Radiance HDR and the GAMMA header field (Message 1 to 3 of 3)
From: clipka
Subject: Radiance HDR and the GAMMA header field
Date: 10 Sep 2009 11:57:40
Message: <4aa921f4$1@news.povray.org>
Does anyone know *any* software that either reads or writes a GAMMA
field in the Radiance HDR file header (I mean, except for POV-Ray 3.7
betas), or even happens to know how to properly interpret the field?
From: Ive
Subject: Re: Radiance HDR and the GAMMA header field
Date: 10 Sep 2009 13:05:37
Message: <4aa931e1$1@news.povray.org>
clipka wrote:
> Does anyone know *any* software that either reads or writes a GAMMA > field in the Radiance HDR file header (I mean, except for POV-Ray 3.7 > betas), or even happens to know how to properly interpret the field?
There is no such thing like a GAMMA field in the Radiance HDR file
header therefor any other software correctly assumes that the image data
is in linear color space.
Anything that follows the #?RADIANCE signature besides the two possible
strings:
"32-bit_rle_rgbe"
"32-bit_rle_xyze"
and the +X / +Y image size definition is nothing else but a comment and
as such you can write there whatever you like but cannot expect that
someone else will make use of it.
-Ive
From: clipka
Subject: Re: Radiance HDR and the GAMMA header field
Date: 10 Sep 2009 16:15:29
Message: <4aa95e61$1@news.povray.org>
Ive schrieb:
> There is no such thing like a GAMMA field in the Radiance HDR file > header therefor any other software correctly assumes that the image data > is in linear color space.> Anything that follows the #?RADIANCE signature besides the two possible > strings:> "32-bit_rle_rgbe"> "32-bit_rle_xyze"> and the +X / +Y image size definition is nothing else but a comment and > as such you can write there whatever you like but cannot expect that > someone else will make use of it.
That's what I suspected after googling arund. Interestingly, not even
POV-Ray 3.7 betas make any use of that field when encountering it in
input images.
Ah, I guess I did open one or two cans of worms when deciding to try and
improve the gamma handling of input files...
