# imagecodecs.py
# Copyright (c) 2008-2021, Christoph Gohlke
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
"""Image transformation, compression, and decompression codecs.
Imagecodecs is a Python library that provides block-oriented, in-memory buffer
transformation, compression, and decompression functions for use in the
tifffile, czifile, zarr, and other scientific image input/output modules.
Decode and/or encode functions are implemented for Zlib (DEFLATE), GZIP,
ZStandard (ZSTD), Blosc, Brotli, Snappy, LZMA, BZ2, LZ4, LZ4F, LZ4HC,
LZW, LZF, PGLZ (PostgreSQL LZ), RCOMP (Rice), ZFP, AEC, LERC, NPY,
PNG, GIF, TIFF, WebP, JPEG 8-bit, JPEG 12-bit, Lossless JPEG (LJPEG, SOF3),
JPEG 2000, JPEG LS, JPEG XR (WDP, HD Photo), JPEG XL, AVIF,
PackBits, Packed Integers, Delta, XOR Delta, Floating Point Predictor,
Bitorder reversal, Bitshuffle, and Float24 (24-bit floating point).
:Author:
`Christoph Gohlke `_
:Organization:
Laboratory for Fluorescence Dynamics. University of California, Irvine
:License: BSD 3-Clause
:Version: 2021.8.26
:Status: Alpha
Requirements
------------
This release has been tested with the following requirements and dependencies
(other versions may work):
* `CPython 3.7.9, 3.8.10, 3.9.6 64-bit `_
* `Cython 0.29.24 `_
* `Numpy 1.20.3 `_
* `bitshuffle 0.3.5 `_
* `brotli 1.0.9 `_
* `brunsli 0.1 `_
* `bzip2 1.0.8 `_
* `c-blosc 1.21.0 `_
* `c-blosc2 2.0.2 `_
* `cfitsio 3.49 `_
* `charls 2.2.0 `_
* `giflib 5.2.1 `_
* `jxrlib 1.1 `_
* `lcms 2.12 `_
* `lerc 3.0 `_
* `libaec 1.0.5 `_
* `libavif 0.9.2 `_
(`aom 3.1.2 `_,
`dav1d 0.9.1 `_,
`rav1e 0.4.1 `_)
* `libdeflate 1.8 `_
* `libjpeg 9d `_
* `libjpeg-turbo 2.1.1 `_
* `libjxl 0.5 `_
* `liblzf 3.6 `_
* `liblzma 5.2.5 `_
* `libpng 1.6.37 `_
* `libtiff 4.3.0 `_
* `libwebp 1.2.1 `_
* `lz4 1.9.3 `_
* `openjpeg 2.4.0 `_
* `snappy 1.1.9 `_
* `zfp 0.5.5 `_
* `zlib 1.2.11 `_
* `zlib-ng 2.0.5 `_
* `zopfli-1.0.3 `_
* `zstd 1.5.0 `_
Required Python packages for testing (other versions may work):
* `tifffile 2021.8.8 `_
* `czifile 2019.7.2 `_
* `python-blosc 1.10.4 `_
* `python-blosc2-0.1.10 `_
* `python-brotli 1.0.9 `_
* `python-lz4 3.1.3 `_
* `python-lzf 0.2.4 `_
* `python-snappy 0.6.0 `_
* `python-zstd 1.5.0.2 `_
* `bitshuffle 0.3.5 `_
* `numcodecs 0.9.0 `_
* `zarr 2.9.2 `_
* `zopflipy 1.5 `_
Notes
-----
The API is not stable yet and might change between revisions.
Works on little-endian platforms only.
Python 32-bit versions are deprecated. Python <= 3.6 are no longer supported.
MacOS wheels may not be available for latest releases. Consider using
`previous `_,
`conda-forge `_ or
`macports `_ releases.
Some codecs are currently decode-only: ``tiff``, ``lzw``, ``packints``, and
``jpegsof3``.
The latest `Microsoft Visual C++ Redistributable for Visual Studio 2015, 2017
and 2019 `_ is required on Windows.
Refer to the imagecodecs/licenses folder for 3rd-party library licenses.
This software is based in part on the work of the Independent JPEG Group.
This software includes a modified version of `dcm2niix's jpg_0XC3.cpp
`_.
This software includes a modified version of `PostgreSQL's pg_lzcompress.c
`_.
This software includes a modified version of `liblj92
`_.
Build instructions and wheels for manylinux and macOS courtesy of
`Grzegorz Bokota `_.
Update pip and setuptools to the latest version before installing imagecodecs:
``python -m pip install --upgrade pip setuptools``
Install imagecodecs using precompiled wheels:
``python -m pip install --upgrade imagecodecs``
Install the requirements for building imagecodecs from source code on
latest Ubuntu Linux distributions:
``sudo apt-get install build-essential python3-dev cython3
python3-setuptools python3-pip python3-wheel python3-numpy python3-zarr
python3-pytest python3-blosc python3-brotli python3-snappy python3-lz4
libz-dev libblosc-dev liblzma-dev liblz4-dev libzstd-dev libpng-dev
libwebp-dev libbz2-dev libopenjp2-7-dev libjpeg-dev libjxr-dev
liblcms2-dev libcharls-dev libaec-dev libbrotli-dev libsnappy-dev
libzopfli-dev libgif-dev libtiff-dev libdeflate-dev libavif-dev
libcfitsio-dev``
Use the ``--lite`` build option to only build extensions without 3rd-party
dependencies. Use the ``--skip-extension`` build options to skip building
specific extensions, e.g.:
``python -m pip install imagecodecs --global-option="build_ext"
--global-option="--skip-bitshuffle"``
The ``jpeg12``, ``jpegls``, ``jpegxl``, ``zfp``, ``avif``, ``lz4f``, ``lerc``,
and ``zlibng`` extensions are disabled by default when building from source.
To modify other build settings such as library names and compiler arguments,
provide a ``imagecodecs_distributor_setup.customize_build`` function, which
will be imported and executed during setup. See ``setup.py`` for examples.
Other Python packages and C libraries providing imaging or compression codecs:
* `numcodecs `_
* `Python zlib `_
* `Python bz2 `_
* `Python lzma `_
* `backports.lzma `_
* `python-lzo `_
* `python-lzw `_
* `python-lerc `_
* `packbits `_
* `isa-l.igzip `_
* `fpzip `_
* `libmng `_
* `APNG patch for libpng `_
* `OpenEXR `_
* `tinyexr `_
* `pytinyexr `_
* `libjpeg `_ (GPL)
* `pylibjpeg `_
* `pylibjpeg-libjpeg `_ (GPL)
* `pylibjpeg-openjpeg `_
* `pylibjpeg-rle `_
* `glymur `_
* `pyheif `_
* `libheif `_ (LGPL)
* `pyrus-cramjam `_
* `QuickLZ `_ (GPL)
* `LZO `_ (GPL)
Revisions
---------
2021.8.26
Pass 5502 tests.
Add BLOSC2 codec via c-blosc2.
Require LERC 3 and libjxl 0.5.
Do not exceed literal-only size in PackBits encoder.
Raise ImcdError if output is insufficient in PackBits codecs (breaking).
Raise ImcdError if input is corrupt in PackBits decoder (breaking).
Fix delta codec for non-native byteorder.
2021.7.30
Add support for more dtypes and axes argument in PackBits encoder.
Fix worst case output size in PackBits encoder.
Fix decoding AVIF created with older libavif.
Fix decoding GIF with disposal to previous for first frame.
Add lossless option in jpeg_encode.
2021.6.8
Fix building with Cython 0.3a7.
Decode TIFF with JPEG compression, YCBCR or CMYK colorspace as RGB24.
Vendor cfitsio/ricecomp.c for shared library builds on Windows (#18).
2021.5.20
Add ZLIBNG codec via zlib-ng library.
Add RCOMP (Rice) codec via cfitsio library.
Fix decoding of 16-bit JPEG with jpeg_decode.
Relax user provided output array shape requirement.
2021.4.28
Change WebP default compression level to lossless.
Rename jpegxl codec to brunsli (breaking).
Add new JPEG XL codec via jpeg-xl library.
Add PGLZ codec via PostgreSQL's pg_lzcompress.c.
Update to libtiff 4.3 and libjpeg-turbo 2.1.
Enable JPEG 12-bit codec in manylinux wheels.
Drop manylinux2010 wheels.
2021.3.31
Add numcodecs compatible codecs for use by Zarr (experimental).
Support separate JPEG header in jpeg_decode.
Do not decode JPEG LS and XL in jpeg_decode (breaking).
Fix ZFP with partial header.
Fix JPEG LS tests (#15).
Fix LZ4F contentchecksum.
Remove blosc Snappy tests.
Fix docstrings.
2021.2.26
Support X2 and X4 floating point predictors (found in DNG).
2021.1.28
Add option to return JPEG XR fixed point pixel types as integers.
Add LJPEG codec via liblj92 (alternative to JPEGSOF3 codec).
Change zopfli header location.
2021.1.11
Fix build issues (#7, #8).
Return bytearray instead of bytes on PyPy.
Raise TypeError if output provided is bytes (breaking).
2021.1.8
Add float24 codec.
Update copyrights.
2020.12.24
Update dependencies and build scripts.
2020.12.22
Add AVIF codec via libavif (WIP).
Add DEFLATE/Zlib and GZIP codecs via libdeflate.
Add LZ4F codec.
Add high compression mode option to lz4_encode.
Convert JPEG XR 16 and 32-bit fixed point pixel types to float32.
Fix JPEG 2000 lossy encoding.
Fix GIF disposal handling.
Remove support for Python 3.6 (NEP 29).
2020.5.30
Add LERC codec via ESRI's lerc library.
Enable building JPEG extensions with libjpeg >= 8.
Enable distributors to modify build settings.
2020.2.18
Fix segfault when decoding corrupted LZW segments.
Work around Cython raises AttributeError when using incompatible numpy.
Raise ValueError if in-place decoding is not possible (except floatpred).
2020.1.31
Add GIF codec via giflib.
Add TIFF decoder via libtiff (WIP).
Add codec_check functions (WIP).
Fix formatting libjpeg error messages.
Use xfail in tests.
Load extensions on demand on Python >= 3.7.
Add build options to skip building specific extensions.
Split imagecodecs extension into individual extensions.
Move shared code into shared extension.
Rename imagecodecs_lite extension and imagecodecs C library to 'imcd'.
Remove support for Python 2.7 and 3.5.
2019.12.31
Fix decoding of indexed PNG with transparency.
Last version to support Python 2.7 and 3.5.
2019.12.16
Add Zopfli codec.
Add Snappy codec.
Rename j2k codec to jpeg2k.
Rename jxr codec to jpegxr.
Use Debian's jxrlib.
Support pathlib and binary streams in imread and imwrite.
Move external C declarations to pxd files.
Move shared code to pxi file.
Update copyright notices.
2019.12.10
Add version functions.
Add Brotli codec (WIP).
Add optional JPEG XL codec via Brunsli repacker (WIP).
2019.12.3
Sync with imagecodecs-lite.
2019.11.28
Add AEC codec via libaec (WIP).
Do not require scikit-image for testing.
Require CharLS 2.1.
2019.11.18
Add bitshuffle codec.
Fix formatting of unknown error numbers.
Fix test failures with official python-lzf.
2019.11.5
Rebuild with updated dependencies.
2019.5.22
Add optional YCbCr chroma subsampling to JPEG encoder.
Add default reversible mode to ZFP encoder.
Add imread and imwrite helper functions.
2019.4.20
Fix setup requirements.
2019.2.22
Move codecs without 3rd-party C library dependencies to imagecodecs_lite.
2019.2.20
Rebuild with updated dependencies.
2019.1.20
Add more pixel formats to JPEG XR codec.
Add JPEG XR encoder.
2019.1.14
Add optional ZFP codec via zfp library (WIP).
Add numpy NPY and NPZ codecs.
Fix some static codechecker errors.
2019.1.1
...
Refer to the CHANGES file for older revisions.
"""
__version__ = '2021.8.26'
import os
import sys
import io
import importlib
import numpy
# names of public attributes by module
# will be updated with standard attributes
_API = {
None: [
'version',
'imread',
'imwrite',
'imagefileext',
'DelayedImportError',
('none', 'numpy', 'jpeg'),
],
'imcd': [
'imcd_version',
'numpy_abi_version',
'cython_version',
(
'bitorder',
'delta',
'float24',
'floatpred',
'lzw',
'packbits',
'packints',
'xor',
),
],
'aec': [],
'avif': [],
# 'exr': [],
'bitshuffle': [],
'blosc': [],
'blosc2': [],
'brotli': [],
'brunsli': [],
'bz2': [],
'deflate': ['deflate_crc32', 'deflate_adler32', ('deflate', 'gzip')],
'gif': [],
'jpeg2k': [],
'jpeg8': [],
'jpeg12': [],
'jpegls': [],
'jpegsof3': [],
'jpegxl': [],
'jpegxr': [],
'lerc': [],
'ljpeg': [],
'lz4': [],
'lz4f': [],
'lzf': [],
'lzma': [],
'pglz': [],
'png': [],
'rcomp': [],
'snappy': [],
# 'szip': [],
'tiff': [],
'webp': [],
'zfp': [],
'zlib': ['zlib_crc32', 'zlib_adler32'],
'zlibng': ['zlibng_crc32', 'zlibng_adler32'],
'zopfli': [],
'zstd': [],
# 'module': ['attribute1', 'attribute2', ('codec1', 'code2')]
}
# map extra to existing attributes
# e.g. keep deprecated names for older versions of tifffile and czifile
_COMPATIBILITY = {
'JPEG': 'JPEG8',
'jpeg_check': 'jpeg8_check',
'jpeg_version': 'jpeg8_version',
'zopfli_check': 'zlib_check',
'zopfli_decode': 'zlib_decode',
'j2k_encode': 'jpeg2k_encode',
'j2k_decode': 'jpeg2k_decode',
'jxr_encode': 'jpegxr_encode',
'jxr_decode': 'jpegxr_decode',
}
# map attribute names to module names
_ATTRIBUTES = {}
# map of codec names to module names
_CODECS = {}
def _add_codec(module, codec=None, attributes=None):
"""Register codec in global _API, _ATTRIBUTES, and _CODECS."""
if codec is None:
codec = module
if attributes is None:
attributes = (
f'{codec}_encode',
f'{codec}_decode',
f'{codec}_check',
f'{codec}_version',
f'{codec.capitalize()}Error',
f'{codec.upper()}',
)
if module in _API:
_API[module].extend(attributes)
else:
_API[module] = attributes
_ATTRIBUTES.update({attr: module for attr in _API[module]})
_CODECS[codec] = module
def _register_codecs():
"""Parse _API and register all codecs."""
for module, attributes in _API.items():
for attr in attributes.copy():
if isinstance(attr, tuple):
attributes.remove(attr)
for codec in attr:
_add_codec(module, codec)
break
else:
_add_codec(module)
def _load_all():
"""Add all registered attributes to package namespace."""
for name in __dir__():
__getattr__(name)
def __dir__():
"""Return list of attribute names accessible on module."""
return sorted(list(_ATTRIBUTES) + list(_COMPATIBILITY))
def __getattr__(name):
"""Return module attribute after loading it from extension.
Load attribute's extension and add its attributes to the package namespace.
"""
name_ = name
name = _COMPATIBILITY.get(name, name)
if name not in _ATTRIBUTES:
raise AttributeError(f"module 'imagecodecs' has no attribute {name!r}")
module_ = _ATTRIBUTES[name]
if module_ is None:
return None
try:
module = importlib.import_module('._' + module_, 'imagecodecs')
except ImportError:
module = None
except AttributeError:
# AttributeError: type object 'imagecodecs._module.array' has no
# attribute '__reduce_cython__'
# work around Cython raises AttributeError e.g. when the _shared
# module failed to import due to an incompatible numpy version
from . import _shared # noqa
module = None
for n in _API[module_]:
if n in _COMPATIBILITY:
continue
attr = getattr(module, n, None)
if attr is None:
attr = _stub(n, module)
setattr(imagecodecs, n, attr)
attr = getattr(imagecodecs, name)
if name != name_:
setattr(imagecodecs, name_, attr)
return attr
class DelayedImportError(ImportError):
"""Delayed ImportError."""
def __init__(self, name):
"""Initialize instance from attribute name."""
msg = f"could not import name {name!r} from 'imagecodecs'"
super().__init__(msg)
def _stub(name, module):
"""Return stub function or class."""
if name.endswith('_version'):
if module is None:
def stub_version():
"""Stub for imagecodecs.codec_version function."""
return f"{name[:-8]} n/a"
else:
def stub_version():
"""Stub for imagecodecs.codec_version function."""
return f"{name[:-8]} unknow"
return stub_version
if name.endswith('_check'):
def stub_check(arg):
"""Stub for imagecodecs.codec_check function."""
return False
return stub_check
if name.endswith('_decode'):
def stub_decode(*args, **kwargs):
"""Stub for imagecodecs.codec_decode function."""
raise DelayedImportError(name)
return stub_decode
if name.endswith('_encode'):
def stub_encode(*args, **kwargs):
"""Stub for imagecodecs.codec_encode function."""
raise DelayedImportError(name)
return stub_encode
if name.islower():
def stub_function(*args, **kwargs):
"""Stub for imagecodecs.codec_function."""
raise DelayedImportError(name)
return stub_function
if name.endswith('Error'):
class StubError(RuntimeError):
"""Stub for imagecodecs.CodecError class."""
def __init__(self, *args, **kwargs):
raise DelayedImportError(name)
return StubError
class StubType(type):
def __getattr__(cls, arg):
raise DelayedImportError(name)
if module is None:
def __bool__(cls):
return False
if name.isupper():
class STUB(metaclass=StubType):
"""Stub for imagecodecs.CODEC constants."""
return STUB
class Stub(metaclass=StubType):
"""Stub for imagecodecs.Codec class."""
return Stub
def _extensions():
"""Return sorted list of extension names."""
return sorted(e for e in _API if e is not None)
def version(astype=None, _versions_=[]):
"""Return version information about all codecs and dependencies."""
if not _versions_:
_versions_.extend(
(
f'imagecodecs {__version__}',
imagecodecs.cython_version(),
imagecodecs.numpy_version(),
imagecodecs.numpy_abi_version(),
imagecodecs.imcd_version(),
)
)
_versions_.extend(
sorted(
{
getattr(imagecodecs, v)()
for v in _ATTRIBUTES
if v.endswith('_version')
and v
not in (
'imcd_version',
'numpy_abi_version',
'numpy_version',
'cython_version',
'none_version',
)
}
)
)
if astype is None or astype is str:
return ', '.join(ver.replace(' ', '-') for ver in _versions_)
if astype is dict:
return dict(ver.split(' ') for ver in _versions_)
return tuple(_versions_)
def imread(fileobj, codec=None, memmap=True, return_codec=False, **kwargs):
"""Return image data from file as numpy array."""
import mmap
codecs = []
if codec is None:
# find codec based on file extension
if isinstance(fileobj, (str, os.PathLike)):
ext = os.path.splitext(os.fspath(fileobj))[-1][1:].lower()
else:
ext = None
if ext in _imcodecs():
codec = _imcodecs()[ext]
if codec == 'jpeg':
codecs.extend(('jpeg8', 'jpeg12', 'jpegsof3', 'ljpeg'))
else:
codecs.append(codec)
# try other imaging codecs
codecs.extend(
c
for c in (
'tiff',
'png',
'gif',
'webp',
'jpeg8',
'jpeg12',
'jpegsof3',
'jpeg2k',
'jpegls',
'jpegxr',
'jpegxl',
'avif',
'ljpeg',
# 'brunsli',
# 'exr',
'zfp',
'lerc',
'numpy',
)
if c not in codecs
)
else:
# use provided codecs
if not isinstance(codec, (list, tuple)):
codec = [codec]
for c in codec:
if isinstance(c, str):
c = c.lower()
c = _imcodecs().get(c, c)
codecs.append(c)
offset = None
close = False
if isinstance(fileobj, mmap.mmap):
data = fileobj
offset = data.tell()
elif hasattr(fileobj, 'read'):
# binary stream: open file, BytesIO
data = fileobj.read()
elif isinstance(fileobj, (str, os.PathLike)):
# TODO: support urllib.request.urlopen ?
# file name
with open(os.fspath(fileobj), 'rb') as fh:
if memmap:
offset = 0
close = True
data = mmap.mmap(fh.fileno(), 0, access=mmap.ACCESS_READ)
else:
data = fh.read()
else:
# binary data
data = fileobj
exceptions = []
image = None
for codec in codecs:
if callable(codec):
func = codec
else:
try:
func = getattr(imagecodecs, codec + '_decode')
except Exception as exc:
exceptions.append(f'{repr(codec).upper()}: {exc}')
continue
try:
image = func(data, **kwargs)
if image.dtype == 'object':
image = None
raise ValueError('failed')
break
except DelayedImportError:
pass
except Exception as exc:
# raise
exceptions.append(f'{func.__name__.upper()}: {exc}')
if offset is not None:
data.seek(offset)
if close:
data.close()
if image is None:
raise ValueError('\n'.join(exceptions))
if return_codec:
return image, func
return image
def imwrite(fileobj, data, codec=None, **kwargs):
"""Write numpy array to image file."""
if codec is None:
# find codec based on file extension
if isinstance(fileobj, (str, os.PathLike)):
ext = os.path.splitext(os.fspath(fileobj))[-1].lower()[1:]
else:
raise ValueError('no codec specified')
codec = _imcodecs().get(ext, ext)
try:
codec = getattr(imagecodecs, codec + '_encode')
except AttributeError as exc:
raise ValueError(f'invalid codec {codec!r}') from exc
elif isinstance(codec, str):
codec = codec.lower()
codec = _imcodecs().get(codec, codec)
try:
codec = getattr(imagecodecs, codec + '_encode')
except AttributeError as exc:
raise ValueError(f'invalid codec {codec!r}') from exc
elif not callable(codec):
raise ValueError(f'invalid codec {codec!r}')
data = codec(data, **kwargs)
if hasattr(fileobj, 'write'):
# binary stream: open file, BytesIO
fileobj.write(data)
else:
# file name
with open(str(fileobj), 'wb') as fh:
fh.write(data)
def _imcodecs(_codecs_={}):
"""Return map of image file extensions to codec names."""
if not _codecs_:
codecs = {
'avif': ('avif', 'avifs'),
'brunsli': ('brn',),
# 'exr': ('exr',),
'gif': ('gif',),
'jpeg': ('jpg', 'jpeg', 'jpe', 'jfif', 'jif', 'ljpeg'),
'jpeg2k': ('j2k', 'jp2', 'j2c', 'jpc', 'jpx', 'jpf'), # jpm, mj2
'jpegls': ('jls',),
'jpegxl': ('jxl',),
'jpegxr': ('jxr', 'hdp', 'wdp'),
'lerc': ('lerc1', 'lerc2'),
'numpy': ('npy', 'npz'),
'png': ('png',),
'tiff': ('tif', 'tiff', 'tf8', 'tf2', 'btf'),
'webp': ('webp',),
'zfp': ('zfp',),
}
_codecs_.update(
(ext, codec) for codec, exts in codecs.items() for ext in exts
)
return _codecs_
def imagefileext():
"""Return list of image file extensions handled by imread and imwrite."""
return list(_imcodecs().keys())
NONE = True
NoneError = RuntimeError
def none_version():
"""Return empty version string."""
return ''
def none_check(data):
"""Return True if data likely contains Template data."""
def none_decode(data, *args, **kwargs):
"""Decode NOP."""
return data
def none_encode(data, *args, **kwargs):
"""Encode NOP."""
return data
NUMPY = True
NumpyError = RuntimeError
def numpy_version():
"""Return numpy version string."""
return f'numpy {numpy.__version__}'
def numpy_check(data):
"""Return True if data likely contains NPY or NPZ data."""
with io.BytesIO(data) as fh:
data = fh.read(64)
magic = b'\x93NUMPY'
return data.startswith(magic) or (data.startswith(b'PK') and magic in data)
def numpy_decode(data, index=0, out=None, **kwargs):
"""Decode NPY and NPZ."""
with io.BytesIO(data) as fh:
try:
out = numpy.load(fh, **kwargs)
except ValueError as exc:
raise ValueError('not a numpy array') from exc
if hasattr(out, 'files'):
try:
index = out.files[index]
except Exception:
pass
out = out[index]
return out
def numpy_encode(data, level=None, out=None):
"""Encode NPY and NPZ."""
with io.BytesIO() as fh:
if level:
numpy.savez_compressed(fh, data)
else:
numpy.save(fh, data)
fh.seek(0)
out = fh.read()
return out
JpegError = RuntimeError
def jpeg_decode(
data,
bitspersample=None,
tables=None,
header=None,
colorspace=None,
outcolorspace=None,
shape=None,
out=None,
):
"""Decode JPEG 8-bit, 12-bit, and SOF3."""
if header is not None:
data = header + data + b'\xff\xd9'
if bitspersample is None:
try:
return imagecodecs.jpeg8_decode(
data,
tables=tables,
colorspace=colorspace,
outcolorspace=outcolorspace,
shape=shape,
out=out,
)
except Exception as exc:
msg = str(exc)
if 'Unsupported JPEG data precision' in msg:
return imagecodecs.jpeg12_decode(
data,
tables=tables,
colorspace=colorspace,
outcolorspace=outcolorspace,
shape=shape,
out=out,
)
if 'SOF type' in msg:
try:
return imagecodecs.jpegsof3_decode(data, out=out)
except Exception:
return imagecodecs.ljpeg_decode(data, out=out)
# if 'Empty JPEG image' in msg:
# e.g. Hamamatsu NDPI slides with dimensions > 65500
# Unsupported marker type
raise exc
try:
if bitspersample == 8:
return imagecodecs.jpeg8_decode(
data,
tables=tables,
colorspace=colorspace,
outcolorspace=outcolorspace,
shape=shape,
out=out,
)
if bitspersample == 12:
return imagecodecs.jpeg12_decode(
data,
tables=tables,
colorspace=colorspace,
outcolorspace=outcolorspace,
shape=shape,
out=out,
)
try:
return imagecodecs.jpegsof3_decode(data, out=out)
except Exception:
return imagecodecs.ljpeg_decode(data, out=out)
except Exception as exc:
msg = str(exc)
if 'SOF type' in msg:
try:
return imagecodecs.jpegsof3_decode(data, out=out)
except Exception:
return imagecodecs.ljpeg_decode(data, out=out)
# if 'Empty JPEG image' in msg:
raise exc
def jpeg_encode(
data,
level=None,
colorspace=None,
outcolorspace=None,
subsampling=None,
optimize=None,
smoothing=None,
lossless=None,
bitspersample=None,
out=None,
):
"""Encode JPEG 8-bit or 12-bit."""
if lossless:
return imagecodecs.ljpeg_encode(
data, bitspersample=bitspersample, out=out
)
if data.dtype == numpy.uint8:
func = imagecodecs.jpeg8_encode
elif data.dtype == numpy.uint16:
func = imagecodecs.jpeg12_encode
else:
raise ValueError(f'invalid data type {data.dtype}')
return func(
data,
level=level,
colorspace=colorspace,
outcolorspace=outcolorspace,
subsampling=subsampling,
optimize=optimize,
smoothing=smoothing,
out=out,
)
# initialize package
imagecodecs = sys.modules['imagecodecs']
_register_codecs()