GNU bug report logs -
#74476
[PATCH] Explore JPEG loading without quantization
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Your message dated Mon, 2 Dec 2024 10:47:42 +0000
with message-id <Z02QTmx83ZfZm_fv <at> faroe.holly.idiocy.org>
and subject line Re: bug#74476: [PATCH] Explore JPEG loading without quantization
has caused the debbugs.gnu.org bug report #74476,
regarding [PATCH] Explore JPEG loading without quantization
to be marked as done.
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74476: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=74476
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Tags: patch
Hi,
While trying to speed up "emacs as an image viewer", I found that emacs
is using libjpeg with color quantization and it seems that removing this
quantization could speed up JPEG loading a bit.
My simple limited benchmark:
- M-: (clear-image-cache)
- Open an image in folder with some large enough pictures in
it (4000x3000 here)
- M-: (benchmark-run 10 (image-next-file 1))
Here are the results I get:
without this path: (5.415405491 1 0.09232176400000025)
with: (3.079911418 1 0.0751190459999993)
I don't think that this patch could be applied as is (it is rather
ugly). And I also think that I probably have missed some (many?) use
case (where color quantization is mandatory). But I'm submitting this
patch anyway as a conversation starter on the subject.
Thanks,
In GNU Emacs 31.0.50 (build 9, x86_64-unknown-openbsd7.6, X toolkit) of
2024-11-22 built on computer
Repository revision: c66c0942ea9ac10e6d6324e472150de403a03b69
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101014
System Description: OpenBSD computer 7.6 GENERIC.MP#437 amd64
Configured using:
'configure CC=egcc CPPFLAGS=-I/usr/local/include
LDFLAGS=-L/usr/local/lib MAKEINFO=gmakeinfo --prefix=/home/manuel/emacs
--bindir=/home/manuel/bin --with-x-toolkit=lucid
--with-toolkit-scroll-bars=no --without-cairo
--without-compress-install'
[0001-Explore-JPEG-loading-without-quantization.patch (text/patch, attachment)]
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--
Manuel Giraud
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On Sun, Dec 01, 2024 at 12:13:53PM +0100, Manuel Giraud wrote:
> Alan Third <alan <at> idiocy.org> writes:
>
> > I think it should be done for each load. And I just noticed you need
> > to add a free_color_table call after you're done with it.
>
> Yes, I have re-add it in the attached new version of the patch. I also
> re-add the ir, ig and ib indices computation. WDYT?
Looks good to me.
I've pushed this to master. Thanks!
--
Alan Third
This bug report was last modified 202 days ago.
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