Proposal: Add thumbnails of different sizes to .kra files?

Boudewijn Rempt boud at valdyas.org
Mon Jun 6 18:22:44 UTC 2016


On Tue, 7 Jun 2016, Alvin Wong wrote:

> About the mergedimage.png, I see that the png itself isn't compressed
> at all, only compressed by DEFLATE inside the zip container. For a
> completely-transparent image of 3600x2400, the mergedimage.png is 33MB
> uncompressed, which is ridiculous. It's 55KB compressed, much smaller,
> but still a bit larger than expected.
>
> Would compressing the png itself and STORE it inside the zip container
> instead be better? Might want to benchmark and compare.

Oh, yes -- that's a good idea!

>
> 2016-06-07 0:59 GMT+08:00 Boudewijn Rempt <boud at valdyas.org>:
>> On Mon, 6 Jun 2016, Dmitry Kazakov wrote:
>>
>>> The only trouble I see with thumbnail generation is the speed. It would be
>>> great to see the speen benchmarks of saving a PNG of each size.
>>
>>
>> Well that needs checking indeed.
>>
>>> People are complaining
>>> about Krita saving too slow :( I even heard a wish (during the KomMissia)
>>> to disable any preview and mergedimage.png saving into .kra to make the
>>> saving quicker.
>>
>>
>> That's just flat-out not going to happen.
>>
>>
>>>
>>>
>>>
>>>
>>> On Mon, Jun 6, 2016 at 3:44 PM, Boudewijn Rempt <boud at valdyas.org> wrote:
>>>       On Mon, 6 Jun 2016, Alvin Wong wrote:
>>>
>>>             Is that needed? I would imagine whatever plugins or programs
>>> would
>>>             already have known the absolute size they want in pixels,
>>> independent
>>>             of the dpi, and could just automatically take the closest
>>> thumbnail or
>>>             the mergedimage and scale it down accordingly.
>>>
>>>
>>>       I don't know... Hidpi and Retina is still really confusing me across
>>> the board.
>>>
>>>             Perhaps you can also add a thumbnail of size 2048x2048 but I
>>> wonder
>>>             how much it would add to the file size...
>>>
>>>             By the way I remember seeing in the Krita git repo some
>>> scripts which
>>>             look like plugins for certain programs to extract the
>>> thumbnail, but I
>>>             can't seem to find them now. Does anyone know, other than the
>>> Windows
>>>             shell extension, what other file managers or programs
>>> currently
>>>             supports extracting thumbnails from Krita files/
>>>
>>>
>>>       Code for Qt applications is in the kimageformats repo now, I moved
>>>       that some time ago. There are also scripts for nautilus and gnome.
>>>
>>>
>>>             Best Regards,
>>>
>>>             Alvin
>>>
>>>
>>>             2016-06-06 14:54 GMT+08:00 Boudewijn Rempt <boud at valdyas.org>:
>>>                   I think we can easily do this: but maybe we should at
>>> the same time
>>>                   add thumbnails with a @2 extension to prepare for hidpi
>>> and retina
>>>                   displays?
>>>
>>>
>>>                   On Mon, 6 Jun 2016, Alvin Wong wrote:
>>>
>>>                         Hi,
>>>
>>>                         I would like to suggest Krita add (uncropped)
>>> thumbnail images of
>>>                         different sizes to the file to allow faster
>>> extraction of thumbnails
>>>                         by external applications.
>>>
>>>                         There is currently one preview.png which is at
>>> maximum 256x256, so
>>>                         generating thumbnails larger than that would
>>> require scaling down from
>>>                         the mergedimage.png which could be very large and
>>> may take a
>>>                         comparatively long time to process. Even though
>>> the actual time per
>>>                         file might not be much, it could add up for a lot
>>> of files.. Also, the
>>>                         preview.png is cropped to the non-transparent
>>> region
>>>                         (https://bugs.kde.org/show_bug.cgi?id=363968)
>>> which makes things a bit
>>>                         weird and inconsistent.
>>>
>>>                         I think having thumbnails for the sizes
>>> (maintaining aspect ratio) of
>>>                         256x256 and 1024x1024 would suffice, but boud
>>> suggested having 512x512
>>>                         might be nice too. Adding in these sizes means
>>> that, for thumbnails
>>>                         equal to or below the available sizes, they can be
>>> extracted and
>>>                         optionally scaled down from those instead of
>>> scaling down from the
>>>                         mergedimage.png. Obviously, sizes larger than that
>>> would still require
>>>                         using the mergedimage.png, but hopefully it would
>>> be quite rare for an
>>>                         application to request for thumbnails larger than
>>> 1024x1024... (4K
>>>                         displays aren't popular yet... right?)
>>>
>>>                         For the record, according to this MSDN page
>>>
>>>
>>> (https://msdn.microsoft.com/en-us/library/windows/desktop/cc144118(v=vs.85).aspx)
>>>                         Windows asks for the sizes 32/96/256/1024.
>>>
>>>                         I am asking for this as the developer of the
>>> Windows Shell Extension.
>>>
>>>                         Any suggestions?
>>>
>>>                         Best Regards,
>>>
>>>                         Alvin
>>>                         _______________________________________________
>>>                         Krita mailing list
>>>                         kimageshop at kde.org
>>>                         https://mail.kde.org/mailman/listinfo/kimageshop
>>>
>>>
>>>
>>>                   --
>>>                   Boudewijn Rempt | http://www.krita.org,
>>> http://www.valdyas.org
>>>                   _______________________________________________
>>>                   Krita mailing list
>>>                   kimageshop at kde.org
>>>                   https://mail.kde.org/mailman/listinfo/kimageshop
>>>
>>>             _______________________________________________
>>>             Krita mailing list
>>>             kimageshop at kde.org
>>>             https://mail.kde.org/mailman/listinfo/kimageshop
>>>
>>>
>>>       --
>>>       Boudewijn Rempt | http://www.krita.org, http://www.valdyas.org
>>>       _______________________________________________
>>>       Krita mailing list
>>>       kimageshop at kde.org
>>>       https://mail.kde.org/mailman/listinfo/kimageshop
>>>
>>>
>>>
>>>
>>> --
>>> Dmitry Kazakov
>>>
>>>
>>
>> --
>> Boudewijn Rempt | http://www.krita.org, http://www.valdyas.org
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-- 
Boudewijn Rempt | http://www.krita.org, http://www.valdyas.org


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