Bug 164026

Summary:	wish: use embedded thumbs within jpegs to speedup album display
Product:	[Applications] digikam	Reporter:	Michael <Michael.NoSpam>
Component:	Thumbs-Image	Assignee:	Digikam Developers <digikam-bugs-null>
Status:	RESOLVED NOT A BUG
Severity:	wishlist
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed In:	1.0.0
Sentry Crash Report:

Description Michael 2008-06-14 11:00:36 UTC

Version:            (using KDE 3.5.9KDE 1.2)
Installed from:    SuSE RPMsSuSE RPMs
OS:                Linux

Currently thumbnails are created on the fly and stored within subdirectory ~/.thumbnails. This - from my point of view - has two disadvatages:
1. occupies extra diskspace for thumbnails (for each user, for each computer within network)
2. re-building thumbnails is timeconsuming (especially on slow computers like mine:-)

My wish: Instead of storing thumbnails within separate directory use thumbnails already embedded by digital camera within jpeg file. Of course then one cannot change the size of thumbs, orientation of thumbs might be wrong. But if that approch will speedup display of albums and simultaneously reduces diskspace consumption, I'd really like that new feature.


Thanks, Michael

Comment 1 caulier.gilles 2008-06-14 12:09:26 UTC

Michael,

And how you will do with read only file format like RAW ?

Gilles Caulier

Comment 2 Michael 2008-06-15 16:19:25 UTC

Hello!

Currently, I'm not using RAW, thus I can only guess... To my knowledge RAW files, too, include jpeg previews (I'm using the Dynax D7, and it somewhere stores thumbnails for RAWs - maybe side by side to the RAW file?).

From your question I guess that you are already considering editing/changing of pictures? In that case you are right, the embedded jpeg thumbnail needs to be adapted.

My main intention is to use the in-camera generated, jpeg-embedded thumb (maybe ugly/coarse, e.g. extracted by "jhead -st thumb.jpg your-photo.jpg") to get fast thumb preview within albums. If RAW won't work then one might use the currently available mechanisms.

My main concern is to speedup thumbnail display for slow machines. Maybe extraction of embedded tumbnail is a slower process anyhow compared to creating a fresh thumb. In that case my idea simply won't make any sense.


Regards, Michael

Comment 3 caulier.gilles 2009-06-19 14:34:47 UTC

With current implementation of digiKam, a new thumbnails database is used (based on SQlite file), against to use ~/.thumbnails directory.

Thumbs are saved in PGF file format (wavelets based) instead PNG to optimize disk space.

Thumbs database is stored at the same place than digiKam database. Later, you will be able to set a dedicated place.

Rebuilding thumbs is now faster and more optimized.

To use this new thumbnails database, set this CMake flag : -DENABLE_THUMBS_DB=ON. For digiKam 1.0.0, this option will be turned on by default.

Gilles Caulier