# imagecodecs.py # Copyright (c) 2008-2026, 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. r"""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 tifffile, liffile, czifile, zarr, and other scientific image input/output packages. Decode and/or encode functions are implemented for Zlib (DEFLATE), GZIP, LZMA, ZStandard (ZSTD), Blosc, Brotli, Snappy, BZ2, LZ4, LZ4F, LZ4HC, LZ4H5, LZW, LZO, LZF, LZFSE, LZHAM, PGLZ (PostgreSQL LZ), RCOMP (Rice), ZFP, SZ3, Meshopt, Pcodec, SPERR, AEC, SZIP, LERC, EER, NPY, BCn, DDS, BMP, PNG, APNG, GIF, TIFF, WebP, JPEG (2 to 16-bit), Lossless JPEG (LJPEG, LJ92, JPEGLL), JPEG 2000 (JP2, J2K), High-throughput JPEG 2000 (HTJ2K, JPH), JPEG LS, JPEG XL, JPEG XS, JPEG XR (WDP, HD Photo), Ultra HDR (JPEG_R), MOZJPEG, AVIF, HEIF, QOI, RGBE (HDR), PixarLog, Jetraw, DICOM RLE, CCITT (RLE, T.4 and T.6), PackBits, Packed Integers (TIFF, MONO p and packed), Delta, XOR Delta, Floating Point Predictor, Bitorder reversal, Byteshuffle, Bitshuffle, Float24 (24-bit floating point), Bfloat16 (brain floating point), Quantize (Scale, BitGroom, BitRound, GranularBR), and CMS (color space transformations). Checksum functions are implemented for CRC-32, Adler-32, Fletcher-32, and Jenkins lookup3. :Author: `Christoph Gohlke `_ :License: BSD-3-Clause :Version: 2026.3.6 :DOI: `10.5281/zenodo.6915978 `_ Quickstart ---------- Install the imagecodecs package and all dependencies from the `Python Package Index `_:: python -m pip install -U "imagecodecs[all]" Imagecodecs is also available in other package repositories such as `Anaconda `_, `MSYS2 `_, and `MacPorts `_. See `Requirements`_ and `Notes`_ for building from source. See `Examples`_ for using the programming interface. Source code and support are available on `GitHub `_. Requirements ------------ This revision was tested with the following requirements and dependencies (other versions may work): - `CPython `_ 3.11.9, 3.12.10, 3.13.12, 3.14.3 64-bit - `numpy `_ 2.4.2 - `numcodecs `_ 0.16.5 (optional, for Zarr file format 2 compatible codecs) Build requirements: - `cython `_ 3.2.4 - `brotli `_ 1.2.0 - `bzip2 `_ 1.0.8 - `c-blosc `_ 1.21.6 - `c-blosc2 `_ 2.23.0 - `charls `_ 2.4.3 - `giflib `_ 6.1.1 - `jxrlib `_ 1.2 - `lcms2 `_ 2.18 - `lerc `_ 4.0.4 - `libaec `_ 1.1.6 - `libavif `_ 1.4.0 (`aom `_ 3.13.1, `dav1d `_ 1.5.3, `rav1e `_ 0.8.1, `svt-av1 `_ 4.0.1, `libyuv `_ main, `libxml2 `_ 2.15.2) - `libdeflate `_ 1.25 - `libheif `_ 1.21.2 (`libde265 `_ 1.0.16, `x265 `_ 4.1) - `libjpeg-turbo `_ 3.1.3 - `libjxl `_ 0.11.2 - `libjxs `_ 2.0.2 - `liblzma `_ 5.8.2 - `libpng `_ 1.6.55 - `libpng-apng `_ 1.6.55 - `libtiff `_ 4.7.1 (with issue 789 fix) - `libultrahdr `_ 1.4.0 - `libwebp `_ 1.6.0 - `lz4 `_ 1.10.0 - `meshoptimizer `_ 1.0.1 - `openjpeg `_ 2.5.4 - `openjph `_ 0.26.3 - `pcodec `_ 1.0.1 (with PR 369) - `snappy `_ 1.2.2 - `sperr `_ 0.8.4 - `sz3 `_ 3.3.2 - `zfp `_ 1.0.1 - `zlib `_ 1.3.2 - `zlib-ng `_ 2.3.3 - `zstd `_ 1.5.7 Unmaintained or discontinued build requirements: - `brunsli `_ 0.1 - `jetraw `_ 23.03.16.4 - `lzfse `_ 1.0 - `lzham_codec `_ 1.0 - `lzokay `_ db2df1f - `mozjpeg `_ 4.1.5 - `zopfli `_ 1.0.3 Vendored requirements: - `bcdec.h `_ 93628fe - `bitshuffle `_ 0.5.2 - `cfitsio ricecomp.c `_ modified - `h5checksum.c `_ modified - `jpg_0XC3.cpp `_ modified - `liblj92 `_ modified - `liblzf `_ 3.6 - `libspng `_ 0.7.4 - `nc4var.c `_ modified - `pg_lzcompress.c `_ modified - `qoi.h `_ 4461cc3 - `rgbe.c `_ modified Test requirements: - `tifffile `_ 2026.3.3 - `czifile `_ 2019.7.2.3 - `liffile `_ 2026.2.16 - `zarr `_ 3.1.5 - `python-blosc `_ 1.11.4 - `python-blosc2 `_ 4.0.0 - `python-brotli `_ 1.2.0 - `python-lz4 `_ 4.4.5 - `python-lzf `_ 0.2.6 - `python-snappy `_ 0.7.3 - `pyliblzfse `_ 0.4.1 - `backports.zstd `_ 1.3.0 - `zopflipy `_ 1.12 Revisions --------- 2026.3.6 - Pass 8575 tests. - Add CCITTRLE, CCITTFAX3 and CCITTFAX4 codecs (decode only). - Implement packints_encode function. - Support lerc subcodec in tiff_encode function. - Support packed integers, ccitt and pixarlog compression in TIFF codec. - Support bitorder option in PACKINTS codec. - Support rounding in BFLOAT16 codec. - Support more BMP types. - Update PCODEC to new API. - Fix buffer overflows in third-party code. - Fix code review issues. 2026.1.14 - Add tiff_encode function. - Add extra options for HTJ2K (#134). - Add linear RGB option to cms_profile. - Change ZSTD default compression level to 3. 2026.1.1 - Enforce positional-only and keyword-only parameters (breaking). - Base numcodecs.Jpeg on JPEG8 codec (breaking). - Add HTJ2K codec based on OpenJPH library (#125). - Add MESHOPT codec based on meshoptimizer library. - Fix decoding concatenated ZStandard frames. - Fix potential issues in TIFF and WEBP codecs. - Fix pyi stub file. - Change default Brotli compression level to 4. - Use Brotli streaming API for decoding. - Enable decoding UltraHDR to uint16. - Tweak memory allocation and reallocation strategies. - Use fused types. - Improve code quality. 2025.11.11 - Fix EER superresolution decoding (breaking; see tifffile #313). - Add option to eer_decode to add to uint16 array. - Add option to specify CICP/NCLX parameters in avif_encode (#131). - Add BFLOAT16 codec. - Build ABI3 wheels. - Require Cython >= 3.2. - Deprecate Python 3.11. 2025.8.2 - Fix szip_encode default output buffer might be too small (#128). - Fix minor bugs in LZ4H5 codec (#127). - Avoid grayscale-to-RGB conversions in AVIF codecs. - Improve AVIF error messages. - Add flag for free-threading compatibility (#113). - Do not use zlib uncompress2, which is not available on manylinux. - Do not build unstable BRUNSLI, PCODEC, SPERR, and SZ3 codecs. - Require libavif >= 1.3 and Cython >= 3.1. - Support Python 3.14 and 3.14t. - Drop support for Python 3.10 and PyPy. 2025.3.30 - Fix some codecs for use with Zarr 3, zarr_format=2 (#123). - Fix LZ4H5 codec when block size is less than compressed size (#126). - Fix pglz_compress is not thread-safe. - Set __module__ attribute on public objects. - Drop support for Python 3.9, deprecate Python 3.10. 2024.12.30 - … Refer to the CHANGES file for older revisions. Objectives ---------- Many scientific image storage formats, such as TIFF, CZI, XLIF, DICOM, HDF, and Zarr are containers that store numerous small data segments (chunks, tiles, stripes). These segments are encoded using various compression and pre-filtering methods. Metadata common to all data segments are typically stored separately from the segments. The purpose of the Imagecodecs library is to support Python modules in encoding and decoding such data segments. The specific aims are: - Provide functions for encoding and decoding small image data segments in-memory (as opposed to in-file) from and to bytes or numpy arrays for many compression and filtering methods. - Support image formats and compression methods that are not available elsewhere in the Python ecosystem. - Reduce the runtime dependency on numerous, large, inapt, or unmaintained Python packages. The Imagecodecs package only depends on numpy. - Implement codecs as Cython wrappers of third-party libraries with a C API and permissive license if available; otherwise use own C library. Provide Cython definition files for the wrapped C libraries. - Release the Python global interpreter lock (GIL) during extended native/C function calls for multi-threaded use. Accessing parts of large data segments and reading metadata from segments are outside the scope of this library. Notes ----- This library is largely a work in progress. The API is not stable yet and might change between revisions. Python <= 3.10 is no longer supported. 32-bit versions are deprecated. Works on little-endian platforms only. Supported platforms are ``win_amd64``, ``win_arm64``, ``win32``, ``macosx_x86_64``, ``macosx_arm64``, ``manylinux_x86_64``, and ``manylinux_aarch64``. Wheels may not be available for all platforms and all releases. Not all features are available on all platforms. The ``bcn``, ``ccittfax3``, ``ccittfax4``, ``ccittrle``, ``dds``, ``dicomrle``, ``eer``, ``jpegsof3``, and ``lzo`` codecs are currently decode-only. The ``brunsli`` codec is distributed as source code only because the underlying library is unstable. The ``heif``, ``jetraw``, and ``jpegxs`` codecs are distributed as source code only due to license and possible patent usage issues. The latest `Microsoft Visual C++ Redistributable for Visual Studio 2017-2026 `_ 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. Update pip and setuptools to the latest version before installing imagecodecs:: python -m pip install -U pip setuptools wheel Cython. When building against libjpeg or libjpeg_turbo < 3, set the environment variable ``IMAGECODECS_JPEG8_LEGACY=1`` to enable legacy API support. Before building imagecodecs from source code, install required tools and libraries. For example, on latest Ubuntu Linux distributions:: sudo apt-get install build-essential python3-dev cython3 python3-pip \ python3-setuptools python3-wheel python3-numpy libdeflate-dev libjpeg-dev \ libjxr-dev liblcms2-dev liblz4-dev liblerc-dev liblzma-dev \ libopenjp2-7-dev libpng-dev libtiff-dev libwebp-dev libz-dev libzstd-dev To build and install imagecodecs from source code, run:: python -m pip install . Many extensions are disabled by default when building from source. To define which extensions are built, or to modify build settings such as library names and compiler arguments, provide a ``imagecodecs_distributor_setup.customize_build`` function, which is imported and executed during setup. See ``setup.py`` for pre-defined ``customize_build`` functions. Other projects providing imaging or compression codecs: `stdlib-zlib `_, `stdlib-bz2 `_, `stdlib-lzma `_, `backports.lzma `_, `python-lzo `_, `python-lzw `_, `python-lerc `_, `wavpack-numcodecs `_, `packbits `_, `isa-l.igzip `_, `fpzip `_, `libmng `_, `openexr `_, `openzl `_, `openhtj2k `_, `pyjetraw `_, `tinyexr `_, `pytinyexr `_, `pyroexr `_, `jasper `_, `libjpeg `_ (gpl), `pylibjpeg `_, `pylibjpeg-libjpeg `_ (gpl), `pylibjpeg-openjpeg `_, `pylibjpeg-rle `_, `glymur `_, `pyheif `_, `pyrus-cramjam `_, `pylzham `_, `brieflz `_, `quicklz `_ (gpl), `lzo `_ (gpl), `nvjpeg `_, `nvjpeg2k `_, `pyturbojpeg `_, `ccsds123 `_, `lpc-rice `_, `compression-algorithms `_, `compressonator `_, `wuffs `_, `tinydng `_, `grok `_ (agpl), `mafisc `_, `b3d `_, `fo-dicom.codecs `_, `jpegli `_, `crackle `_, `hdf5plugin `_. Examples -------- Import the JPEG2K codec: >>> from imagecodecs import ( ... jpeg2k_encode, ... jpeg2k_decode, ... jpeg2k_check, ... jpeg2k_version, ... JPEG2K, ... ) Check that the JPEG2K codec is available in the imagecodecs build: >>> JPEG2K.available True Print the version of the JPEG2K codec's underlying OpenJPEG library: >>> jpeg2k_version() 'openjpeg 2.5.4' Encode a numpy array in lossless JP2 format: >>> import numpy >>> array = numpy.random.randint(100, 200, (256, 256, 3), numpy.uint8) >>> encoded = jpeg2k_encode(array, level=0) >>> bytes(encoded[:12]) b'\x00\x00\x00\x0cjP \r\n\x87\n' Check that the encoded bytes likely contain a JPEG 2000 stream: >>> jpeg2k_check(encoded) True Decode the JP2 encoded bytes to a numpy array: >>> decoded = jpeg2k_decode(encoded) >>> numpy.array_equal(decoded, array) True Decode the JP2 encoded bytes to an existing numpy array: >>> out = numpy.empty_like(array) >>> _ = jpeg2k_decode(encoded, out=out) >>> numpy.array_equal(out, array) True Not all codecs are fully implemented, raising exceptions at runtime: >>> from imagecodecs import dicomrle_encode >>> dicomrle_encode(array) Traceback (most recent call last): ... NotImplementedError: dicomrle_encode Write the numpy array to a JP2 file: >>> from imagecodecs import imwrite, imread >>> imwrite('_test.jp2', array) Read the image from the JP2 file as numpy array: >>> image = imread('_test.jp2') >>> numpy.array_equal(image, array) True Create a JPEG 2000 compressed Zarr array: >>> import zarr >>> import numcodecs >>> from imagecodecs.numcodecs import Jpeg2k >>> numcodecs.register_codec(Jpeg2k) >>> zarr.zeros( ... (4, 5, 512, 512, 3), ... chunks=(1, 1, 256, 256, 3), ... dtype='u1', ... compressor=Jpeg2k(), ... zarr_format=2, ... ) <...Array ...(4, 5, 512, 512, 3) ...uint8> Access image data in a sequence of JP2 files via tifffile.FileSequence and dask.array: >>> import tifffile >>> import dask.array >>> def jp2_read(filename): ... with open(filename, 'rb') as fh: ... data = fh.read() ... return jpeg2k_decode(data) ... >>> with tifffile.FileSequence(jp2_read, '*.jp2') as ims: ... with ims.aszarr() as store: ... dask.array.from_zarr(store) ... dask.array>> store.write_fsspec( ... 'temp.json', url='file://', codec_id='imagecodecs_jpeg2k' ... ) >>> from kerchunk.utils import refs_as_store >>> zarr.open(refs_as_store('temp.json'), mode='r') shape=(1, 256, 256, 3) dtype=uint8> View the image in the JP2 file from the command line:: python -m imagecodecs _test.jp2 """ from __future__ import annotations __version__ = '2026.3.6' import contextlib import functools import importlib import io import os import sys import threading from typing import TYPE_CHECKING if TYPE_CHECKING: import mmap from collections.abc import Callable from types import ModuleType from typing import IO, Any from numpy.typing import ArrayLike, NDArray import numpy # map extension module names to attribute names # sync with __all__ in __init__.pyi _MODULES: dict[str, list[str]] = { '': [ '__version__', 'version', 'imread', 'imwrite', 'imagefileext', 'DelayedImportError', 'NONE', 'none_encode', 'none_decode', 'none_check', 'none_version', 'NoneError', 'NUMPY', 'numpy_encode', 'numpy_decode', 'numpy_check', 'numpy_version', 'NumpyError', 'JPEG', 'jpeg_encode', 'jpeg_decode', 'jpeg_check', 'jpeg_version', 'JpegError', ], '_imcd': [ 'imcd_version', 'numpy_abi_version', 'cython_version', 'BFLOAT16', 'Bfloat16Error', 'bfloat16_encode', 'bfloat16_decode', 'bfloat16_check', 'bfloat16_version', 'BITORDER', 'BitorderError', 'bitorder_encode', 'bitorder_decode', 'bitorder_check', 'bitorder_version', 'BYTESHUFFLE', 'ByteshuffleError', 'byteshuffle_encode', 'byteshuffle_decode', 'byteshuffle_check', 'byteshuffle_version', 'DELTA', 'DeltaError', 'delta_encode', 'delta_decode', 'delta_check', 'delta_version', 'DICOMRLE', 'DicomrleError', 'dicomrle_encode', 'dicomrle_decode', 'dicomrle_check', 'dicomrle_version', 'EER', 'EerError', 'eer_encode', 'eer_decode', 'eer_check', 'eer_version', 'FLOAT24', 'Float24Error', 'float24_encode', 'float24_decode', 'float24_check', 'float24_version', 'FLOATPRED', 'FloatpredError', 'floatpred_encode', 'floatpred_decode', 'floatpred_check', 'floatpred_version', 'LZW', 'LzwError', 'lzw_encode', 'lzw_decode', 'lzw_check', 'lzw_version', 'PACKBITS', 'PackbitsError', 'packbits_encode', 'packbits_decode', 'packbits_check', 'packbits_version', 'PACKINTS', 'PackintsError', 'packints_encode', 'packints_decode', 'packints_check', 'packints_version', 'XOR', 'XorError', 'xor_encode', 'xor_decode', 'xor_check', 'xor_version', ], '_aec': [ 'AEC', 'AecError', 'aec_encode', 'aec_decode', 'aec_check', 'aec_version', ], '_apng': [ 'APNG', 'ApngError', 'apng_encode', 'apng_decode', 'apng_check', 'apng_version', ], '_avif': [ 'AVIF', 'AvifError', 'avif_encode', 'avif_decode', 'avif_check', 'avif_version', ], '_bitshuffle': [ 'BITSHUFFLE', 'BitshuffleError', 'bitshuffle_encode', 'bitshuffle_decode', 'bitshuffle_check', 'bitshuffle_version', ], '_blosc': [ 'BLOSC', 'BloscError', 'blosc_encode', 'blosc_decode', 'blosc_check', 'blosc_version', ], '_blosc2': [ 'BLOSC2', 'Blosc2Error', 'blosc2_encode', 'blosc2_decode', 'blosc2_check', 'blosc2_version', ], '_bmp': [ 'BMP', 'BmpError', 'bmp_encode', 'bmp_decode', 'bmp_check', 'bmp_version', ], '_brotli': [ 'BROTLI', 'BrotliError', 'brotli_encode', 'brotli_decode', 'brotli_check', 'brotli_version', ], '_brunsli': [ 'BRUNSLI', 'BrunsliError', 'brunsli_encode', 'brunsli_decode', 'brunsli_check', 'brunsli_version', ], '_bz2': [ 'BZ2', 'Bz2Error', 'bz2_encode', 'bz2_decode', 'bz2_check', 'bz2_version', ], '_ccitt': [ 'CCITTRLE', 'CcittrleError', 'ccittrle_encode', 'ccittrle_decode', 'ccittrle_check', 'ccittrle_version', 'CCITTFAX3', 'Ccittfax3Error', 'ccittfax3_encode', 'ccittfax3_decode', 'ccittfax3_check', 'ccittfax3_version', 'CCITTFAX4', 'Ccittfax4Error', 'ccittfax4_encode', 'ccittfax4_decode', 'ccittfax4_check', 'ccittfax4_version', ], '_cms': [ 'CMS', 'CmsError', 'cms_transform', 'cms_profile', 'cms_profile_validate', 'cms_encode', 'cms_decode', 'cms_check', 'cms_version', ], '_bcn': [ 'BCN', 'BcnError', 'bcn_encode', 'bcn_decode', 'bcn_check', 'bcn_version', 'DDS', 'DdsError', 'dds_encode', 'dds_decode', 'dds_check', 'dds_version', ], '_deflate': [ 'DEFLATE', 'DeflateError', 'deflate_crc32', 'deflate_adler32', 'deflate_encode', 'deflate_decode', 'deflate_check', 'deflate_version', 'GZIP', 'GzipError', 'gzip_encode', 'gzip_decode', 'gzip_check', 'gzip_version', ], '_gif': [ 'GIF', 'GifError', 'gif_encode', 'gif_decode', 'gif_check', 'gif_version', ], '_h5checksum': [ 'H5CHECKSUM', 'h5checksum_version', 'h5checksum_fletcher32', 'h5checksum_lookup3', 'h5checksum_crc', 'h5checksum_metadata', 'h5checksum_hash_string', ], '_heif': [ 'HEIF', 'HeifError', 'heif_encode', 'heif_decode', 'heif_check', 'heif_version', ], '_htj2k': [ 'HTJ2K', 'Htj2kError', 'htj2k_encode', 'htj2k_decode', 'htj2k_check', 'htj2k_version', 'htj2k_init', ], # '_isal': [ # 'ISAL', # 'IsalError', # 'isal_crc32', # 'isal_adler32', # 'isal_encode', # 'isal_decode', # 'isal_check', # 'isal_version', # ], '_jetraw': [ 'JETRAW', 'JetrawError', 'jetraw_init', 'jetraw_encode', 'jetraw_decode', 'jetraw_check', 'jetraw_version', ], '_jpeg2k': [ 'JPEG2K', 'Jpeg2kError', 'jpeg2k_encode', 'jpeg2k_decode', 'jpeg2k_check', 'jpeg2k_version', ], '_jpeg8': [ 'JPEG8', 'Jpeg8Error', 'jpeg8_encode', 'jpeg8_decode', 'jpeg8_check', 'jpeg8_version', ], # '_jpegli': [ # 'JPEGLI', # 'JpegliError', # 'jpegli_encode', # 'jpegli_decode', # 'jpegli_check', # 'jpegli_version', # ], '_jpegls': [ 'JPEGLS', 'JpeglsError', 'jpegls_encode', 'jpegls_decode', 'jpegls_check', 'jpegls_version', ], '_jpegsof3': [ 'JPEGSOF3', 'Jpegsof3Error', 'jpegsof3_encode', 'jpegsof3_decode', 'jpegsof3_check', 'jpegsof3_version', ], '_jpegxl': [ 'JPEGXL', 'JpegxlError', 'jpegxl_encode', 'jpegxl_decode', 'jpegxl_encode_jpeg', 'jpegxl_decode_jpeg', 'jpegxl_check', 'jpegxl_version', ], '_jpegxr': [ 'JPEGXR', 'JpegxrError', 'jpegxr_encode', 'jpegxr_decode', 'jpegxr_check', 'jpegxr_version', ], '_jpegxs': [ 'JPEGXS', 'JpegxsError', 'jpegxs_encode', 'jpegxs_decode', 'jpegxs_check', 'jpegxs_version', ], '_lerc': [ 'LERC', 'LercError', 'lerc_encode', 'lerc_decode', 'lerc_check', 'lerc_version', ], '_ljpeg': [ 'LJPEG', 'LjpegError', 'ljpeg_encode', 'ljpeg_decode', 'ljpeg_check', 'ljpeg_version', ], '_lz4': [ 'LZ4', 'Lz4Error', 'lz4_encode', 'lz4_decode', 'lz4_check', 'lz4_version', 'LZ4H5', 'Lz4h5Error', 'lz4h5_encode', 'lz4h5_decode', 'lz4h5_check', 'lz4h5_version', ], '_lz4f': [ 'LZ4F', 'Lz4fError', 'lz4f_encode', 'lz4f_decode', 'lz4f_check', 'lz4f_version', ], '_lzf': [ 'LZF', 'LzfError', 'lzf_encode', 'lzf_decode', 'lzf_check', 'lzf_version', ], '_lzfse': [ 'LZFSE', 'LzfseError', 'lzfse_encode', 'lzfse_decode', 'lzfse_check', 'lzfse_version', ], '_lzham': [ 'LZHAM', 'LzhamError', 'lzham_encode', 'lzham_decode', 'lzham_check', 'lzham_version', ], '_lzma': [ 'LZMA', 'LzmaError', 'lzma_encode', 'lzma_decode', 'lzma_check', 'lzma_version', ], '_lzo': [ 'LZO', 'LzoError', 'lzo_encode', 'lzo_decode', 'lzo_check', 'lzo_version', ], '_meshopt': [ 'MESHOPT', 'MeshoptError', 'meshopt_encode', 'meshopt_decode', 'meshopt_check', 'meshopt_version', ], '_mozjpeg': [ 'MOZJPEG', 'MozjpegError', 'mozjpeg_encode', 'mozjpeg_decode', 'mozjpeg_check', 'mozjpeg_version', ], # '_openzl': [ # 'OPENZL', # 'OpenzlError', # 'openzl_encode', # 'openzl_decode', # 'openzl_check', # 'openzl_version', # ], '_pcodec': [ 'PCODEC', 'PcodecError', 'pcodec_encode', 'pcodec_decode', 'pcodec_check', 'pcodec_version', ], '_pglz': [ 'PGLZ', 'PglzError', 'pglz_encode', 'pglz_decode', 'pglz_check', 'pglz_version', ], '_pixarlog': [ 'PIXARLOG', 'PixarlogError', 'pixarlog_encode', 'pixarlog_decode', 'pixarlog_check', 'pixarlog_version', ], '_png': [ 'PNG', 'PngError', 'png_encode', 'png_decode', 'png_check', 'png_version', ], '_qoi': [ 'QOI', 'QoiError', 'qoi_encode', 'qoi_decode', 'qoi_check', 'qoi_version', ], '_quantize': [ 'QUANTIZE', 'QuantizeError', 'quantize_encode', 'quantize_decode', 'quantize_check', 'quantize_version', ], '_rgbe': [ 'RGBE', 'RgbeError', 'rgbe_encode', 'rgbe_decode', 'rgbe_check', 'rgbe_version', ], '_rcomp': [ 'RCOMP', 'RcompError', 'rcomp_encode', 'rcomp_decode', 'rcomp_check', 'rcomp_version', ], '_snappy': [ 'SNAPPY', 'SnappyError', 'snappy_encode', 'snappy_decode', 'snappy_check', 'snappy_version', ], '_sperr': [ 'SPERR', 'SperrError', 'sperr_encode', 'sperr_decode', 'sperr_check', 'sperr_version', ], '_spng': [ 'SPNG', 'SpngError', 'spng_encode', 'spng_decode', 'spng_check', 'spng_version', ], '_sz3': [ 'SZ3', 'Sz3Error', 'sz3_encode', 'sz3_decode', 'sz3_check', 'sz3_version', ], '_szip': [ 'SZIP', 'SzipError', 'szip_encode', 'szip_decode', 'szip_check', 'szip_version', 'szip_params', ], '_tiff': [ 'TIFF', 'TiffError', 'tiff_encode', 'tiff_decode', 'tiff_check', 'tiff_version', ], '_ultrahdr': [ 'ULTRAHDR', 'UltrahdrError', 'ultrahdr_encode', 'ultrahdr_decode', 'ultrahdr_check', 'ultrahdr_version', ], '_webp': [ 'WEBP', 'WebpError', 'webp_encode', 'webp_decode', 'webp_check', 'webp_version', ], '_zfp': [ 'ZFP', 'ZfpError', 'zfp_encode', 'zfp_decode', 'zfp_check', 'zfp_version', ], '_zlib': [ 'ZLIB', 'ZlibError', 'zlib_crc32', 'zlib_adler32', 'zlib_encode', 'zlib_decode', 'zlib_check', 'zlib_version', ], '_zlibng': [ 'ZLIBNG', 'ZlibngError', 'zlibng_crc32', 'zlibng_adler32', 'zlibng_encode', 'zlibng_decode', 'zlibng_check', 'zlibng_version', ], '_zopfli': [ 'ZOPFLI', 'ZopfliError', 'zopfli_encode', 'zopfli_decode', 'zopfli_check', 'zopfli_version', ], '_zstd': [ 'ZSTD', 'ZstdError', 'zstd_encode', 'zstd_decode', 'zstd_check', 'zstd_version', ], } # map extra to existing attributes _ALIASES: dict[str, str] = { 'JPEG': 'JPEG8', 'JpegError': 'Jpeg8Error', 'jpeg_check': 'jpeg8_check', 'jpeg_version': 'jpeg8_version', 'zopfli_check': 'zlib_check', 'zopfli_decode': 'zlib_decode', # 'zopfli_encode' is a different algorithm } # map attribute names to module names _ATTRIBUTES: dict[str, str] = { attribute: module for module, attributes in _MODULES.items() for attribute in attributes } # set of imported modules _IMPORTED: set[str] = set() _LOCK = threading.RLock() __all__ = [ attribute for attributes in _MODULES.values() for attribute in attributes ] def _add_codec( module: str, codec: str | None = None, attributes: tuple[str, ...] | None = None, /, ) -> None: """Register codec in global _MODULES and _ATTRIBUTES.""" 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 _MODULES: _MODULES[module].extend(attributes) else: _MODULES[module] = list(attributes) _ATTRIBUTES.update(dict.fromkeys(attributes, module)) def _load_all() -> None: """Add all registered attributes to package namespace.""" for name in __dir__(): __getattr__(name) def __dir__() -> list[str]: """Return list of attribute names accessible on module.""" return sorted(list(_ATTRIBUTES) + list(_ALIASES)) def __getattr__(name: str, /) -> Any: """Return module attribute after loading it from extension module. Load attribute's extension and add its attributes to the package namespace. """ name_ = name name = _ALIASES.get(name, name) if name not in _ATTRIBUTES: msg = f"module 'imagecodecs' has no attribute {name!r}" raise AttributeError(msg) module_name = _ATTRIBUTES[name] if not module_name: return None with _LOCK: if module_name in _IMPORTED: # extension module was imported in another thread # while this thread was waiting for lock return getattr(imagecodecs, name) try: module = importlib.import_module('.' + module_name, 'imagecodecs') except ImportError: module = None except AttributeError: # AttributeError: type object 'imagecodecs._module.array' has no # attribute '__reduce_cython__' # work around Cython raises AttributeError, for example, when # the _shared module failed to import due to an incompatible # numpy version from . import _shared # noqa: F401 module = None for n in _MODULES[module_name]: if n in _ALIASES: continue attr = getattr(module, n, None) if attr is None: attr = _stub(n, module) # TODO: do not set __module__? # it might interfere with introspection tools attr.__module__ = 'imagecodecs' setattr(imagecodecs, n, attr) attr = getattr(imagecodecs, name) if name != name_: setattr(imagecodecs, name_, attr) _IMPORTED.add(module_name) return attr def _set_module() -> None: """Set __module__ attribute on public objects.""" globs = globals() for item in _MODULES['']: if item in globs: obj = globs[item] if hasattr(obj, '__module__'): obj.__module__ = 'imagecodecs' class DelayedImportError(ImportError): """Delayed ImportError.""" def __init__(self, name: str, /) -> None: """Initialize instance from attribute name.""" msg = f"could not import name {name!r} from 'imagecodecs'" super().__init__(msg) def _stub(name: str, module: ModuleType | None, /) -> Any: """Return stub constant, function, or class.""" if name.endswith('_version'): if module is None: def stub_version() -> str: """Stub for imagecodecs.codec_version function.""" return f'{name[:-8]} n/a' else: def stub_version() -> str: """Stub for imagecodecs.codec_version function.""" return f'{name[:-8]} unknown' return stub_version if name.endswith('_check'): def stub_check(arg: Any, /) -> bool: """Stub for imagecodecs.codec_check function.""" return False return stub_check if name.endswith('_decode'): def stub_decode(*args: Any, **kwargs: Any) -> None: """Stub for imagecodecs.codec_decode function.""" raise DelayedImportError(name) return stub_decode if name.endswith('_encode'): def stub_encode(*args: Any, **kwargs: Any) -> None: """Stub for imagecodecs.codec_encode function.""" raise DelayedImportError(name) return stub_encode if name.islower(): def stub_function(*args: Any, **kwargs: Any) -> None: """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: Any, **kwargs: Any) -> None: raise DelayedImportError(name) return StubError class StubType(type): """Stub type metaclass.""" def __getattr__(cls, arg: str, /) -> Any: raise DelayedImportError(name) if module is None: def __bool__(cls) -> bool: return False if name.isupper(): class STUB(metaclass=StubType): """Stub for imagecodecs.CODEC constants.""" available: bool = False return STUB class Stub(metaclass=StubType): """Stub for imagecodecs.Codec class.""" return Stub def _extensions() -> tuple[str, ...]: """Return sorted names of extension modules.""" return tuple(sorted(e for e in _MODULES if e)) def _codecs(*, available: bool | None = None) -> tuple[str, ...]: """Return sorted names of codecs. If `available` is not None, all extension modules are imported into the process. """ codecs: tuple[str, ...] = tuple( sorted(c.lower() for c in _ATTRIBUTES if c.isupper()) ) if available is None: return codecs if available: return tuple( c for c in codecs if getattr(imagecodecs, c.upper()).available ) return tuple( c for c in codecs if not getattr(imagecodecs, c.upper()).available ) def version( astype: type | None = None, / ) -> str | tuple[str, ...] | dict[str, str]: """Return version information about all codecs and dependencies. All extension modules are imported into the process. """ versions: tuple[str, ...] = ( f'imagecodecs {__version__}', imagecodecs.cython_version(), imagecodecs.numpy_version(), imagecodecs.numpy_abi_version(), imagecodecs.imcd_version(), *sorted( # use set to filter duplicates { str(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: str | os.PathLike[Any] | bytes | mmap.mmap, /, codec: ( str | Callable[..., NDArray[Any]] | list[str | Callable[..., NDArray[Any]]] | None ) = None, *, memmap: bool = True, return_codec: bool = False, **kwargs: Any, ) -> NDArray[Any] | tuple[NDArray[Any], Callable[..., NDArray[Any]]]: """Return image data from file as numpy array.""" import mmap # determine list of codecs based on file extension or provided codec codecs: list[str | Callable[..., NDArray[Any]]] = [] if codec is None: # find codec based on file extension ext_to_codec, codec_list = _imcodecs() if isinstance(fileobj, (str, os.PathLike)): ext = os.path.splitext(os.fspath(fileobj))[-1][1:].lower() else: ext = None if ext in ext_to_codec: codec = ext_to_codec[ext] if codec == 'jpeg8': codecs.extend(('jpeg8', 'ljpeg')) # 'jpegsof3' else: codecs.append(codec) # also try other imaging codecs codecs.extend(c for c in codec_list if c not in codecs) else: # use provided codecs if not isinstance(codec, (list, tuple)): # collections.abc.Iterable codec = [codec] for c in codec: if isinstance(c, str): cl = c.lower() codecs.append(_imcodecs()[0].get(cl, cl)) else: codecs.append(c) del codec # read data from file object func: Callable[..., NDArray[Any]] | None = None exceptions: list[str] = [] image: NDArray[Any] | None = None data: bytes | bytearray | mmap.mmap offset: int = -1 close = False try: # TODO: support urllib.request.urlopen ? if isinstance(fileobj, (str, os.PathLike)): # 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() elif isinstance(fileobj, mmap.mmap): data = fileobj offset = data.tell() elif hasattr(fileobj, 'read'): # binary stream: open file, BytesIO data = fileobj.read() assert isinstance(data, (bytes, bytearray)) else: # binary data data = fileobj assert isinstance(data, (bytes, bytearray, mmap.mmap)) # try decode data using codecs numthreads = kwargs.pop('numthreads', None) for codec in codecs: # get decoder function or class if callable(codec): func = codec else: try: func = getattr(imagecodecs, codec + '_decode') assert callable(func) except Exception as exc: exceptions.append(f'{repr(codec).upper()}: {exc}') continue _numthreads = numthreads if _numthreads is not None and not func.__name__.startswith( ('avif', 'jpeg2k', 'jpegxl', 'zfp') ): _numthreads = None # decode data try: if _numthreads is None: image = func(data, **kwargs) else: image = func(data, numthreads=_numthreads, **kwargs) assert isinstance(image, numpy.ndarray) if image.dtype.kind == 'O': msg = 'failed' raise ValueError(msg) # noqa: TRY301 break except DelayedImportError: pass except Exception as exc: # raise # uncomment for debugging exceptions.append(f'{func.__name__.upper()}: {exc}') if offset >= 0: assert isinstance(data, mmap.mmap) data.seek(offset) finally: if close: assert isinstance(data, mmap.mmap) data.close() if image is None: raise ValueError('\n'.join(exceptions)) if return_codec: if func is None: msg = 'no valid decoder found' raise ValueError(msg) return image, func return image def imwrite( fileobj: str | os.PathLike[Any] | IO[bytes], data: ArrayLike, /, codec: str | Callable[..., bytes | bytearray] | None = None, **kwargs: Any, ) -> None: """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: msg = 'no codec specified' raise ValueError(msg) codec = _imcodecs()[0].get(ext, ext) try: codec = getattr(imagecodecs, codec + '_encode') except AttributeError as exc: msg = f'invalid {codec=!r}' raise ValueError(msg) from exc elif isinstance(codec, str): codec = codec.lower() codec = _imcodecs()[0].get(codec, codec) try: codec = getattr(imagecodecs, codec + '_encode') except AttributeError as exc: msg = f'invalid {codec=!r}' raise ValueError(msg) from exc if not callable(codec): msg = f'invalid {codec=!r}' raise TypeError(msg) image: bytes | bytearray = codec(data, **kwargs) if hasattr(fileobj, 'write'): # binary stream: open file, BytesIO fileobj.write(image) else: # file name with open(fileobj, 'wb') as fh: fh.write(image) @functools.cache def _imcodecs() -> tuple[dict[str, str], list[str]]: """Return map of image file extensions to codec names and codec names.""" codecs = { 'apng': ('apng',), 'avif': ('avif', 'avifs'), 'bmp': ('bmp', 'dip'), # 'rle' 'brunsli': ('brn',), 'dds': ('dds',), # 'exr': ('exr',), 'gif': ('gif',), 'heif': ( 'heif', 'heic', 'heifs', 'heics', 'hif', # 'avci', 'avcs' ), 'htj2k': ( 'htj2k', 'jph', # HTJ2K with JP2 boxes 'jhc', # HTJ2K codestream # 'j2c', ), 'jpeg2k': ( 'j2k', 'jp2', 'j2c', 'jpc', 'jpx', 'jpf', 'jpg2', # 'jph', # HTJ2K with JP2 boxes # 'jhc', # HTJ2K codestream ), 'jpeg8': ('jpg', 'jpeg', 'jpe', 'jfif', 'jfi', 'jif'), # 'jpegli': ('jli',), 'jpegls': ('jls',), 'jpegxl': ('jxl',), 'jpegxr': ('jxr', 'hdp', 'wdp'), 'jpegxs': ('jxs',), 'lerc': ('lerc1', 'lerc2'), 'ljpeg': ('ljp', 'ljpg', 'ljpeg'), 'numpy': ('npy', 'npz'), 'png': ('png',), 'qoi': ('qoi',), 'rgbe': ('hdr', 'rgbe', 'pic'), # 'tga': ('tga'), 'tiff': ('tif', 'tiff', 'ptif', 'ptiff', 'tf8', 'tf2', 'btf'), 'ultrahdr': ('uhdr', 'jpr'), # jpg 'webp': ('webp', 'webm'), 'zfp': ('zfp',), } return ( {ext: codec for codec, exts in codecs.items() for ext in exts}, list(codecs.keys()), ) def imagefileext() -> list[str]: """Return list of image file extensions handled by imread and imwrite.""" return list(_imcodecs()[0].keys()) class NONE: """NONE codec constants.""" available = True """NONE codec is available.""" class NoneError(RuntimeError): """NONE codec error.""" def none_version() -> str: """Return empty version string.""" return '' def none_check(data: Any, /) -> None: """Return None.""" def none_decode(data: Any, *args: Any, **kwargs: Any) -> Any: """Return data unchanged.""" return data def none_encode(data: Any, *args: Any, **kwargs: Any) -> Any: """Return data unchanged.""" return data class NUMPY: """NUMPY codec constants.""" available = True """NUMPY codec is available.""" class NumpyError(RuntimeError): """NumPy codec error.""" def numpy_version() -> str: """Return Numpy library version string.""" return f'numpy {numpy.__version__}' def numpy_check(data: bytes | bytearray, /) -> bool: """Return whether data is NPY or NPZ encoded or None if unknown.""" 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: bytes, /, index: int = 0, *, out: NDArray[Any] | None = None, **kwargs: Any, ) -> NDArray[Any]: """Return decoded NPY or NPZ data.""" with io.BytesIO(data) as fh: try: result = numpy.load(fh, **kwargs) except ValueError as exc: msg = 'not a numpy array' raise ValueError(msg) from exc if hasattr(result, 'files'): with contextlib.suppress(Exception): index = result.files[index] result = result[index] return result # type: ignore[no-any-return] def numpy_encode( data: ArrayLike, /, level: int | None = None, *, out: int | bytearray | None = None, ) -> bytes: """Return NPY or NPZ encoded data.""" with io.BytesIO() as fh: if level: numpy.savez_compressed(fh, data) else: numpy.save(fh, data) fh.seek(0) return fh.read() def jpeg_decode( data: bytes, /, *, tables: bytes | None = None, header: bytes | None = None, colorspace: int | str | None = None, outcolorspace: int | str | None = None, shape: tuple[int, ...] | None = None, bitspersample: int | None = None, # required for compatibility out: NDArray[Any] | None = None, ) -> NDArray[Any]: """Return decoded JPEG image.""" del bitspersample if header is not None: data = b''.join((header, data, b'\xff\xd9')) try: return imagecodecs.jpeg8_decode( # type: ignore[no-any-return] data, tables=tables, colorspace=colorspace, outcolorspace=outcolorspace, shape=shape, out=out, ) except Exception as exc: # try LJPEG codec, which handles more precisions and colorspaces msg = str(exc) if ( 'Unsupported JPEG data precision' in msg or 'Unsupported color conversion' in msg or 'Bogus Huffman table definition' in msg or 'SOF type' in msg ): with contextlib.suppress(Exception): return imagecodecs.ljpeg_decode( # type: ignore[no-any-return] data, out=out ) # elif 'Empty JPEG image' in msg: # for example, Hamamatsu NDPI slides with dimensions > 65500 # Unsupported marker type raise def jpeg_encode( data: ArrayLike, /, level: int | None = None, *, colorspace: int | str | None = None, outcolorspace: int | str | None = None, subsampling: str | tuple[int, int] | None = None, optimize: bool | None = None, smoothing: bool | None = None, lossless: bool | None = None, predictor: int | None = None, bitspersample: int | None = None, out: int | bytearray | None = None, ) -> bytes | bytearray: """Return JPEG encoded image.""" if ( lossless and not getattr(imagecodecs.JPEG8, 'all_precisions', False) and bitspersample not in {None, 8, 12, 16} ): return imagecodecs.ljpeg_encode( # type: ignore[no-any-return] data, bitspersample=bitspersample, out=out ) return imagecodecs.jpeg8_encode( # type: ignore[no-any-return] data, level=level, colorspace=colorspace, outcolorspace=outcolorspace, subsampling=subsampling, optimize=optimize, smoothing=smoothing, lossless=lossless, predictor=predictor, bitspersample=bitspersample, out=out, ) imagecodecs = sys.modules['imagecodecs'] _set_module()