OpenImageIO 3.1

Programmer Documentation

Editor: Larry Gritz, lg@openimageio.org

OpenImageIO (OIIO) is a library for reading, writing, and processing images in a wide variety of file formats, using a format-agnostic API. OIIO emphasizes formats and functionality used in professional, large-scale visual effects and feature film animation, and it is used ubiquitously by large VFX studios, as well as incorporated into many commercial products.

Quick Links: Web site / GitHub repository / Developer mail list / Apache 2.0 License

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Contents

• Copyright Notice
• Introduction

The OpenImageIO Library APIs

• Image I/O API Helper Classes
  • Data Type Descriptions: TypeDesc
  • Non-owning string views: string_view
  • Efficient unique strings: ustring
  • Non-owning array views: span / cspan
  • Rectangular region of interest: ROI
  • Image Specification: ImageSpec
  • “Deep” pixel data: DeepData
  • Global Attributes
  • Miscellaneous Utilities
  • Startup and Shutdown
  • Environment variables
• ImageOutput: Writing Images
  • Image Output Made Simple
  • Advanced Image Output
  • ImageOutput Class Reference
• ImageInput: Reading Images
  • Image Input Made Simple
  • Advanced Image Input
  • ImageInput Class Reference
• Writing ImageIO Plugins
  • Plugin Introduction
  • Image Reader Plugins
  • Image Writers
  • Tips and Conventions
• Bundled ImageIO Plugins
  • BMP
  • Cineon
  • DDS
  • DICOM
  • DPX
  • FITS
  • GIF
  • HDR/RGBE
  • HEIF/HEIC/AVIF
  • ICO
  • IFF
  • JPEG
  • JPEG-2000
  • JPEG XL
  • Movie formats (using ffmpeg)
  • Null format
  • OpenEXR
  • OpenVDB
  • PNG
  • PNM / Netpbm
  • PSD
  • Ptex
  • RAW digital camera files
  • RLA
  • SGI
  • Softimage PIC
  • Targa
  • Term (Terminal)
  • TIFF
  • Webp
  • Zfile
• Cached Images
  • Image Cache Introduction and Theory of Operation
  • ImageCache API
• Texture Access: TextureSystem
  • Texture System Introduction and Theory of Operation
  • Helper Classes
  • TextureSystem API
  • UDIM texture atlases
  • Batched Texture Lookups
• ImageBuf: Image Buffers
  • ImageBuf Introduction and Theory of Operation
  • Constructing, destructing, resetting an ImageBuf
  • Getting and setting information about an ImageBuf
  • Copying ImageBuf’s and blocks of pixels
  • Getting and setting pixel values
  • Deep data in an ImageBuf
  • Error Handling
  • Miscellaneous
  • Writing your own image processing functions
  • Iterators – the fast way of accessing individual pixels
  • Dealing with buffer data types
• ImageBufAlgo: Image Processing
  • ImageBufAlgo common principles
  • Pattern generation
  • Image transformations and data movement
  • Image arithmetic
  • Image comparison and statistics
  • Convolutions and frequency-space algorithms
  • Image Enhancement / Restoration
  • Morphological filters
  • Color space conversion
  • Import / export
  • Deep images
• Python Bindings
  • Overview
  • TypeDesc
  • ROI
  • ImageSpec
  • DeepData
  • ImageInput
  • ImageOutput
  • ImageBuf
  • ImageBufAlgo
  • Miscellaneous Utilities
  • Python Recipes

Image Utilities

• oiiotool: the OIIO Swiss Army Knife
  • Overview
  • oiiotool Tutorial / Recipes
  • oiiotool commands: general flags
  • oiiotool commands for control flow
  • oiiotool commands: reading and writing images
  • oiiotool commands that print information about the current image
  • oiiotool commands that change the current image metadata
  • oiiotool commands that shuffle channels or subimages
  • oiiotool commands that adjust the image stack
  • oiiotool commands that make entirely new images
  • oiiotool commands that do image processing
  • oiiotool commands for color management
  • oiiotool commands for deep images
• Getting Image information With iinfo
  • Using iinfo
  • iinfo command-line options
• Converting Image Formats With iconvert
  • Overview
  • iconvert Recipes
  • iconvert command-line options
• Searching Image Metadata With igrep
  • Using igrep
  • igrep command-line options
• Comparing Images With idiff
  • Overview
  • Using idiff
  • idiff Command Line Argument Reference
• Making Tiled MIP-Map Texture Files With maketx or oiiotool
  • Overview
  • maketx
  • oiiotool

Appendices

• Metadata conventions
  • Description of the image
  • Display hints
  • Color information
  • Disk file format info/hints
  • Substituting an IOPRoxy for custom I/O overrides
  • Photographs or scanned images
  • Thumbnails / postage stamps / preview images
  • Texture Information
  • Exif metadata
  • GPS Exif metadata
  • IPTC metadata
  • SMPTE metadata
  • Extension conventions
• Glossary