Overview
ISO/IEC 21794-2:2021 - "Information technology - Plenoptic image coding system (JPEG Pleno) - Part 2: Light field coding" defines a coded codestream format and associated light-field-specific metadata descriptors for storage and exchange of light field modalities. Part 2 of the JPEG Pleno family focuses on how to represent, encode and decode sampled plenoptic data (light fields) and documents the encoding tools and functional requirements for both encoders and decoders.
Keywords: ISO/IEC 21794-2:2021, JPEG Pleno, light field coding, plenoptic, light field codestream, light field metadata.
Key topics and technical requirements
- Codestream format: A standardized binary codestream structure designed to carry light field image data and related metadata for robust storage and interoperability.
- Metadata descriptors: Light-field-specific descriptors to capture camera geometry, subaperture view layout, disparity and depth-related information.
- Encoding tools and modes: Description of encoding primitives used for light field compression and representation (including references to 4D transform modes, bit-plane decomposition and prediction residuals).
- View types and processing: Concepts such as reference views, normalized disparity views, and intermediate views used for rendering and view synthesis.
- 4D structures and partitioning: Use of multi-dimensional blocks (4D block partitioning, hexadeca-tree bit-plane decomposition) for efficient processing of the spatial and angular dimensions of light fields.
- Merging and warping mechanisms: Parameters for merging reference textures, sparse filters and least-squares merging weights to reconstruct intermediate views.
- Encoder and decoder requirements: Functional overview of the decoding process and mandatory guidance for encoder behavior, decoder interoperability and random access.
- Normative references: Integrates existing image coding standards such as JPEG 2000 (ISO/IEC 15444-1/-2) and references to IEEE/ISO floating‑point (ISO/IEC 60559).
Practical applications
- Computational photography and light-field camera workflows for post-capture refocusing and depth editing.
- Virtual reality (VR), augmented reality (AR) and mixed-reality content pipelines requiring multi-view or plenoptic representations.
- 3D scene capture, view synthesis and free-viewpoint video for broadcast, cinematic production and immersive media.
- Archival and exchange formats for research datasets, industrial imaging and advanced visual effects where accurate angular and depth data are required.
Who should use this standard
- Camera and imaging hardware manufacturers implementing light-field capture devices.
- Codec and software developers building light-field encoders, decoders and viewers.
- Content producers and post‑production houses targeting immersive media and view synthesis.
- Research institutions and standards bodies working on plenoptic imaging, VR/AR, and 3D visualization interoperability.
Related standards
This standard is essential for consistent, interoperable handling of light field codestreams and metadata within the JPEG Pleno ecosystem.