Re: yank-media: allow users to limit image types that can be inserted

[pinmacs <pinmacs@cas.cat>]

Before yank-media, I was using org-download [1], so I got used to just 
insert a screenshot with no question to answer (such as the type of the 
image).

Recently, I moved to yank-media, but to have the same functionality, I 
had to tweak it a little bit, full detail here [2].

I see utility on asking for the image/png and image/jpeg and here you 
have details why you would care about [3]. But I am not familiar with 
image/pbm, image/xbm, image/xpm, image/tiff; for me, it is a nonsense to 
appear as types to select. But maybe somebody wants them, so that's why 
an option to pre-filter (or not) the candidates; and also the option to 
just stick with png (and save a keystroke, and a nonrelevant decision).

[1] https://github.com/abo-abo/org-download

[2] https://mail.gnu.org/archive/html/emacs-orgmode/2024-09/msg00209.html

[3]

   > The JPEG compression algorithm operates at its best on photographs
   > and paintings of realistic scenes with smooth variations of tone
   > and color (...) However, JPEG is not well suited for line drawings
   > and other textual or iconic graphics, where the sharp contrasts
   > between adjacent pixels can cause noticeable artifacts. Such
   > images are better saved in a lossless graphics format such as
   > TIFF, GIF, PNG, or a raw image format. The JPEG standard includes
   > a lossless coding mode, but that mode is not supported in most
   > products.

   https://en.wikipedia.org/wiki/JPEG#Typical_use

   > The JPEG (Joint Photographic Experts Group) format can produce a
   > smaller file than PNG for photographic (and photo-like) images,
   > since JPEG uses a lossy encoding method specifically designed for
   > photographic image data, which is typically dominated by soft,
   > low-contrast transitions, and an amount of noise or similar
   > irregular structures. Using PNG instead of a high-quality JPEG for
   > such images would result in a large increase in file size with
   > negligible gain in quality. In comparison, when storing images
   > that contain text, line art, or graphics – images with sharp
   > transitions and large areas of solid color – the PNG format can
   > compress image data more than JPEG can. Additionally, PNG is
   > lossless, while JPEG produces visual artifacts around
   > high-contrast areas.

   https://en.wikipedia.org/wiki/PNG#JPEG

On 2024-09-23 13:34, Eli Zaretskii wrote:
>> From: Robert Pluim <rpluim@gmail.com>
>> Cc: visuweshm@gmail.com,  pinmacs@cas.cat,  emacs-devel@gnu.org
>> Date: Mon, 23 Sep 2024 18:10:43 +0200
>>
>>>>>>> On Mon, 23 Sep 2024 18:54:25 +0300, Eli Zaretskii <eliz@gnu.org> said:
>>      >> From: Robert Pluim <rpluim@gmail.com>
>>      >> Cc: Visuwesh <visuweshm@gmail.com>,  pinmacs@cas.cat,  emacs-devel@gnu.org
>>      >> Date: Mon, 23 Sep 2024 17:09:03 +0200
>>      >>
>>      Eli> IMO, for users we already have what is needed: when we detect several
>>      Eli> formats, we show them to the user and ask him/her to tell us which
>>      Eli> format he/she wants to use.
>>      >>
>>      >> But that requires user interaction. I think the original request could
>>      >> be summed up as "if the list contains image/png, donʼt ask me, just
>>      >> insert the image".
>>
>>      Eli> That's not how I understand the request.  It was not always PNG, it
>>      Eli> was "sometimes PNG, but if so-and-so-happens, the JPEG" etc.
>>
>> Yes, but the "so-and-so" is determined by a user option. So
>>
>> 1. Always prefer "png" -> user option == "png"
>> 2. Want to choose between "png" and "jpeg" -> user option == ("png"
>> "jpeg")
>> 3. All of the formats -> user option == nil
> That makes little sense to me: how can the user decide in advance to
> use only PNG? by what logic?
>
> And anyway, this is not what the OP said.  Let's get back to what he
> said:
>
>>      Eli> And no one has explained yet why I would prefer PNG to JPEG or vice
>>      Eli> versa, btw.  The usual choices I'm familiar with is whether or not to
>>      Eli> preserve typefaces, colors, and other fancy attributes; regarding
>>      Eli> images, there's just a decision whether you want to paste the material
>>      Eli> as a picture or as some kind of text, whether rich or not.  So the
>>      Eli> background and the context for this request is still not clear to me.
>>
>> I can definitely see a use for case 1 above: "donʼt bother asking me,
>> if png is available just use that".
> I don't understand why would someone define their preference in the
> terms of image format.  It makes no sense.
>