Warp schrieb:
> clipka <ano### [at] anonymousorg> wrote:
>> In 3.6, however, the rgb 0.5 object (B) will look way darker: POV-Ray 
>> will have output "127"
> 
>   You mean that POV-Ray 3.6 didn't gamma-correct the output at all, while
> POV-Ray 3.7 now does?

I mean that 3.6 didn't do it /by default/ (which is what you've been 
asking about all the time).

>   Does that mean there's now a new option to set the gamma correction of
> the created image (the actual pixels, not just some header data in the
> image file format)? Is there a way to turn this off, if one so desires
> (eg. if you really *want* the pixels to be exactly (127,127,127) and
> nothing else)?

Yup. "File_Gamma" is the magic ini file option. Set it to 1.0 and you'll 
get linear pixel values, plus (for PNG and HDR) a header saying that the 
data is linear. Set it to 2.2 and you'll get gamma pre-corrected pixel 
values, plus a header saying that the data is pre-corrected for a gamma 
of 2.2. (The latter is highly recommended though, as not all viewers - 
browsers included - support linear image data.)

Note that this makes it impossible to deliberately mess with gamma for 
artistic effect in POV-Ray when you use PNG output and all your image 
processing software handles gAMA chunks properly: You can only affect 
the encoding of pixels - and thereby the dynamic ranges of highlights 
vs. shadows - but not their interpretation.

At least that's the theory as known to me. I never tested in detail 
whether it indeed works exactly as intended.

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