Keeping you quite busy, sorry
I needed to remove the requirement for SubFileType to get the config file to report the MyCompression tag for the scanned TIFF (the Desired tags aren't used so they can go too).
The group they are reported in now is e.g. ExifTool:IFD0, not EXIF:IFD0. How do I fix that?
I've updated the attached config file in my last post accordingly.
This works! (but what if the Compression tag is not in EXIF? Isn't it safer to use GetGroup($key, 0) and use that as the SetGroup? I attached my change.
Update: I noticed that with the Compression tag in SubIFD, MyCompression reports it as coming from IFD0…
Can you send me the sample (phil at owl.phy.queensu.ca)?
Take for instance the DNG from the DNG preview discussion
, but any file that has the compression tag in a SubIFD shows the same problem (e.g. NEFs).
The problem seems to be that (without showing duplicates), a different composite tag (the last instead of the first?) is used instead of the one selected for the non-composite… I'm not sure how easy this is to fix.
PS. I guess you prefer this custom tag approach instead of my hack as this way is more future proof?Yes. But not completely since we are still accessing some ExifTool internals.
Hmm, given all the extra (though for me VERY worthwhile) work we now have gone through, my original quick hack still seems easier though (and almost as maintainable).
Besides, it doesn't introduce a new tag but integrates seamlessly
P.S. I tried to understand the TIFF way of handling the JPEG compression by reading the TIFF specs, but I haven't found a definite answer there (probably meaning that the tags alone don't contain the answer). Perhaps the answer lies in the JPEG standard?