[Digikam-users] png huge

[Milan Knížek]

jdd píše v Út 19. 01. 2010 v 18:59 +0100:
> Le 19/01/2010 18:01, Gilles Caulier a écrit :
> 
> > Never use JPEG for
> > archiving purpose.
> 
> sorry, but it's perfectly safe to use jpg for archiving purpose given
> you wont ever edit the image again, what is what most of the people
> do. I will probably never edit again my 18000 photos :-).
> 
> It's only superior quality images that needs raw storage (and then,
> raw is probably better than PNG)
> 
I agree.

As a photographer, I aim for keeping the "untouched" original - i.e. RAW
or JPEG file from cameras and then the final edited version for
archiving, usually JPEG only.

It does not add much value to store the final image in PNG for
archiving. If it is touched already, I cannot revert the editing anyway.
If I want to have the possibility of reverting the edits, I would look
for layered GIMP/CinePaint xcf or Photoshop PSD and similar.

Though, PNG might still be a good option for archiving images with 16bit
colour depth per channel. The lossy-compressing alternatives (JPEG2000,
PGF) are not yet widely spread and supported, hence risky for archiving
purposes.

The trouble comes with organising the archive: writing meta info to
proprietary raw files is controversial and often unsupported, converting
to DNG does not result in the same raw data (unless keeping untouched
original raw data, too). At the moment, I add meta data only to JPEGs
and look for a moment, when digiKam would support easy handling of image
variants (raw + edit versions + archival version).

P.S. Those having multi-terabyte disk storage systems + 1 or better 2
another for backups, the above discussion is worthless, of course :-)

regards,

Milan Knizek
knizek (dot) confy (at) volny (dot) cz
http://www.milan-knizek.net - About linux and photography (Czech
language only)