RGB Color Value Conversion

[Chris Wright]

8-bit color (28 = 256 colors
16-bit color (216 = 65,536 colors)

8 bit is bad, it loses data on blue colors. so render out at least 16 to reduce banding in nested comps.
you need at least 16 bpc to work in green screen for 64 levels of green or else you get a bad key.

https://forums.creativecow.net/thread/2/917115

[Darby Edelen]

[Chris Wright] “8-bit color (28 = 256 colors
16-bit color (216 = 65,536 colors)

8 bit is bad, it loses data on blue colors. so render out at least 16 to reduce banding in nested comps.
you need at least 16 bpc to work in green screen for 64 levels of green or else you get a bad key.”

Huh? Where did you get those specific details? How are you defining ‘blue colors’? There are just as many code values dedicated to blue as there are to green or red in any of AE’s bit depths.

Also, 8-bit color, as you defined it, and 8bpc are different. 8bpc is 8-bits per channel, and there are 4 channels (RGBA) meaning a total of 32-bits per pixel (or ’32-bit color’).

While I agree that 16bpc is generally better than 8bpc, often it’s unnecessary and just adds to render time… and I’m not sure where the specific reasons you cited came from.

Back to the original question. If you’re asking how to convert the code value, you would divide each component of the color by 256 and then multiply by 65,536.

Darby Edelen

NVIDIA
Santa Clara, CA

[Chris Wright]

“32-bit color” is generally a misnomer in regard to display color depth. While actual 32-bit color at ten to eleven bits per channel produces over 4.2 billion distinct colors, the term ?32-bit color? is most often a misuse.

The so-called 32 bpp display graphic mode is identical in precision to the 24 bpp mode; there are still only eight bits per component, and the eight extra bits are often not used at all or alpha information.

With only 8 bit per component, rounding errors tend to accumulate with each filtering algorithm that is employed, distorting the end result with human eyes seeing mostly the blue errors first.

using 8 bpc- 8 bits a channel in a heavily nested effects comp will produce bad artifacts, but at least your render time is reduced.