IEC 61966-12-2:2024

Overview

IEC 61966-12-2:2024 - "Multimedia systems and equipment - Colour measurement and management - Part 12-2: Simple metadata format for identification of colour gamut" - defines a compact, unambiguous metadata format to identify the colour gamut for video systems targeted at consumer electronics (CE) devices. The standard is a technical revision of the 2014 edition and is fundamentally based on the conventional VESA-EDID format. It provides a lightweight Gamut ID suitable for displays and content that use three primary additive colours whose white and black points share the same chromaticity.

Key topics and technical requirements

• Simple gamut description: Encodes the chromaticities of the three primaries (R, G, B) plus white using CIE-xy values in a fixed-point representation derived from VESA-EDID.
• Encoding details:
  • CIE-xy values for R, G, B and white are provided in a 10-bit fixed-point form (range 0.0–1.0).
  • White Absolute Luminance (WAL) is encoded as a 16-bit unsigned integer (cd/m²).
  • Black Level Ratio (BLR) is encoded as a 32-bit fixed-point value (range 0.0–1.0).
• Assumptions and scope:
  • Intended only for device types with three additive primaries and identical white/black chromaticity.
  • Designed for CE devices with limited CPU/software resources - provides the simplest unambiguous metadata profile for interoperability.
• Updates in 2024 edition:
  • Extended number of bits in metadata (Clause 4) to better support wider dynamic ranges.
  • Annex C added to address handling of HDR content.
• Interoperability: Works when associated with either content (to describe content creation gamut) or displays (to describe device gamut), enabling controlled colour reproduction and improved gamut mapping.

Applications and who uses it

• CE manufacturers (TVs, set-top boxes, projectors, monitors): embed or read simple Gamut ID metadata to improve out-of-box colour reproduction.
• Content creators and post-production houses: tag video with the gamut for which content was authored to guide display rendering.
• Display engineers and color management system developers: implement simplified gamut exchange in devices with limited processing resources.
• Streaming services and broadcasters: include lightweight gamut metadata with delivered content to ensure more predictable colour across diverse displays, including HDR-aware workflows.

Related standards

• IEC 61966-12-1 - Metadata for identification of colour gamut (full/medium/simple profiles)
• VESA EDID - EDID structure used as a basis for CIE-xy encoding
• Video colour and HDR standards referenced in IEC guidance: ITU‑R BT.2100, BT.2020, BT.709, and IEC 61966-2-4 (xvYCC)

IEC 61966-12-2:2024 is a practical standard for lightweight gamut metadata, bridging content creators and CE displays to improve colour fidelity, interoperability, and HDR-aware reproduction in consumer ecosystems.