GNU bug report logs - #74476
[PATCH] Explore JPEG loading without quantization

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From: Manuel Giraud <manuel <at> ledu-giraud.fr>
To: Alan Third <alan <at> idiocy.org>
Cc: Eli Zaretskii <eliz <at> gnu.org>, 74476 <at> debbugs.gnu.org
Subject: bug#74476: [PATCH] Explore JPEG loading without quantization
Date: Sat, 30 Nov 2024 17:26:03 +0100

Alan Third <alan <at> idiocy.org> writes:

> On Sat, Nov 30, 2024 at 03:54:38PM +0100, Manuel Giraud wrote:
>> Alan Third <alan <at> idiocy.org> writes:
>> 
>> [...]
>> 
>> > Manuel, I think you want to use lookup_rgb_color when setting the
>> > pixels in the final image buffer. This should do the right thing. You
>> > presumably also need to call init_color_table before using it, and I
>> > see calls to colors_in_color_table and free_color_table which look
>> > necessary, but I think they're already in the jpeg code.
>> 
>> Hi Alan,
>> 
>> I don't really understand: my proposed patch is getting rid of calls to
>> lookup_rgb_color and init_color_table.
>
> Yes, but they're internal Emacs functions, not related to libjpeg. All
> the other image library code uses them, so I think they are necessary
> to handle systems that use colour mapping (and possibly Windows too,
> it has a different implementation of lookup_rgb_color).
>
> For example, the PNG code looks like this:

Ok.  Thanks for the clarification, I'll modify my patch.
-- 
Manuel Giraud

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