From: Alan BRASLAU <alan.braslau@cea.fr>
To: Harald Koenig <koenig@tat.physik.uni-tuebingen.de>
Cc: ConTeXt users <ntg-context@ntg.nl>
Subject: Re: shrink JPGs to some resolution (dpi) ?
Date: Mon, 9 Mar 2015 22:50:29 +0100 [thread overview]
Message-ID: <20150309225029.3bb46a86@iram-ha-003587.extra.cea.fr> (raw)
In-Reply-To: <20150309211224.GA11660@hl.fritz.box>
Harald,
I use ImageMagick/GraphicsMagick to resample HUGE high resolution tiff
images to something more manageable to work with. Using a script, I
converted hundreds of images to lower resolution copies. Then it was
simply a question of pointing ConTeXt to use the appropriate directory
to find the right figures.
The basic comand is
convert -resample 300x300
(or 100x100) and you can play with "-quality 75%"
This can be done once and is much better than getting ConTeXt to
convert every time on the fly.
Alan
On Mon, 9 Mar 2015 22:12:24 +0100
Harald Koenig <koenig@tat.physik.uni-tuebingen.de> wrote:
> Hi,
>
> so here's my very generic question #1 for my India book:
>
> is it possible that context (lua?) will "shrink" all \externalfigure
> jpegs automatically to some specified dpi resolution and quality
> (e.g. 300 dpi with 95% jpeg 'quality' for print and
> 100 dpi and 75% for screen quality) ?
>
> since I'm only using Linux, using Acrobat unfortueately is not an
> option (thanks, Adobe:-(
>
>
> that book will be ~100 A4 pages with ~50% and 50% pictures,
> trying to have 2 pictures per page with text flowing around.
>
> the pictures are JPG photos with quite high resolution, upto 24
> Mpixel. so those picutres are HUGE and horrible overkill for a final
> print on A4 with typical images withs around 0.5\textwith.
>
>
> I know about ghostscript being able to convert/shrink PDFs,
> but first the "original" PDF with full size JPGs with be really huge,
> and ghostscript takes ages to shrink them. so that's not real fun
> doing this too often...
>
>
> right now I write the real typeset size of all images to the log file
> and use some external script to calculate the current resolution
> and then create a new set of images which e.g. 300 dpi.
>
> but that's still an ugly hack still has some issues with EXIF data,
> rotation, clipping, ... and right now leads to strage problems (see
> mext mail;)
>
>
>
> any hints to read the original large JPGs, but only write "print
> quality" 300dpi images, or low quaity 75dpi images for speed (and
> saving net bandwidth when mailing PDFs to co-workers of the group)?
>
>
> thanks,
>
> Harald
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next prev parent reply other threads:[~2015-03-09 21:50 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-09 21:12 Harald Koenig
2015-03-09 21:47 ` Aditya Mahajan
2015-03-09 23:33 ` Harald Koenig
2015-03-10 0:05 ` Hans Hagen
2015-03-09 21:50 ` Alan BRASLAU [this message]
2015-03-09 22:10 ` luigi scarso
2015-03-09 22:25 ` Hans Hagen
2015-03-09 23:18 ` Harald Koenig
2015-03-10 0:17 ` Hans Hagen
2015-03-10 1:33 ` Harald Koenig
2015-03-10 6:34 ` Henning Hraban Ramm
2015-03-10 11:12 ` Hans Hagen
2015-03-09 21:54 ` Pablo Rodriguez
2015-03-10 6:44 ` Peter Münster
2015-03-10 7:43 ` Harald Koenig
2015-03-10 9:08 ` Peter Münster
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