Gamma correction process for colour film video signals

摘要

The colour film is scanned and a digital data word is obtained indicating RGB values, and is applied to a logarithmic stage 2 that uses stored table values to generate a colour component signal Y that is added to 3 and is multiplied 4 by correction factors. The modified values are processed 5,6 and used in a second adder 7 that allows the black level to be raised and a second multiplier 8 allows amplification adjustment. A third adder 9 is used to allow the signal to be changed from fade to white. Transformation tables 11 and a logarithm/analogue converter 12 complete the system.