libjxl-0.12.0

[Bruce Dubbs]

New minor version.

[Joe Locash]

## [0.12.0] - 2026-07-01

### Added

- A new buffering flag is now available in the CLI, alongside support for
  streaming input with buffered output. (#4634)
- Introduced the new `jxltran` tool, which supports extracting codestreams from
  `jxlp` boxes and packing raw codestreams into `jxlc` boxes. (#4161, #4165,
  #4168, #4196)
- Added the `--reconstruct_jpeg` flag to `djxl` to losslessly reconstruct a
  JPEG and fail if impossible (mutually exclusive with `--pixels_to_jpeg` and
  `--jpeg_quality`). (#4498)
- Added `JXL_DEC_UNSUPPORTED` (`kUnsupported`) status code to the core API to
  better indicate when requested features or operations are not supported by
  the decoder. (#4390)
- tools: added support for `ProPhoto` (#4824) and `Adobe98` / `AdobeRGB`
  (#4199) color space names in CLI arguments (`cjxl` / `djxl`).
- decoder API: support for out-of-order `jxlp` boxes (ftyp minor version 1).
  (#4741)
- encoder API: `JXL_ENC_FRAME_SETTING_OUTPUT_MODE` frame setting to control how
  the codestream is written to the output. Mode 0 (default) buffers the output
  internally and produces a normally ordered, progressively decodable
  codestream. Mode 1 uses seek-based streaming (reduces peak memory for large
  images, requires a seekable output stream). Mode 2 uses out-of-order `jxlp`
  boxes (reduces peak memory without requiring seeking, but requires a decoder
  that supports ftyp minor version 1). (#4745)

### Changed

- Major overhaul for faster decoding and progressive lossless. (#4201, #4641,
  #4811)
  - Progressive lossless images are around 30-40% smaller and are now
    multithreaded increasing encoding performance by 2-5x.
  - Lossless images with faster decoding are now 30-80% smaller and their
    decoding speeds properly scale as the faster decoding level increases
    from 1-4.
  - Disabled global palette for progressive images, fixing glitchy progressive
    loading for indexed/low color images and restoring transparency support
    (Note: this causes a density/speed penalty for very low bit-depth images).
- Numerous speed/memory usage improvements.
  - Improved encoding speeds by SIMDifying `EstimateCost` (+5% performance) and
    speeding up uint-coding trials. (#4322, #4330)
  - Accelerated modular encoding and decoding via SIMD optimizations for
    forward RCT transforms and upsampling (up to 4x faster). (#4332, #4384)
  - Massive overhaul to histogram encoding and decoding, providing significant
    performance optimizations for modular mode. (#4123, #4132, #4136, #4185)
  - Tweaked JPEG recompression logic to improve density and efficiency. (#4202)
  - Fixed performance regressions in fast lossless modes and optimized
    text-like patch detection. (#4341, #4448)
  - Refined x86 `XCR0` CPU checks to prevent issues on specific hardware.
    (#4449)
  - Migrated Windows release builds to use `clang-cl`, which improves
    performance across the board. (#4529)
  - Improved use of SIMD in tree construction hot loop. (#4720)
  - Improved spline caching. (#4857)
  - Postponed JPEG coeffs allocation until first SOS. (#4863)
- The default buffering level in the CLI has been changed to `2`, greatly
  improving encoding performance for images under 2048x2048. Additionally,
  output is buffered by default to allow basic progressive loading. (#4635,
  #4637, #4642)
- Better Density/Speed tradeoff for lossless effort levels. (#4236)
- Improved visual quality of gradients by using channel-offset blue noise
  dithering instead of bayer when decoding to lower bitdepths. (#4305, #4559)
- Lossy modular encoding quality/density improvements. (#3575)
- `local_tone_map` tool: Now produces SDR output in the `DisplayP3` color space
  rather than `Rec2020`. Also added an optional third command-line argument to
  dump the HDR image as a raw `rgba1010102` file for use with the `libultrahdr`
  example app. (#4210)
- Significant improvements to EXR input/output handling for cjxl. Now supports
  reading float32, multilayer, per-channel bitdepth, and writing greyscale
  EXR images. (#4312, #4460)
- The decoder API for `JxlDecoderSetImageOutBuffer` and
  `JxlDecoderSetPreviewOutBuffer` has been clarified; their timeframes are now
  non-intersecting, preventing accidental buffer overwrites. (#4671)
- Layered JXL files are no longer coalesced when re-encoding with cjxl, and
  can now be decoded to separate PNG/PAM files with djxl by using
  `--no_coalescing`. (#4299)
- The progressive flag `-p` in cjxl will now encode a more progressive image.
  (#4258, #4699)
- When lossy encoding, resampling 2 is now enabled at distance 10, and is up to
  10x faster below effort 10 by using a faster downsampling method. (#4147)
- Faster PNG compression. (#3819)
- decoder API: documented that at most one preview image exists in a
  codestream.
  (#4671)
- encoder API: corrected documentation for box size header in
  `JxlEncoderAddBox` (0 means box extends to end of file, 1 means 64-bit size
  follows). (#4081)
- Performance & memory: tracked memory for temporary box/codestream storage
  (#4852) and reduced allocation overhead in `ValidateTree` (#4851) and low
  memory rendering pipeline. (#4495, #4496)
- Quality: improved HDR behavior at effort 8+. (#3885)
- tools: `jxlinfo` rewritten in C++ with human-friendly output formatting.
  (#4300)
- tools: image viewers now perform CMS color transforms in parallel across
  threads. (#4326)

### Deprecated

- encoder API: `JXL_ENC_FRAME_SETTING_BUFFERING` mode 3 is deprecated; output
  buffering should now be controlled via `JXL_ENC_FRAME_SETTING_OUTPUT_MODE`.
  (#4745)

### Removed

- The `jpegli` codebase has been removed as it is now maintained as a separate
  project at [google/jpegli](https://github.com/google/jpegli). (#4657)
- Dropped GIMP plugin (`libjxl-gimp-plugin`). (#4875)

### Fixed

- Allows -E to be used in jpeg-transcoding again. (#4729)
- Fixed an issue where Lossy Delta Palette encoding failed on images larger
  than 2048x2048. (#4201)
- Fixed Delta Palette with Weighted Predictor decoding. (#4837)
- `JxlEncoderAddChunkedFrame` incorrectly called `JxlEncoderCloseInput`
  instead of `JxlEncoderCloseFrames`, resulting in corrupted files when
  trying to add more boxes. (#4466)
- Float16 values roundtrip more accurately. (#4461)
- JXL input to cjxl no longer gets double orientation applied and also now
  keeps frame names. (#4374, #4561)
- `JxlBasicInfo.alpha_premultiplied` was not correctly forwarded. (#4357)
- CMYK JXL files would not decode to PNG correctly. (#4301)
- Encoder would hang with specific parameters on images containing more than
  256 groups. (#4302)
- Decoding would fail with LZ77 runs that crossed entropy-coded streams within
  the same section. (#4298)
- Images could be corrupted when encoding effort 1 lossless. (#4027, #4291)
- Extremely high quality lossy would not conform to Level 5 of the spec.
  (#4238)
- Density regression with Predictor Zero since v0.11. (#4225)
- Progressive VarDCT encoding would create non-progressive files. (#4223)
- Extremely tall/wide images failed to encode using modular. (#3937, #4308)
- Empty DHT markers no longer cause JPEG transcoding to fail. (#2704)
- Fixed photon noise encoding for progressive images. (#4866)
- Correctly handled mistakenly set "interleaved" alpha. (#4862)
- Fixed grayscale over-read in `EncodeWithSJpeg`. (#4871)
- Fixed `djxl` `SelectFormat` failure when converting grayscale images to PPM.
  (#4691)
- Fixed segmentation fault when attempting to open non-existing input files in
  CLI tools. (#4846)
- Fixed GIF always being decoded as RGBA. (#4849)
- Added a warning when an unsupported GIF disposal mode is encountered. (#3918)
- Fixed PNG color space information reading. (#4598)
- Fixed MSVC ARM64 build and restricted `_sub_overflow_i32` to x86/x64. (#4877)
- Corrected specialized decoding path for fast lossless. (#4836)
- Rejected duplicate out-of-order `jxlp` indices. (#4814)
- Used `png_bit_depth` to correctly determine pixel layout. (#4854)
- Fixed memory leak in `GetContext()` in `jxl_cms.cc`. (#4663)
- Fixed stdin evaluation if file `-` exists. (#4668)
- Fixed JXL primary color representation detection. (#4618)

### Security

- Extensive security and hardening fixes across the core decoder/encoder, box
  buffers, and plugins (EXR, GIF, APNG/PNG, PAM/PNM/PGX). This includes fixes
  for integer overflows/underflows, out-of-bounds reads/writes, buffer
  overflows, and null pointer guards. (#4629, #4631, #4646, #4683, #4685,
  #4687, #4688, #4722, #4746, #4758, #4764, #4766, #4773, #4775, #4777,
  #4778, #4788, #4791, #4792, #4795, #4797, #4799, #4808, #4839, #4840,
  #4850, #4855, #4870, #4874)

Fixed at b6e5021b83. Leaving open for SA.

[Bruce Dubbs]

Advisory sa-13.0-171 has been issued.