perceptual quantization (EOTF) (PQ)

Perceptual Quantization(PQ) is a correction curve for display on high- resolution displays with High Dynamic Range( HDR). The correction curve is used by the two transfer functions Opto-Electrical Transfer Function( OETF) and Electro-Optical Transfer Function( EOTF).

The PQ correction curve is about adapting the voltage changes generated by image sensors and displays to the human perception of brightness. The PQ correction curve is comparable to the gamma correction and has a similar curve to it. However, it is flatter and has a smaller slope compared to a gamma curve with a factor of 2.4. The black area becomes more dynamic with the PQ curve.

Perceptual Quantization (PQ) requires a resolution of at least 10 bits and is therefore used in HDR10 and Dolby Vision. Another correction curve is Hybrid Log Gamma( HLG), which is very similar to the gamma curve.