What is the format of the OLED gamma table?
See here for a modded version of vitabright that allows experimenting with gamma tables without restarting your Vita!
Format of the vitabright_lut.txt file:
- Each line corresponds to a brightness level. First lines in the file correspond to high brightness levels, and last lines to low brightness levels.
- A line has 21 values, which are actually 7 groups of 3 RGB colors, each group corresponding to a specific grayscale value.
See image below for more information. Note that a line in vitabright_lut.txt corresponds to a column in this image (from P2 to P22). The parameter (cd/m²) is the luminance, so each column corresponds to a brightness level.
For example the Green V171 value corresponds to the voltage value (after multiplication + offset) that will be output by the screen for a pixel that needs to display a green value of 171 (color values are between 0 and 255).
I believe that values between two lookup values are interpolated. Say the screen wants to display Green V190. There is no corresponding value so it will interpolate it from Green V171 and Green V255.
Last but not least: built a cool new gamma table? Contribute it back by opening an issue on the repo! 👍
- AMS495QA04 Datasheet: https://wiki.henkaku.xyz/vita/File:AMS495QA04_Ver2.0_20121113_201509238327.pdf
- US20140118228A1 Patent Application about the gamma table system: https://patents.google.com/patent/US20140118228
- HENkaku's Wiki Page about OLED: https://wiki.henkaku.xyz/vita/SceOled