HDR Tone Mapping, Perceptual Quantizer & ABL Window Size Physics
Unlike SDR (Standard Dynamic Range) gamma curve 2.2 relative luminance, HDR10 utilizes the SMPTE ST.2084 Perceptual Quantizer (PQ) Electro-Optical Transfer Function (EOTF). The PQ curve defines absolute target luminance values from 0.0001 nits up to 10,000 nits. When a display's physical peak brightness capability is lower than the encoded signal (e.g. 1000 nits display receiving 4000 nits master), the display engine applies tone mapping to clip or roll off highlight details.
Measures maximum burst brightness for small highlights (e.g. sun reflections, explosions) without ABL limiting.
Auto Brightness Limiter restricts power supply overload, reducing full-screen white brightness (e.g., 250 nits on OLED).
Passes raw PQ EOTF signals without secondary TV tone mapping curves, allowing game console calibration menus to control clipping.
VESA DisplayHDR Compliance Tier Specifications Reference
CTS 1.2 Standards MatrixThe following reference matrix outlines the mandatory hardware performance requirements established by the Video Electronics Standards Association (VESA) DisplayHDR Compliance Test Specification (CTS v1.2) for LCD and OLED displays.
| Certification Tier | Peak 10% Window | Full-Screen White | Max Black Level | Local Dimming | Color Gamut Coverage |
|---|---|---|---|---|---|
| DisplayHDR 400 | 400 cd/m² | 320 cd/m² | 0.40 cd/m² | Global (None) | 95% ITU-R BT.709 (sRGB) |
| DisplayHDR 500 | 500 cd/m² | 320 cd/m² | 0.10 cd/m² | Local Dimming Required | 90% DCI-P3 / 99% BT.709 |
| DisplayHDR 600 | 600 cd/m² | 350 cd/m² | 0.10 cd/m² | Local Dimming Required | 90% DCI-P3 / 99% BT.709 |
| DisplayHDR 1000 | 1,000 cd/m² | 600 cd/m² | 0.05 cd/m² | Multi-Zone FALD Required | 90% DCI-P3 / 99% BT.709 |
| DisplayHDR 1400 | 1,400 cd/m² | 900 cd/m² | 0.02 cd/m² | Advanced Multi-Zone FALD | 95% DCI-P3 / 99% BT.709 |
| True Black 400 (OLED) | 400 cd/m² | 250 cd/m² | 0.0005 cd/m² | Pixel-Level Self-Emissive | 90% DCI-P3 / 99% BT.709 |
| True Black 500 (OLED) | 500 cd/m² | 300 cd/m² | 0.0005 cd/m² | Pixel-Level Self-Emissive | 90% DCI-P3 / 99% BT.709 |
| True Black 600 (OLED) | 600 cd/m² | 350 cd/m² | 0.0005 cd/m² | Pixel-Level Self-Emissive | 90% DCI-P3 / 99% BT.709 |
WARNING: PHOTOSENSITIVE SEIZURE & FLICKER HAZARD
A small percentage of individuals may experience epileptic seizures or photosensitive reactions when exposed to flashing lights, high-contrast strobing, or rapidly moving visual patterns. In compliance with WCAG 2.1 Success Criterion 2.3.1 (Three Flashes or Below Threshold), Display Test Online limits default strobing animations. However, dynamic visual tests inherently involve rapid refresh intervals.
Discontinue use immediately and consult a physician if you experience dizziness, altered vision, twitching, loss of awareness, or disorientation while running tests.
Browser & OS Color Management Limitations
Software-based visual evaluation patterns are subject to Web browser color space mapping (sRGB / Display P3), operating system display scaling, ICC profile overrides, and GPU driver settings. While Display Test Online utilizes hardware-accelerated WebGL 2.0 rendering pipelines, browser-based tests cannot fully replace physical hardware colorimeters or spectrophotometers (e.g., Calbrite Display Plus HL, X-Rite i1Display Pro) for color-critical prepress workflows.