openimageio 3.1.6.1

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Created by brew bump

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Created with brew bump-formula-pr.

Details

release notes

Release 3.1 (Oct 2, 2025) -- compared to 3.0.x
-----------------------------------------------------
- Beta 1: Aug 22, 2025
- Beta 2: Sep 19, 2025
- Release candidate 1: Sep 27, 2025
- Full release, v3.1.6.1: Oct 2, 2025
Executive Summary / Highlights:

New image file support: Ultra HDR (HDR images in JPEG containers).
oiiotool new commands: --layersplit, --pastemeta, --demosaic,

--create-dir and new expression expansion tokens: IS_CONSTANT,

IS_BLACK, SUBIMAGES.
New IBA image processing functions: scale(), demosaic().
New 2-level namespace scheme that we hope will make it possible in the

future for our annual releases to NOT need to break backward ABI

compatibility.
Support in Python for ImageBuf._repr_png_ method allows use of OIIO

inside Jupyter Notebooks to display computed

images.
Color management improvements: Conform to Color Interchange Forum and

OpenEXR new conventions for naming and specifying color spaces. PNG,

HEIC, and ffmpeg/video files now support reading CICP metadata.

New minimum dependencies and compatibility changes:

Python: 3.9 minimum (from 3.7) #4830 (3.1.4.0)
OpenColorIO: 2.3 minimum (from 2.2) #4865 (3.1.4.0)

⛰️  New features and public API changes:

New image file format support:

jpeg: Support reading Ultra HDR images #4484 (by Loïc Vital) (3.1.0.0/3.0.1.0)


oiiotool new features and major improvements:

New expression eval tokens: IS_CONSTANT, IS_BLACK #4610 (by Lydia Zheng) (3.1.1.0); SUBIMAGES #4804 (3.1.3.0)
--layersplit, new command to split layers #4591 (by Loïc Vital) (3.1.1.0)
--pastemeta now takes additional modifiers that allows options for merging rather than rewriting, and is able to copy only a subset of the metadata specified by a regex. #4672 #4674 #4676 (3.1.1.0)
--demosaic add X-Trans demosaicing #4579 (by Anton Dukhovnikov) (3.1.1.0)
--render_text new modifiers measure= and render= can

be used to measure the size of rendered text without drawing it.` #4681 (3.1.3.0)
--create-dir flag creates directories needed by -o

if they doesn't already exist #4762 (by Dharshan Vishwanatha) (3.1.3.0)
--eraseattrib new modifier :fromfile=1 reads from a file

to get a list of patterns to specify the attributes to erase. #4763 (by Lydia Zheng) (3.1.3.0)
oiiotool: Allow easy splitting of subimages by name #4874 (3.1.5.0)


Command line utilities:

iv: Implement files drag and drop into an iv window #4774 (by Aleksandr Motsjonov) (3.1.3.0)
iv: Area probe #4767 (by Danielle Imogu) (3.1.3.0)
iv: Add min/max/avg and sizing to pixel closeup view #4807 (by Aleksandr Motsjonov) (3.1.4.0)


ImageBuf/ImageBufAlgo:

New ImageBuf::merge_metadata(): merges one IB's metadata into another's without deleting the metadata already present. It can also filter which metadata are copied using a regex. #4672 (3.1.1.0)
New ImageBufAlgo::scale(): scales all channels of a multi-channel image by the single channel of a second image. #4541 (by Anton Dukhovnikov) (3.1.0.0/3.0.1.0)
ImageBufAlgo::demosaic() added support for X-Trans demosaicing #4579 (by Anton Dukhovnikov) (3.1.1.0)


APIs moving to span and image_span:

Add API calls using span and image_span as the preferred alternative for

the historical calls that took raw pointers and spans to designate buffers

to read from or write into.

image_span.h: Add image_span template, deprecate image_view #4703 #4784 (3.1.3.0)
ImageInput / ImageOutput: #4669 (3.1.1.0) #4727 #4748 (3.1.3.0)
ImageCache/TextureSystem: #4783 (3.1.3.0) #4838 (3.1.4.0)
ImageBuf: #4814 (3.1.3.0) #4827 (3.1.4.0)


ImageCache/TextureSystem:

maketx: Add maketx flags to increase feature parity with txmake #4841 (by Scott Milner) (3.1.4.0)


New global attribute queries via OIIO::getattribute():

Added queries for available font families and styles #4523 (by peterhorvath111) (3.1.0.0/3.0.1.0)
api: Add global attribute imageinput:strict #4560 (3.1.0.0)


Miscellaneous API changes:

api: Make a 2-level namespace scheme #4567 (by Larry Gritz) #4603 (by Brecht Van Lommel) (3.1.1.0) #4869 (3.1.5.0)
api: ImageSpec::scanline_bytes, tile_bytes, image_bytes #4631 (3.1.1.0)
python: ImageBuf _repr_png_ method added, which allows use of

ImageBuf in Jupyter Notebooks as a displayable object. #4753 (by Oktay Comu) (3.1.3.0)
python: Add python stub files #4692 (by Chad Dombrova) (3.1.3.0)
api: Add new ImageInput::supports() query: "mipmap" #4800 (3.1.3.0)


Color management changes

color mgmt: Don't assume unlabeled OpenEXR files are lin_rec709 #4840 (3.1.4.0)
color mgmt: Color space renaming to adhere to CIF conventions #4860 (3.1.4.0)
Ability to read CICP metadata from PNG #4746 (by Zach Lewis) (3.1.5.0), HEIC #4880 (by Brecht Van Lommel) (3.1.5.0), and video files/ffmpeg #4882 (by Brecht Van Lommel) (3.1.5.0).



🚀  Performance improvements:

perf: IBA::unsharp_mask() speed and memory optimization #4513 (by Vlad (Kuzmin) Erium) (3.1.0.0/3.0.1.0)
perf: Oiiotool --line --text --point --box speedups #4518 (3.1.0.0/3.0.1.0)
perf: Jpeg2000 valid_file implementation, much faster than trying to open #4548 (by Aras Pranckevičius) (3.1.0.0/3.0.1.0)
perf: Faster utf8<->utf16 conversion on Windows #4549 (by Aras Pranckevičius) (3.1.0.0/3.0.1.0)
perf: Speed up maketx --envlatl when multithreaded by over 10x. #4825
perf: Speed up OpenEXR non-core header read time #4832

🐛  Fixes and feature enhancements:

oiiotool: Better handling of wildcards that match no files #4627 (3.1.1.0)
oiiotool: Invalid loop bound when appending mipmap textures using oiiotool #4671 (by Basile Fraboni) (3.1.1.0)
oiiotool: -i:native=1, fix --native behavior, fix convert datatype #4708 (3.1.3.0)
oiiotool: Fixes to --missingfile behavior #4803 (3.1.3.0)
oiiotool: Allow thread control for --parallel-frames #4818 (3.1.3.0)
oiiotool: Use normalized path when creating wildcard path pattern #4904 (by Jesse Yurkovich) (3.1.6.0)
oiiotool: Ignore empty subimage(s) when calculating non-zero region #4909 (by Carine Touraille) (3.1.6.0)
color mgmt: Support OCIO Viewing Rules, other OCIO-related improvements #4780 (by zachlewis) (3.1.3.0)
iv: Fix crash on .DS_Store; fix uppercase extensions #4764 (by Anton Dukhovnikov) (3.1.3.0)
iv: Do not resize on open and other zoom fixes #4766 (by Aleksandr Motsjonov) (3.1.3.0)
iv: Bug fix for iv window losing focus on mac on startup #4773 (by Aleksandr Motsjonov) (3.1.3.0)
iv: Use screen pixel ratio to render sharp text in pixel view tool #4768 (by Aleksandr Motsjonov) (3.1.3.0)
IBA: IBA:demosaic add white balancing #4499 (by Anton Dukhovnikov) (3.1.0.0/3.0.1.0)
IBA: IBA::demosaic - fix roi channels #4602 (by Anton Dukhovnikov) (3.1.1.0)
IBA: Add 'auto' value for all options of IBA::demosaic() #4786 (by Anton Dukhovnikov) (3.1.3.0)
ImageBuf: IB::pixeltype() did not always return the right value #4614 (3.1.1.0)
ImageBuf: Fix bug in ImageBuf construction from ptr + neg strides #4630 (3.1.1.0)
ImageBuf: Better errors for nonexistent subimages/mips #4801 (3.1.3.0)
ImageInput: Incorrect IOProxy logic related to valid_file #4839 (3.1.4.0)
python: Disable loading Python DLLs from PATH by default on Windows #4590 (by zachlewis) (3.1.1.0)
python: Fix handle leak #4685 (3.1.3.0)
python: IBA.demosaic had GIL release in wrong spot #4777 (3.1.3.0)
python: Python ImageBuf.init_spec did not return correct value #4805 (3.1.3.0)
python: Got strides wrong passing 2D numpy pixel array #4843 (3.1.4.0)
exr: Allow an empty "name" metadata to be read #4528 #4536 (3.1.0.0/3.0.1.0)
exr: Avoid integer overflow for large deep exr slice strides #4542 (3.1.0.0/3.0.1.0)
exr: Fill in OpenEXR lineOrder attribute when reading #4628 (by vernalchen) (3.1.1.0)
exr: Did not properly allocate 'missingcolor' vector #4751 (3.1.3.0)
exr: Not honoring 'missingcolor' for scanline files #4757 (3.1.3.0)
ffmpeg: FFmpeg incorrectly set zero oiio:BitsPerSample #4885 (by Brecht Van Lommel) (3.1.5.0)
ffmpeg: Add ability to read CICP metadata #4882 (by Brecht Van Lommel) (3.1.5.0)
gif: Gif output didn't handle FramesPerSecond attribute correctly #4890 (3.1.5.0)
heic: Read and write of CICP and support for bit depth 10 and 12 #4880 (by Brecht Van Lommel) (3.1.5.0)
ico: More robust to corrupted ICO files #4625 (3.1.1.0)
iff: Improved IFF support reading and writing z buffers #4673 (by Mikael Sundell) (3.1.3.0)
jpeg: Support encoding/decoding arbitrary metadata as comments #4430 (by Lukas Stockner) (3.1.0.0/3.0.1.0)
jpeg-2000: Write .j2c by adding HTJ2K Encoding using the OpenJPH library. #4699 (by Sam Richards) (3.1.3.0)
png: Alpha premultiplication adjustment and attribute #4585 (3.1.1.0)
png: Increase allowed width/height limit #4655 (by Jesse Yurkovich) (3.1.1.0)
png: CICP metadata support for PNG #4746 (by Zach Lewis) (3.1.5.0)
pnm: Broken pgm having memory access error #4559 (3.1.0.0)
psd: Perform endian byteswap on correct buffer area for PSD RLE #4600 (by Jesse Yurkovich) (3.1.1.0)
psd: ICC profile reading improvements, especially for PSD #4644 (3.1.1.0)
psd: Updated tag recognition for psb #4663 (by Lydia Zheng) (3.1.1.0)
raw: Fix channel layout #4516 (by Anton Dukhovnikov) (3.1.0.0/3.0.1.0)
raw: Add black level and BPS metadata #4601 (by Anton Dukhovnikov) (3.1.1.0)
raw: Add raw:ForceLoad ImageInput configuration hint #4704 (by Anton Dukhovnikov) (3.1.3.0)
raw: Add thumbnail support to the raw input plugin #4887 (by Anton Dukhovnikov) (3.1.5.0)
rla: More robust to corrupted RLA files that could overrun buffers #4624 (3.1.1.0)
sgi: Fix valid_file to properly swap bytes on little-endian platforms #4697 (by Jesse Yurkovich) (3.1.3.0)
tiff: The default value for bitspersample should be 1 #4670 (by vernalchen) (3.1.1.0)
webp: Respect the oiio:UnassociatedAlpha attribute #4770 (by Jesse Yurkovich) (3.1.3.0)
webp: Allow finer grained control over WEBP compression settings #4772 (by Jesse Yurkovich) (3.1.3.0)
webp: Support reading/writing the ICCProfile attribute #4878 (by Jesse Yurkovich) (3.1.5.0)
various formats: Detect invalid ICC profile tags #4557 #4561 (3.1.0.0)
various formats: IPTC fields have length limits #4568 (3.1.0.0)

🔧  Internals and developer goodies

int: Some LoggedTimer instances lacked a variable name #4571 (3.1.0.0)
int: Various internal fixes to address Sonar and other warnings #4577 (3.1.0.0)
int: No longer need OIIO_INLINE_CONSTEXPR macro #4607 (3.1.1.0)
int: Get rid of some compiler symbols no longer needed #4606 (3.1.1.0)
int: Switch to spans for some exif manipulation, fixing warnings #4689 (3.1.1.0)
int: Rearrange initialize_cuda() for better err check, no warn #4726 (3.1.3.0)
int: Experimental default_init_allocator and default_init_vector #4677 (3.1.3.0)
int: Address some nitpick sonar warnings about TileID initialization #4722 (3.1.3.0)
int: Address safety warnings in pvt::append_tiff_dir_entry #4737 (3.1.3.0)
int: ImageInput/ImageOutput did not set per-file threads correctly #4750 (3.1.3.0)
int/iv: Add raw string syntax modifier for VSCode and Cursor to understand its glsl #4796 (by Aleksandr Motsjonov) (3.1.3.0)
int/iv: Use R"()" syntax for glsl shader strings for better readability #4795 (by Aleksandr Motsjonov) (3.1.3.0)
int: ImageOutput::check_open logic was flawed #4779 (3.1.3.0)
int: Switch to posix_spawnp for macOS background launch to enable PATH lookup #4834 (by Mikael Sundell) (3.1.4.0)
filesystem.h: Filesystem::getline() #4569 (3.1.1.0)
fmath.h: Add span-based bit_unpack() utility #4723 (3.1.3.0)
fmath.h: Renaming and fixing of shuffle template #4739 (3.1.3.0)
paramlist.h: ParamValue as_span, as_cspan (3.1.1.0)
span.h: span_memcpy is a safer memcpy when you know the span boundaries #4597 (3.1.1.0)
span.h: Only allow span-from-array if array for compatible size #4656 (3.1.1.0)
span.h: OIIO::span improvements #4667 (3.1.1.0)
span.h: Eliminate needless definitions of std::size #4652 (3.1.1.0)
sysutil.h: Improve the implementation of Sysutil::put_in_background on macOS #4640 (by Mikael Sundell) (3.1.1.0)
typedesc.h: Tidying of type trait templates #4705 (3.1.3.0)

🏗  Build/test/CI and platform ports:

CMake build system and scripts:

build: Add hardening options #4538 (3.1.0.0/3.0.1.0)
build: Use target_compile_options (fixes a LibRaw build issue) #4556 (by Don Olmstead) (3.1.0.0)
build: Python wheels workflow and build backend #4428 (by zachlewis) (3.1.1.0)
build: Recent change broke when using non-Apple clang on Apple #4596 (3.1.1.0)
build: Fix recently broken rpath setting #4618 (3.1.1.0)
build: Improve OpenJpeg version detection. #4665 (by jreichel-nvidia) (3.1.1.0)
build: Fix recently broken rpath to restore python wheel building #4633 (3.1.1.0)
build: Ensure python-based builds use maj.min.patch SO versioning #4634 (by zachlewis) (3.1.1.0)
build: Better disabling of work when USE_PYTHON=0 #4657 (3.1.1.0)
build: Bump auto-build libdeflate to 1.23 to avoid AVX512 not available errors #4679 (by LI JI) (3.1.1.0)
build: Cmake 4.0 compatibility #4686 #4688 (3.1.1.0)
build: Make sure the CHANGES-2.x.md makes it into the installation #4611 (3.1.1.0)
build: Address Robin-map vs CMake 4.0 compatibility #4701 (3.1.3.0)
build: Fix broken OIIO_SITE customization #4709 (3.1.3.0)
build: Restore OIIO_AVX512ER_ENABLED preprocessor symbol #4735 (3.1.3.0)
build: Address compiler warnings #4724 (3.1.3.0)
build: Fix furo requirement after recently breaking docs #4743 (3.1.3.0)
build: Clean up Windows compilation warnings #4706 (3.1.3.0)
build/python: Wheel upload_pypi step should only run from main repo #4820 (3.1.3.0)
build: Fix typo related to finding ccache #4833 (3.1.4.0)
build: C++23 support #4844 (3.1.4.0)
build: Clean up obsolete logic for old compilers #4849 (3.1.5.0)
build: Update autobuild defaults for some dependencies #4910 (3.1.6.1)


Dependency and platform support:

build(OCIO): Support static OCIO self-builds #4517 (by zachlewis) (3.1.0.0/3.0.1.0)
build(PNG): Add build recipe for PNG #4423 (by zachlewis) (3.1.0.0/3.0.1.0); PNG auto-build improvements #4835 (3.1.4.0)
deps(cmake): Fix build_cmake.bash script for aarch64, bump its default version #4581 (3.1.1.0)
deps(dcmtk): Fix new dcmtk 3.6.9 vs C++ warning #4698 (3.1.3.0)
deps(ffmpeg): Ffmpeg 8 support #4870 (3.1.5.0)
deps(ffmpeg): Replace deprecated and soon removed avcodec_close with avcodec_free_context #4837 (by Vlad Erium) (3.1.4.0)
deps(fmt): Fix failed test with old fmt #4758 (3.1.3.0)
deps(fmt): Fix fmt throwing behavior warnings #4730 (3.1.3.0)
deps(freetype): Test freetype 2.14 and document that it works #4876 (3.1.5.0)
deps(freetype): Update ref image for slightly changed freetype accents #4765 (3.1.3.0)
deps(jpeg2000): Update jpeg2000input.cpp to include cstdarg #4836 (by Peter Kovář) (3.1.4.0)
deps(libheif): Add new ref output for libheif updates #4525 (3.1.0.0/3.0.1.0)
deps(libheif): Use get_plane2 introduced by libheif 1.20.2 #4851 (by toge) (3.1.4.0)
deps(libraw): Fix libraw definitions (again) #4588 (3.1.1.0)
deps(libultrahdr): Detect libultrahdr version and enforce minimum of 1.3 #4729 (3.1.3.0)
deps(OCIO): Raise OpenColorIO minimum to 2.3 (from 2.2) #4865 (3.1.4.0)
deps(openexr): OpenEXR 3.4 supports two compression types for HTJ2K #4871 (by Todica Ionut) (3.1.5.0)
deps(openexr): Several OpenEXR and OpenJPH build related fixes #4875 (3.1.5.0)
deps(openjph): Fix openjph target use #4894 (3.1.5.0)
deps(openvdb): Look for boost headers for OpenVDBs older than 12 #4873 (by Alex Fuller) (3.1.5.0)
deps(python): Raise minimum supported Python from 3.7 to 3.9 #4830 (3.1.4.0)
deps(opencolorio): Support for OpenColorIO 2.5 #4916 (3.1.6.1)
windows: Include Windows version information on produced binaries #4696 (by Jesse Yurkovich) (3.1.3.0)
windows: Propagate CMAKE_MSVC_RUNTIME_LIBRARY #4842 (3.1.4.0)
windows + ARM64: Add arm_neon.h include on Windows ARM64 with clang-cl #4691 (by Anthony Roberts)
NetBSD: Fix build on NetBSD #4857 (by Thomas Klausner) (3.1.4.0)
build: Fix some build issues encountered on a musl libc system #4903 (by omcaif) (3.1.6.0)


Testing and Continuous integration (CI) systems:

tests: Improve Ptex testing #4573 (3.1.1.0)
tests: Better testing coverage of null image reader/writer #4578 (3.1.1.0)
tests: At long last, set up a softimage reading test (3.1.1.0)
tests: Additional ref output for jpeg-corrupt test #4595 (3.1.1.0)
ci: Increased the macos timeout slightly to fix spurious failures #4526 (3.1.0.0/3.0.1.0)
ci: Don't rebuild docs in CI when only CMakeLists.txt changes #4539 (3.1.0.0/3.0.1.0)
ci: Fix broken CI for ASWF 2021 and 2022 containers #4543 (3.1.0.0/3.0.1.0)
ci: Refactor using a single steps workflow #4545 (3.1.0.0)
ci: Fixups of analysis workflow #4572 (3.1.0.0)
ci: Upgrade to newer actions #4570 (3.1.1.0)
ci: Test and document support for WebP 1.5 and fmt 11.1 #4574 (3.1.1.0)
ci: Only pass build-steps the secrets it needs #4576 (3.1.1.0)
ci: Fix Windows 2019 CI -- make python version match the runner #4592 (3.1.1.0)
ci: Raise 'latest' tests to use new fmt 11.1.2 #4593 (3.1.1.0)
ci: Adjust some pugixml versions #4594 (3.1.1.0)
ci: Allow special branch names to prune CI jobs #4604 (3.1.1.0)
ci: Unbreak the scorecard workflow #4605 (3.1.1.0)
ci: Switch to using ARM-native linux runners #4616 (by zachlewis)...

View the full release notes at https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.1.6.1.

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