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From: Alan Braslau via ntg-context <ntg-context@ntg.nl>
To: Henning Hraban Ramm <texml@fiee.net>
Cc: mailing list for ConTeXt users <ntg-context@ntg.nl>,
	Alan Braslau <alan.braslau@icloud.com>
Subject: [NTG-context] Re: Downsampling images (again)
Date: Sun, 22 Sep 2024 19:48:19 -0600	[thread overview]
Message-ID: <20240922194819.72acb7bd@boo.my.domain> (raw)
In-Reply-To: <8995c3d7-024c-4d3b-9cb6-649a9d05be1f@fiee.net>

On Sat, 21 Sep 2024 21:44:53 +0200
Henning Hraban Ramm <texml@fiee.net> wrote:

> Am 21.09.24 um 16:30 schrieb Alan Braslau:
> > I would first "fix" my image sources, individually, to contain
> > missing resolution information.  
> 
> The resolution setting is just metadata, it doesn’t affect pixel or
> file size. I need a function that works with “real” (pixel) sizes of
> images.

Exactly. The raw data is just pixels, and metadata sets what the
expected pixel size might be. Of course, this metadata can be
meaningless as the user can and often does rescale the image to meet
the typesetting needs.

The image manipulation tools use this metadata to resample resolution.
I found this very useful as I used *hundreds* of scanned X-ray images
that had real sizes, high resolution and 16 or even 24 bit depth. Of
course, I had to reduce all of this in order to include them in a
digestible and printable pdf.

Alan
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  reply	other threads:[~2024-09-23  1:57 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-21 11:21 [NTG-context] " Henning Hraban Ramm
2024-09-21 14:30 ` [NTG-context] " Alan Braslau via ntg-context
2024-09-21 19:44   ` Henning Hraban Ramm
2024-09-23  1:48     ` Alan Braslau via ntg-context [this message]
2024-09-22  7:06 ` Peter Münster
2024-10-09 16:52   ` Henning Hraban Ramm
2024-10-16 17:59   ` Henning Hraban Ramm
2024-10-17 11:11     ` Peter Münster

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