I think you're playing semantics with the definition of "lossless".
Me? A semantic argument? Surely you jest... (and don't call me
Shirley... :)
If you
apply a transformation to data, the transformation is considered lossless if
none of the data is lost. A transformation from PEF to DNG format preserves
all of the data and is lossless. A DNG file is just as "archival" as a PEF
file because both contain the same data, represented in different structures.
It's not strictly speaking lossy, you're right. All the
data and metadata is there. It *is* de-facto lossy under the assumption
that some software can deal with PEFs and not DNGs.
The transformation from DNG to PEF is certainly possible, it just hasn't been
done because it isn't something which a high value priority. If it were, a
utility to do it could be constructed. There's nothing lossy about it, unless
you consider the loss of metadata added to the DNG file which has no
possibility of representation in the PEF file.
In my (relatively unique) situation, DNG is much less useful. ...
That much we agree upon.
(BTW: DNG files are yet another specialization of TIFF in structure, so the
same utilities that work on PEF files as specialized TIFFs would also work on
DNG files.)
Godfrey
--
*************************************************************************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
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