mikmach at wp.pl
Wed Jun 21 21:29:18 BST 2006
Dnia środa, 21 czerwca 2006 19:06, Caulier Gilles napisał:
> 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.
So, why previous method was faster? Weren't image loaded?
> 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
What about generating necessary method by Digikam/Image Editor?
> > 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 ?
From ImageMagick man:
sampling factors used by JPEG or MPEG-2 encoder and YUV
This option specifies the sampling factors to be used by the
JPEG encoder for chroma downsampling. If this option is omit-
ted, the JPEG library will use its own default values. When
reading or writing the YUV format and when writing the M2V
(MPEG-2) format, use -sampling-factor 2x1 to specify the 4:2:2
downsampling method. To use the same sampling factors as those
found by the JPEG decoder, use the -define jpeg:preserve-set-
More information about the Digikam-devel