Re: [ft-devel] gamma correction and FreeType

[Antti Lankila]

Dave Arnold <address@hidden> kirjoitti 8.11.2013 kello 20.45:

> Hi Antti,
> 
> I agree that there is nothing like an analog video cable in modern displays, 
> and that individual pixels are digitally addressed, but isn't there still 
> some analog circuitry? It seems to me that the voltage applied to each pixel 
> cell, and the electric field that rotates the crystals, must be analog. Is 
> there a digital-to-analog conversion involved? I'd appreciate any references 
> to this.

Yes, these parts are analog. It’s always analog at some point in the end, I 
guess, until we have HDMI ports in our heads, and a digital cyborg brain, I 
suppose.

> While gamma 2.2 seems like it should be correct, my experience on multiple 
> devices is that a lower value works better for text. For example, there is 
> the effect that another gol discussed, where white text appears too heavy at 
> 2.2. I'd really like to understand that.

It may be the ”white on black” looks stronger than ”black on white” issue. It 
may be a human eyesight issue. An artificially lowered gamma will happen to 
compensate somewhat for the effect, because it does extra darkening. It would 
be better, perhaps, to apply stem darkening based on luminance of the 
foreground color, if this theory proves to be correct.

— 
Antti