Overview - ISO/IEC 21794-5:2024 (JPEG Pleno - Part 5: Holography)
ISO/IEC 21794-5:2024 specifies the JPEG Pleno Holography codec: a standardized syntax and decompression process for representing binary and continuous‑tone digital holograms, including support for one or multiple color/spectral components. The standard defines compression mechanisms (lossless for binary holograms; lossy for continuous‑tone holograms), encoding tool descriptions, and extensions to the JPEG Pleno File Format plus holography‑specific metadata descriptors. It is part of the JPEG Pleno family and intended for robust, interoperable hologram coding and storage.
Key technical topics and requirements
- Supported hologram types: Binary holograms and continuous‑tone holograms; single or multi‑spectral/color components.
- Compression modes: Lossless coding for binary holograms; lossy coding for continuous‑tone holograms with documented encoding tools.
- File format & metadata: Extensions to the JPEG Pleno File Format and dedicated metadata descriptors for holographic modalities.
- Codestream and syntax: Normative codestream syntax for holography, including hierarchical boxes/superboxes for integration into JPEG Pleno files.
- Tiling & block structure: Definitions for tiles, transform blocks, code blocks and quantization blocks to enable independent coding and random access.
- Transforms & analysis tools: Use of transforms (Fourier/DFT, FFTSHIFT), Short‑Time Fourier Transform (STFT) and multi‑dimensional transform blocks.
- Quantization & arithmetic coding: Normative quantization schemes and arithmetic coding methods for entropy coding.
- Light propagation models: Formal models for wavefront propagation used during encoding/decoding and reconstruction.
- Encoder/decoder requirements: Functional overviews, input/output (source/decoded holograms) definitions, and interoperability guidelines.
- Scalability & random access: Mechanisms to support scalable decoders and independent tile/block access for efficient streaming and editing.
Practical applications and user groups
This standard targets developers and organizations working with holographic data and 3D wavefront imagery, including:
- Holographic microscopy and tomography - efficient archival and transmission of hologram datasets.
- Interferometry and metrology - storage and exchange of phase/amplitude holograms.
- Holographic displays and printing - standardized codestreams for production workflows.
- Research labs and imaging device manufacturers - interoperable capture-to‑decode pipelines.
- Codec/software developers and file format implementers - building compliant encoders, decoders and players.
- Standards bodies and system integrators - integrating holography into larger JPEG Pleno ecosystems.
Related standards and notes
- Part of the JPEG Pleno series: see ISO/IEC 21794‑1 (Framework), 21794‑2 (Light field), 21794‑3 (Conformance testing), 21794‑4 (Reference software).
- Implementers should review normative annexes (codestream syntax, tiling, STFT, quantization, arithmetic coding, rate‑distortion) and be aware that patent claims may exist for some technologies.