Broadcast term: PQ transfer function
PQ, the perceptual quantizer, is the transfer function HDR10 uses to map signal values to absolute brightness. HLG, hybrid log-gamma, is the alternative designed for broadcast. From 3 source pages, read 2026-09-25; no maker pays to be listed.
1Reference
Color depth 10 bits or 12 bits Color primaries Rec. 2020
YouTube Help, upload HDR videos
Image parameter values for high dynamic range television for use in production and international programme exchange
ITU, Recommendation BT.2100
One vendor names both PQ and HLG deliveries.
YouTube's HDR requirements name 10-bit or 12-bit colour depth and Rec. 2020 primaries alongside the transfer function.
PQ describes brightness in absolute terms, so a PQ master looks the same on every calibrated display; HLG describes it relative to the display, which suits live broadcast. A delivery spec usually names one.
Among AI video vendors the transfer function is rarely printed at all.
HLG has one practical advantage for mixed delivery: an HLG picture still looks acceptable on an SDR screen without a separate version.
2Vendors whose figures use it
| Tool | Figure as printed |
|---|---|
| Runway | Gen-4.5 renders true HDR graded into BT.2020 with HDR10 metadata; HDR10, HLG, 12-bit PQ master, ProRes and OpenEXR deliveries |
Inclusion rule. Tools on the sheet whose recorded figure uses the term or its usual shorthand. Order. Alphabetical by tool name.
- Upload requirementsHDR uploads carry 10-bit or 12-bit colour depth and Rec. 2020 primariescolour
- Recommendation pageITU-R BT.2100 sets image parameters for high dynamic range television; version 3 (02/2025) is in force
- HDR and high bit-depth (Gen-4.5 only)Gen-4.5 renders true HDR graded into BT.2020 with HDR10 metadata; HDR10, HLG, 12-bit PQ master, ProRes and OpenEXR deliveries
3Adjacent terms
4How one pipeline outputs it
For a delivery question like “PQ transfer”, SceneMixer states the following about what it produces:
That is SceneMixer's core design: characters live in a persistent asset library with locked reference art, and every segment that features a character is generated against those references — same face in episode 1 and episode 50.
SceneMixer, The AI Micro Drama Production Pipeline — “Can AI keep the same actors across 50 episodes?” (read 2026-10-13)
Its character becomes the tone of the episode’s own score, which is planned from the episode’s storyboard — usually one to three pieces — and mixed under the voices.
SceneMixer, Remake: How Spoken Lines and Music Are Read From the Clip, and What Ends Up in Your Episode — “Is the source music reused?” (read 2026-10-13)