OpenEXR#

OpenEXR provides the specification and reference implementation of the EXR file format, the professional-grade image storage format of the motion picture industry.

The purpose of the EXR format is to accurately and efficiently represent high-dynamic-range scene-linear image data. This is a significant difference from most image formats, which store images that are ready for display. Software may need to process OpenEXR images differently from other image formats such as JPEG (see Scene-Linear Image Representation for more details). OpenEXR files have strong support for multi-part, multi-channel use cases, and extensive representation of associated metadata.

OpenEXR is widely used in host application software where accuracy is critical, such as photorealistic rendering, texture access, image compositing, deep compositing, and DI.

OpenEXR is a project of the Academy Software Foundation.

Latest News#

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November 11, 2026 - OpenEXR 3.5.4 Released

Patch release that addresses several build and security issues, and also fixes a regression introduced in v3.3.0 that leads to excessive memory usage during write, especially with DWA compression (Issue #2791).

  • Fix a configuration issue with OpenJPH 0.33.0 that caused it to silently and incorrectly fall back to the vendored version (PR #2813)

  • The vendored OpenJPH is now built in a custom namespace to avoid symbol collision with other versions when built statically (2811) built statically,

  • The vendored OpenJPH version is now 0.33.0.

  • Fix exrmultipart -convert on tiled and deep single-part files

  • OPENEXR_USE_INTERNAL_IMATH/OPENJPH are are now included in OpenEXRConfig.h alongside OPENEXR_USE_INTERNAL_DEFLATE/ZSTD.

  • 32-bit glibc builds now guarantee support for files of size 2GiB or more (2812)

This release addresses the following security vulnerabilities:

  • *CVE Pending* (GHSA-PP92-4RV3-WFQ6) OpenEXR: a signed-int data-window-origin overflow in the OpenEXRUtil Image API turns Imf::loadImage into an attacker-steered out-of-bounds write

  • *CVE Pending* (GHSA-2V77-PVHX-25C3) Integer overflow in legacy OpenEXR.OutputFile.writePixels() causes heap over-read

Imath#

The OpenEXR project includes Imath, a basic, light-weight, and efficient C++ representation of 2D and 3D vectors and matrices and other simple but useful mathematical objects, functions, and data types common in computer graphics applications, including the half 16-bit floating-point type.

Imath also includes optional python bindings for all types and functions, including optimized implementations of vector and matrix arrays.

Quick Start#

You can install OpenEXR using package managers or build the library yourself from the source on github following the compile instructions

For a simple program that uses the C++ API to read and write a .exr file, see the Hello, World examples.

Community#

Resources#