Why does Call of Duty 4 have a limited color range ?

[Skybuck Flying]

Hello,

Some time ago I did some video/graphics analysis of Call of Duty 4.

I noticed how Call of Duty 4 only uses 232 reds, 232 greens and 232 blue's.

Why does it not use the full range ? 0 to 255 ?

I can think of a number of reasons:

1. It's a bug.
2. It's an optimization.
3. It's a tga/video capture problem in cod4.
4. Maybe weird gamma-round-off ?

I find this odd/weird.

Anybody have any explanation ?

Bye,
Skybuck.

[Wolfgang Draxinger]

Skybuck Flying wrote:

> Anybody have any explanation ?

I don't know CoD4, but I presume they're using some sort of HDR
rendering with postprocessing tonemapping to match the color
range. Usually the tonemapping is done by analyzing the
histogram of the postprocessed image and using the lowest and
highest channels as indicators for under- and overexposure (i.e.
if the majority of the luminancy is in the upper/lowermostmost 5
channels, adjust the tonemapping).

Also take notice, that completely black or very dark areas are
rarely seen in games; In the old days players tended to notch up
the gamma manually to see the monster lurking in some dark
corner, sacrifying in image quality. Thus game developers
adjusted their strategy and give the player what they want.

Wolfgang Draxinger
--
E-Mail address works, Jabber: hexa...@jabber.org, ICQ: 134682867

[Juha Nieminen]

Skybuck Flying wrote:
> 4. Maybe weird gamma-round-off ?

Well, if you have an original color channel with 256 distinct values
and you apply a gamma correction to it (other than linear), the
resulting color will certainly not have 256 distinct values anymore but
less.

I'm not sure that's the correct explanation in this case, though.