Re: [ft] Regression in font clarity with Adobe engine

[Dave Arnold]

Hi Mike,

I don't know what setting "X.org gamma" does, but it sounds like it might be 
the wrong place to look. I'm not talking about changing a system setting for your 
monitor. Your monitor should most commonly be in a non-linear space, like sRGB. That's 
necessary for displaying most images, photos, videos, etc. The gamma I am talking about 
is used used for compositing anti-aliased text into an image. Anti-aliasing requires the 
blending operation to be done in a linear color space. When compositing into a non-linear 
space, the steps are:
 1) convert foreground (text color) and background pixels to a linear color 
space
 2) blend the two colors according to the anti-alias density (alpha) value
 3) convert the result back to the original non-linear space
This calculation is performed only in the code that composites anti-aliased 
text. The calculation needn't be precise, so a simple table lookup of a power 
function with an exponent (gamma) of about 1.8 can be used.

Thanks.

-Dave

On 1/14/2014 8:33 AM, Michael Cronenworth wrote:
> Yes, your assumption is correct. X.org defaults to 1.0 gamma and any screenshot 
> results in 1.0 gamma. Setting my X.org gamma to 1.8 makes my screen look like 
> the surface of the sun. Not a good option.