'{tifffile.TIFF.DATATYPES(self.ttype).name}: {self.value!r}'
         else:
-            return f'{tifffile.TIFF.DATATYPES(self.ttype).name} @ {self.offset}: {self.value}'
+            return f'{tifffile.TIFF.DATATYPES(self.ttype).name} @ {self.offset}: {self.value!r}'
 
-    def type_check(self):
+    def type_check(self) -> None:
         try:
             self.bytes_and_count(Header())
         except Exception:
             raise ValueError(f"tif tag type '{tifffile.TIFF.DATATYPES(self.ttype).name}' and "
                              f"data type '{type(self.value[0]).__name__}' do not correspond")
 
-    def bytes_and_count(self, header):
+    def bytes_and_count(self, header: Header) -> tuple[bytes, int]:
         if isinstance(self.value, bytes):
             return self.value, len(self.value) // struct.calcsize(self.dtype)
         elif self.ttype in (2, 14):
             if isinstance(self.value, str):
-                bytes_value = self.value.encode('ascii') + b'\x00'  # noqa
+                bytes_value = self.value.encode('ascii') + b'\x00'
             else:
-                bytes_value = b'\x00'.join([value.encode('ascii') for value in self.value]) + b'\x00'
+                bytes_value = b'\x00'.join([value.encode('ascii') for value in self.value]) + b'\x00'  # type: ignore
             return bytes_value, len(bytes_value)
         elif self.ttype in (5, 10):
-            return b''.join([struct.pack(header.byteorder + self.dtype,
+            return b''.join([struct.pack(header.byteorder + self.dtype,  # type: ignore
                                          *((value.denominator, value.numerator) if isinstance(value, Fraction)
                                            else value)) for value in self.value]), len(self.value)
         else:
             return b''.join([struct.pack(header.byteorder + self.dtype, value) for value in self.value]), \
                    len(self.value)
 
-    def write_tag(self, fh, key, header, offset=None):
+    def write_tag(self, fh: BinaryIO, key: int, header: Header, offset: int = None) -> None:
         self.fh = fh
         self.header = header
         if offset is None:
@@ -220,8 +231,8 @@ class Tag:
         if empty_bytes:
             fh.write(empty_bytes * b'\x00')
 
-    def write_data(self, write=None):
+    def write_data(self, write: Callable[[BinaryIO, bytes], None] = None) -> None:
-        if self.bytes_data:
+        if self.bytes_data and self.fh is not None and self.header is not None and self.offset is not None:
             self.fh.seek(0, 2)
             if write is None:
                 offset = self.write(self.bytes_data)
@@ -230,24 +241,25 @@ class Tag:
             self.fh.seek(self.offset + self.header.tagsize - self.header.offsetsize)
             self.fh.write(struct.pack(self.header.byteorder + self.header.offsetformat, offset))
 
-    def write(self, bytes_value):
+    def write(self, bytes_value: bytes) -> Optional[int]:
+        if self.fh is not None:
             if self.fh.tell() % 2:
                 self.fh.write(b'\x00')
             offset = self.fh.tell()
             self.fh.write(bytes_value)
             return offset
 
-    def copy(self):
+    def copy(self) -> Tag:
         return self.__class__(self.ttype, self.value[:], self.offset)
 
 
 class IFD(dict):
-    def __init__(self, fh=None):
+    def __init__(self, fh: BinaryIO = None) -> None:
         super().__init__()
         self.fh = fh
-        self.header = None
+        self.header: Optional[Header] = None
-        self.offset = None
+        self.offset: Optional[int] = None
-        self.where_to_write_next_ifd_offset = None
+        self.where_to_write_next_ifd_offset: Optional[int] = None
         if fh is not None:
             header = Header(fh)
             fh.seek(header.offset)
@@ -279,11 +291,12 @@ class IFD(dict):
                     fh.seek(caddr)
 
                 if ttype == 1:
-                    value = fh.read(count)
+                    value: Tag.Value = fh.read(count)
                 elif ttype == 2:
                     value = fh.read(count).decode('ascii').rstrip('\x00')
                 elif ttype in (5, 10):
-                    value = [struct.unpack(header.byteorder + dtype, fh.read(dtypelen)) for _ in range(count)]
+                    value = [struct.unpack(header.byteorder + dtype, fh.read(dtypelen))  # type: ignore
+                             for _ in range(count)]
                 else:
                     value = [struct.unpack(header.byteorder + dtype, fh.read(dtypelen))[0] for _ in range(count)]
 
@@ -293,20 +306,20 @@ class IFD(dict):
                 self[code] = Tag(ttype, value, pos)
             fh.seek(header.offset)
 
-    def __setitem__(self, key, tag):
+    def __setitem__(self, key: str | int, tag: str | float | Fraction | Tag) -> None:
         super().__setitem__(Tag.tiff_tag_registry[key.lower()] if isinstance(key, str) else key,
                             tag if isinstance(tag, Tag) else Tag(tag))
 
-    def items(self):
+    def items(self) -> Generator[tuple[int, Tag], None, None]:  # type: ignore[override]
         return ((key, self[key]) for key in sorted(self))
 
-    def keys(self):
+    def keys(self) -> Generator[int, None, None]:  # type: ignore[override]
         return (key for key in sorted(self))
 
-    def values(self):
+    def values(self) -> Generator[Tag, None, None]:  # type: ignore[override]
         return (self[key] for key in sorted(self))
 
-    def write(self, fh, header, write=None):
+    def write(self, fh: BinaryIO, header: Header, write: Callable[[BinaryIO, bytes], None] = None) -> BinaryIO:
         self.fh = fh
         self.header = header
         if fh.seek(0, 2) % 2:
@@ -321,11 +334,12 @@ class IFD(dict):
             tag.write_data(write)
         return fh
 
-    def write_offset(self, where_to_write_offset):
+    def write_offset(self, where_to_write_offset: int) -> None:
+        if self.fh is not None and self.header is not None:
             self.fh.seek(where_to_write_offset)
             self.fh.write(struct.pack(self.header.byteorder + self.header.offsetformat, self.offset))
 
-    def copy(self):
+    def copy(self) -> IFD:
         new = self.__class__()
         new.update({key: tag.copy() for key, tag in self.items()})
         return new
@@ -345,14 +359,17 @@ class IJTiffFile:
                             or Copyright=Tag('ascii', 'Made by me'). See tiff_tag_registry.items().
         wp@tl20200214
     """
-    def __init__(self, path, shape, dtype='uint16', colors=None, colormap=None, pxsize=None, deltaz=None,
+    def __init__(self, path: str | Path, shape: tuple[int, int, int], dtype: DTypeLike = 'uint16',
-                 timeinterval=None, compression=(50000, 22), comment=None, **extratags):
+                 colors: Sequence[str] = None, colormap: str = None, pxsize: float = None,
+                 deltaz: float = None, timeinterval: float = None,
+                 compression: tuple[int, int] = (50000, 22), comment: str = None,
+                 **extratags:  Tag.Value | Tag) -> None:
         assert len(shape) >= 3, 'please specify all c, z, t for the shape'
         assert len(shape) <= 3, 'please specify only c, z, t for the shape'
         assert np.dtype(dtype).char in 'BbHhf', 'datatype not supported'
         assert colors is None or colormap is None, 'cannot have colors and colormap simultaneously'
 
-        self.path = path
+        self.path = Path(path)
         self.shape = shape
         self.dtype = np.dtype(dtype)
         self.colors = colors
@@ -362,45 +379,46 @@ class IJTiffFile:
         self.timeinterval = timeinterval
         self.compression = compression
         self.comment = comment
-        self.extratags = {} if extratags is None else Tag.to_tags(extratags)
+        self.extratags = {} if extratags is None else Tag.from_dict(extratags)  # type: ignore
         if pxsize is not None:
-            pxsize = Tag.fraction(pxsize)
+            pxsize_fraction = Tag.fraction(pxsize)
-            self.extratags.update({282: Tag(pxsize), 283: Tag(pxsize)})
+            self.extratags.update({282: Tag(pxsize_fraction), 283: Tag(pxsize_fraction)})
 
         self.header = Header()
-        self.frames = []
         self.spp = self.shape[0] if self.colormap is None and self.colors is None else 1  # samples/pixel
         self.nframes = np.prod(self.shape[1:]) if self.colormap is None and self.colors is None else np.prod(self.shape)
-        self.frame_extra_tags = {}
+        self.frame_extra_tags: dict[tuple[int, int, int], dict[int, Tag]] = {}
-        self.fh = FileHandle(path)
+        self.fh = FileHandle(self.path)
         self.hashes = PoolSingleton().manager.dict()
         self.pool = ParPool(self.compress_frame)
         self.main_process = True
 
-        with self.fh.lock() as fh:
+        with self.fh.lock() as fh:  # noqa
             self.header.write(fh)
 
-    def __setstate__(self, state):
+    def __setstate__(self, state: dict[str, Any]) -> None:
         self.__dict__.update(state)
         self.main_process = False
 
-    def __hash__(self):
+    def __hash__(self) -> int:
         return hash(self.path)
 
-    def get_frame_number(self, n):
+    def get_frame_number(self, n: tuple[int, int, int]) -> tuple[int, int]:
         if self.colormap is None and self.colors is None:
             return n[1] + n[2] * self.shape[1], n[0]
         else:
             return n[0] + n[1] * self.shape[0] + n[2] * self.shape[0] * self.shape[1], 0
 
-    def ij_tiff_frame(self, frame):
+    def ij_tiff_frame(self, frame: np.ndarray) -> bytes:
-        with BytesIO() as framedata:
+        with BytesIO() as frame_bytes:
-            with tifffile.TiffWriter(framedata, bigtiff=self.header.bigtiff, byteorder=self.header.byteorder) as t:
+            with tifffile.TiffWriter(frame_bytes, bigtiff=self.header.bigtiff,
+                                     byteorder=self.header.byteorder) as t:  # type: ignore
                 # predictor=True might save a few bytes, but requires the package imagecodes to save floats
-                t.write(frame, compression=self.compression, contiguous=True, predictor=False)
+                t.write(frame, compression=self.compression, contiguous=True, predictor=False)  # type: ignore
-            return framedata.getvalue()
+            return frame_bytes.getvalue()
 
-    def save(self, frame, c, z, t, **extratags):
+    def save(self, frame: np.ndarray | Any, c: int, z: int, t: int,
+             **extratags: Tag.Value | Tag) -> None:
         """ save a 2d numpy array to the tiff at channel=c, slice=z, time=t, with optional extra tif tags
         """
         assert (c, z, t) not in self.pool.tasks, f'frame {c} {z} {t} is added already'
@@ -408,10 +426,10 @@ class IJTiffFile:
             'frame {} {} {} is outside shape {} {} {}'.format(c, z, t, *self.shape)
         self.pool(frame.astype(self.dtype) if hasattr(frame, 'astype') else frame, handle=(c, z, t))
         if extratags:
-            self.frame_extra_tags[(c, z, t)] = Tag.to_tags(extratags)
+            self.frame_extra_tags[(c, z, t)] = Tag.from_dict(extratags)  # type: ignore
 
     @property
-    def description(self):
+    def description(self) -> bytes:
         desc = ['ImageJ=1.11a']
         if self.colormap is None and self.colors is None:
             desc.extend((f'images={np.prod(self.shape[:1])}', f'slices={self.shape[1]}', f'frames={self.shape[2]}'))
@@ -427,17 +445,18 @@ class IJTiffFile:
             desc.append(f'spacing={self.deltaz}')
         if self.timeinterval is not None:
             desc.append(f'interval={self.timeinterval}')
-        desc = [bytes(d, 'ascii') for d in desc]
+        desc_bytes = [bytes(d, 'ascii') for d in desc]
         if self.comment is not None:
-            desc.append(b'')
+            desc_bytes.append(b'')
             if isinstance(self.comment, bytes):
-                desc.append(self.comment)
+                desc_bytes.append(self.comment)
             else:
-                desc.append(bytes(self.comment, 'ascii'))
+                desc_bytes.append(bytes(self.comment, 'ascii'))
-        return b'\n'.join(desc)
+        return b'\n'.join(desc_bytes)
 
     @cached_property
-    def colormap_bytes(self):
+    def colormap_bytes(self) -> Optional[bytes]:
+        if self.colormap:
             colormap = getattr(colorcet, self.colormap)
             colormap[0] = '#ffffff'
             colormap[-1] = '#000000'
@@ -448,13 +467,13 @@ class IJTiffFile:
             return b''.join([struct.pack(self.header.byteorder + 'H', c) for c in colormap.T.flatten()])
 
     @cached_property
-    def colors_bytes(self):
+    def colors_bytes(self) -> list[bytes]:
         return [b''.join([struct.pack(self.header.byteorder + 'H', c)
                           for c in np.linspace(0, 65535 * np.array(mpl_colors.to_rgb(color)),
                                                65536 if np.dtype(self.dtype).itemsize == 2 else 256,
-                                               dtype=int).T.flatten()]) for color in self.colors]
+                                               dtype=int).T.flatten()]) for color in self.colors] if self.colors else []
 
-    def close(self):
+    def close(self) -> None:
         if self.main_process:
             ifds, strips = {}, {}
             for n in list(self.pool.tasks):
@@ -462,7 +481,7 @@ class IJTiffFile:
                 ifds[framenr], strips[(framenr, channel)] = self.pool[n]
 
             self.pool.close()
-            with self.fh.lock() as fh:
+            with self.fh.lock() as fh:  # noqa
                 for n, tags in self.frame_extra_tags.items():
                     framenr, channel = self.get_frame_number(n)
                     ifds[framenr].update(tags)
@@ -501,21 +520,21 @@ class IJTiffFile:
                     warnings.warn('Some frames were not added to the tif file, either you forgot them, '
                                   'or an error occured and the tif file was closed prematurely.')
 
-    def __enter__(self):
+    def __enter__(self) -> IJTiffFile:
         return self
 
-    def __exit__(self, *args, **kwargs):
+    def __exit__(self, *args: Any, **kwargs: Any) -> None:
         self.close()
 
     @staticmethod
-    def hash_check(fh, bvalue, offset):
+    def hash_check(fh: BinaryIO, bvalue: bytes, offset: int) -> bool:
         addr = fh.tell()
         fh.seek(offset)
         same = bvalue == fh.read(len(bvalue))
         fh.seek(addr)
         return same
 
-    def write(self, fh, bvalue):
+    def write(self, fh: BinaryIO, bvalue: bytes) -> int:
         hash_value = sha1(bvalue).hexdigest()  # hash uses a random seed making hashes different in different processes
         if hash_value in self.hashes and self.hash_check(fh, bvalue, self.hashes[hash_value]):
             return self.hashes[hash_value]  # reuse previously saved data
@@ -527,17 +546,17 @@ class IJTiffFile:
             fh.write(bvalue)
             return offset
 
-    def compress_frame(self, frame):
+    def compress_frame(self, frame: np.ndarray) -> tuple[IFD, tuple[list[int], list[int]]]:
         """ This is run in a different process"""
         stripbytecounts, ifd, chunks = self.get_chunks(self.ij_tiff_frame(frame))
         stripbyteoffsets = []
-        with self.fh.lock() as fh:
+        with self.fh.lock() as fh:  # noqa
             for chunk in chunks:
                 stripbyteoffsets.append(self.write(fh, chunk))
         return ifd, (stripbyteoffsets, stripbytecounts)
 
     @staticmethod
-    def get_chunks(frame):
+    def get_chunks(frame: bytes) -> tuple[list[int], IFD, list[bytes]]:
         with BytesIO(frame) as fh:
             ifd = IFD(fh)
             stripoffsets = ifd[273].value
@@ -551,20 +570,20 @@ class IJTiffFile:
 
 class FileHandle:
     """ Process safe file handle """
-    def __init__(self, name):
+    def __init__(self, path: Path) -> None:
         manager = PoolSingleton().manager
-        if os.path.exists(name):
+        if path.exists():
-            os.remove(name)
+            path.unlink()
-        with open(name, 'xb'):
+        with open(path, 'xb'):
             pass
-        self.name = name
+        self.path = path
         self._lock = manager.RLock()
         self._pos = manager.Value('i', 0)
 
     @contextmanager
-    def lock(self):
+    def lock(self) -> Generator[BinaryIO, None, None]:
         with self._lock:
-            with open(self.name, 'rb+') as f:
+            with open(self.path, 'rb+') as f:
                 try:
                     f.seek(self._pos.value)
                     yield f