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 EXR format is to accurately and efficiently represent high-dynamic-range scene-linear image data. This is a significant difference to most image formats, which store images that are ready for display. Software that handles OpenEXR images may need to process them differently to images in other 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


OpenEXR v3.2.4 is released and available for download from v3.2.4.

Patch release that fixes handling of dwa compression in OpenEXRCore library.

Other miscellaneous changes:

  • Add CMake find_dependency for libdeflate, to fix a vcpkg build error

  • Remove the unused CMake option OPENEXR_INSTALL_EXAMPLES

  • Fix some other compiler warnings.

Also, the dwa bug fix has been back-ported to v3.1 and is available for download at v3.1.13.


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

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