An electro-optical transfer function (EOTF) is a correction function that converts electrical voltages into brightness values. The EOTF function is used to adapt the brightness of displays or televisions to the human perception of brightness. Since this does not run linearly with the voltage values, the display representation must be adapted.
If such an adjustment is made by a gamma curve, it is called a gamma correction, and in the case of more complex dependencies between voltage and brightness, it is called an electro-optical transfer function (EOTF). It forms the counter function to the recording side and is formed by the optical-electrical transfer function, Opto-Electro Transfer Function( OETF). The OETF function compensates for the nonlinearities between the incident brightness level and the voltage generated in the image sensor.
Since the dependencies between brightness and voltage are different for different display technologies and resolutions, such as SDTV, HDTV, UHDTV, HDR10 and Dolby Vision, there are several correction curves in addition to gamma correction: Perceptual Quantization( PQ) and Hybrid Log Gamma( HLG), which is described in SMPTE 's ST.2084 standard for video transmission ofHigh Dynamic Range( HDR).