DNG: include check codes for jpeg image data, like there are for raw image data.

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I just noticed that jpeg images do not enjoy the same benefit as raw images when wrapped in DNG. I assume this was just an "oops", since I can see no technical reason for it. The value in so doing is the same for master jpegs as master raws.

Please include & check codes for jpeg image data too.

Bonus idea:
Include and check codes for proprietary raw too (store codes in catalog at a minimum, and preferably xmp too).

PS - While you're at it, how about adding jpeg wrapping option to DNG converter *and* Lr import - thanks.

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Rob Cole

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  • not holding my breath, but not biting my tongue either...

Posted 7 years ago

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Michel BRETECHER, Champion

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Very interested with jpeg wrapping option to DNG converter.
- batch conversion of jpegs before importing in the Elements Organizer.
That would enable opening one or several jpegs in ACR directly from the Organizer, instead of having to use the editor to open jpegs one by one in ACR. The workflow would be the same as with raw files. Result : much quicker worflow. Not only for opening, but to apply common edits to several pictures.

It would also make obvious in the browsing space the difference between 'plain' jpegs and converted ones. You could see at a glance the raws, the jpegs and the dngs.

Using the 'save' option in the ACR dialog would enable to save variants with the automatic numbering without losing the original (non destructive workflow) which would compensate the lack for virtual copies. That save option would also enable the lossy compression in ACR 7.
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Rob Cole

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The main element of this feature request has been implemented.

I'd still like to see check codes for proprietary raw too, and option for DNG Converter to wrap jpegs...
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I would love to see that for all files actually. For a begining store the info in the DB, but then the best is of course to store it in xmp
I am sure there is already a feature request for that.
By the way how do you check that such check sums were computed for the dng, I cannot find anything about this check sum in LR5
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Rob Cole

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If I remember correctly, when you do a DNG check in Lr (i.e. 'Validate DNG Files' on Library Menu), it'll flag the ones that can't be checked (i.e. don't have the check codes).
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Jörgen Claesson

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I also would like to see the "jpeg wrapping option" in DNG converter
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Bruce Baker-Johnson

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I have come to this JPG to DNG thing relatively new. I'd had to switch from RAW to JPG on my Lumix in order to take 'advantage' of some of it's low light capabilities (no tripod) and forgot to switch back next day. I keep an archive of all  my native RAW pics and a backup in DNG  (I use a number of different cameras and DNG gives me a 'common' ) .  I have noticed that the DNG conversions are slightly 'softer' than many of the native formats  but I digress. I carried out the  Lightroom 'Import' (JPG) and 'Export' to DNG the results are very poor indeed.  Put in the terms of my simplest test the magnification of the detail of a ship - at 8x the name of the ship on the JPG is still sharp but the (pseudo) DNG at 8x is virtually unreadable!  This is true with all my 'conversions from JPG.  So what is the point of going on with all this unless Adobe can 'rectify' the degradation of the image on conversion. A clue maybe to why they have not proceeded with it?