Hi digiKamers, hi KDErs, hi planet,
few days ago I blogged about the progress of non-destructive editing in digiKam. According to your comments, I take it that there is some misunderstaning in the whole concept. So let me explain it to you :)
The non-destructive editing will be done in such way, that if (and only if) you do some edit to some image, there is automatically created new file, which is a copy of the original with applied changes and with list of edits you've made saved in metadata.
This is a companion discussion topic for the original entry at https://digikam.org/news/2010-06-17_gsoc_explaining_digikam_s_non-destructive_editing_concept/