[Digikam-users] Out of curiosity: digiKam is a very fast viewer for RAWs. How?

[Marcel Wiesweg]

> Hi,
>
> I like it a lot, that a user can scroll in-between the views of his
> RAWs in digiKam very fast.
>
> Out of curiosity and because I couldn't find infos in the handbook
> about that feature:
> How did you realized such a fast viewing for such big files?
> Just the concept, technical details are not important.

Short answer: Don't load the big file, load the small file.
Most RAW files have an embedded preview which is already generated by the 
camera when creating the file. The camera has obviously the same problem with 
displaying big files on its display as we have. If such a preview is 
available, we use it in the preview mode (you can opt to always view the full 
size image in the setup).
If no preview is available, we will use the fastest method for decoding a RAW 
file available from dcraw, but in this case, loading is slow.

>
> I looked into the albums and into the directory
> ".kde/share/apps/digikam" but I did not find any cache.

We dont use an on-disk cache for preview, they are too large. Thumbnails are 
stored on disk of course.

>
> Andreas