Overview
IEC 62977-3-7:2022 - "Electronic displays - Part 3-7: Evaluation of optical performance - Tone characteristics" specifies standardized measurement and evaluation methods for grey and colour tone reproduction of electronic displays under darkroom conditions. It defines how to measure the electro‑optical transfer function (EOTF), tone rendering for neutral grey, primary and secondary colours, and colour saturation tone for displays with unbounded input signals. The standard is intended to make tone‑related optical performance measurements repeatable, comparable and suitable for reporting.
Key topics and technical requirements
- Standard measuring equipment and setup: guidance on video signal generators, luminance/colour measuring instruments, and layouts for close‑up and non‑close‑up measurements.
- Standard measuring conditions: environmental and darkroom requirements, display adjustment and defined starting conditions before measurement.
- Test patterns and input signals: specified multi‑colour and single‑colour patterns and RGB input ranges for tone and saturation measurements.
- EOTF and display gamma: methods to measure EOTF, calculation of average gamma and log‑log gamma, and evaluation of grey scale tracking accuracy.
- Colour saturation tone accuracy: procedures to measure luminance variation with constant hue across varying saturation.
- Tone additivity and inter‑channel behaviour: evaluation of how grey and colour tones combine (tone additivity function) and diagnostics for non‑additive behaviour or clipping.
- Functional tone quantization: methods to detect quantization artifacts and to evaluate effective bit depth and minimum luminance differences between neighboring inputs.
- Reporting requirements: required outputs and recommended formats for test results and diagnostics. Annex A covers interlevel gamma analysis.
Practical applications and who uses this standard
- Display manufacturers: product design verification, tuning, and production QA of LCD, OLED, microLED and other display types.
- Test and calibration laboratories: formal conformance testing, benchmarking and certification testing under repeatable conditions.
- System integrators and OEMs: ensuring display subsystems meet tone reproduction requirements for consumer, professional and industrial products.
- Imaging researchers and R&D teams: characterizing EOTF behaviour, directional dependence and artefact diagnosis.
- Content creators and post‑production facilities: understanding device tone behaviour to optimize master workflows and color grading for target displays.
Related standards
- Other parts of the IEC 62977 series (Electronic displays) and documents published by IEC TC 110.
- Industry EOTF/gamma references commonly used alongside this standard (consult IEC webstore or committee guidance for specific normative references).
For official purchase and the complete normative text, obtain IEC 62977-3-7:2022 from the IEC Webstore.