[Digikam-users] Lossless rotation is lossy!

Bast! bast at abwesend.de
Fri Apr 18 21:32:02 BST 2014

> I cannot explain the behavior, I assume there is either a tiny logical detail 
> that we do not see or some fact deep in the JPEG compression technique.
> It's at least symmetric.
> If you read my definition closely you will see that is does not require 
> O = R90
> It only requires any lossless operation R to have an operation R' so that
> O = R'RO

True, you wrote this before and your definition is correct. Furthermore:
let R''= (2a+1)R90 where a=-n..0..n
then 0=O-(ORR'')


Since the error is reversible and very small, I will and can live with it.

Thank you all for your responses.

>> Thread solved and closed. <<


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