Hybrid Log-Gamma (HLG)

A mathematical function (known as a transfer function) that relates image signal values to scene-relative light levels and is compatible with standard-dynamic-range (SDR) displays without the need for metadata. HLG is one of the two supported systems in the ITU-R Rec. 2100 standard for high-dynamic-range (HDR) video. HLG was developed by the BBC and NHK broadcasting networks.

HLG is also an HDR format for video and still images that uses the HLG transfer function.