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

August 21, 2026 - OpenEXR 3.4.15, 3.3.14, 3.2.12 Released

v3.4.15, v3.3.14, and v3.2.12 fix two memory issues when parsing IDManifests. Corrupt or maliciously formed OpenEXR images could trigger excessive memory allocation, but only in code which decodes the idmanifest attribute. Other code is unaffected, even when handling files with idmanifest attributes

CVEs have been requested for these issues.

The v3.4.15 release also fixes a missing export for Windows builds, and reduces compiler warnings when compiling example code.

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

• Ask a question:

  • Email: openexr-dev@lists.aswf.io

  • Slack: academysoftwarefdn#openexr

• Attend a meeting:

  • Technical Steering Committee meetings are open to the public, fortnightly on Thursdays, 1:30pm Pacific Time.

  • Calendar: https://zoom-lfx.platform.linuxfoundation.org/meetings/openexr

  • Meeting Notes: https://wiki.aswf.io/display/OEXR/TSC+Meetings

• Report a bug:

  • Submit an Issue: https://github.com/AcademySoftwareFoundation/openexr/issues

• Report a security vulnerability:

  • Email security@openexr.com

• Contribute a Fix, Feature, or Improvement:

  • Read the Contribution Guidelines and Code of Conduct

  • Sign the Contributor License Agreement

  • Submit a Pull Request: https://github.com/AcademySoftwareFoundation/openexr/pulls

  • If you’d like to contribute and could use some ideas of what to do, browse “good first issues” here or on Clotributor.

Resources

• Reference images: https://github.com/AcademySoftwareFoundation/openexr-images

• Security policy: SECURITY.md

• Release notes: CHANGES.md

• Contributors: CONTRIBUTORS.md

• Porting Guide: OpenEXR/Imath 2.x to 3.x Porting Guide