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

Mikolaj Machowski mikmach at wp.pl
Fri Jun 12 19:56:49 BST 2009

On Thursday 11 June 2009 19:36:44 Marcel Wiesweg wrote:
> SVN commit 980402 by mwiesweg:
> Adding the lines that switch on using a thumbnail database - not enabled
> per default:
> You need to remove the comment signs around albummanager.cpp, lines
> 685-687, to test the thumbnail database.
> For simplicity, it is always created in the directory of the main database
> and named "thumbnails-digikam.db". It is using the PGF format to store
> thumbnails. I am aware there are suggestions to use JPEG or Djvu.

Used this for my files (15,000):

1) size of database: 243 MB, size of .thumbnails/large: 1.3GB 
2) creation time - for me recreation of all thumbnails takes so long that I 
have to do other things in meantime so it is incomparable (and data useless) 
but just for interest it was cut 20% - and "live" creation of thumbs 
(displaying them with empty database) was faster for me than previously
3) what for me is most important - time of display of images which thumbs are 
already in database: unfortunately there is scientific method, just feelings -  
maybe bit faster, definitely not slower
4) quality of images (used default PGF, q=4, don't know how to switch to JPG): 
in normal, landscapes, portraits, etc. no difference, slightly lower quality 
(comparing to .thumbnails PNGs) with images with "hard" borders, eg. texts.
5) strange effect: very, very slow closing, window closes fast but after that 
digiKam makes multiple disk operations taking ca 50% of CPU


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