Re: [ft-devel] gamma correction demo images

[Nikolaus Waxweiler]

> I did not work on subpixel rendering in FreeType, but I assume it is
> similar to what Adobe does. Here is a brief summary.

I'm currently writing up the documentation for ftautoh.h, do I 
understand correctly that the steps for linear alpha blending and gamma 
correction of gray and subpixel-rendered glyphs are exactly the same? 
Meaning:
1. Take the foreground and background colors (e.g., in sRGB space) and 
apply gamma to get them in a linear space.
2. Blend the two linear colors using the alpha value from the glyph's 
coverage bitmap
3. Apply inverse gamma (e.g. 1.8) to the blended pixel and write it back 
to the image.

> The density computed for each subpixel must be distributed equally to
> all color channels.

Werner, 
http://freetype.org/freetype2/docs/reference/ft2-lcd_filtering.html 
suggests [0x10, 0x50, 0x60, 0x50, 0x10] as a possible LCD filter to use 
when doing LAB+GC. Is this correct and does what Dave suggests here? The 
sum seems to go above 0x100? And if it is, would it make a good 
candidate for a new FT_LCD_FILTER_EQUAL_WEIGHT that LAB+GC-enabled libs 
can set?