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From: Peter Rolf <indiego@gmx.net>
To: mailing list for ConTeXt users <ntg-context@ntg.nl>
Subject: Re: compresslevel and png graphics (mkiv)
Date: Wed, 25 May 2011 18:05:15 +0200	[thread overview]
Message-ID: <4DDD28BB.4000504@gmx.net> (raw)
In-Reply-To: <4DDD16A3.6000005@elvenkind.com>

Am 25.05.2011 16:48, schrieb Taco Hoekwater:
> 
> 
> On 05/25/11 16:39, Hans Hagen wrote:
>> On 25-5-2011 2:43, Peter Rolf wrote:
>>> Hi,
>>>
>>> I just made a one pager (TEXpage) out of a big png graphic (5900x4094).
>>> The compressed size of the graphics is normally around 1.37MB on the
>>> highest png compress level (9) and 1.32MB after using optipng (only
>>> around 3% reduction this time). To my surprise the size of the final PDF
>>> was about 2.3MB. After adding '\pdfcompresslevel9' the size went down to
>>> 1.48MB. Still not what I wanted...
>>>
>>> So I was wondering: is there an option to embed the png graphic as it is
>>> (no re-compression)? Otherwise the time consuming usage of optipng would
>>> be a complete waste of time. Believe it or not, but size matters  :-)
> 
> Well, that depends on what optipng does to your image. PDF can do some
> types of png compression natively (no re-compression), but for that the
> png has to follow some rules: not everything in the png spec is
> supported that way. If you see '<png copy>' during inclusion, then the
> png follows those rules. Otherwise, it is included in recompressed form,
> where everything is possible that is allowed by png, but it will not
> be as small as the original.
>
optipng -o7 -nx file.png

best compression (stupid brute force method) with no color reduction.
the resulting png is valid (TweakPNG), but as expected not supported by
luatex. no <png copy> in this case.


> The finer details are in writepng.w from the luatex source and/or
> the pdf specification, it is much too detailed to repeat here.
> 
Thanks for the info. :-)

> Best wishes,
> Taco
> ___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to the Wiki!
> 
> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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> ___________________________________________________________________________________
> 

___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________


  reply	other threads:[~2011-05-25 16:05 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-25 12:43 Peter Rolf
2011-05-25 14:39 ` Hans Hagen
2011-05-25 14:48   ` Taco Hoekwater
2011-05-25 16:05     ` Peter Rolf [this message]
2011-05-25 19:54   ` Hartmut Henkel
2011-05-26 10:52     ` Peter Rolf
2011-05-26 11:22       ` luigi scarso
2011-05-26 16:17       ` Peter Rolf
2011-05-27 11:57         ` Peter Rolf
2011-05-27 13:09           ` Hartmut Henkel
2011-05-27 15:11             ` Peter Rolf
2011-05-27 15:19               ` luigi scarso
2011-05-27 15:34                 ` Peter Rolf
2011-05-25 14:40 ` Hans Hagen
2011-05-26 17:32   ` mathew
2011-05-26 17:43     ` mathew
2011-05-27  6:17       ` Henning Hraban Ramm
2011-05-27  7:43         ` Hans Hagen
2011-05-26 17:55     ` mathew
2011-05-26 17:58   ` Martin Schröder
2011-05-26 22:52   ` George N. White III

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