POV-Ray : Newsgroups : povray.general : PNG output always lossless Server Time
29 Jul 2024 08:17:59 EDT (-0400)
  PNG output always lossless (Message 1 to 5 of 5)  
From: Sereib
Subject: PNG output always lossless
Date: 25 Oct 2012 00:25:01
Message: <web.5088be65cf1c28f78be086270@news.povray.org>
Hi,

is the png output file format of POV-Ray (when using +FN in the ini file) always
lossless, independent from any computer system settings? I ask because most
image editing software allows to set a compression level before saving a png
file.

Thanks!


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From: Patrick Elliott
Subject: Re: PNG output always lossless
Date: 25 Oct 2012 01:50:12
Message: <5088d314$1@news.povray.org>
On 10/24/2012 9:21 PM, Sereib wrote:
> Hi,
>
> is the png output file format of POV-Ray (when using +FN in the ini file) always
> lossless, independent from any computer system settings? I ask because most
> image editing software allows to set a compression level before saving a png
> file.
>
> Thanks!
>
>
Uh.. The whole point of PNG is that its lossless.


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From: Warp
Subject: Re: PNG output always lossless
Date: 25 Oct 2012 11:04:14
Message: <508954ee@news.povray.org>
Sereib <nomail@nomail> wrote:
> is the png output file format of POV-Ray (when using +FN in the ini file) always
> lossless, independent from any computer system settings? I ask because most
> image editing software allows to set a compression level before saving a png
> file.

The PNG format doesn't even support lossy compression.

-- 
                                                          - Warp


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From: clipka
Subject: Re: PNG output always lossless
Date: 25 Oct 2012 11:19:09
Message: <5089586d$1@news.povray.org>
Am 25.10.2012 06:21, schrieb Sereib:

> is the png output file format of POV-Ray (when using +FN in the ini file) always
> lossless, independent from any computer system settings? I ask because most
> image editing software allows to set a compression level before saving a png
> file.

I guess you're mixing up png (which is always lossless) with jpeg (which 
is always lossy).

As for jpeg compression level, in POV-Ray 3.7 you can set that with the 
"compression=" ini file setting (specifying a value from 0.0 to 1.0, 
with 1.0 being highest quality).


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From: "Jérôme M. Berger"
Subject: Re: PNG output always lossless
Date: 25 Oct 2012 14:13:16
Message: <5089813c$1@news.povray.org>
Sereib wrote:
> Hi,
> 
> is the png output file format of POV-Ray (when using +FN in the ini fil
e) always
> lossless, independent from any computer system settings? I ask because 
most
> image editing software allows to set a compression level before saving 
a png
> file.
> 
	As others have said, PNG is always lossless. The "compression
level" setting that some software offers is simply a compromise
between speed/memory and file size (same as for zip files since PNG
uses the same compression algorithm as zip).

		Jerome
-- 
mailto:jeb### [at] freefr
http://jeberger.free.fr
Jabber: jeb### [at] jabberfr


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