[Digikam-devel] extragear/graphics/digikam/kioslave

Caulier Gilles caulier.gilles at kdemail.net
Wed Jun 21 18:06:58 BST 2006

Le Mercredi 21 Juin 2006 16:08, Mikolaj Machowski a écrit :
> Dnia środa, 21 czerwca 2006 13:46, Gilles Caulier napisał:
> > SVN commit 553524 by cgilles:
> >
> > digikam from trunk : digiKam KIO slave image preview extractor use now
> > the new DMetadata IPTC image preview extraction method ! It's very fast
> > !!!
> Don't know how for RAW files but preview speed for JPEG files is
> much slower...

Because, if no preveiw data is found in IPTC tags, the whole image is loaded 
uing Qt.

There is somthing missing for that : the Exif makernote preview tag 
extraction. Exiv2 need to be improved for that. It's planed for the next 

> > IMPORTANT : actually, digiKam image editor store a JPEG preview image of
> > 640x680 compressed to 75% factor. Please let's me hear if these settings
> > is right for you. Note that preview IPTC tag size is limited to 256 Kb
> > to store image.
> Quality isn't so great.
> 1. What about 80% quality? Even when making size smaller. Smoothing of
>    Qt is really good and personally I would prefer to see some Qt-blur
>    instead of JPEG artefacts. (note: I use full screen Digikam in
>    1152x864 resolution - on bigger screens it may look different).

yes. of course. but preview is not the whole image. It's different. perhaps i 
can increase preview image size and compression factor.

> 2. What is sampling factor? In most systems 1x2 (or lower) is default
>    but offers significantly reduced quality for modest size gains
>    comparing to 1x1.

sampling factor ?


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