Google Summer of Code (GSoC) students: start here.

OpenImageIO is a library for reading and writing images, and a bunch of related classes, utilities, and applications.  There is a particular emphasis on formats and functionality used in professional, large-scale animation and visual effects work for film.  OpenImageIO is used extensively in animation and VFX studios all over the world, and is also incorporated into several commercial products.

Main features include:
  • Extremely simple but powerful ImageInput and ImageOutput APIs for reading and writing 2D images that is format agnostic -- that is, a "client app" doesn't need to know the details about any particular image file formats. Specific formats are implemented by DLL/DSO plugins.
  • Format plugins for TIFF, JPEG/JFIF, OpenEXR, PNG, HDR/RGBE, Targa, JPEG-2000, DPX, Cineon, FITS, BMP, ICO, RMan Zfile, Softimage PIC, DDS, SGI, Maya IFF, PNM/PPM/PGM/PBM, Field3d, WebP, Photoshop PSD, Wavefront RLA. More coming! The plugins are really good at understanding all the strange corners of the image formats, and are very careful about preserving image metadata (including Exif, GPS, and IPTC data).
  • An ImageCache class that transparently manages a cache so that it can access truly vast amounts of image data (thousands of image files totaling hundreds of GB) very efficiently using only a tiny amount (tens of megabytes at most) of runtime memory. Additionally, a TextureSystem class provides filtered MIP-map texture lookups, atop the nice caching behavior of ImageCache.
  • An ImageBuf class that makes it easy to deal with whole images, and a whole bunch of image processing algorithms that operate on them.
  • Several image tools based on these classes, including iinfo (print detailed info about images), iconvert (convert among formats, data types, or modify metadata), idiff (compare images),igrep (search images for matching metadata), and oiiotool (Swiss army knife tool that does practically everything). Because these tools are based on ImageInput/ImageOutput, they work with any image formats for which ImageIO plugins are available.
  • A really nice image viewer, iv, also based on OpenImageIO classes (and so will work with any formats for which plugins are available).
  • C++ and Python bindings.
  • Supported on Linux, OS X, Windows, and FreeBSD.
  • All available under the "new" BSD license, so you may modify it and use it in both open source or proprietary apps.

You can find the main PDF documentation here: openimageio.pdf

Mail Lists

There are two mail lists associated with OpenImageIO development:
  • oiio-dev  For developers of the OpenImageIO code itself, or users who are really interested in the OIIO internals. This is where we discuss the code (including bug reports).
  • oiio-announce  For announcements about major OIIO releases or other important news.

You can sign up for these mail lists on your own.

Downloading and building the code

Our code is hosted on GitHub:

You can also directly download a zip file of the source code:

At present, there is not a separate precompiled or binary-only distribution of OpenImageIO (though we hope to eventually have one). For now, you'll have to build the code yourself.

Read access to the main git repository is available for anybody. Commit access is restricted to senior developers. Though you are of course welcome to "fork" the repository to create your own work area on GitHub.

Please refer to Checking out and building OpenImageIO for details on how to check out and build OpenImageIO.

Please refer to Developing OpenImageIO for various rules and procedures for developing OpenImageIO.


For more information, contact Larry Gritz.

Subpages (1): GSoC