Re: [gentoo-user] gentoo-user+unsubscr...@lists.gentoo.org

[Michael]

Roger, you are using the wrong email address to unsubscribe.  Try sending a 
message to:

gentoo-user+unsubscr...@lists.gentoo.org

Just as this message headers and the gentoo website advises you to do:

https://www.gentoo.org/get-involved/mailing-lists/instructions.html

HTH.


On Friday, 18 September 2020 16:29:53 BST Roger Cahn wrote:
> 



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[gentoo-user] gentoo-user+unsubscr...@lists.gentoo.org

[Roger Cahn]

Re: [gentoo-user] How do I compress jpeg files?

[Michael]

On Friday, 18 September 2020 14:58:59 BST tastytea wrote:
> On 2020-09-18 13:32+ Alan Mackenzie  wrote:
> > Hello, Gentoo!
> > 
> > I've a number of jpeg files, 17 to be precise, which are high
> > resolution and are around 3½ megabytes each.  I would like to
> > compress them down to around 100 kb each.
> > 
> > I'm sure this is possible, if tedious, in gimp, somehow, but I can't
> > for the life of me work out how (since it's years since I last did
> > this).
> > 
> > What is the best way (minimal learning, scriptable if possible), to do
> > this?
> 
> I'm not aware of a way that allows you to specify a file size, but you
> can use convert from media-gfx/imagemagick to re-compress and/or resize
> the files. For example:
> 
> convert -quality 50 in.jpg out.jpg
> convert -resize 1000 in.jpg out.jpg
> 
> The last command makes the image 1000px wide and sets the height
> automatically to the right value.
> 
> Hope this helps,
> tastytea

I would also recommend convert, which can be scripted to run in a directory 
and compress all jpeg files therein to a lower resolution.  Something like 
this ought to do the job:

#!/bin/bash
for i in *.jpg; do
  name=${i%.jpg}
  convert -compress JPEG -quality 95 ${i} ${name}_compressed.jpg
done

You'll need to adjust the -quality parameter to your liking.

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[gentoo-user] gentoo-user+ unsubscr...@lists.gentoo.org

[Roger Cahn]

Re: [gentoo-user] How do I compress jpeg files?

[tastytea]

On 2020-09-18 13:32+ Alan Mackenzie  wrote:

> Hello, Gentoo!
> 
> I've a number of jpeg files, 17 to be precise, which are high
> resolution and are around 3½ megabytes each.  I would like to
> compress them down to around 100 kb each.
> 
> I'm sure this is possible, if tedious, in gimp, somehow, but I can't
> for the life of me work out how (since it's years since I last did
> this).
> 
> What is the best way (minimal learning, scriptable if possible), to do
> this?

I'm not aware of a way that allows you to specify a file size, but you
can use convert from media-gfx/imagemagick to re-compress and/or resize
the files. For example:

convert -quality 50 in.jpg out.jpg
convert -resize 1000 in.jpg out.jpg

The last command makes the image 1000px wide and sets the height
automatically to the right value.

Hope this helps,
tastytea

-- 
Get my PGP key with `gpg --locate-keys tasty...@tastytea.de` or at
.


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Re: [gentoo-user] How do I compress jpeg files?

[Jarry]

jpeg is already compressed. You can reduce its size by resampling
to lower resolution and/or higher-level lossy compression. In both
cases you are going to loose quality...

Jarry

On 18-Sep-20 15:32, Alan Mackenzie wrote:

Hello, Gentoo!

I've a number of jpeg files, 17 to be precise, which are high resolution
and are around 3½ megabytes each.  I would like to compress them down to
around 100 kb each.

I'm sure this is possible, if tedious, in gimp, somehow, but I can't for
the life of me work out how (since it's years since I last did this).

What is the best way (minimal learning, scriptable if possible), to do
this?

Thanks in advance!


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[gentoo-user] How do I compress jpeg files?

[Alan Mackenzie]

Hello, Gentoo!

I've a number of jpeg files, 17 to be precise, which are high resolution
and are around 3½ megabytes each.  I would like to compress them down to
around 100 kb each.

I'm sure this is possible, if tedious, in gimp, somehow, but I can't for
the life of me work out how (since it's years since I last did this).

What is the best way (minimal learning, scriptable if possible), to do
this?

Thanks in advance!

-- 
Alan Mackenzie (Nuremberg, Germany).