POV-Ray : Newsgroups : povray.general : Dumping RGB rendering results in float format ... Server Time
25 Dec 2024 13:54:46 EST (-0500)
  Dumping RGB rendering results in float format ... (Message 1 to 5 of 5)  
From: flatline
Subject: Dumping RGB rendering results in float format ...
Date: 17 Sep 2007 03:55:01
Message: <web.46ee32455e57d0b2948923d30@news.povray.org>
is dumping RGB rendering results in float format possible within POV-ray (or
MegaPOV)?

Thanks a lot for any help,


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From: Alain
Subject: Re: Dumping RGB rendering results in float format ...
Date: 17 Sep 2007 09:29:04
Message: <46ee8120$1@news.povray.org>
flatline nous apporta ses lumieres en ce 2007/09/17 03:52:
> is dumping RGB rendering results in float format possible within POV-ray (or
> MegaPOV)?
> 
> Thanks a lot for any help,
> 
> 
> 
> 
No.
If you output as PPM or PNG, you can have from 5 up to 16 bits per chanel 
integer values.
PNG offers good compression.
PNG can also have an alpha chanel of the same lenght as the colour chanels.
At some time, there was RAW and DMP, but they were discarted as obsolete. They 
were still integer based.

-- 
Alain
-------------------------------------------------
You know you've been raytracing too long when you are compulsive, neurotic, 
anti-social, paranoid and manic-depressive but basically happy.
Quietly Watching


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From: Zeger Knaepen
Subject: Re: Dumping RGB rendering results in float format ...
Date: 17 Sep 2007 12:51:52
Message: <46eeb0a8$1@news.povray.org>
"Alain" <ele### [at] netscapenet> wrote in message 
news:46ee8120$1@news.povray.org...
> flatline nous apporta ses lumieres en ce 2007/09/17 03:52:
>> is dumping RGB rendering results in float format possible within POV-ray 
>> (or
>> MegaPOV)?
>>
>> Thanks a lot for any help,
>>
>>
>>
>>
> No.
> If you output as PPM or PNG, you can have from 5 up to 16 bits per chanel 
> integer values.
> PNG offers good compression.
> PNG can also have an alpha chanel of the same lenght as the colour 
> chanels.
> At some time, there was RAW and DMP, but they were discarted as obsolete. 
> They were still integer based.

MegaPOV can output HDR-images, aren't those float-based?

cu!
-- 
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com


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From: Alain
Subject: Re: Dumping RGB rendering results in float format ...
Date: 18 Sep 2007 00:34:04
Message: <46ef553c$1@news.povray.org>
Zeger Knaepen nous apporta ses lumieres en ce 2007/09/17 12:51:
> "Alain" <ele### [at] netscapenet> wrote in message 
> news:46ee8120$1@news.povray.org...
>> flatline nous apporta ses lumieres en ce 2007/09/17 03:52:
>>> is dumping RGB rendering results in float format possible within POV-ray 
>>> (or
>>> MegaPOV)?
>>>
>>> Thanks a lot for any help,
>>>
>>>
>>>
>>>
>> No.
>> If you output as PPM or PNG, you can have from 5 up to 16 bits per chanel 
>> integer values.
>> PNG offers good compression.
>> PNG can also have an alpha chanel of the same lenght as the colour 
>> chanels.
>> At some time, there was RAW and DMP, but they were discarted as obsolete. 
>> They were still integer based.
> 
> MegaPOV can output HDR-images, aren't those float-based?
> 
> cu!
I don't use MegaPov. Yes, HDR is, and need to be, float based. It's also, in my 
view, the only reason you may need, or want, float based image data.

-- 
Alain
-------------------------------------------------
"If you see me running, try to keep up."
       ...Back of bomb technician's shirt


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From: scott
Subject: Re: Dumping RGB rendering results in float format ...
Date: 19 Sep 2007 02:46:47
Message: <46f0c5d7$1@news.povray.org>
>>> No.
>>> If you output as PPM or PNG, you can have from 5 up to 16 bits per 
>>> chanel integer values.
>>> PNG offers good compression.
>>> PNG can also have an alpha chanel of the same lenght as the colour 
>>> chanels.
>>> At some time, there was RAW and DMP, but they were discarted as 
>>> obsolete. They were still integer based.
>>
>> MegaPOV can output HDR-images, aren't those float-based?
>>
>> cu!
> I don't use MegaPov. Yes, HDR is, and need to be, float based. It's also, 
> in my view, the only reason you may need, or want, float based image data.

It's just useful to be able to change the brightness/contrast/gamma after a 
long render without having to re-render or see lots of artifacts.  Also 
useful to do post-process effects like bloom, where having knowledge of 
colours outside the 0-255 range is needed.

If you know a little C it is pretty trivial to modify one of the simple 
image writing routines in the POV source (eg BMP format) to output floats 
instead of the integers.  Or just use MegaPOV as suggested.


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