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

[Boudewijn Rempt]

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
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-- 
Boudewijn Rempt | http://www.krita.org, http://www.valdyas.org